Yella Terra 1.85 rocker on L92/LS3 heads dyno results

[Patrick G]

The Gen IV rectangular port GM heads really respond to lift. This has been proven time and time again. But instead of a cam swap, I wanted to see how much power I would pick up just by swapping some higher ratio rocker arms to increase the lift at the valve.

The test engine was a 2009.5 G8 GT with a 6.0L L76 engine with active fuel management (DOD). All AFM motors are saddled with a very small 200/208 .472/.474" 116LSA camshaft. The 1.85 rockers would effectively increase the lift at the valve from .472 to .514". This small but noticeable increase in lift will get the large intake valve further away from the cylinder wall plus into a position where it flows more air. Effectively my engine now has a 200/208 .514/.516" cam.

For those who can't read the dyno chart, peak power increased from 342rwhp to 355rwhp (a gain of 13rwhp) and torque peak increased from 355rwtq to 362rwtq. Interestingly, both the power and torque peaks with the high ratio rockers occurred at lower rpm, but carried the power better at higher rpm. This helps pump up the overall power under the curve.

http://www.guerragroup.com/YT6685_test.JPG

While this is a very easy mod to install, it does require a couple of other items. The heavy solid stemmed intake valves of the L92 heads did not like running the high ratio rockers with a stock valve spring. We ran into valve control issues at 5400 rpm with the stock springs. We swapped some Comp 26918 beehive springs and the curve was beautiful. The Yella Terra rockers also require a longer 7.450" pushrod to keep the valvetrain as quiet as stock.

So if you're looking to gain 13rwhp without swapping cams, the Yella Terra 1.85 ratio rockers are an excellent way to boost the power of your L92/L76/L99/LS3 engine without opening up the motor.

[fiveoh]

Thanks for the info. It was good to meet you at the track last weekend. So I'm going to assume you decided to go with a dod cam since you swapped out the rockers? :)

[Devilish34]

Interesting I wonder what effect this would have on a car with an aftermarket cam. I don't know the PTVC on my car to know if I have the room but maybe some of the stage 1 cams would benefit

[sacsrpc]

Great info. I was looking into doing this mod instead of a cam swap (stock car with a maggie TVS1900). Do these fit under the stock valve covers?

[SpeedRacerX]

Interesting post. Thorough. Thank you.

FWIW: G8-4-Speed went 13.06 with some 1.85 Rockers and HPTuners on stock RSAs. It's in his sig.

[Patrick G]

Interesting post. Thorough. Thank you.

FWIW: G8-4-Speed went 13.06 with some 1.85 Rockers and HPTuners on stock RSAs. It's in his sig.Yes, I remember seeing that. Unfortunately, he never did back to back testing so he never knew what kind of gains the rockers alone gave him. These rockers do fit under the stock valve covers with no problems. I will still do a cam swap in the future. I'm just not sure if I will go with a DOD cam or not. If I do choose to go with a DOD cam, I will keep these rockers as most of the good DOD cams are limited to .500" lift (with a stock 1.7 rocker). These rockers would put the net lift closer to .544" on a DOD cam.

These rockers won't really affect piston to valve clearance as they have very little affect on duration. Your valves are at maximum lift when the piston is near the bottom of the cylinder. It's excessive duration that keeps the valves open as the piston nears TDC that gets you into problems. The biggest issue with adding these rockers to a high lift cam is coil bind and valve control. Make sure your springs can handle the increased lift and faster acceleration of the valves.

[grapeman]

How much did the rockers, springs and push-rods run you?

[Mike P]

Great post Patrick & great information.......



...

[G8-4-Speed]

The SLP rockers needed 7.450 pushrods also. With 7.400, there is next to no pre-load and will tick on start ups.

Good post and numbers! I've been better about posting before and after results now.

[Voice of Reason]

A few questions, I've been looking at this as an alternative for a while so I'm glad to see someone (especially you) try this out:

1) Are springs the only limiting factor with going above .500 lift? I thought I read somewhere that the DOD lifters themselves have issues with higher lift and over time could fail.
2) What other mods were on this engine? CAI? Headers?
3) Was the car retuned to achieve the 13hp increase or is that an untuned increase? Would a retune help any? And if it's not retuned any idea what the impact to a/f ratio would be?

Thanks!

[G8-4-Speed]

Yes, I remember seeing that. Unfortunately, he never did back to back testing so he never knew what kind of gains the rockers alone gave him. These rockers do fit under the stock valve covers with no problems. I will still do a cam swap in the future. I'm just not sure if I will go with a DOD cam or not. If I do choose to go with a DOD cam, I will keep these rockers as most of the good DOD cams are limited to .500" lift (with a stock 1.7 rocker). These rockers would put the net lift closer to .544" on a DOD cam.

These rockers won't really affect piston to valve clearance as they have very little affect on duration. Your valves are at maximum lift when the piston is near the bottom of the cylinder. It's excessive duration that keeps the valves open as the piston nears TDC that gets you into problems. The biggest issue with adding these rockers to a high lift cam is coil bind and valve control. Make sure your springs can handle the increased lift and faster acceleration of the valves.


My experience with the DoD and the .326 lobe is:
Dead quiet in DoD mode from what I can tell driving.
There is no issue with bumping the valve open in DoD mode(O2's/fuel trims show no sign of leakage)
I do tend to notice a little valvetrain noise when hot at low rpm. I believe the lifters may bleed down slightly at lower rpm like a Rhoads lifter but at higher rpm stay pumped up. I am going to check other pushrod lengths to see if it changes anything.
Removed the cam after 1200 miles and cam looked the same across all the lobes. No funny marks on the cam lobes for the DoD cylinders.
Just change out the Lunati cam for the Comp Thumpr. Could have went with 114 LC but didn't. Only reason fro the change was to see if my flat spot at 6200 went away, and it did(was less noticeable with the change to headers). Both cams pulled to 6500 with no feed back on the MAF or MAP sensor(signs of valve float/flutter). MPH was very strong in the 1/4. Never skipped a beat running the 1/4 mi even when "hot-lapped". All et's were with in a tenth of each other and MPH was with 1.

The last test will be mileage. Fact or theroy if the lifters will last. To me it will amount to valvetrain control as to how long they live. Control it and they will be fine.

[It's A G8!]

Subscribed!

[Patrick G]

A few questions, I've been looking at this as an alternative for a while so I'm glad to see someone (especially you) try this out:

1) Are springs the only limiting factor with going above .500 lift? I thought I read somewhere that the DOD lifters themselves have issues with higher lift and over time could fail.The DOD lifters are supposed to run into problems with lobe lift above .300". With a 1.7 ratio rocker, this would be a little over .500" at the valve. It's the acceleration of the lifter over the cam lobe at issue more than the acceleration of the valve at the cylinder head. The springs with the higher rate help control the heavy valves that are accelerating faster.

2) What other mods were on this engine? CAI? Headers?Vararam CAI, stock exhaust manifolds and cats, but with an X-pipe in the mid-section with stock mufflers out back. Tuned with EFI Live on a chassis dyno.

3) Was the car retuned to achieve the 13hp increase or is that an untuned increase? Would a retune help any? And if it's not retuned any idea what the impact to a/f ratio would be?
Thanks!The car was dyno tuned for the before run. A/F ratio was around 12.8:1 and there was no knock retard. The after run required no retuning as the air/fuel curve was an overlay of the before run. No timing changes either.

[Fatdaddy]

Nice work Patrick. So the hardware for this mod is rockers, pushrods, and valve springs correct? No retainers or keepers? Anything else? I'm looking for total material cost.

[Patrick G]

Nice work Patrick. So the hardware for this mod is rockers, pushrods, and valve springs correct? No retainers or keepers? Anything else? I'm looking for total material cost.That's all you need Mitch. Of course, you may want to buy a few extra keepers. Those little locks have a way of falling during an install and not hitting the floor, LOL.:facepalm2:

Glad we found all of them.

[Fatdaddy]

That's all you need Mitch. Of course, you may want to buy a few extra keepers. Those little locks have a way of falling during an install and not hitting the floor, LOL.:facepalm2:

Glad we found all of them.

Yeah. Fat fingers are not your friends. This is a great addition. You have to be pushing around 420-430 hp at the crank, and you don't even have headers. The intake would give you away to those in the know but otherwise, an engine compartment inspection looks totally stock. And she doesn't sound off on the other end. A total, normal driving, four door grocery getting, soccer mom, I warned you not to mess with me, sleeper. I like it!

[Patrick G]

Yeah. Fat fingers are not your friends. This is a great addition. You have to be pushing around 420-430 hp at the crank, and you don't even have headers. The intake would give you away to those in the know but otherwise, an engine compartment inspection looks totally stock. And she doesn't sound off on the other end. A total, normal driving, four door grocery getting, soccer mom, I warned you not to mess with me, sleeper. I like it!Next sleeper mod will probably be a ported intake manifold. Jeremy Formato has been getting some good results (10-15 rwhp) with ported LS3 intakes. Nobody would ever be able to tell from an underhood glance.

Haha, I hijacked my own thread.

[Voice of Reason]

Next sleeper mod will probably be a ported intake manifold. Jeremy Formato has been getting some good results (10-15 rwhp) with ported LS3 intakes. Nobody would ever be able to tell from an underhood glance.

Haha, I hijacked my own thread.

Glad to hear you're thinking a ported intake is in your future. If I go with 1.85 rockers I'll do a ported intake/tb at the same time so I'd like to see how yours turns out.

My optimistic self would like to think that with my current mods + 1.85 rockers and a ported intake that I could get close to 390rwhp.

[fiveoh]

Next sleeper mod will probably be a ported intake manifold. Jeremy Formato has been getting some good results (10-15 rwhp) with ported LS3 intakes. Nobody would ever be able to tell from an underhood glance.

Haha, I hijacked my own thread.

I'd really like to see a dyno of a ported intake. The only ones i've seen are from shops that port them.

[Patrick G]

Glad to hear you're thinking a ported intake is in your future. If I go with 1.85 rockers I'll do a ported intake/tb at the same time so I'd like to see how yours turns out.

My optimistic self would like to think that with my current mods + 1.85 rockers and a ported intake that I could get close to 390rwhp.I'm pretty confident that with long tube headers, ported intake, under drive pulley, 1.85 rockers, and CAI, we can get to 400 rwhp without cracking open the motor. Pretty killer to do this with a wimpy AFM camshaft.

[wyldman]

I'm pretty confident that with long tube headers, ported intake, under drive pulley, 1.85 rockers, and CAI, we can get to 400 rwhp without cracking open the motor. Pretty killer to do this with a wimpy AFM camshaft.

To say the least. I think it's frickin amazing! :woohoo:

[Speed6]

Woudn't casting 0821 have hollow stemmed valves (ie lighter weight) than 5364 heads? that is also used on G8

[Patrick G]

Woudn't casting 0821 have hollow stemmed valves (ie lighter weight) than 5364 heads? that is also used on G8You would think so, but apparently not. It's very much like the 243 castings on Gen III vehicles. The original 243 castings has sodium filled lightweight valves for the Corvette Z06, but later 243 castings also made their way to Trucks and SUVs with solid stemmed valves. Regardless of whether they have the light valves or not, the stock valve springs are barely adequate for the .472" cam and 6000 rpm.

[GeorgeInNePa]

I'm pretty confident that with long tube headers, ported intake, under drive pulley, 1.85 rockers, and CAI, we can get to 400 rwhp without cracking open the motor. Pretty killer to do this with a wimpy AFM camshaft.

My dyno sheet says 353hp. Will I pick up 47hp from the rockers? I have the other mods.

;)

[Patrick G]

My dyno sheet says 353hp. Will I pick up 47hp from the rockers? I have the other mods.

;)George, I'm pretty sure your high stall converter is gobbling up a good deal of your chassis dyno power...even if it's locked up. I bet your dyno numbers would be higher (and ET slower, haha) with the stock torque converter.

[Torqued]

I'm pretty confident that with long tube headers, ported intake, under drive pulley, 1.85 rockers, and CAI, we can get to 400 rwhp without cracking open the motor. Pretty killer to do this with a wimpy AFM camshaft.

Patrick, the low octane fuel doesn't seem to be holding you back. Do you think you can crack 400 on the low octane fuel?

[GT G8]

If I install Cams, is installing this Yella Terra rocker required or recommended?

[It's A G8!]

If I install Cams, is installing this Yella Terra rocker required or recommended?

If you installed a DoD cam these rockers would help a lot.

[GT G8]

If you installed a DoD cam these rockers would help a lot.

By "DoD Cam", do you mean DOD Delete?

I was thinking of these cams from Livernois (http://www.livernoismotorsports.com/product.phtml?p=1927). Should I get the Yella Terra with that cam set-up?

[It's A G8!]

By "DoD Cam", do you mean DOD Delete?

I was thinking of these cams from Livernois (http://www.livernoismotorsports.com/product.phtml?p=1927). Should I get the Yella Terra with that cam set-up?

No, DoD cam keep the AFM stock lifters and valve train.

[phpd7102]

By "DoD Cam", do you mean DOD Delete?

I was thinking of these cams from Livernois (http://www.livernoismotorsports.com/product.phtml?p=1927). Should I get the Yella Terra with that cam set-up?

on a side note these motors only have 1 camshaft so its "cam" not "cams".

just saying..... :D

[GT G8]

on a side note these motors only have 1 camshaft so its "cam" not "cams".

just saying..... :D

.....I know. It takes some getting used to coming from an Evo where we have 2.

[616 of 933]

what is the biggest cam you can use to keep DOD and use the 1.85 rockers

[G8-4-Speed]

what is the biggest cam you can use to keep DOD and use the 1.85 rockers


Depends........I am trying to get away with .603" w/1.85 and it works good so far but....it has been said the DoD lifters don't like it. I'm at 1200 miles and counting. DoD still works as advertise.

[Mighty Horse]

So as I'm looking for a "cheaper/easier" alternative to a cam swap. I find this thread and it caught my attention and got me thinking about this possible alternative. But, my question is how much cheaper will this be? Does anyone have the part #'s for the push rods, valve retainers and locks? I assume all components were Comp Cams? Where can you buy the Yella Terra rockers? How do they compare to the SLP 1.85's?

[Mighty Horse]

Anyone?

[r33pwrd]

Where can you buy the Yella Terra rockers? How do they compare to the SLP 1.85's?

http://neweraperformanceparts.com/default.asp?SID=xD62C682KAA7W4ZM2M8UT3&S=503&A=E&PKV=yt6667g8|0

[GeorgeInNePa]

http://neweraperformanceparts.com/default.asp?SID=xD62C682KAA7W4ZM2M8UT3&S=503&A=E&PKV=yt6667g8|0 (http://neweraperformanceparts.com/default.asp?SID=xD62C682KAA7W4ZM2M8UT3&S=503&A=E&PKV=yt6667g8%7C0)

Those are 1.7s, but maybe Mike@NEP can get the 1.85s if you give him a call.

You could also PM Patrick, the OP of the thread, and ask him where he bought them. You could also Google Yella Terra 1.85, or something like that...


As far as the SLPs, looking at the pics of both and knowing that SLP rebrands things to their name (my underdrive pulley for an example), it wouldn't surprise me to find that the SLP rockers are in fact Yella Terras.


ETA:
http://www.chevyraceparts.com/details/yella-terra/yt6685

You could PM Greg@Pace to see if he has a price...

[G8-4-Speed]

So as I'm looking for a "cheaper/easier" alternative to a cam swap. I find this thread and it caught my attention and got me thinking about this possible alternative. But, my question is how much cheaper will this be? Does anyone have the part #'s for the push rods, valve retainers and locks? I assume all components were Comp Cams? Where can you buy the Yella Terra rockers? How do they compare to the SLP 1.85's?


Yella Terra looks like the same rocker. You only need springs and pushrods unless you want to get titainium stuff.

[Patrick G]

Yella Terra makes the 1.85:1 rockers for SLP. They are the same. Cheaper buying Yella Terra and bypassing SLP's mark up. You want to use the Comp 26918 beehive springs or PAC 1218 beehive springs. You'll definitely need the .050" longer pushrods (7.450" chrome moly) to keep the lifter preload the same as stock. You can reuse stock retainers and locks. Scoggin Dickey Parts Center sells them.

[G8-4-Speed]

Yella Terra makes the 1.85:1 rockers for SLP. They are the same. Cheaper buying Yella Terra and bypassing SLP's mark up. You want to use the Comp 26918 beehive springs or PAC 1218 beehive springs. You'll definitely need the .050" longer pushrods (7.450" chrome moly) to keep the lifter preload the same as stock. You can reuse stock retainers and locks. Scoggin Dickey Parts Center sells them.


Correct. With my cam I am at 7.500" and it is nice and quiet.

[Mighty Horse]

Ok this is probably a dumb question but, has anyone ever ran increased ratio rockers on only intake side or only exhaust side with stock ratio on the other? For example intake=1.85 exhaust=1.7(stock)? Would there be any advantage or am I completly f'd up for even thinking this would be possible?

[Patrick G]

Ok this is probably a dumb question but, has anyone ever ran increased ratio rockers on only intake side or only exhaust side with stock ratio on the other? For example intake=1.85 exhaust=1.7(stock)? Would there be any advantage or am I completly f'd up for even thinking this would be possible?The rockers come as pairs on a shaft for each cylinder. You would need to have Yella Terra make this change for you, but even if they could, why would you? The greater lift is important for both the intake and exhaust side.

[vert]

Ok this is probably a dumb question but, has anyone ever ran increased ratio rockers on only intake side or only exhaust side with stock ratio on the other? For example intake=1.85 exhaust=1.7(stock)? Would there be any advantage or am I completly f'd up for even thinking this would be possible?

I think for a turbo set up it would be useful, at least some of the turbo mustang's run that way.

[wnt2gofst]

So been looking into buy the rockers, pushrods, and springs. From what i read earlier i might not need to retune. Is this correct?

[Mighty Horse]

The greater lift is important for both the intake and exhaust side.

That's exactly what I was wondering. If there would be any advantage to having more lift on one set of valves or the other. Ok, thanks.

[AVIDMOTION]

Total parts list with numbers and prices?
thanks

[1meand]

Total parts list with numbers and prices?
thanks

Yella Terra Rockers - $429.95 from NewEra
Comp Cams 26918 Springs - $174.99
Comp Cams 7.450 Pushrods - $99.95

I have it on my list of "To do" mods.

[Patrick G]

So been looking into buy the rockers, pushrods, and springs. From what i read earlier i might not need to retune. Is this correct?No retuning required in my case.

[wnt2gofst]

No retuning required in my case.

Im tracking now....pm'd you on it while back...think i wait and just do a complete cam later this yr..or while i am deployed agian. But thank you for the info agian.

[GT Drew]

Mighty Horse brings up a very good point. It is called a spilt ratio rockers set up. It was found that on the NA 3800 motors a combination of 1.85I & 1.80E rockers produced more power that using 1.9 rockers on both. Now we had ZZP and Easy performance to do all the dyno testing. Best power and torque under the curve were with smaller rockers. Our heads are much better than the 3800. I don't know if Yella Terra has ever done testing like this.

http://www.easyperformance.com/Tech_Info/ER_Rockers_Test_Frameset.html

[Patrick G]

Mighty Horse brings up a very good point. It is called a spilt ratio rockers set up. It was found that on the NA 3800 motors a combination of 1.85I & 1.80E rockers produced more power that using 1.9 rockers on both. Now we had ZZP and Easy performance to do all the dyno testing. Best power and torque under the curve were with smaller rockers. Our heads are much better than the 3800. I don't know if Yella Terra has ever done testing like this.

http://www.easyperformance.com/Tech_Info/ER_Rockers_Test_Frameset.htmlTesting has shown that the more exhaust lift and rate you can throw at the L92 heads, the better they like it. Look at the LS3 cam shootout in the GMHTP magazine. All the top performers had high lift on the exhaust. Specifically, the Thunder Cam and the Lingenfelter cam used identical valve events for intake and exhaust, but the Lingenfelter cam used higher lift/faster ramps on the exhaust. The LPE cam was measurably better than the Thunder cam. You do not want a lazy lobe on the exhaust. The 1.85 rockers on both intake and exhaust perform best.

[Mighty Horse]

Patrick, do the increased ratio rockers change the idle any? Does it make it sound choppy? I know that it doesn't change duration but wondered if the increased lift was noticeable at idle?

[SS DAVE]

well i just fitted these rockers ,springs and push rods.it doesnt make the idle sound any different,my l 76 has a custom oztrack comp cam dod,lsxr 102 intake,nw102tb,1inch7/8 longe tube extractors,100 cell race cats,twin 3 inch to the centre cannons with merge and twin 2 1/2 inch to the rear hp cans,duss otr and oztrack mafless tune.pretty much all i can throw at it and still keep the afm.it made 274.5 rwkw before the rockers and springs .il put it back on the rollers this week and see what its got.cheers dave

[Patrick G]

Patrick, do the increased ratio rockers change the idle any? Does it make it sound choppy? I know that it doesn't change duration but wondered if the increased lift was noticeable at idle?No change in idle tone or drivability. Just more power.

[616 of 933]

is this a good idea for a car with no bolt ons or tune?

[It's A G8!]

is this a good idea for a car with no bolt ons or tune?

It wont affect anything if it not tuned. Also this could be the 1st bolt on if that's what you want.

[G8-4-Speed]

well i just fitted these rockers ,springs and push rods.it doesnt make the idle sound any different,my l 76 has a custom oztrack comp cam dod,lsxr 102 intake,nw102tb,1inch7/8 longe tube extractors,100 cell race cats,twin 3 inch to the centre cannons with merge and twin 2 1/2 inch to the rear hp cans,duss otr and oztrack mafless tune.pretty much all i can throw at it and still keep the afm.it made 274.5 rwkw before the rockers and springs .il put it back on the rollers this week and see what its got.cheers dave


Nice!!


I just milled .030" off the stands to bring the geometry of the rockers closer to where it should be. I removed my 7.500" re-installed my 7.450" pushrods and it sounds nice and quiet, even after serveral hard runs at the track. If anyone has put these lifters thru a hard test, it has been me.......
I could have milled them more but I would rather take small steps and see what it does. The reason for milling the rocker stands was to get the correct preload and fix the rocker geometry closer to correct. The only issue I ever had was once hot, if I ran it hard there would be a little tick from the lifters bleading down some and not pumping back up right away. I figures it was at the extremes of the preload range with both sets of pushrods and the geometry wasn't helping. Now I am very happy....It is just as quiet and the LS7's.

[SS DAVE]

your a sik puppy,11.38 im never goin to beat that,thanks for sharing your progress if anyone is goin to have lifter trouble its got to be you,lol.i ended up with a turn and three quaters of preload with 7.450 push rods,and all is quiet.my utes goin on the dyno on friday,im puttin the stock 18;s on the rear as ive been told the 22's hurt the rwkw reading by around 10 kw.the engine is definately a lot stronger with this mod,using more fuel too,oztrack has just dialled in the tune so im hoping for 300 rwkw .il post a graph when i have it.than off to the track at the end of the month to get a time slip

[SS DAVE]

well i made the 300 club ,it pumped out 303.4 rwkw,so i reckon this rocker mod is worth 18 rwkw to me,heres the graph,i believe this is the most powerful afm car in aus atm
http://i797.photobucket.com/albums/yy257/opti_photos/102_2503.jpg

[fiveoh]

What does that equal in rwhp?

[TooManyHobbies]

What does that equal in rwhp?

303.4 rwkW = 406.9 rwhp

[SS DAVE]

i realise 406 hp is not huge by any means ,but i only have a 500 lift cam 544 at the valve with these rockers,it still get 8 liters per 100 klm on the hwy and 13 liters per hundred around town,this is my daily driver work car,i think the rockers are a good mod for a small cam,i could feel straight away the power increase ,before the dyno.

[norm8332]

well i made the 300 club ,it pumped out 303.4 rwkw,so i reckon this rocker mod is worth 18 rwkw to me,heres the graph,i believe this is the most powerful afm car in aus atm


Thats a pretty good gain.

[todds87ss]

Patrick, hate to bring this one back from the dead, but...
I'm considering going this route, but have a question. I have a set of Crane 832 duals in the garage. IIRC, I took them off of my LS1 Camaro after going to a larger cam. Mileage would be less than 10K. Will these work?
Thanks.

[94guy]

has anyone else tried these rockers and seen hp?

['02 ws6]

I have a set (YT Ultralites 1.7) on my TA, but didn't install them for hp purposes. I wanted to alleviate any potential problems with factory needle bearing rockers and to quiet the valvetrain down some.

Sent from my SPH-M900 using Tapatalk

[Patrick G]

Patrick, hate to bring this one back from the dead, but...
I'm considering going this route, but have a question. I have a set of Crane 832 duals in the garage. IIRC, I took them off of my LS1 Camaro after going to a larger cam. Mileage would be less than 10K. Will these work?
Thanks.The AFM/DOD lifters are very sensitive to pressure. Too much is not good. I believe the 832 duals are borderline for being too much pressure. I would not run them personally when all you need is a beehive that's just slightly better than the stock beehives.

[todds87ss]

how about yellow ls6 springs? also got a set of these lying around...

['02 ws6]

how about yellow ls6 springs? also got a set of these lying around...

I haven't heard much of anyone outside of the LS4 MonteSS/GPGXP crown running them with DOD hardware.

If you're gonna be running a cam that has a soft ramp rate and under .550 lift they might be fine. Some have put on extensive miles with cams nearing .575 lift as well with those springs, but IIRC the advertised max was .550. That said majority of those I've seen are non-DOD setups.

Sent from my SPH-M900 using Tapatalk

[todds87ss]

I haven't heard much of anyone outside of the LS4 MonteSS/GPGXP crown running them with DOD hardware.

If you're gonna be running a cam that has a soft ramp rate and under .550 lift they might be fine. Some have put on extensive miles with cams nearing .575 lift as well with those springs, but IIRC the advertised max was .550. That said majority of those I've seen are non-DOD setups.

Sent from my SPH-M900 using Tapatalk

Right. I was just talking about the stock cam with DoD lifters.

[Patrick G]

how about yellow ls6 springs? also got a set of these lying around...I'm pretty sure those would work great with the YT 1.85 rockers.

[Mike P]

Patrick:

Any recent mods to the G8? Anything planned for the near future? Cam? Forced induction?

Just curious..... :)



...

[Patrick G]

Patrick:

Any recent mods to the G8? Anything planned for the near future? Cam? Forced induction?

Just curious..... :)



...Yes, heads, cam, DOD delete, and 3200 stall in the near future. Might get very experimental on the heads (high velocity runners). Stay tuned.

[Mike P]

Yes, heads, cam, DOD delete, and 3200 stall in the near future. Might get very experimental on the heads (high velocity runners). Stay tuned.


Cool info. about the heads......

Any balpark idea on the cam that you are thinking of using?

(I wish I had your tranny tune......) I tried going the route of getting tuned via HP Tuners, but because the car was tuned by LS2 Edit (and is unlocked), HP Tuners is not able to tune my car......

I'll keep an eye out for your new mods. Good luck & hope everything is good in Texas........



...

[fiveoh]

Cool info. about the heads......

Any balpark idea on the cam that you are thinking of using?

(I wish I had your tranny tune......) I tried going the route of getting tuned via HP Tuners, but because the car was tuned by LS2 Edit (and is unlocked), HP Tuners is not able to tune my car......

I'll keep an eye out for your new mods. Good luck & hope everything is good in Texas........



...

Why dont you buy a new ecm? They aren't that expensive. The tranny tunes can't be locked from my understanding so you should be fine on that end.

[94guy]

anyone one else try these? i want to try these on a new camaro L99 motor but for the amount it would cost i'm not sure if they will be worth it.

[todds87ss]

mine are in the mail. I'll post up when installed.

[94guy]

can't wait to see the results.

[texn884]

I read all this and I am suprised at that all can be done to this car and engine.
Partick's tune has made me drive a bit faster and love to put the hammer down.
I was running with a GTO Wednesday up 35 from New Braunfels to south os Austin at a good 90-95. The GTO was driven by a cute chick and when I came up on her rear she increasing the speed and and it was fun. I got off on the toll road just south of Austin and Kept it at a good 74 on cruise. and love that 26 mpg.

This car kicks ass.

[94guy]

todds87, any results from the rockers?

[94guy]

anyone else tried these and made more power?

[todds87ss]

todds87, any results from the rockers?

They are sitting on my coffee table. The only result I have seen is slightly tighter pants when I walk by them :).

Patrick, did you use any of the pedestal shims, or with the stock cam and 7.450 pushrods did you just bolt them on? Also, did you have to use the valve cover "extensions" that come with the rockers?
Thanks.

[Patrick G]

They are sitting on my coffee table. The only result I have seen is slightly tighter pants when I walk by them :).

Patrick, did you use any of the pedestal shims, or with the stock cam and 7.450 pushrods did you just bolt them on? Also, did you have to use the valve cover "extensions" that come with the rockers?
Thanks.I did not use the rocker shims. The longer pushrods were necessary even unshimmed. My rockers did not come with the valve cover extensions. If yours did, they are worth installing.

[G8V8]

Anymore feedback from additional guys doing these?

Patrick, any concerns about doing these on an early '08 with the original cam tensioner?

[laserred]

So Patrick, for the budget minded (as it seems I am always associated with), what do you think the LS3 springs and LS7 1.8 rockers should pick up? This would be an outlay of about $250 but should add maybe 10HP and peace-of-mind to 6600RPM?

[Patrick G]

So Patrick, for the budget minded (as it seems I am always associated with), what do you think the LS3 springs and LS7 1.8 rockers should pick up? This would be an outlay of about $250 but should add maybe 10HP and peace-of-mind to 6600RPM?LS7 rockers will not fit our L92 heads unfortunately.

[laserred]

Then which 1.8 rockers for $208 were the other people talking about? Were they confused or am I missing some hidden secret?

[Patrick G]

Then which 1.8 rockers for $208 were the other people talking about? Were they confused or am I missing some hidden secret?People were spreading misinformation that the $208 LS7 rockers will work on the L92 head. They are wrong and people are going to get mad when they try to bolt them up and the geometry is off.

[recii8472]

Patrick

Could the geometry be corrected? I think I may be the offending cretin who helped spread this misinformation. Just goes to show how a little bit of knowledge can be a dangerous thing. Can you explain why they won't work for the benefit of the uninformed like myself.

Rich


Sent from my iPhone using Tapatalk

[2QUIK4U]

Will these rockers work with the New Era high lift DOD cam? By my calculations it would be .620 lift. Would that cause any PTV issues?

[G8-4-Speed]

Will these rockers work with the New Era high lift DOD cam? By my calculations it would be .620 lift. Would that cause any PTV issues?
Depends on intake duration and ICL. Should be ok as long as you have enough spring.

[G8V8]

Nice!!

I just milled .030" off the stands to bring the geometry of the rockers closer to where it should be. I removed my 7.500" re-installed my 7.450" pushrods and it sounds nice and quiet, even after serveral hard runs at the track. If anyone has put these lifters thru a hard test, it has been me.......
I could have milled them more but I would rather take small steps and see what it does. The reason for milling the rocker stands was to get the correct preload and fix the rocker geometry closer to correct. The only issue I ever had was once hot, if I ran it hard there would be a little tick from the lifters bleading down some and not pumping back up right away. I figures it was at the extremes of the preload range with both sets of pushrods and the geometry wasn't helping. Now I am very happy....It is just as quiet and the LS7's.

[edit]
OK I read this whole thread several times and see the push rod issue. Your longer rods and stand milling were because of your cam, not the stock cam. I got it. Right?
[edit]

[2QUIK4U]

[edit]
OK I read this whole thread several times and see the push rod issue. Your longer rods and stand milling were because of your cam, not the stock cam. I got it. Right?
[edit]

He has a DOD cam in his car. But Patrick mentioned in his original post longer pushrods and stiffer valve springs are required. The milling should not be required.

[G8-4-Speed]

[edit]
OK I read this whole thread several times and see the push rod issue. Your longer rods and stand milling were because of your cam, not the stock cam. I got it. Right?
[edit]

I ran the stock cam first with the SLP rockers and had the preload issue with the stock cam also. The rocker stands are too tall and you loose all your preload so it needs fixed no matter what cam you run. If you mill the rocker stands, you can run the stock pushrods. If you run a cam, you will need a longer pushrods to offset for the smaller base circle on the cam. They are both a seperate issue but if not addressed it will change the pushrod length for what you would normally run for just a cam swap.

[Patrick G]

I just dynoed a 2010 LS3 Camaro that installed the Yella Terra 1.85 rockers. It gained 15rwhp over the stock rockers. It was able to run stock springs, but needed the longer 7.450" pushrods. This Camaro is now making 440rwhp with stock LS3 cam, heads, plus all the available bolt-ons.

[G8V8]

I ran the stock cam first with the SLP rockers and had the preload issue with the stock cam also. The rocker stands are too tall and you loose all your preload so it needs fixed no matter what cam you run. If you mill the rocker stands, you can run the stock pushrods. If you run a cam, you will need a longer pushrods to offset for the smaller base circle on the cam. They are both a seperate issue but if not addressed it will change the pushrod length for what you would normally run for just a cam swap.

OK. Let's see how I'm doing.
If I do not intend to change cams but just want the YT rockers the problem I would need to address is the rocker stands are too tall and they loose preload with the 7.450" long pushrods. If the stands were not too tall the 7.450" rods would be OK. If they need to be milled, they could be milled to allow shorter or even stock pushrods. Is this right? Guess I'll need to find out how to check preload.

[G8-4-Speed]

OK. Let's see how I'm doing.
If I do not intend to change cams but just want the YT rockers the problem I would need to address is the rocker stands are too tall and they loose preload with the 7.450" long pushrods. If the stands were not too tall the 7.450" rods would be OK. If they need to be milled, they could be milled to allow shorter or even stock pushrods. Is this right? Guess I'll need to find out how to check preload.

7.450" are what you need with 1.85 rockers. To avoid the 7.450 pushrods, you need to mill the stands to correct the geometry so you can use stock pushrods.

Patrick, 440 is impressive for a "stock" cam setup.... Been waiting for soemone to post a dyno from 1.85's on a LS3.

[G8-4-Speed]

I just dynoed a 2010 LS3 Camaro that installed the Yella Terra 1.85 rockers. It gained 15rwhp over the stock rockers. It was able to run stock springs, but needed the longer 7.450" pushrods. This Camaro is now making 440rwhp with stock LS3 cam, heads, plus all the available bolt-ons.


I thought LS3 springs ran into coil bind at @.600 lift?

[Patrick G]

I thought LS3 springs ran into coil bind at @.600 lift?The 1.85 rockers put the lift at .598" but we had no valve control issues up to the 6600 rpm rev limiter.

[G8V8]

7.450" are what you need with 1.85 rockers. To avoid the 7.450 pushrods, you need to mill the stands to correct the geometry so you can use stock pushrods.



I get the picture. Is there any reason to want to avoid the 7.450" pushrods? Any reason milling the stands is a better option than the 7.450" pushrods, especially if a future cam swap is NOT in the plans?

[Patrick G]

I get the picture. Is there any reason to want to avoid the 7.450" pushrods? Any reason milling the stands is a better option than the 7.450" pushrods, especially if a future cam swap is NOT in the plans?No reason to avoid the longer pushrods. They're essential if you want quiet valvetrain and good geometry. Consider them a required component.

[G8V8]

No reason to avoid the longer pushrods. They're essential if you want quiet valvetrain and good geometry. Consider them a required component.

Thanks. I guess i got wrapped around the axle about milling and what the problem was. From what I've learned, the way the Y-T rockers are made, to get the right preload, you either need to use the longer 7.450" push rods or use the stock pushrods and mill the stands to allow for how the rockers are made.

If all that is needed is to buy the Y-T rockers, LS3 springs and 7.450" pushrods and then install them, it seems like a very straight forward mod. It sounds very plug-and-play, right? Does anything need to be measured or checked, like valve clearances or anything else?

I still have the original yellow tensioner and the DOD lifters are the original design, not the later one because mine is an 888 car. Because I'm pretty conservative my tune has the car shifting at less than 6100 rpm and my limiter is set at about 6300. My other mods are a Roto-Fab, VMS ported intake, Solo HFC, Corsa catback and VMS 93 tune. Would this work well?

What might switching to Kooks 1 3/4 LTs and x-pipe-cats yield over what I have now?

[G8V8]

Not sure if I missed it or not, what is the desired lifter preload for the Y-T rockers?

[todds87ss]

todds87, any results from the rockers?

Finally dyno'd with typical intake /exhaust mods. 403RWHP. I figure that, based on other dyno runs that day, I got 15-18 rwhp from the 1.85s with LS6 yellow springs (I do not recommend them, they are just what I had lying around)

[todds87ss]

UPDATE...
I believe that I may have the first failure of this type of a Yella Terra rocker.

http://i452.photobucket.com/albums/qq245/todds87ss/DSC_01611.jpg
The pushrod has penetrated the cup in the rocker, and the oil restrictor in the tip of the rocker is snapped off.
Shipped back to YT for analyzing, not sure if I'll try them again(I have been known to be a glutton for punishment).
Opinions?

[Voice of Reason]

Well that sucks. Which springs did you go with? Any chance that they were too strong and put too much pressure on the rocker cup? And did you go with the longer pushrods? What kind of noise did it make when it failed?

This is still on my list of potential mods so I'm very curious how this turns out for you. Good luck

[todds87ss]

LS6 springs. the noise was like that of a collapsed lifter. I have to decide today whether or not to refund or replace...

[Voice of Reason]

Bumpity Bump.

todds87ss - How did things turn out for you?

I think I'm a month away from a go/no go decision on these. I want one last power mod before I stop messing with my G8 and start saving up for a weekend only car, and I think this is it. Any last advice from anyone?

[todds87ss]

I left them off. Planning a cam this spring, and saw no need for the rockers. I did notice the increase in power, and miss it.

[G8-4-Speed]

I think milling the stands is a much better way to go in making the rockers work correctly. Its easy for someone with a lathe. Longer pushrods only fixes the preload issue, it doesn't fix the messed up geometry. My rockers have been great and I beat them as hard or harder than anyone.....They were the first mod I did to the car.

[todds87ss]

So you have to pull the heads to mill the stands...I would think that this is the point at which this is no longer a bolt-on. If I'm pulling the heads, I'm going after a lot more lift than 1.85s will buy you.

[G8-4-Speed]

So you have to pull the heads to mill the stands...I would think that this is the point at which this is no longer a bolt-on. If I'm pulling the heads, I'm going after a lot more lift than 1.85s will buy you.

No, don't have to pull the heads to fix. The rockers come with spacers (stands) that are too long. The spacers need cut down in a lathe. I cut mine down .035" which seemed to be pretty close.

[todds87ss]

Ahhhh, you refer to the shims in the rocker kit. Thanks.

[G8-4-Speed]

Ahhhh, you refer to the shims in the rocker kit. Thanks.

Yeah, they give shims but the rocker stands that come with the rockers are already too tall. I think they added the washer thickness to the stand instead of subtracting it when they machined them. If you were to get longer valves for longer springs, then rockers would be fine.

[desertg8]

With non dod and ls7 lifters and lifter trays on an ls9 cam would 7.40 pushrods work? New Era believes so. I know the ls7 lifters and trays would push the pushrod up some and I do not think the ls9 cam has a low base circle or what ever you call it.

[Voice of Reason]

I'm (slowly) on my way to making this mod happen. Today I ordered a Value Spring Compressor (http://www.summitracing.com/parts/CRN-99475-1/) and Air Valve Holder (http://www.summitracing.com/parts/WMR-W84003/). The rockers, spring, and pushrods will be ordered on a week or so.

[UGotSmkd]

Would these be the ones for our G8s, or are these strictly for LS1s?
http://www.hinsonsupercars.com/p-926-yella-terra-ultralite-shaft-mount-non-adjustable-roller-rocker-185-ratio-ls3l92.aspx

I guess, basically, my question is do we want adjustable for a cam in the future?

[Voice of Reason]

Would these be the ones for our G8s, or are these strictly for LS1s?
http://www.hinsonsupercars.com/p-926-yella-terra-ultralite-shaft-mount-non-adjustable-roller-rocker-185-ratio-ls3l92.aspx

I guess, basically, my question is do we want adjustable for a cam in the future?

I'm pretty sure that's the same website I found and at the best price. The pic looks correct, one of the rockers is offset like that on our heads.

[Voice of Reason]

I wimped out on the Livernois non DOD cam swap and I've put my order in for YT 1.85s, PAC springs, and 7.45 pushrods. I'll post up my impressions once I have them installed.

[RyeLou]

I wimped out on the Livernois non DOD cam swap and I've put my order in for YT 1.85s, PAC springs, and 7.45 pushrods. I'll post up my impressions once I have them installed.

I just read over this whole thread again, and will be waiting for your results. It's very tempting, and I like the idea that you don't have to get a retune after the upgrades.

For those that have done this already, how long has it been taking you guys to install this stuff?

[Patrick G]

I just read over this whole thread again, and will be waiting for your results. It's very tempting, and I like the idea that you don't have to get a retune after the upgrades.

For those that have done this already, how long has it been taking you guys to install this stuff?Spring, rocker, pushrod swap takes about 2 hours.

[RyeLou]

The last thing I'm failing to grasp is why this doesn't require the car to be tuned after you install these parts? If you're increasing the duration the valves are open, wouldn't you have to accommodate for that?

[Voice of Reason]

duration doesn't increase. You get more air/fuel because the value is opened more.

[G8-4-Speed]

The last thing I'm failing to grasp is why this doesn't require the car to be tuned after you install these parts? If you're increasing the duration the valves are open, wouldn't you have to accommodate for that?

Yes, you do add duration at the valve. You do not have to retune to run the rockers. The rich factory tune has enough fuel in it, just helps to bring the faster with a tune as well as a few other tweeks. The MAF picks up the added airflow.

[RyeLou]

Yes, you do add duration at the valve. You do not have to retune to run the rockers. The rich factory tune has enough fuel in it, just helps to bring the faster with a tune as well as a few other tweeks. The MAF picks up the added airflow.

What if you're not on the factory tune? Im not questioning anyone about not needing a tune, just trying to see why.

[todds87ss]

There are even cams that do not need a tune. This is along the line of a very subtle cam change. The stock tune is fine, but performance could be optimized with a tune.

[RyeLou]

It just seems to me if it doesn't make a big enough difference to require a retune then it couldn't make that much of a difference period. Case in point, just changing headers you're strongly advised to get it retuned.

I realize I'm wrong and just playing devils advocate, I was just hoping for a good explination. I'll do some more research and come up with the answer I'm sure.

[GT Drew]

Why would you not want to be tuned? In stock form you can gain 10 to 15 hp with a tune alone. This means the stock tune is ultra safe, nothing is optimized.
Yes you will see an increase without tuning by adding rockers. Anything that helps increase airflow through the engine will need the tune modified to get the most out of it.
A vehicle with an Intake, headers and full exhaust will see a larger gain from rockers than a stock car will. Same for a cam. The more supporting mods the greater increase and the greater need to tuning

[RyeLou]

Why would you not want to be tuned? In stock form you can gain 10 to 15 hp with a tune alone. This means the stock tune is ultra safe, nothing is optimized.
Yes you will see an increase without tuning by adding rockers. Anything that helps increase airflow through the engine will need the tune modified to get the most out of it.
A vehicle with an Intake, headers and full exhaust will see a larger gain from rockers than a stock car will. Same for a cam. The more supporting mods the greater increase and the greater need to tuning

Nobody is questioning any of that. And I think everyone would agree a tune is always the best way to optimize your setup if you make a change. The question is how you're able to replace the rockers without HAVING to retune. Patrick says it back on the first page I believe, that it isn't necessary just for the rockers. The car that started it all (in the 1st post of this thread) was tuned before the rockers were replaced.

[desertg8]

got the pushrods. comp. 7956-16. 7.450 5/16

Patrick, are those correct?

[Voice of Reason]

The pushrods that were just delivered to me are comp 7639-16, 7.450, 5/16. I think the ones you posted desertg8 are dimensionally the same, but yours are harder/stronger.

[AVIDMOTION]

Ok I am about to jump in with the new SLP 1.85 rockers. 7.450 rods and Pac 1218 springs. Is this still the hot ticket or anything change? Anyone with the best prices? Vendors dont hesitate to email me any sales you might have. If I go with the comp 1218 .600 springs do I need anything else, or do I use the stock retainers etc? Would like to get all parts and gaskets etc needed. thanks any help appreciated.

[hflores3]

Ok I am about to jump in with the new SLP 1.85 rockers. 7.450 rods and Pac 1218 springs. Is this still the hot ticket or anything change? Anyone with the best prices? Vendors dont hesitate to email me any sales you might have. If I go with the comp 1218 .600 springs do I need anything else, or do I use the stock retainers etc? Would like to get all parts and gaskets etc needed. thanks any help appreciated.

I did this. I used PAC 1518 springs...... are PAC 1218 double springs?

I used my stock retainers (rpm is not high enough to warrant the higher cost titanium versions - so I just didn't spend the money) .....my opionion.

[Joeygr8gt]

Holy old thread revive lol. Yeti did rockers and liked this mod more than gears I believe. This is my next mod since I can do it in my driveway. Just bought pat g tuning so ill have to wait

[G8GTCYA]

Good mod if your not going to do a cam latter. Also a good mod if you later decide to do a cam that still keeps dod. Otherwise, if you plan on doing a dod delete cam later it's a waste.

[AVIDMOTION]

Be lucky if I can get this done, car will get cam when it needs rings and a rebuild. Just need 30 more hp off the motor for a bit more top end charge. Got 93,000 miles on her. Synthetic oil etc. runs great but I think the springs are a little beat up on, so with new rockers fresh rods and new springs I exspect nothing more then a freshening up, another kick in the ass for the old grey mare. Yee Haaa
BTW if I get as much SOTP feel I got from the Under Drive Pulley I would be shit hot happy!

[AVIDMOTION]

This is PAC 1218: they are not dual springs.....
PAC 1218-16
Beehive LS1/ls3 Spring
OD: 1.290"
130 lbs @ 1.800"
318 lbs @ 1.200"
Lift: 0.600"
PAC 1218 Beehive Valve Springs (.600")

PAC 1218 Beehive Valve Springs are engineered to fit the stock valve seat and spring retainer.PACPAC-1218Regular Price: $179.99
On Sale For: $159.99

[pir4te]

I reckon you are only going to do this once, so don't skimp, go for gold, get the PAC 1500 Pro Series.
I have PAC1511, very happy with result. +14.5rwkw @ 5650 then flatlines (not drop) past 6100 to cutout.
Amazingly more useful all over, more under both torque and kw curve.

[pir4te]

PAC1511 drop in beehive LS spring
Features:
• 130lbs @ 1.800”
• 384lbs @ 1.140”
• Spring rate 385lbs per inch
• Coil bind 1.080”
• Max valve lift .660”
• Frequency 32952
• Nitride surface heat treat
• Polished
• Nano peen
• Extreme high levels of fatigue life

[G8-4-Speed]

They have the new Pac-1211x which is part of their new rpm series. Very similar specs.

[pir4te]

Rick I assume the flatline at 5650 is the limit of the cam more than flow, as is pretty darn flat next 450rpm to limiter? I have no clue.
Extra lift starts the new power ramp earlier than previous at 2500 to gain 14.5rwkw when it reaches +300rpm higher peak (prev 5350).
I am keen to see how the ram air mod and ported TB will improve the curve.
Already have a good CAI, tri-y extractors, 3" modded cats going to 2.5" at back, and apparently pump and injector cycle is spec'ed up for flex fuel.

[AVIDMOTION]

Question, are these an ok substitute for the Yella Terra rockers?
Competition Cams - Ultra Pro Magnum Rocker Arm P/N 1676-8
Are these any good? Looking to do the 1.85 rocker upgrade with PAC 1218 springs and comp 7.450 push rods.
Found the Yell a Terra 1.85 rockers for 460 and these
For 202.00 I guess the YT are better but budget dictates if the Comps are workable equivalent I would have to go with them because of price. Any opinion appreciated.

[pir4te]

High revving well-balanced L76 AFM valvetrain is still newly chartered territory. Call me risk averse because i make wine not engines, but it seems this is THE key component. That's why I was happy to spend extra to get the unbreakable ones.
For the price of a tyre or two tanks of gas, I wouldn't change course from 1511, 1211x, or the 1218.

[AVIDMOTION]

Those are all springs. I will do the comps 918 or the PAC 1218. But wanted to know if the Comp Cams pro magnum roller rocker was acceptable equivalent?

[pir4te]

My bad, aren't those rockers only 1.8?

[STL_G8GT]

Those are all springs. I will do the comps 918 or the PAC 1218. But wanted to know if the Comp Cams pro magnum roller rocker was acceptable equivalent?

As an fyi I have been happy with my beehive pac springs

[pir4te]

As an fyi I have been happy with my beehive pac springs

Haha now that makes more sense, wondering about Beatrice all night!

[STL_G8GT]

Haha now that makes more sense, wondering about Beatrice all night!

Lol yeah I reread and the autocorrect had done a real number on that one lol.

[AVIDMOTION]

I ordered the Comp 7.450 rods, PAC 1218 springs and the Yella Terra 1.85 rockers all from same company shipping only 10 bucks.

[Joeygr8gt]

I ordered the Comp 7.450 rods, PAC 1218 springs and the Yella Terra 1.85 rockers all from same company shipping only 10 bucks.

What was the total for the three? I had an estimate shipped a while ago and just want to compare. Pm me if possible

[AVIDMOTION]

joeygr8gt your private mailbox is full

Comp Cams 5/16" Hi-Tech Chromemoly Pushrods-Default Comp Cams Hi-Tech Chromemoly Pushrods, 7.450" (+.050"), 7956-16------ $129.99

YT6685 Yella Terra Ultralite Shaft Mount Non-Adjustable Roller Rocker 1.85 Ratio (LS3/L92) $485.00

PACPAC-1218 PAC 1218 Beehive Valve Springs (.600") $159.99

SubTotal: $774.98
Shipping: FedEx Home Delivery $18.08
Tax: $0.00
Total: $793.06

[Joeygr8gt]

Yip that's close to what I was quoted. Thanks sir

[G8Headache]

Yella Terra Rockers - $429.95 from NewEra
Comp Cams 26918 Springs - $174.99
Comp Cams 7.450 Pushrods - $99.95

I have it on my list of "To do" mods.

So Im looking to do this and Im on Summit Racing looking at the springs and push rods. For the Push Rods, I know we need 7.450 in length, but what Diameter do we need? Also, Will the stock Seats and Retainers work with the new hardware? Thanks.

[G8Headache]

Scratch that, I found the info, 5/16" right?

[STL_G8GT]

Scratch that, I found the info, 5/16" right?

Yes I believe you are correct

[6.0 Liter Fever]

Does anyone have any concern with the DOD lifters and the high lift, high presurre springs?

[STL_G8GT]

Does anyone have any concern with the DOD lifters and the high lift, high presurre springs?

Those things drop in a stock setup, so yes... How much of a concern, well that's up to the roll of the dice.

[6.0 Liter Fever]

Yea, that is my only issue with getting the bigger PAC springs, I'm concerned that the weak DOD lifers might explode. I'm leaning towards the PAC 1215's (115/293lbs.) or the LS9 springs. Mace out of Australia makes a 1.90 roller rocker, too, for about $400 if any one is interested in squeezing out that last little bit.

Will increasing the lift extend the RPM range? Did someone allude to that? I wasn't sure if it increased power under the curve or extended the curve, also.

[pir4te]

Yes Mace do 1.9s here, similar results, seems the mandatory brand for this mod in the Holden SV6 community.
My donk does rev harder, faster, longer (ahoy!), I think prolly cause it makes torque earlier, which increases power under curve and carries hp peak higher.
HP peak is 5650rpm (+300 higher) then flat (without drop or valve bounce) and wants past preset 61xx cutout. ie plateau - no higher power yet stays till cutout (needs spec'd cam).
I guess it wouldn't rev as well with just rockers rods and stock springs.
Also I doubt anyone would recommend this with the first DoD lifter type, no probs with the revised brand at all... (Anyone?)
I've done 70,000 miles in two years since new, lifter noise(s) there from day one, all but disappeared with new preload, measured rods and nitrided springs - sounds like a Pfaff now but you have to listen carefully.

[Voice of Reason]

I did this mod 2 years and 25k miles ago. Search my name, I think I did a small write up about my experience. I saw a small gain in peak hp over a friends G8 that was otherwise very similarly modded, but driving around town it felt much more torquey. My wife is driving the G8 now as I've moved on to a new weekend toy and I don't worry a bit about longevity or mechanical issues with it. Oh, and it quieted the engine sewing machine noises down nicely.

[pir4te]

Even with TC on, difference is more than seat of pants.