Looking for info on an LS-1 build, ANYONE

[piecesparts]

I have a 2000 LS-1 out of a Firbird and I want to install it into a 1968 C-10 Streetrod truck. I want to build the engine with more than the factory 320 HP and am considering a cam setup to help boost the HP to an area around 375 to 400. I saw a gentleman down in Tulsa, OK with a similar truck setup, but using a 5.3 truck engine as his engine. He used a Texas Speed 25-224XE cam with the following info 224/224 @.50 and .566/.566 and it is set at 112 degrees for a good rough idle. He has the engine installed with a set of 42 lb injectors and the factory intake, but it has a tune done to the computer. He followed it up with a 3600 stall converter to his OD tranny. Comp Cams has suggested their cam profile on the following cam ---XFI camshaft series part# 54-54-414-11---

I believe that he may have overdone the injectors and the stall numbers a little bit, but the truck undeniably runs great. Can anyone provide a good copmbination for a good streetable engine. I have been told that I would be better with a set of 36 lb injectors and my past experience tells me that I may need a lower stall converter. I want to update the intake to an LS6 intake and will be using Doug Thorley LT headers to a set of duals feeding an automatic to a 3.42 or 3.73 geared rear end.

Anyone that has played w ith the LS1 engines can you provide feedback?

[neuralfraud]

I haven't played with LS1's, in fact, I really haven't played with much beyond a chrysler 2.2 turbo and a buick 3.8 turbo. That being said, I believe the stall is a bit high.

Stall speed is the speed at which there is no more slippage in the converter. The motor will not run any higher than the stall speed without forcibly moving the wheels. With that having been said, with a 3600 rpm stall converter, you can hold the engine at around 3600 rpm without breaking the tires loose and that obviously helps by getting you into the power band right at launch, but that's only good for drag racing, and unless you're also installing a transbrake and/or linelock, that's overkill.

If someone could perhaps enlighten me as to why, but I don't see why not just go with a 2800 stall converter, That is considerably loose and the cam you're talking about is still somewhat DD friendly, you could probably get away with a lower converter.

Additionally, correct me if I'm wrong, based on your setup, are you using a TH-700 or 200-4R? I believe those run 12" converters, most aftermarkets are in a 9" variety which means less rotational mass and that'll help your engine wind up a little quicker.

As far as injectors, You can run big injectors if you properly calibrate the duty cycle curve, and (As far as I recall) the injector constant, of course I have no idea what's changed in the LS1 ecu vs the old 1980's PROM setup, so you may have more of a challenge. You need to talk to a good builder who can tell you exactly how much fuel you need to make the horsepower you want with the parts you want, and get the best match. It makes no sense to go with 42lb injectors if 36lb injectors will work sufficiently, it's harder to tune, they won't spray the same and because you're getting less air into the engine, it *will* make a difference.

I've made a lot of assumptions in this post, but hopefully they're somewhat informative.

[Patrick G]

A 224/224 112LSA cam is a main staple for 5.7L LS1s. If you have a free flowing exhaust (like you mentioned), then you can't go wrong with one. Stock 2001-2002 injectors are 28.8lb and will support up to 440rwhp. The 1999-2000 injectors are 26 lb and are good for around 400rwhp. LS6 manifold is worth 7-10rwhp at that power level. An underdrive crank pulley is worth a tenth in the 1/4 mile. I would keep the stall between 2800-3200 rpm. If you're looking for the best info for LS1s on the web, go to www.LS1Tech.com . I am the senior administrator there.