New engine assembled, won't start - backfires

[meissen]

I used LS7 lifters and I used 1/2 turn preload.

Disclaimer: The exhaust was really rattling for some reason - it went away as soon as the exhaust warmed up and has not rattled again even after letting the car cool off over night LOL go figure.
[ame="http://www.youtube.com/watch?v=Tg4UwF0Epew&feature=channel_page"]YouTube - LT1 012[/ame]
[ame="http://www.youtube.com/watch?v=C_CPswSsTiM&feature=channel_page"]YouTube - Cruise by in Red Alert[/ame]

Deceiving videos though - my LTerms are about 20 counts off. I'm really hoping it's just the fact that it's the stock tune and will be fixed when I take it to the local tuner. Only bad part is the guy who is doing my tune is an hour away... so he's going to review my data logs and as long as he deems it to be OK I'll drive it out to him... if he says it's not safe to drive on the stock tune then I'll have to get a car trailer from U-Haul and tow it to his shop.

On a positive note, the DataMaster logs seem to be really good aside from the fuel trims (lol... guess that's a really good contradiction). The knock sensor isn't registering knocks like it used to - the first try with the LT1 (when it had the two spun bearings) right from the first start up it would register knocks. And, another positive is that the spark retard stays at 0 to 0.1 - it's so dang smooth. If anyone has datamaster and wants to look for shits and giggles - http://www.meissenation.com/datamaster/


Oil pressure has been great - about 60 when it starts cold and then 30-40 psi when it idles. New oil pump and the white spring mod seems to have been worth it. RPMs are spot on for the tachometer at idle with what datamaster shows. Haven't verified how accurate the speedometer is. I'm using a 1997 z28 gauge cluster in my 1998+ dash with a 1995 LT1 in a 1994 Camaro. And I can't forget my 2000 Trans Am door panels or my 1998+ rear end. I swear I need to get a spreadsheet to keep track of what year vehicle each item in my car came from.

[ThreeHonks]

Very nice! so are you still using the 30lb. injectors or did you switch back to stock?

[meissen]

30lbers - I wanted to go back to stock but the PCM was already calibrated for the 30lbers.

[ThreeHonks]

OK j/w because i was reading on mifbody that you thought the larger injectors may have casued a problem. Its definately a good idea to keep those larger injectors, I think the stockers would be just about maxed out. I have 42lb. SVO's that I will be running

[meissen]

Well the cat was let out of the bag on MiFbody today after a few guys started putting 2 and 2 together that I've been too quiet with updates. I drove the car to Port Huron (45-60min drive) to the guy who is tuning the car. Drove BEAUTIFULLY... closed loop idle was a little too low (650) so it'd stumble but Steve said he's going to put it at about 800 or so. If all goes as planned I should be picking it up tomorrow or Thursday night.

[JAKEJR]

Great to hear it! but honestly dont rush it to have it at the meet and greet, do it right the first time. I just dropped my motor out today and am planning on just doing things slow and getting it right. I cant wait to see it on WW soon tho!

Thanks a lot JAKEJR, I really appreciate it. Would u have any idea how much preload an LS7 lifter needs? I am using those for my build

I never checked LS7 lifters, but if was going to run them, I'd put a dial indicator on the rocker, then use 1/2 turn on the poly-lock and see what plunger depression/preload I'd get. I'd shoot for .030", give or take .010".

If I just went with the standard 1/2 turn, I wouldn't know how much that actually depressed the plunger; how mcuh actual preload I'd have. Checking comes with the territory when swapping to new and different parts; gotta check.

Jake

West Point ROCKS!