One thing that happened to me last year was when I reassembled my motor the Throttle position sensor got messed up so at WOT it was telling the PCM that the TB is only 75% open. I swapped in a new TPS and noticed a huge difference.

But I would start with the rockers. Maybe they're too tight.

 

561 castings refer to the Casting # on the heads on an LT1 block.
The 561's came on the late96 and 97 LT1's. They flow better than previous years heads by about 8-10 CFM. If you plan on porting them they are NOT the ones to use. They do not have much material for porting as they were lightened up to reduce weight aswell. If you want a to port LT1 heads I recomend getting non 561 casting as I did.

 

Ok good, my heads are off of a 95 that I'm working on.

 

93 is reportedly the best year for all out porting on stockers.

 

that's some very good non common knowledge info as that's the first time I've ever heard that..

thanks for passing that on, I'll look for a pair of 95 heads to get ported whenever I go that route

 

Well, the saga continues... I have had just about every single problem that you could imagine with my heads and cam swap, and now I HAVE ANOTHER!!!! The cc306 that I bought used IS FREAKING BENT!!!! Jordon put it in, and he said it felt a little stiff so he had it checked out, and it is bent so I am unable to use it. It is ok though, because I found another better cam to replace it. It is a billet custom grind and the specs are as follows : 234/241dur, 578/595lift, on a 111 lobe sep. Things keep screwing up, and the parts that I find to replace them keep getting better. I guess it will all work out eventually, but it has been almost a month with no car now and I am starting to get a bit tired of everything going wrong. Oh well, I will set you all know if anything else goes wrong.

WISH ME LUCK!!!!

Aaron

 

That sounds like a pretty sweet cam. I hope things workout for you.

 

from what i hear the 561 are better than other lt1 heads. but i want to know what cars they car on. i heard that they came on the 97. does anyone know if thats correct.

 

 

I had my heads flowed last night to get an ideal of how I am doing so far. I was hoping to get better numbers, but that did not happen, but I have some more things to fix.

But, what I did get were some numbers on the exhaust side with a 2" pipe. This is what I got without the pipe.

Lift------I---------E-------2" pipe
0.200--131.0--89.9-----NA
0.300--186.2--123------NA
0.400--225.1--146------NA
0.500--NA -----163.8----NA
0.600--258.9--176.6---196.0
0.700--258.6--184.2---202.9

I would highly doubt a stock exhaust flowing 175.

I am learning quite a bit about porting LT1 heads lately.

 

1993

 

I'm gonna take a completely different angle on this.

Before I did my heads, cam, headers, and all that stuff my car ran a 14.158 @ ~99.

After all the engine stuff, it ran a 13.733 @ 102.71 at US 41 this past weekend. 60' was 2.294.

You might say that the heads and cam didn't do jack. But then when you consider that my car only has 2.73's, stock radials, A4, no tuning, and stock suspension, you'll see there's a TON of potential there. Throw in slicks, 4.10's, tuning, suspension, and a little weight reduction here and there and that car can break into the 11's.

I didn't see much stuff in your sig about traction-specific stuff. Remember, your car will only go fast if it can get all the power to the ground.

 

Big difference between 13.7's and 11's....you need to see what is wrong with your current combo...there are many cars with stock programing running in the deep 12's...

 

Good point--one of the major issues (aside from no traction in the 60') was that the tranny wouldn't shift into 3rd gear... the car spent almost 2 solid seconds stuck right around 100 mph bouncing off the rev limiter like crazy. Plus it would help if I could drive better

 

I wasn't spinning that bad at all, if any and we went from a roll so I don't think that was the problem. I think that there were just many things that were causing it to not run right. I will make a list:
1.Valves were not set correctly
2.no tuning
3.hub and harmonic dampner were wabbling
4.timing chain gear was cracked
5.timing chain was abnormally loose because of that
6.and I was short shifting it pretty bad

All of these things should be taken care of with the dbl roller timing chain, new billet cam, SVO 30# injectors, comp R's, crane 10308 spring kit that we had to re-shim tonight because of the bigger cam(what a freaking pain!), CSI electric WP, and some jordon musser tuning. He said that because my heads flow 260 I should be limited to about 390-400rwhp at most N/A. I do have a nice 150 shot to add on top of that though

I have subframes, LCA's and LCA reloc brackets as far as suspension, and I have 315 nitto DR's on some 17x11 ZR1's so I hook pretty darn well. The problem that I am going to have next is that darn 10 bolt. Might swap an auto so I shouldn't have to worry as much about the 10 bolt but we will see. Jordon said it should all be finished by sunday so I will post the story (success or failure) to let you all know how it goes.

PRAY FOR ME!!!

Aaron