this is my problem, I have a basically stock LT-1 inmy race car which seems to run out of rpms at around 5500 rpm (won't rev past 5500). here are the specs on the motor:

stock cam
stock heads and springs
aftermarket intake for carb
holley 750 vs
new stock HEI dist. with a new accell super coil
Holley "red" fuel pump (holding 7 psi whole run)
timming set 34* at 3000 rpm
open headman long tubes
running 93 octane pump gas

I found this out while experimenting with a friends MSD 6AL, I put a 6000 pill in for the rev limiter and wanted to test it, in park-- car won't rev past about 5500 so it never got to the "pill", what do you think is the problem -- crappy cam??---weak valve springs??---crappy heads????

the car pulls consistant 8.11's in the 1/8th at about 84 mph, I usually shift at 5,000 because it seems to run out of power above that. I know bracket racing is "consistancy" but I would think the motor would rev higher than 5500 and whatever the problem is may be killing some low end power as well.

 

I believe you have found your engins limits with the stock cam. Rev. any higher, you could loose some parts! 8.11s in the 1/8th with a 60ft under 2.00 is dam good for your combo! I'd be happy with that for sure. With the need for speed, what you have you get used to, then it seems like it's not as fast anymore hence, more parts!! You can put a bigger cam in and reach that new rpm, but then, your going to have to put in stronger bottom end parts to take the strain.

 

Time for some real valve spings and a real camshaft. I wouldent personally wing an engine to 5500 in N but.....

 

A clue, I think; especially the springs

 

ordinarily I don't wing it that high in neutral, I first noticed the problem during a T&T pass when I missed second (damn Pro-stick) and went to neutral with my foot on the floor, the tach went to 5500 and stayed there until I got my foot unglued from the floorboard. I figured that the stock ignition wasn't up to the task at hand hence "experimenting" with the MSD. I guess I'm lucky the motor won't rev that high or I'd of had chunks on the track after that pass. It was my belief that the LT-1's were good up to about 6500 on the bottom end anyway, or not ?????