Engine Tech

[mplover2]

Say fellow gear heads i have a problem with my BBC. Rebuilt the 750 holley and the distributor back and forth with plugs, R44, #5, i cannot get past 5400RPM without the engine acting like it has a rev limiter on it. Took it to a mechanic friend and he seems to think it is valve spring failure.
What do you think? Motor specs below.
396 + .030=402cid
540 lift hydraulic cam
10 to 1 compression (.250 dome pistons)
Edelbrock Aluminum Heads
Performer RPM RECT.PORT
EdelbrockAir Gap Intake
Mucie 4 speed

[JEFF69Z28]

ARE THE SPRINGS NEW,SOUNDS LIKE YOU MIGHT BE TO LEAN,TRY SOME BIGGER JETS IN THE CARB.

[blowninjected540]

is this something new ? Did it rev up befor ? Is your distributor locked out ?

[bluedawg357]

i had the same issues with the valve springs on my edelbrock heads. i would go to a better spring.

[TheRabbit]

Is it a 4 - 7 swap cam? ( I'm not sure if hyd cam 4-7 swaps are avail :oops:)

This may sound stupid, but do you have a chip or some other kind of rev limiter on it? Chips do go bad. If you do have a chip change it or if it's a dial make sure it is well above 5,400. I run my limiter at 8,500 eventhough I only turn 7,800 to 8,000.

It also could be in the distributor. Are you sure the rotor is phased correctly and it's not cross firing?