i recently completed my 393 ford stroker, the following has been installed in
it: holley 750HP,performer rpm air gap, air flow research 185cc heads, harlan
sharp rollers, 10.3 compression, comp cams retro fit, extreme energy roller
232/240 duration 565/575 lift and 112 deg lobe separation, MSD pro billit #8584
distributor, MSD blaster 2 coil with tower added, mallory hyfire,VI-AL ignition,
Taylor 8mm wires.
Engine performs great EXCEPT when it gets to 5800 rpms it will not climnb any
higher. I changed springs to comp bee hives- stiil will not climb past 5800
rpms. what could be the problem???

 

Well, i dont know about it messing with the RPM's but Air Gap manifolds have given me some problems. WHen i put in a 280 cam in my chevy 350, it wouldn't run for crap for a long time. WE just figured out it's the Scorpion Intake we have on it.

 

The cam might have low end, so it wont high rev.

 

Does your Mallory ignition have a built in rev limiter?

 

stroker engines dont rev. period. theres nothing wrong with it at all

 

Be careful with blanket statements. My 408c makes peak power at 7k.



Picking a cam for a stroker motor is hard, they always perform at a level much tamer than advertised. What does the cam card say about operating range for your cam? What fuel pump are you using? Have you confirmed you carb is opening to full throttle?

 

yes i do have a rev limiter and its set past the 5800, holley black fuel pump which is rated at max 140 gph @14psi, still using the stock mustang fuel tank but have ran 3/8 line from tank to carb.. yes the carb is opening to full throttle. comp cam catalog - the cam is listed for 302 and the operating range is 2600-6500.
thanks for the help, its much needed!!

 

IMO this could be an indication of the problem. The same cam running in a 393 is going to make power a lot lower in the power band. You could call up comp's tech line and ask them what they think the performance of that cam in a 393 would be like or a much better idea would be to contact a custom cam spec guy (like Ed curtis at Flowtech) and ask his opinion and see if it validates or contradicts mine.

 

I'LL DO SOME CONTACTING AND WILL LET YOU KNOW. BUT THIS CAM IS THE SAME EXACT CAM IN FORD RACING 392 CRATE MOTOR, AND I HAVE SEEN THE DYNO TESTING DONE ON THE FORD RACING EXCEPT THEY USED A VICTOR JR. INSTEAD OF A RPM AIRGAP AND THAT MADE PEAK HP AT 5900! THANKS AGAIN FOR YOUR HELP