I know some of you guys are running the 224/236 xe high lift cams in 383's and would like to know what kind of rpm's you see, and what springs your using. Mine is ground with a 116 lsa by the way.
My engine completely drops power @5400 and won't rev past about 5900.
Any thoughts on the afr rev kit, beehive springs?
Thanks, Steve

 

I've got a 230/236 hydraulic roller XE series, on a 112 LSA. The dyno chart shows peak power is made to 6300 RPM then drops off from there. My rev limiter is set to 6700 and I tickle it on the autocross circuit sometimes.

I dont use the rev kit: Mine was interfering with the pushrods. Instead, I use titanium retainers and Comp #687 springs which have a significant amount of stiffness. I'd have to check the numbers, I dont remember exactly what they are.

I'd suggets the beehive springs, but with power loss at 5400 RPM, I'd look elsewhere first. It sounds like there's something else wrong. Are the springs worn out? Timing okay? Pull the springs and check their strength to see if they are still in spec.

 

From what I've seen most people use too light of a spring and too heavy of a valvetrain. With the proper setup a rev kit is unnecessary and is not much help in extending the usuable rpm range anyway.

What are your valvesprings set up at (open and closed pressure). Titanium or steel retainer? Have you checked valvetrain geometry?

 

224/236-114 high lift lobes, 1.6 intake, 1.52 exhaust. I used Comp 977's set up at 145 on the seat and had decent luck, reving all the way to 6800 with my old T-trim. Last time I pulled it apart, I found that the seat pressure had fallen off to 125 and they could not be shimmed without getting into coil bind. I swapped out to some Crane 99893 set up at 160 lb on the seat and they work great also. The turbo motor only peaks at 5700 rpm, but it goes to 6400 clean.

Mike