scopam

what is the rev limiter on a hp 500efi 5250 or 5400 turning props at 5150 want to know how much more I have to go

Von Bongo

I believe:

4800-5250 is normal op

5400 is rev limit

Griff

Rev limit is supposed be at 5350rpms. Keep in mind this can vary 50-100rpms and tachs can be off as well.

scopam

griff I have a 32 AT 2002 , I pulled the motors and did the top end I beleive after doing everything that I am now down approx 150 rpm and 1-2 mph. Top ends have inconnell severe duty and manley valves, hi comp springs. Drives and props all the same, all the alignment is the same. We also put in new mounts to realign the motors the drives would not go back on also replaced one coupler. I thought it should run better, at a loss

Griff

Sounds strange for sure. Is the speed off 2mph as well???? If you're down 150 rpms, and everything else is the same, it should be.
Did you change cams???? or just basically a stock refresh with better parts??? What valve springs did you use???

It could be as simple as a valve or 2 being just adjusted a little too tight or not tight enough.

scopam

hi comp springs, Your thoughts are the same on the valve adjustment, was going to look at all that this weekend and just go through everything again. what are you running in your boat and did you ever run hp500efi.

Griff

I have 502mpi's with CMI's and Stelling boxes. It runs 72-74mph. I've had the boat 2 years and bought it from the second owner who had the engines installed. It was originally built with 700+ HP SC'd engines and ran over 100mph.

scopam

what affect do the boxes have for you , I also have a pair of nose cones but not shure if Im going to use them. I have stock bravo's and have heard mixed emotion on the performance of them.

Griff

I don't know for sure. It was built with them originally. It seems my prop slip numbers are maybe a little lower than most other 32's. I do not have a notched transom, like the newer 32's though. It still has the original 1.36 drives with nose cones as well. My engines are also moved forward a foot with driveshafts to help give the boat better balance.

Whipple Charged

Rev limit is 5400, peak power is 5600rpm if you raise rpm limit, motor has 28deg timing from 3600-5200 and 34 at 5400.