chuckyarus

Ok, I have a 88 scarab excel. Originally had a 454 365hp motor last year and I ran GPS 56.2 which seems slower than other people with excels but I figured there are alot of people who think there boat is running faster than it is, and have never really brough along the Heart breaker(GPS). This winter I put in a zz502, 500 hp, took the heads off and had them shaved 30 thousands and have what looks like just the stainless gill risers on stock manifolds. 800 cfm holley carb and high rise single plane team g intake. Whick I've always wondered why alot of people are running single plane vs dual plane because I would think the dual plane would be better for torque, anyway. I had a 25p 3 blade rapture prop laying around so I figured this would be a good starting point since I have alot more power and didn't want to buy an expensive prop til I know what I needed. Took it out with my buddy with maybe a half a tank. GPS at 57 turning only 4600. Put a 25p mirage plus 3 blade hit 57 and could only turn this one 4200. The motor runs perfect and I'm running thunderbolt 4 ign. with 8 deg adv. at 800 rpms and there's no hook in the hull went through all that last year. I know I should try a 24p next to get my r's up but i mean come on 365hp to 530hp I should be screaming down the river!! Any Idea's

humpster

did you get your new motor on the dino ?

chuckyarus

no, no one around here can dyno a motor unless it's in a car

turbo rr

iTrader: (3)

Seems like too much prop to me.

scarabman

iTrader: (1)

Wouldnt the best way to establish your baseline, given lack of dyno, be to use the prop on the new set-up that you ran the 56.2 with on your old set-up? You can tweak it from there.

Unless you have already raised the drive height you will likely not benefit from a 4-blade. It will only slow you down.

chuckyarus

I still have my old 23p mirage, I'll throw it on this weekend if I get a chance and let you know the results

chuckyarus

threw the 23p on it and ran 60.7 at 4800 rpms. I must have more power but I don't believe 500hp, also the motor has square port heads and the zz came with oval port heads if i'm correct. Guess I'll play with the timing and jets etc.. just was hoping for better results

fastscarab22

iTrader: (1)

Could you have a rev limiter problem, there was a guy who put a bigger motor in his scarab 22 and he was hit the rev limiter on it 4850 . I had a extra fire wire box (its like msd box, fire wire boxes were put on hp 465 and hp500 ) and he got his revs ups to 5350 and the boat really hooked runnning a 26 bravo 1 . I might be able to find another there like 200.00 and they work with a standard mercury dist and thunder bolt stuff it wires in like 10 min . call htg racing in grand island ny they can tell you the same story scott

humpster

a friend of mine build a motor to 500 hp specs off a build sheet when he put on dyno only made 420 had to change the cam put it back on dyno and it made 505hp hard to tell what motor does without that dyno you may have to tweek it to get to your goal

chuckyarus

no rev limiter