MILD THUNDER

454, gm forged cranks, rods, arp bolts, srp pistons, dart marine alum heads, hyd roller cam (238/246 600+ lift) 8.5 compression, b&m 174's. What kind of power should it make??

badluck

I would guess around 550hp @ 5-6psi boost with good exhaust.

MILD THUNDER

I think the hawk 525's dynoed around 525HP using the iron gm heads, hyd flat tappet cams, and lower Compression, and the 174 blowers from what I gather.

I would like to think with the better flowing alum heads, little more compression, and a hydraulic roller cam with more lift and duration than the hawk 525 cam, should be worth a few ponies, no?

I would think a naturally aspirated version of the above build with alum heads and roller cam, would make close to 500HP? Didnt the HP450 run a hyd roller cam and gm heads to make 450HP@ the prop?

HiPerf2000

575hp. i had a very similar motor in my old boat.

MILD THUNDER

How did it run? I hear the small blowers make lots of heat, but also hear the 525SC and 525 Hawk engines were very reliable with the small blowers.

Griff

Ditto on that. The 174's have to spin pretty fast to make boost and the faster they spin, the more heat.

MILD THUNDER

Correction, sorry, they are 177 blowers, cam is a 236/245 629/632 on a 114 lsa. Stellings headers.

Would a chiller be a good idea? For reliablity purposes, and a few more HP doesnt hurt either. Mainly looking to keep the motors together for a little while.

badluck

What boost are you running? If you are above 6psi, a chiller is a good investment.

Griff

Thats a pretty big cam for a 454. You should spin the engine up to about 5800 to make max hp.

A chiller will help reduce the heat created by the smaller blower. It will allow you run more boost and make more hp.

How fast are you spinning the blower???? Recommended max rpm for the blower is 12,500-13000rpms.

cdscarab

Hawks were rated at 525 horse, was told they made closer to 540 horse. The guy I bought mine from, replaced them with merc 525s and the boat was 3 mph slower. Actually had to install coolers and bump the boost to get back to where he was with the Hawks.
The Hawks were 420 mercs (8.75:1), the merc 525s were (7.5:1).