hpy540

@ 4 to 5 psi boost? Say a B&M 250 with an intercooler, put it ina 236 ELIMINATOR EAGLE AND WHAT DO YOU THINK IT WOULD RUN FOR SPEED? Would a Bravo 1 hold up?
Merc 502 block
Howard hydraulic roller cam R6212
Mark 4 push rods
7/16 arp studs
JE strip pistons 8.9 cr
10 degree retainers
10 degree machine locks
miller billet aluminum rockers 1.7 r
Detroit race gasket set
HOLLEY 80870 AUTOMOTIVE STYLE W/ELECTRIC CHOKE AND VAC SECONDARYS
98611 VALVE SPRINGS
SINGLE PLANE ALUMINUM INTAKE
H SERIES BEARINGS
ROLLMASTER tc
7/16 dimple rods 4340
mellings oil pump
arp ballancer kit
hiperf 502 oil pan
stainless intake bolts
stainless race valves
bored honed deck plates
decked
balanced
blueprinted
comp head work
4 bolt main
open cahmber rec port heads
forged crank

OkieTunnel

With 8.9 compression you probably could get away with 4-5 lbs boost. I had a B@M 250 on a 454 mag. Yours will make about 550 to 575 hp I would guess based on what mine made but I know nothing about your cam. I would bet low to mid eighties in that Eagle with the right prop and x dimension. I never lost a drive in about 130 hours on mine. If you take care of it the Bravo handles 500 or so hp ok.

US1 Fountain

iTrader: (1)

My 502 with a B&M 250 @ 5# boost, 1050 dominator dynoed 625hp. Only motor work done on mine other than new bearings, rings and valve job was a change to the Crane 741 Crane hyd roller cam in place of the stock flat tappit and titanium spring retainers. Stock 8.75CR, rect port heads, JE forged pistons. Ran in a 27 Fever for a solid 6 yrs in front of a stock Bravo and never a hint of drive troubles. Just never hammered out of the hole.

OkieTunnel

My setup was the EFI blower and was rev limited to 5200. US1's numbers might be closer to what you will make than mine because yours won't be set up with a rev limit. The faster you spin the more power you will make.

hpy540

Thanx... this is a great forum.

HPJunkie

Your boat should run 85-90 mph. My 25 eagle goes 94 with the wrong prop on it! The only diff. is 7psi boost and alum heads, my compression is 9.1 to 1. Greg

jspeeddemon

Is there much price difference between a 420 and 250 B-M blower. Depending on your budget, I would think that spinning the 420 slower for the same boost with less heat. Also check for a good deal on aluminum heads, by the time you pay to redo rectangular port Chevys for $400-500 w/guides and valve job, springs,etc. you can step up for a better set of heads reasonably. The new version Rec. port aluminum Chevys I've seen for $1100.00 on ebay. I would prefer these over the oval ports, for this application, because of better exhaust flow numbers out of the box, the rec. ports are much better out of the box on the exhaust side. Otherwise this motor looks great, what is your anticipated budget to build this piece?

hpy540

I am looking a t a hull right now. I am currently a bentop boater i just sold mine about 2 weeks ago. I am working on a deal for the B&M used right now for about 3200 w/carb and chiller used but rebuilt. the motor is a showroom piece sitting inthe display area of the dealer that i am looking to buy th ehull from. the hull w 500 hp books for 27800 and i am hoping to get the wholething in the water yet this year. i am thinking i should runn the motor wiout the B&M for 15/20 hrs or so just to make sure it is all working rpoperly before i put the squeeze to it. Should i get a 1.36 drive or will the 1.5 be acceptable?

Cignificant

I didn't see it on the list, but make sure your exhaust valves are Inconel, or I think some manufacturers also call them "severe duty". My 502's are like US1's, except I run twin carbs..

hpy540

God THIS IS FUN!!!...... Any who, i do not know if the exhaust valves are inconell they are listed as stainless Steele race valves. The motor is put together and is ready to drop in so i would not pull it apart just to put severe duty valves in. I am the type of guy who likes to go fast but i do not hammer on something (such a s motor ) until it has total catastrophic failure. If i feel the need to or something happens i will tear into it then. The motor is built for marine usage and i believe the service manager that it will hold up even though they told me No Warranty. They do not warranty race applications. would this be a dependable turn key setup or am i asking too much? The cab on the B&M Right now is listed as a 950. I should ask the person installing the motor if we can swap out the 870 Holley for another 950. that way when i put the B&M on it i can have 2 like carbs on top. This would be slightly better than just one 950, i could rejet the two for better fuel distribution. would 2 950'd be too much for this app?