turbo2256b

iTrader: (1)

A lot has to do with building max power at a certian RPM Max power for a boat needs to be at a lower RPM than say a car or a jet boat. Some depends on the drive unit being used and power it can handle also. An alpha wont handle what a brovo will and so on. Intakes are usally the biggest restriction in air flow as in many engines with ported factory heads most aftermarket as cast intakes cant keep up. On the flip side to much intake requires more rpm at the loss of low end needed in a boat. example stock heads and a vr jr. But well ported factory heads and same intake the intake will work a lot better and not loose as much low end or even improve it a bit (as well as top end) using a rather mild cam compaired to recomened cam for that intake with as cast factory heads.

dereknkathy

those GLM alum exhausts are a LITTLE better than stock iron. stock iron restrict you to about 350 or so hp. you get into a better breathing exhaust with more distance before water hits exhaust flow, then you will be able to run a 110 lobe sep longer duration cam. then your heads will be the problem...AND then the alpha will really be on borrowed time.

SB

iTrader: (1)

I have no experience with that boat, but it does seam to want to go to fast with the power already. The weight and the 19" prop is what is setting my red flags. Not too mention keeping that Alpha together.

Many of the Alpha boats I deal with run 19-21" props wit stock 350's. 21"-23" with mid 300hp 350's and turning 5000-5200rpm.

A lot lighter boats.

You sure it will be worth the extra power ?

You sure the Alpha won't become an issue ?

Yes, I talk about how the Alpha can handle some good power (400+) but, that is on smaller lighter boats.

dereknkathy

the shorter pitch the prop is, the more grip it has on the water. the more your vert driveshaft is at risk of snapping. i think you nadaguided the wrong boat though. power play boats, not powerplay marine., 230 conquest is rated at 4000 lbs. still too heavy for an alpha.

Pee Wee

The Summit vortec heads are rated for a maximum .520" valve lift. Did you modify your heads to handle the lift that your cam is giving? Do you have forged Pistons? Cast pistons may not last if you try to spin more than 5000-5200 rpm.

The AFR's are great heads. Will your intake hold them back? Will the bottom end handle the extra horsepower? I went dow this same road last year. I decided to keep my old engine intact and start over. I'll swap the original engine back in when I decide to sell the boat some day.

powerplay230

The boat is a 89 powerplay230altura and i would be surprised if anyone on here has seen or heard of one.i know the alpha is the weak link and thats why i dont hammer it out of the hole.The heads did have the springs changed to get the right pressures and not coil bind. The bottom end is balanced with srp forged pistons. Been running this set up about 5 yrs now and always felt i was leaving something on the table and always wonder if it was the summit heads

dereknkathy

i would start with the exhaust.

Pee Wee

If you go for new AFR heads consider if you want to stay with the vortec style intake. There are tons of standard style intake manifolds for sbc's on the used market. I could have gone either way with my build. AFR's customer service recommended the standard 195's over the vortec 190's. Also if you buy the heads new, look in to upgrading to inconnel exhaust valves.

powerplay230

I was wondering about that too . Ditching the vortecs and going to the standard alum heads. I know its been done but it sure would be nice to hear from someone that has actually replaced their cast iron heads with some good after market alum heads and hear what kind of results they got

rmbuilder

PP230

406 CID 4.125” x 3.75”_AFR 195 cc Street Program. Twin engine, heavy boat, low compression, conservative hydraulic roller profile.

522.4 TQ @4600

509.5 HP @5600

With a few setup tweaks for a lighter boat this had easily +20 left @ 5800.

Bob