rsvert89

Having a 1997 Roller cam 5.7 engine rebuilt. Speed Pro pistons(dish with 4 valve reliefs) bored .030, decked .017, with a .028 head gasket. Quench should be .046. Should be around 9.3 compression. 600 CFM Edelbrock 1409, and a Performer RPM Air Gap intake. Heads will have Alex's parts Valve springs to handle for lift, and more pressure.

I am running thru Prop exhaust, with stock manifolds. I do not want to go to thru hull Hull exhaust. Manifolds are stock.

I have used Howards Cams before in engine builds for cars, and have been pleased. When I spoke to him, he suggested this cam as a good choice for that engine.
http://www.competitionproducts.com/H.../#.WJ9bjCyV7L8
I have read you don't want to go beyond 112 degrees separation, and this is 114. He said he thinks this would work great

I am not looking for a monster, engine. Would love to see around 325-350 hp at the prop. I know I am getting to the top end of the spectrum with a Alpha One Gen 2, But I think as long as I don't get the prop out of the water, and don't lay on to hard on takeoff, it will live. I also will be installing a drive shower on the drive
Does this seem like a decent combo? Thanks for any input.

rsvert89

Also, specs on the boat. 1997 Larson 206 SEI, bowrider, 5.7, Alpha One Gen 2, 1.62 ratio, 21 pitch Turning Point prop

Bondo

Ayuh,.... That sounds like a steel shim gasket,...
Ya don't want that in a boat motor,....

Ya want a composite gasket, or a multi-layer SSteel gasket,....
Both usually run 'bout .040" or so, which means the block oughta be decked lower to get .045" quench,....

That cam is abit bigger than I'd be lookin' for, it runs 1500 rpms, to 5500 rpms,...
I look for Idle, to 5200 rpms,...

ezstriper

I'm doing a engine like that right now with exception it does have thru hull exhaust, I had Comp custom grind one, to me thats the way to go, they charge no more for a custom one

rsvert89

Bondo, The head gasket that came in my engine from GM/Mercruiser was a .028 thickness. This is the specs of the GM multilayer Stainless Steel and graphite composite head gasket I will be using.

Brand:Chevrolet Performance
Manufacturer's Part Number:14096405
Part Type:Head Gaskets
Product Line:Chevrolet Performance Head Gaskets
Summit Racing Part Number:NAL-14096405
Bore (in): 4.100 in.
Bore (mm): 104.140mm
Gasket Material: Stainless steel and graphite multi-layer
Compressed Thickness (in): 0.028 in.
Lock Wire: No
Quantity: Sold individually.

airjunky

iTrader: (2)

What happened to the cam you had? Thats the gmpp shelf cam ,pretty well optimized unless you upgrade exhaust, displacement and valvetrain and or heads .supports a nice alpha slash reversion friendly low idle.
And they are reasonable priced. Oem right up the the 5.7 scorpion

ACrooks69

iTrader: (1)

That's about as high as you would want to go with stick exhaust. It shouldn't revert, but you are getting close. The 114 LSA helps. 212-215 you'll be even safer. Had a comp 260H flat in my original 5.7 and no problems. You would probably be able to get away with it the cam you picked, but it could have issues.

Mr Maine

Stock vortec heads are good to .48 lift or so. Make sure to check the retainer to valve seal clearance at full lift and have .020 or so.

79formula

I ran a comp xtreme marine 262 cam in my last boat. 355 with vortec heads. Ran awesome.

ACrooks69

iTrader: (1)

That's the cam I like.