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Hey guys,

Well the last time I took my boat out this year it developed a knock. It sucks, but it was slow anyway lol. So now I'm going to rebuild and stroke it. The block is a 1992 454 1 piece seal. Im planning on going with a forged eagle recipricating assy 4.25 stroke, final cubes to be detirmined when i get the motor apart and make a decision on bore. Most likely go with dish pistons 8-8.5-1 so I can have the option of bolting on a blower with a decent amount of boost in the future. I have built many street and drag race motors in the past but realize marine engines are a different animal.

My questions are, what bearing clearances should I be looking for? Am I ok going with a double roller timing set or should I go with something better? I'm going for a mix of power and durability so what lift cam should I go with? I will probably go with a roller cam set up for a blower for the time being while I run N/A until I can afford the blower setup. I have been out of the building game for a few years and could also use a good machine shop in or around jersey.

Any other info you think I should know in building my first marine bbc is also appreciated. Thanks alot guys!

Kenny

I'm very satisfied with Kurts marine in Brick NJ. Drew Wherlan bought the shop from Kurt. I had a similar engine built by them. It came in exactly as they said-both horspower and price! They also have an in house dyno. Ask for Drew or Danny, 732 477-7400

i have built both the 4.25 and the 4" engines.

Either build 1 wa or the other. don't try to build both. Your performance will suck on both side of the coin.

You can build a nice 4.25" engine that will make close, if not over 600HP on just the carb.

Or if you are going blower, then you need to go with a 4" crank and you can get really close if not over 700HP.

Either way, call PM RMBUILDER on this website for your cams.

Either engine, use the 6.385 rod.

go to 9.5:1 comp on the 4.25 engine, or stay at 7.5:1 on the 4" engine.

Use 8-71 blower for your blower to kep the heat down instead of trying to use the smaller 250's or the wieands.

Good luck and have fun.

My .02 avoid the Eagle crank...A friend of mine used it and it broke after only 10hrs of use..He built a 700hp blower motor same type setup your going with..

Ended up using I believe a Carlise Crank after the 2nd time around.

If you are interested I have a brand new 454 stroker shortblock, gen IV 4 bolt main eagle 4.25 crank/rods KB 8.5-1 blower pistons(would run fine NA) balanced...cut you a deal on it...Rob

Always go with the longer stroke when buying a new rotating assy. No substitute for cubic inches. Makes no difference blown or n/a. Just ask Mercruiser, they always use 4.375 in their big supercharged engines. Be careful with Eagle. They have a bad reputation for tapered journals, poor sizing etc.

My .02 on the compression is go 9:1 then you can get away with a smaller blower and spin it slower when you are ready. It works well in a marine app. Plus it will perform well until then. More cubes is better as well.

Also, use only inconnel exhaust valves, mls head gaskets and arp head studs. Then you should be internally blower ready.