Fasttoys1

Rebuilt gen 1V 454 mag. Also has a wieland stealth intake and Holley carb (unknown size carb). Also would like to know what rpms this build should turn at WOT. Sucks they didn't use a roller cam. Seller says the builder estimates 500hp. The boat is propped wrong and I might be able to get a good deal on it. Any help is appreciated. Thanks.

offshore312

since everybody will be asking, here are the cam kits specs...
http://www.compcams.com/Company/CC/c...?csid=404&sb=2

Fasttoys1

^^^^^ Thanks. I am just trying to estimate horsepower so I can use the prop calculator.

The engine is in a 26' boat that weighs 5,200 pounds and he is only getting around 50 MPH out of it. He said when he tried to open it up it reved to almost 6,000 RPMs. The boat has a mirage prop on it that is 14 5/8" and 23 pitch. I'm hoping that this prop is just way off.

The spec sheet on this boat says it will do 54 MPH with a 330hp 7.4. Something has got to be wrong here. It is a bravo 1 outdrive. I will be finding out what gear ratio it is soon. The boat is about 4 hours away from me so it's not like I can just go check it out and see whats going on.

Any information or tips you guys can give me would be awesome. If you need more info just let me know and I will get it from the seller.

Thanks

Fasttoys1

Also it has stock manifolds and risers on it now.

Budman II

iTrader: (1)

Oval or rectangular port heads? I ran the same cam in a 454 ten years ago - oval port 820-casting GM heads, Eddy Performer RPM (non-AG), modified Q-jet, stock exhaust. I did not dyno it, but I was getting around 61-62 MPH in perfect conditions (planets aligned) in an 88 Baja Force 235 25ish boat with a Mirage 21 pitch prop on a 1.36 Bravo. I think that boat weighs around 4200 lbs. On most days I was 55-58 MPH, which was actually kind of in line with what a stock 330 should run. I may have been limited by the stock exhaust coupled with the old school iron heads (they did have the larger valves installed on the intake side). You should be running better than 50 MPH, but not that much better IMO on a 5000 lb boat.

Budman II

iTrader: (1)

Also, I think 500 HP in a 454 with that setup is not attainable, unless he has some really good heads on it and it's using the dyno headers.

Fasttoys1

I will have to check on the heads. They are dart heads, but when I tried to Google the part number I didn't see exactly what they are.

Fasttoys1

I can try to find out exactly what heads and carb is on it.

Fasttoys1

The heads are eagle 345's with large rectangular ports. I spoke with the eningine builder and he said the HP should be between 425-450.


Any idea on what rpm this motor should be at WOT?

mickeymcclgn

iTrader: (1)

I am far from an expert but those heads seem kinda big and the cam seems kinda small. The stock manifolds are definitely holding some power back as I believe they stop making power around 425. Not knowing the compression ratio intake and carb setup it's really a guess but 53-5400 would probably be about right. The cam says max rpm of 5800 but there are tons of other factors that lead into it.

What type of boat?