Is 200 hp enough

[rocksingerca]

I have an Owens sea skiff, It's 25' and weighs in at about 6,000 lbs. I'm having trouble plaining out(it won't) I'm wondering if the 283 chev just isn't enough motor. I have it out of the boat to rebuild it but I'm thinking maybe a 350 would do the trick.<br />Any thoughts on this subject would be greatly appreciated

 

[Trent]

Re: Is 200 hp enough

Put the bigger one in..

 

[cole1340]

Re: Is 200 hp enough

Hey Obriendt,<br />I have a 21 ft Grady-White Cuddy that the motor is bad in. I just priced a new one out from autozone:Chevy 350 series 1 $695.00+tax. $200.00 core charge. 1 year warranty. I am converting it to be marine ie, brass freeze plugs and all the spark arresting stuff.<br />My buddy just got done putting one in his boat it runs great.<br /><br />It is rated at 230hp!

 

[Trent]

Re: Is 200 hp enough

Cole...Make sure you put a marine cam in it or you will be sorry. Oh yea, Bet If they know its going in a boat the warranty is no good.

 

[cole1340]

Re: Is 200 hp enough

trent,<br />Thanx for the heads up! I am using the one out of the old motor, it is in great shape. As a matter of fact, I am using most of the old engine parts such as Altenator, mainfold/carb, starter, ditributor etc...<br />Old motor had head gasket leak and corroded two pistons.

 

[Trent]

Re: Is 200 hp enough

Cole.. Make sure you pressure check your manafolds and risers..Alot of the times you think its a head gasket and its really a bad manafold or riser..just a thought

 

[cole1340]

Re: Is 200 hp enough

Trent,<br />You wouldn't believe it! I came across a brand new set of OMC manifolds with elbows and gaskets for $300. I will be bolting these on the new motor. I bought the boat with the bad motor in it. It had been sitting on a lift for about a year with one of the heads off of it. The man who owned it just wanted to get rid of it so I offered him $500.00 for it and he said OK! I will post a picture of it as soon as I figure out how to.

 

[rocksingerca]

Re: Is 200 hp enough

Thanks guys. I think It's just about writin in stone that I will do the change to a 350.<br />I'm are the crank and cam different both different on a marine 350 or do I just have to change the cam?

 

[its-a-sweater]

Re: Is 200 hp enough

The crank specs would be the same yet the marine crank may be forged as opposed to cast.<br /><br />Usually the block is different too. The marine engine is truck based.

 

[johnkc]

Re: Is 200 hp enough

be sure to check the engine rotation ,don't get new 350 with lh rot when you might need rh rot.also will your transmission hold up to the power of the 350. your 283 was around 200 hp and if you build a new 350 you can get 300 hp easily{i am assuming it is a inboard set up}

 

[MURX]

Re: Is 200 hp enough

I didn't see anyone mention the head gaskets or any the gaskets for that matter, may want to use the felpro marine gasket set if you're raw water cooled. as for the camshaft mercruiser marine cams aren't exactly bumpy by any stretch of the imagination, in fact they feature a whopping .010" more intake valve lift and hold the exhaust valve open for an additional 8 degrees of crankshaft rotaion hardly a noticeable difference in horsepower or torque about 10 horsepower more 15 max I would buy a prestolite electronic distributor and run a quadrajet marine carb bolted directly to a stock quadrajet intake manifold, as I'm not too awfully fond of carb adapters. you can get stock camshaft specifications from the clymer& seloc manuals, and if you want you can compare valve lifts and durations at the Iskendarian or General kinetics websites

 

[evin300]

Re: Is 200 hp enough

Have you experimented with different props? Do you have trim tabs? Is you hull smooth? Have you considered your weight distribution? Has this always been a problem? Your hull could be waterlogged, Will the outdrive handle the increased horsepower? What RPMs are you turning? What are the recomended RPMs? What is your top speed? Is this hull designed to be a planing hull? or displacement hull? And lastly, if you can tell me your top speed and current horsepower, and then tell me the future horsepower, I can tell you what to expect for a increase in top speed, The ability to plane a boat however, involves several factors, and all are worth considering, just throwing more horsepower at this issue, may be missing the bigger issue. Just some things to think about, GOOD LUCK

 

[rocksingerca]

Re: Is 200 hp enough

Thanks again for all the replies.<br />I've only tried the one prop on it and I don't know how to measure it but it's the origonal one the boat had on it.<br />It has a new hull and yes it is a plaining hull.<br />The only thing in the weight distribution would be that I didn't fill the water tank which is in the front of the boat. Would that make that much of a difference?<br />I don't know the speed but I think that it is very slow as one of the heads had a crack in it and it never ran well.I didn't know this untill it was too late.<br />I only had it running for a couple of hours and it overheated(only on one side)with steam coming out of the oil cap. All very bad things.It started losing power there was a lot of blue smoke then there was my father and I in the middle of Rice lake. <br />I have the 283 that was in it in the basement. One cylinder was scratched pretty badly because the piston came apart.A fragment came off the piston and made one heck of a mess.<br />I never considered the outdrive maybe I should ask around as to weather it will handle the extra hp.