Aluminum engine parts - good, bad, no difference?

tmh

Lieutenant Junior Grade
Joined
Aug 16, 2006
Messages
1,136
Just curious.....I saw a boat listed on Craigslist, a 1995 24' Mariah open bow n great shape, with a newly built custom engine. I'll post what the owner says about it and I'm curious as to what the marine engine folks think about it. I'm specifically interested in the aluminum parts for weight reduction and how they'd hold up.

A new small block Chevy 400 was put in at the middle of last season. The motor was professionally built. It has about $10600 in it. It has more horsepower and torgue than a magnum 454 at about 1/2 the weight due to brand new aluminum exhaust and intake manifolds, aluminum cylinder heads and an aluminum fly wheel. I had extra strong connecting rods and forge pistons installed to ensure longevity as well a complete balance on the engine. The motor has about 425 horse power with about 450 pounds of torque. The boat went from 43mph to 55mph.

Opinions?
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,321
Re: Aluminum engine parts - good, bad, no difference?

Aluminum is lighter.... but cast iron is more durable.....
If it ever has 1 moderate overheat you can kiss all those pricey aluminum parts goodbye.
The other thing is
tmh said:
The motor was professionally built
I've heard that one a million times. I betcha if it's not up to snuff coast guard wise. Have a lookse if you want, and take it for a ride if you can :) But pass on buying the boat. When other people start playing manufactorer funny (expensive things) can happen. Does the boat have a bravo1 drive or better?
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: Aluminum engine parts - good, bad, no difference?

I'm with capt. jason on this one not just because my sons name is Jason also haaaaa. Look that boat is pretty to look at goes fast as hell. But within a month or 2 its gonna shake apart. One question i would ask the owner what kinda oil pump he have in there. I bet it's a high recovery and thats the worst thing you can do to a marine engine. Sucks all the oil outta the pan.
 

tmh

Lieutenant Junior Grade
Joined
Aug 16, 2006
Messages
1,136
Re: Aluminum engine parts - good, bad, no difference?

Thanks for the info, guys. I'm not in the market to buy, just curious. It IS a very nice, fast boat though........

It came with and still has an Alpha gen 2 drive. Obviously, they're way pushing the max. hp for that drive so more issues there. I think we're dealing with a car mechanic who had a fun project making a beast boat engine - but maybe didn't think of the 'what if's". I did email asking a few questions and the owner said it's "not just all marine parts. it's marine AND BETTER" which cracked me up. That alone would have had me running away if I was considering it.
 
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