Why don't you see more all aluminum blocks in the fresh water boats ? Are there any negitives to this in reguards to it being in a marine environment ? My current boat is all aluminum and I hope it serves me well,time will tell. hf...

The only negatives are:

cost and much more sensitive to corrosion than cast iron.

Cost, and most boaters aren't worried about trying to save 200 lbs in a twin engine boat.

In cars weight savings means increased MPG.

We worry about GPM.......

Most common aluminum blocks are probably 5.7's & 5.3 SBC's anyway they are still kinda pricey, the thing I ran into was making it stand alone power there is so much wiring, modules, & water sensitive stuff. The risk didn't seem worth the reward. IMO

For instance I just sold a blown LS1 with wiring harness basically stand alone power. Engine was totally disassembled & needed block, cylinder & head work. I was asking 3K got 2700.00 SOLD!

One of my cat buddies has an aluminum Donovan 540 in his 26' Daytona . Only problem is getting and keeping heat in the oil and there are remedies for that .

The 'Razzmatazz' 38 Flat Deck that sold not too long ago had some big Donovan aluminum blocks in it. I think they were like 622 or 632 or something like that.

even in fresh water any aluminum block or heads are going to corrode...best bet is a closed cooling system and anti freeze in the engine...

Cost..

Good , Feel better now. hf ...