GM Gen V engines

[DLNorth]

Anybody use/put in a GM Gen V engine, ie, alum block, to save weight?
If so, any issues?

 

[Scott Danforth]

are you talking the Gen V big block from 1991-1995?

or are you talking the Gen V 6.0 and 6.2 small block (LS motors from 2013 and on)?

if so, the Gen V LS motors have been used since 2013 in marine motors (Just like the prior LS motors going back to 2006). you need to get a complete marine version, or you need to build a complete marine version with heat exchangers, etc.

 

[DLNorth]

I was thinking the 5.3 all alum engine, like that in my truck except marinized.
More power than the 4.3 and lighter then the 5.7.

 

[Scott Danforth]

the block is the same as your truck, different heads, cam, etc. EFI is marine specific

https://www.gmpowertrain.com/marine.html (click on the fly-out on the right)

or click here https://www.gmmarinepower.com/products.html

to marinize the LS, you need a heat exchanger, a marine exhaust (only available as catalyst exhaust for the LS or expensive headers) and a marine EFI setup. Cheaper to sell boat and buy what you want.

https://www.hardin-marine.com/c-2078-ls-engine-parts-and-accessories.aspx

however aluminum manifolds and heads available for your motor if your worried about weight.

 

[DLNorth]

Thanks Scott,
I was just wondering out loud. I see a lot of the 4.3 and 5.7's but no 5.3's.
I have an alum project boat that I'm not sure what I want to do with it,
and am not even sure it's worth any effort/money.

 

[alldodge]

We know what boat means

Boating with regular stuff means regular money

Boating with irregular stuff usually means irregular (more) money

We boat for fun until it starts costing more then anticipated, then most stop boating

 

[scoflaw]

It's not a race car either, weight can work in your favor to cushion the ride.

 

[aimlow]

Aren't those engines 100% digital?

 

[DLNorth]

The subject boat has a 470, so a 4.3 is already a weight adder. And no, this isn't a high performance boat by any means, just a family day cruiser.

I had my eye on a nice '95 donor with the 4.3, but it didn't get winterized after it was test run this fall.

 

[scoflaw]

manufacturer and model top secret ?

 

[DLNorth]

1979 18' Starcraft SS w/V5 hull, 470 IO

 

[Scott Danforth]

Then get a new mercruiser 4.5/alpha longtail

They dont use the 5.3 because the 6.0 costs the same. Mercruiser decided to make their own, however Ilmor/Indmar/Volvo use the 6.0 and 6.2

 

[DLNorth]

That looks like a great motor but way too expensive.
If this boat gets a $1000 replacement that will be a lot.

 

[Scott Danforth]

That looks like a great motor but way too expensive.
If this boat gets a $1000 replacement that will be a lot.

for only $1000, buy an edelbrock FE aluminum head (429/460), drill the large hole, throw a new mercruiser head gasket on it and run it.

you may be able to find a 4.3/alpha G2 for a bit more money.

 

[DLNorth]

Or just leave it. I don't have an issue with the weight of the 470 or the 4.3, but I think the 5.0/5.7 would be too heavy.

Using your guidance from previous posts, I am looking for mid 90's 4.3, and actually found one, but it wasn't cared for, and is now likely cracked. But I'll keep looking. The "problem" is most of the "donors" actually look better/nicer then the project boat. So the question becomes "why not just a new/different boat?

It's going to be a long winter.

 

[Scott Danforth]

The "problem" is most of the "donors" actually look better/nicer then the project boat.

same goes with cars and trucks..... many of my hot rods started life as donors.