Turboing a 2.5L Mercruiser 120HP

Fordiesel69

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Sep 18, 2009
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I have 3 old volvo turbos laying around that all came from 2.3L engines. All are good. Is there an easy way make this work without spending a ton of money. I know the engine is not designed for boost, but im sure a few PSI wouldn't hurt too much. Has anyone done it to any marine 4 cyl?
 

bigskiohio

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Re: Turboing a 2.5L Mercruiser 120HP

running the exhaust thru the turbo sounds like no fun plus the exhaust and water are mixed and the heat. Maybe thats why you dont see any turbos just superchargers.?
 

JustJason

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Re: Turboing a 2.5L Mercruiser 120HP

sure some applications have factory turbos such as the turbocharged and aftercooled volvo diesels.... But fabricating all of the mounting and plumbing that you would need to TC a 2.5 would be an engineering marvel in itself. And thats not including rebuilding the existing block to a 7ish to 1 compression ratio.
 

Bondo

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Re: Turboing a 2.5L Mercruiser 120HP

Is there an easy way make this work without spending a ton of money.
Nope...
It would take Alot of talent,& resources....
And a Big Pile of Money.....
 

bigskiohio

Master Chief Petty Officer
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Re: Turboing a 2.5L Mercruiser 120HP

wow that it is a turbo has to be aftermarket or it wouldnt be a 140.
 

chasespeed

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Jun 8, 2009
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Re: Turboing a 2.5L Mercruiser 120HP

Man, if I could find one of those, I would rebuild my 3.slow.

Or, even just the design. Though, you would need the manifold, etc to be made, since its a single piece casting.

Chase
 

chasespeed

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Jun 8, 2009
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Re: Turboing a 2.5L Mercruiser 120HP

Actually, upon looking at the manifold again, it could be done... need to make an adapter to take the place of the riser.... something that would allow you to mount a t3 flange to the exhaust, and route the water around the turbo, to dump in the exhaust POST turbo. Then, you would have to decide either blow through carb, or draft through.....then, mounting all that....

Then of course, lower compression slugs.... and possibly beefing up the rods depending on how far you want to push it... this is just for starters...

Chase
 

45Auto

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May 31, 2002
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Re: Turboing a 2.5L Mercruiser 120HP

It's been done many times. There used to be a kit for turboing a 3.0. People came to realize pretty quickly that it's much more cost efficient and reliable to just drop in a V6 or a V8. The ad and pic below came from the "Trailerboats" bulletin board.

It is a 1979 Glastron Carlson CVX16SS. It does run and float. I have replaced the bellows, exhaust bellows and impeller. It currently has through hull exhaust, but the hole is there for the standard exhaust and it was leaking. It has a Mercruiser engine and final drive. What makes this boat unique is the aftermarket Rayjay turbo charger set up. I did everything needed to make it run and took it out for a spin. It pulls about 7 psi of boost in current configuration. Unfortunately, my aunt took it for a spin as well and ground most of the prop off in the gravel! All gauges work. It has a big thick ski post that sets into the floor and braced on the sides. The hull is in decent shape, but has a couple of gouges and dings.

mercruiser140turbo.jpg
 

45Auto

Commander
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Re: Turboing a 2.5L Mercruiser 120HP

M&W is the company I was thinking about that made the turbo kits. They were very popular on lots of tractors also. The blurb below is from the HPBook "Turbocharging" from the mid 80's.

MW.jpg
 

rcig

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Oct 25, 2009
Messages
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Re: Turboing a 2.5L Mercruiser 120HP

I used M&W turbo kits on my mercruiser 165 (250 cid) inline 6 cylinder engines very sucessfully.
 
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