Motor modification

[Medic2556]

I was told, and maybe I am wrong, but that you could use an engine from a car and place it in a boat. I am looking to put a motor from a Chevy Blazer into my 1989 Glasstream in place of the Mercruiser 120hp that is there already. Is this possible, or do I need to buy another Mercruiser engine?

 

[wire2]

Re: Motor modification

If the bellhousing matches, you can do it.

From a safety standpoint you MUST use a marine alternator, starter, carb, fuel pump and distributor.

The frost plugs should be changed to brass.

The cam profile of the Chev engine will not be optimized for boating use.

 

[Medic2556]

Re: Motor modification

So it would be possible, but not practical, as it would probably blow since the cams would not be made to take the load then?

 

[thrasher]

Re: Motor modification

The cams are not going to blow, but you can damage the engine as cars cams allow a significant overlap where the exhaust and inlet valves are both open at the same time, this can cause water to be sucked up the exhaust!! This is not a desirable feature on a boat engine. You need to slip a marine cam in and then you should be good to go. Wire2 didn't mention it, but you also need to change the thermostat housing.

 

[wire2]

Re: Motor modification

It won't blow, you will just not get the best all around performance from it.
A boat has to work much harder than a car to get up to speed.
You could put a marine spec cam in it if it turns out quite noticeable.

 

[Haut Medoc]

Re: Motor modification

The 2.5 or 3.0 Merc is a marine/industrial engine only.....
You will not find that particular engine in any automobile.....
You need to buy a GM marine engine....
A used Merc, Volvo or OMC will work, as they are all the same GM block.....​

 

[BRG25]

Re: Motor modification

I'm guessing the Blazer has a 4.3 V6 and like Haut says...it's not a direct swap.

 

[Medic2556]

Re: Motor modification

I am not sure what size it is, but I know it was more than the 120. I was looking to upgrade the engine, but looks like it would be easier to find another Mercruiser engine. Thank you for all your replies.

 

[180shabah]

Re: Motor modification

... I was looking to upgrade the engine, but looks like it would be easier to find another Mercruiser engine...

Or a different boat that already has/is set up for a V6 or V8. It will be cheaper and much easier in the long run.