3L mercruiser had engine swapped for 2.5 L s10. Issues?

[boatdude100]

Thought I bought 1995 3L Mercruiser - alpha one but engine I was then told, had been swapped for 2.5L engine from s10 from an "old truck". Was this a compatible engine? What issues may I have?

How can I check if starter and alternator are "marine" both have been painted black

Starts and runs well but overheats (assume) within 5 minutes .... then drops in speed and makes a ticking sound
engine temp gage doesnt work...

Help and thoughts please? Many thanks

 

[boatdude100]

This is it.. curious it has a Mercruiser tag and doesnt seem to have a temperature sender at front?

 

[boatdude100]

the tag...

 

[boatdude100]

and block...apparantly from an s10 2.5 L truck engine? is all of this ok or is it prone to failure?

 

[Bondo]

I was then told, had been swapped for 2.5L engine from s10 from an "old truck". Was this a compatible engine? What issues may I have?

Ayuh,.... Welcome Aboard,..... I'm doubtin' the story you were told, because the 2.5l used in S10s is a very different motor than the 2.5ls, 'n 3.0ls used in boats,....

Boat motors are based on an old Chevy design, where as the S10 motors, 'n all the GM 2.5l car motors are based on an old Pontiac design,....

 

[boatdude100]

Thank you for your reply. And the welcome. seems to be an outstanding forum.

So where do you think this leaves me? He actually said 2.4 L engine from an "old S10"
Could this have been a successful swap? The previous owners were "mechanics" and firmly believed(?) this was a great trouble free motor. How can I tell if the swap was done as it should have been.... camshaft, starter, alternator and whatever else you smart people know should have happened...?
Thanks again

 

[Bondo]

So where do you think this leaves me? He actually said 2.4 L engine from an "old S10"
Could this have been a successful swap? The previous owners were "mechanics" and firmly believed(?)

Ayuh,.... I guess it leaves ya with bad info,....

As I said, the automotive 2.5l motors are a completely different architecture,... donno of any 2.4l motors,...
Not the same motors,...
The bolt holes are in the wrong places for such a swap,.....

 

[boatdude100]

Just a followup. You Sirs are correct.
They did a rebuild as it turns out, not a swap. My info was indeed bad, and you were right!