Mercruiser re-power. What motors and outdrives to look for and to avoid?

[HT32BSX115]

Now that's nicely powered. I would prefer a 5.7, but the 4.3 is a Alpha Gen II, at a good price.

I didn't notice if you said ran that boat with the 165, and it'll certainly perform as well and probably better with a good running 4.3L V-6.

If it's a nice one, low time and you can get it "cheap", I don't think I'd walk away from it.:thumb:

 

[pckeen]

Now this is interesting, a 5.7 MPI at a good price. The motor came off a v drive boat. What do you think?

http://www.kijiji.ca/v-powerboat-mo...ne/1264322189?enableSearchNavigationFlag=true

 

[Scott06]

Strange that if there was nothin wrong with it as the engine is not a complete take out. It's missing the accessories, intake, mpi parts including ECM and wiring. To me by what's there looks like long block and exhaust was questionable so someone bought those items and transferred all accessories to the new engine. To be honest it looks like the remnants of the cracked block I pulled out of my boat after buying it as a handymans special with a cracked block.

 

[pckeen]

There is an interesting history behind this motor. Basically, the owner was chasing problems with it, and a mechanic suggested the block was the problem, so they switched it out....which didn't solve the problem. The problem was eventually traced to an electrical issue. This appears to be a long block with a few additional parts on it. I'm waiting for some more information on the motor.

I also have a line on a Mercruiser 898, but that's a little older than what I was hoping for...

 

[HT32BSX115]

Now this is interesting, a 5.7 MPI at a good price. The motor came off a v drive boat. What do you think?

http://www.kijiji.ca/v-powerboat-mo...ne/1264322189?enableSearchNavigationFlag=true

If there's really nothing wrong with it, It might be a good engine. You would need to come up with an intake manifold, carb dist etc.

Also, I might be concerned about running an MPI block with a carb. The camshaft might need to be changed to use a carb and it wouldn't be able to make 300hp but would certainly be worth considering.

 

[pckeen]

Here are the compression numbers on that motor.

# 1 185 # 5 165
2 185 6 150
3 130 7 180
4 170 8 180

Wet test, #3 went to 150, and #6 went to 190.

 

[HT32BSX115]

You might consider doing a cooling system pressure check too

 

[Scott06]

As mentioned it may be good, I think it comes down to your comfort level with risk. If you bought what is offered with this engine (base engine plus exhaust) new
It will cost $3500 or so (assuming you're in the US). By the time you buy an intake carb, accessories, wire harness, ignition/module that's probably another $1500-2000 as I don't think these components will swap from your original 6 cylinder.

One issue others may know better than I is flywheel size and coupler style on this engine vs what's in your boat. Were you planning on upgrading the drive as well as I think the bellhousing and rear mount spacing changed in the early 1980s but I think Bondo outlined this in post #15

If you look eBay there's a guy out of Detroit offering whole drive/ transom/ engine set ups.

 

[pckeen]

Thanks. The engine is well priced, and compression numbers seem OK, but given that it was from a velvet drive, I'll pass.....unless I can find a donor with cracked block.