Engine Question

[cproc501]

Hello, I just purchased a 1985 Chappral with a 2.5 Mercruiser inboard engine, the boat was NOT winterized and I need to replace the engine, my question is this, can I use a 2.5 Chevrolet short block? or do I have to get a Mercruiser?

Thanks in advance.

 

[Don S]

Re: Engine Question

can I use a 2.5 Chevrolet short block?

Nope, completely different type of engine, assuming you are referring to something newer than the 60's

 

[cproc501]

Re: Engine Question

No sir, it's a 1985 I assume, The guy I bought it from said it was made by Chevy, but it has Mercruiser on it, I thought I could make a 2.5 Chevy work in it they are a dime a dozen at the salvage yards, The quest continues........

 

[180shabah]

Re: Engine Question

Don was referring to your "new" engine being from the 60's. If that 2.5 came from an s-10, camaro, celebrity, etc - it will not work.

The "merc" 4 cyls have not been used in ANY automotive application in 4 decades.

 

[cproc501]

Re: Engine Question

I understand, This boat has a alpha one outdrive, how difficult would it be to put a V8 or V6 in it? I have found several complete 5.7 and 4.3 Mercruisers relatively reasonable, does the outdrive have a bellhousing like a automobile? Looks to me like after getting it mounted the big difference will be exhaust, am I getting into more than I want here or should I just suck it up and drop 1300 for a remanufactured 2.5? I am a "fair" auto mechanic, but I have not yet ventured into boats........but it looks like I am now! thanks for all input.

 

[180shabah]

Re: Engine Question

$1300 won't sound too bad compared to all the other parts you will need for a conversion.

Exhaust, side engine mounts instead of front, possibly requiring some stringer work, re-gear/replace drive, potentially new prop if the regear isn't close enough, etc, etc, etc.

If this was a classic hull with some collector or sentimental value - might be worth it.

 

[JustJason]

Re: Engine Question

As others have said, the 2.5 liter you have was last used in an automotive application 40+ years ago. You'd find one in an old vega from the early 60's. Problem is, you probably won't find one in a bone yard, it's just to old.

The 2.5 is not current from Mercruiser any more either. The replacement is the 3.0. The 3.0 is a GM industrial engine, and never used in an automotive application.

Converting to a v6 or v8 is possible, just not economically feasable. You'd have to fabricate motor mounts for it, build a new dog house, measure to see if you even have the clearence for the exhaust, regear or buy a new/used drive, etc etc. The list goes on.

Your best bet is sticking with a 2.5. A 3.0 will fit in there, but you may have some exhaust issues depending on the vintage of it.

 

[Bondo]

Re: Engine Question

You'd find one in an old vega from the early 60's. Problem is,

Ayuh,.... Problem is,... Vega were Intro'd in 72 I think....

Chevy IIs, before they were Nova had the old 2.5ls.....
62 to 65, or 67 I think....

 

[JustJason]

Re: Engine Question

I think you may be right! It is the Nova and not the vega. I have a 2.5, and 10+ years ago I did the same hunting around for engine parts in the automotive world. It was a pretty futile attempt as I remember it.

 

[Bondo]

Re: Engine Question

It was a pretty futile attempt as I remember it.

Ayuh,.... Junk boats are Much easier to find.....

 

[180shabah]

Re: Engine Question

Yup - Vega's had the aluminum block 4cyl. Too bad nobody at mercruiser was paying attention - we coulda skipped the whole 470 thing...

 

[cproc501]

Re: Engine Question

Well guys after some diggin it looks like I may have lucked out, I talked with the former owner and he advised that he bought the boat and it had been sitting outside uncovered with the carb off of it, I'm hoping that's were all the water came from, I checked the block as far as I could see and found a freeze plug popped out of the front hole, I pulled the head off and I can see no cracks, Im gonna stick the head back on fix the freeze plug and flush out the motor with kerosene, change the oil and filter and see what happens, I'm hoping the freeze plug actually did it's job, but I'm not holding my breath. BTW I found a used 77 model 2.5 that runs good for $500, may go that route.

 

[Alpheus]

Re: Engine Question

I'm hoping the freeze plug actually did it's job,

A "Core" plug is not there to relieve the pressures of freezing water. That is a very common misconception. You may get lucky...

 

[180shabah]

Re: Engine Question

I'm hoping the freeze plug actually did it's job

It's job is to fill the hole left from the casting process - it already failed that job, but you may get lucky yet - likewise, I am not holding my breath, but I will cross my fingers for ya....

 

[cproc501]

Re: Engine Question

Found out today after getting my head back from the machine shop that I have a 3.0, not a 2.5 as i had originally thought, also, I filled the block with water and it has sat for 3 days with the oil plug out of the pan and no water in the drip pan and the block remains full, keep them fingers crossed!!!

Also, should I buy new head bolts or replace them? I have done it both ways in automotive settings, any information is appriciated in advance.


While I have your attention, is $1400 too much for a new interior? or is that a good price? Thanks again for your feedback.