Topic: 2.5L Rebuild using a commercial 3.0L stroker?

[Bikerjr1]

That sounds about more like the motor he was talking about. Don't know why I didn't find the gas version when I did my search.  He also said he may have one that I can pick up from a friend of his if he still has the old boat.  He said something about taking the hole boat,  has a busted hull.  The wife is looking REAL forward to that one.  I guess I can cut it up with a sawsall.  I do have a question, are all the blocks the same from the XJs, MJs and YJs?  The block that the salvage yard has is like a 1986-1990 vintage, or will I have to use my 1993 block.  He was talking about this engine combination (stroker) in the mini sprints that he use to race.  when I talk to him again I'll try and get more info.
JR

[little97tj]

he atually ran this in his sprint car with the amc/jeep block?... are you sure he wasn't useing the chevy iron duke 150?

[Mr_Random]

he atually ran this in his sprint car with the amc/jeep block?... are you sure he wasn't useing the chevy iron duke 150?

This is my concern too...

If we're talking about using the 2.8 to stroke an iron duke, it just goes back to the commercial 3.0 discussion... I do believe they are all the same block.

Oh and it's the pontiac iron duke, just for nit-pickey purposes.

To answer another question; all 86-01/2 blocks should be the same. I do believe they added a girdle and NVH stuff in 97ish, but otherwise they all have the same dimensions...

Now, my own question; in all these pages did anyone take an Iron Duke crank and compare it to the AMC2.5 crank? Or have any other cranks been compared otherwise? If not, let's try, or we're just going back to the offset grinding discussion...

[Jeffy]

Ok this is the storey its the 2.8l merc made from 1987 to 1989, its a gas motor and based off the gm iron duke... thats all pretty promising. I cant find the cranks and rod details on line though. So it looks like a trip to the machine shop in the morning to go threw there books.

The Chevy 2.8L is a V6 and not in the same family as the Pontiac 2.5L I4...

If you have a decent engine shop, they should be able to find some pistons and connecting rods that would work though.  IIRC, a guy on the mailing list mentioned finding some pistons and forged rods that might work.

[Mr_Random]

The Chevy 2.8L is a V6 and not in the same family as the Pontiac 2.5L I4...

If you have a decent engine shop, they should be able to find some pistons and connecting rods that would work though.  IIRC, a guy on the mailing list mentioned finding some pistons and forged rods that might work.

Is that what we're talking about? The diesel 2.8 I read about earlier is actually a four cylinder, but I don't know about the gas one.

[little97tj]

Bikerjr1 friend is talking about a boat motor that was only used from 86 to 89. They had a 2.5 and a 2.8L but they were not refered to as such. It was a mercury marine 160 or something to that effect and it is a 4cyl. Thats all I know at this point, I'll get this pinned down in the morning when I go to the shop. they have a room the size of a two car garage full of every know tech manual to man. I have a couple other things I need to look at too. I have this week actually, then I'm off the france and Noway for 5 weeks.

I'll do a compare with the iron duke crank to our 2.5 as well.

[Jeffy]

Bikerjr1 friend is talking about a boat motor that was only used from 86 to 89. They had a 2.5 and a 2.8L but they were not refered to as such.

Mercruiser used GM engines.  The standard were the 2.8L and the 2.5L Iron Duke.

[Mr_Random]

Mercruiser used GM engines.  The standard were the 2.8L and the 2.5L Iron Duke.

yeah, once again we're getting back to that discussion... hopefully littletj97's research will prove something useful, if not from the iron duke, but other four cylinders that could work....

[little97tj]

Its sure sounded nice first thing this morning, but a headache later it does seem to come right back to were this thread started from.

[little97tj]

Just a quick update I've turned over just about every stone and nothing has been found thus far.  Starting to think it would have been easier to go .060 over and supercharge it instead. My quick run to the shop the other morning for a morning of research has turned into several days of going threw books. If I dont come up with something today, I'll call off the search.

On another note these 2.5 crank and rods have plenty of beef to take a turbo of supercharger and live a long time. 

[Mr_Random]

Just a quick update I've turned over just about every stone and nothing has been found thus far.  Starting to think it would have been easier to go .060 over and supercharge it instead. My quick run to the shop the other morning for a morning of research has turned into several days of going threw books. If I dont come up with something today, I'll call off the search.

On another note these 2.5 crank and rods have plenty of beef to take a turbo of supercharger and live a long time. 

too bad the crank didn't come forged from the factory like most amc v8's! But yeah, compare pretty much any part of the rotating assembly to a honda four cylinder, everything is like twice the size.

Hm... wish turbo and supercharging was as cost-effective and stock-like as the strokers the 4.0 crowd gets to make!

[Jeffy]

Turbo or SC is cost effective IF you do your own work.

[Bikerjr1]

I haven't been able to catch up to my friend to verify some facts we are talking about.  He does know that my Jeep is a 1993, it was parked right outside when I talked to him.  He said that the only thing that I needed from the other engine was the crank, rods, and flattop pistons.  I sure that him being a Jeep/Dodge factory mechanic he knows the differance between the two Jeep motors.
more later when I find out,
JR

[Mr_Random]

Turbo or SC is cost effective IF you do your own work.

yeah, you're right... I only haven't looked into it because I can't weld, or at least haven't learned yet... my dad knows how, but isn't confident enough to weld anything up like a custom header...


and to bikerjr1, good luck on extracting that information! *crosses fingers*

[Bikerjr1]

Good news.
I talked to him last night.  This is the motor we want (2.8L Merc).  The crank will bolt in with no clearance problems.  There are a couple of choices for the rods and pistons.  When I track down my Merc-cruiser engine and start building I'll post every thing I can.
The wife even said I could build the stroker 
Gotta go at work.
JR