225 to 231 should I do this?

My 225 is blowing blue smoke pretty badly. I have found a 1982 231 that supposedly runs good, with unknown mileage for $300. It came out of a CJ for a v8 swap.

Will there be any issues with the transmission input? It was in front of an SM420.

So, is this worth considering? Or should I fix the 225. I have not done any diagnosing yet. I'll get to that tomorrow.

Thanks for the input.

Greg

 

Be sure and get plenty of opinions / ideas on this question before you jump.
IMO, if the 231 wasn't adequate for the previous CJ, destined for a V8, then it may have been driven fairly hard. The owner may be power hungry.
The tranny inputs should be the same, though.
I think you should fix / overhaul your 225. You know it runs and there's no conversion issues (like flywheel) to address.

 

The 231 will bolt up just as 225 did. I just did same thing. You could take a compression test on the 225 and see where you stand. You could also run the 231 on a stand and check compression and oil pressure. Larry

 

An '82 is an even fire V6? If so, you'll need a different flywheel. If the flywheel comes with it, so much the better.

Certainly the cheapest way to keep an old car running, if the engine is worn out, is to install another used engine. You take something of a chance buying a used engine, but usually it works out ok. Put the 225 away in the basement or corner of the garage... it is a running engine, and you can always fall back to the 225 if something goes wrong with the 231.

The other cheap option is to overhaul your 225. How much oil pressure does it have? If it smokes all the time, that usually indicates the rings are worn out. An old-school overhaul would mean new rod bearings, rings and a valve job. I'd do a few might-as-wells too, like the timing set, lifters and water pump. Putting new rings into tapered bores won't go 100,000 miles, like a rebuild ... but it may be good enough for a hobby car.

 

Do you know the history/condition of the 231? Does it come with the flywheel? If yes and the condition is good I'd buy to put it in then down the road go through the 225 at your leisure. If no then I'd pass. 231 even fire flywheels can be hard to find.
Blue smoke could be as simple as a bad PCV valve or could be worn pistons/rings. A compression test is a good place to start as well as changing PCV valve.

 

Thanks for the ideas.

The guy who has the 231 had a v8 sitting in the garage. He was replacing the front trans seal and decided to go ahead and put in the v8.

It comes with the flywheel, newish clutch, bell housing, power steering pump.

Checking the compression and a new PCV will be first on my list when I get home tomorrow. I don't specifically remember what the oil pressure was running. It never concerned me as being low though.

The 225 developed a knock a few months ago that just went away on its own. No issues since then until it started smoking.

I also have an OFFY manifold, TA470, and cam I was planning on using on the 225 that I won't be able to use on the 231.

 

Got the new PCV, still smoked. While it was running I noticed, which I hadn't before, that there was smoke coming out around the PCV and the oil breather.

Checked compression 1,3,5 all 120psi. #2-0, 4-100, 6-120.

So now I'm thinking having the heads redone is all I need at this point?

Either bad valve seals or burned valve seats or both is the problem?

That being the case, should I use these heads? I have another set I could have the machine shop start on while I pull these off.

Thanks again for all the input.

Greg

 

Take the suspect head off the block and inspect for exact cause of problem. Pulling a head (or heads) doesn't take that long. After you get them off, post a picture of the combustion chamber portion, if you're still not sure of the problem. Your machine shop will be able to assist you as well.

 

If you decide to use "the other set of heads" make sure that they are for a 225 and not a 231. They don't interchange.

 

Well, not so easy as the heads. #2 piston seems to be missing a piece.

[/IMG]

 

Is it possible this was the knock I had a while back and the piece broke up small enough to pass through?

 

A single cylinder at zero usually means a burnt exhaust valve, but it could be something more insidious like a hole in a piston. Do you have a compressor? A leakdown check will tell you more about where the compression is going. There are several articles on the web about making your own leakdown checker out of generic parts.

Leaky valve seals usually smoke a lot right at startup, but less after warmup. Worn rings smoke all the time, but you'd expect low compression on al cylinders.

<edit> Oh well ... head is already off.

 

I thought about doing the leak down test. I figured the head was going to have to come off anyway. Glad I did.