Does it cause overheating or not???

The engine won't run hotter because of this. Think of it this way: your engine is at .040 overbore now. Going to .060 is only .010 per side of the cylinder. The average human hair is .004. Many of the newer engines are designed with thinner cylinder wall castings to save weight, but at the expense of not being able to bore the block as much, if at all. The 32 valve Cadillac Northstar engine is one that is not recommended to be overbored at all, and some of the 4.0 Jeep engines being made into stroker engines are being bored out .120 (after sonic testing). If you are concerned about it, you can pay someone to sonic check the block for cylinder wall thickness, but in all honesty, a 9-1 compression 258 isn't going to have a problem with a .060 overbore.

Chris

And after all this, I am guessing that until someone A) funds a scientific study, or B) you take the plunge, no one will know, so follow your gut man. Just have the spare $$ to pick up a used or rebuilt motor after the fact, in case it all goes south.

Thanks guys,

That's why I come here.... for a reality check. I can understand one of the sources of this mis-information (a engine remanufacturer in LA

) who's trying to project quality or higherstandards I guess. Who knows. Marketing mis-information. But the other sources were life time mechanics.

Thanks,

Bill

L.W. (ßill) Hughes III wrote: | I used to run spare engines. | God Bless America, ßill O|||||||O | mailto: snipped-for-privacy@aol.com

| | Joseph P wrote: || || And after all this, I am guessing that until someone A) funds || a scientific study, or B) you take the plunge, no one will || know, so follow your gut man. Just have the spare $$ to pick || up a used or rebuilt motor after the fact, in case it all || goes south. || || -- || -- || Joe Pribe || NC || jpribe 'at' nc.rr.com

If it was mine I would toss that block in the trash.

I believe all the wear and polished up parts was due to lack of lubrication because of gas wash. Too much gas in the oil makes thin oil. Your bearings were textbook for a gas wash or lack of lubrication, so are the polished cylinders.

So in light of that, all the metal that wore away has to be somewhere right? Think of all those little oil passages and how many of them are blocked or partially blocked with the metal particles.

Then to make things even more interesting, you think it is a 0.040 overbore with 0.058 overbore pistons in it?????

I would be checking out the local wreckers for a low mileage used 4.0 out of a Cherokee or newer Wrangler. I got one with 40K on it for $400.00 Canadian. The full long block. The thing runs beautiful, has excellent compression, doesn't burn oil and goes like a scalded cat. It will pull out fast up to 4500 rpm.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

William Oliveri wrote:

Mike, I have to partially agree and disagree with you on this. I'm not trying to start a flame war or argument or anything, so please bear with me. I will say that I read all your posts and have learned a great deal from you and I respect your opinions and advice.

If an engine block is properly cleaned and checked before and after machining, it really doesn't matter how dirty or gritty it was to begin with. The key phrase here being "properly cleaned". Taking the block down to the local car wash and spending $2 on a quicky cleaning job doesn't cut it obviously, although I hate to count how many engines have been cleaned this way. There are several ways that engine shops are cleaning blocks and heads these days, including hot taning, pressure jet solvent washers, and vibratory baking cleaners. No matter which process is used, and they are all effective, there is still much work to be done. You are right in saying that there are oil passages that are probably crudded up with God knows what, but a good engine shop will deal with that by removing every oil passage plug in the block and running stiff, nylon cleaning brushes thru the passages several times with both solvent, and then hot soapy water until the passages are all spotless. Every oil pressure passage in a block is accessible by a brush since they were originally drilled from the factory. It is easy to get these blocks cleaner than they were the day the factory assembled them if the time is taken. Heck, on the small block Chevys I build for racing we actually enlarge many of the passages with very long drills and then clean them meticulously afterwards. These particular engines are noted for starving the main bearings at very high RPM, so in order for them to keep the bearings in them it is almost a necessity. I won't even get into how bad the Ford 351C oiling system is and how much needs to be done to them. My point here though, is that the block can be used again if properly prepped. Now, finding a good engine shop to do this may be tough, but depending on the area it might be easier than finding another engine. Some areas seem to have a good supply of either cores or good running engines, but some areas it is a lot tougher.

If his block ends up being .060 overbored already, then I agree it is time for a different block/engine. I don't know if he has had the block measured or not, so that is the first thing that he should do. If the block it at .040, and everything else checks out, then it is time to find a good engine builder. I think Bill O. is in California, but I'm not sure exactly where, so I can't help recommend an engine builder. If I were close enough, I'd gladly do the rebuild for him. I mostly do engine work as a hobby now and would love to tinker with a 258 or 4.0. The last inline 6 I messed with was a Chev 250 for a hobby stock class oval racer a couple years ago. We had a lot of fun with that once we found out that Chev 307 pistons interchange with the 250, and it just so happens that there are 12-1 pistons made for the 307 :-). The rest is history as they say.

BTW, your engine you're selling sounds like a heck of a deal for someone. Too bad Bill is so far away, but maybe he can find something locally. No matter what way he goes, I hope is works out well for him. Just my 3 cents (damn inflation).

Chris

"Mike Romain" wrote in message news: snipped-for-privacy@sympatico.ca...

How much does your timing retard when you push the go button? And what compression ratio are you running in the nitrous engine again?

Chris

I won't disagree.

Finding the right rebuilder and being prepared to spend the money and just about anything can be cleaned up properly. I have just seen too many lazy workers so get a bit cynical sometimes....

I have doubts about the information he is getting sometimes. His pistons are marked 58 so I don't know where the .040 over comes from.

I don't mind a rebuilt once engine although they normally won't last as long as a factory original. Rebuilt twice, well.... Turned parts aren't near as perfect as the factory ones 'usually' and the turn itself means a different sized friction area.

Given a choice, I would, well I actually I did choose the used engine with Low, 40K miles vs rebuilding my 258 myself. My old 258 is in 100% better shape than Bills even still. I inspected it and there is minimal bearing wear, it just leaked like a pincusion. I still have it sitting in my garage and likely will take my time and do it up pretty.

Mike

c wrote:

That's could be why you knocked the cylinders out of an engine. Nitrous needs the timing to be retarded or the cylinder pressures go through the roof. Most nitrous systems will retard the timing anywhere from 2 to over 12 degrees depending on how much nitrous you are using, as well as octane, compression ratio, etc. Also to prevent detonation, colder plugs are required, sometimes up to 4 steps. Here is a good page for this info:

Chris

Mike, you are confusing two different theads. My pistons are marked 40, not

1. I was looking at a possible doner engine instead of using mine. His pistons are marked 58 which I didn't understand. Have you seen anything like that?

Thanks, Bill

lubrication,

Chris, thank you for the rebuild help if you were closer. I'm still kicking myself for not having a place to pull the engine myself. Not only for the cash savings but for the educational value. I expect to have this CJ or another like if for a long time and pulling an engine when it comes time will be part of it.

I have been given several references to good machine shops by Robert Bills and JeepsRUs locally I still have the problem of pulling the engine.

So, I have found a guy locally whom I trust who will do the R&R for 2200.00 out the door including a new clutch.

If I'm having gas wash like Mike said it doesn't matter what engine I get so I will have that looked at right away after the rebuild so I don't destroy this new rebuild.

I appreciate you, Mike, Bill, Robert and others for the continued help and I am learning.

Thanks,

Bill

Ahh, ok, sorry about that, yup confused the threads.

You can buy pistons for any of the common (over)bores for that type of block. .058 is .002 off the max so it kinda makes sense. A .058 piston in a .060 cylinder bore maybe even. The .060 rings likely fit both... Maybe that's all they could find? Who knows when it comes to a 'rebuilt' unless you do it yourself.

Just a guess.

My opinion on the old block and rebuilding it twice still stands. 'I' wouldn't do it if it was mine....

I also think of your engine as being a gas washed worn out one, in my mind that makes it a boat anchor. Heat happens with all that wear and temper is affected maybe, I don't know, just always was told they were boat anchors by folks I trusted.

Used low mileage engines can be great and sometimes found cheap.

I figure I will get twice the miles out of my $400.00 used engine then I would on a good rebuilt....

Mike

William Oliveri wrote: