what say ye experts?

[JeepSJ]

So, at this point I am convinced that the blow-by and the knock are both related to the cylinder scoring in #8. Yeah, I should have dealt with it when the engine was on the stand (three year ago...), but we were getting ready to move and I just needed to dump the engine in and get the vehicle shipped.

The engine (supposedly) only had 17K miles on it when I acquired it. From the looks of the bearings and cylinder walls (except #8), I'd say that was pretty accurate.

Place I bought the engine from said that it is too long after I bought it and they are not willing to do anything to help out.

The plan - pull it, strip it, get it bored, throw in new pistons and rings, and put it all back together using existing bearings, etc... I need to get it done as inexpensively and quickly as possible. This will only cost me the pistons/rings/gaskets/machine work. I figure one weekend to pull and strip, drop at the machine shop Monday, get it back a few days later, assemble, dress, and install the following weekend. I would probably splurge and go with 18:1 pistons over the stockers.

[moondoggie]

Good Day!

"I need to get it done as inexpensively and quickly as possible." "I would probably splurge and go with 18:1 pistons over the stockers." These two statements disagree. If you're thinking of 18:1 pistons, you must be thinking of more power in the future. Without doing something to the bottom end (I favor splayed mains), your more power may not be long for the world, which would be a shame, since you're opeing 'er up. If you're doing all the work you can yourself, you might want to consider getting RJ or someone to do the splayed mains while you're in there.

Best of luck; let us know, inquiring minds...

Blessings!

[john8662]

IMHO,

What you're saying is doable.

18:1 C/R isn't well suited for a daily driver, it's more suited for an engine that'll pull heavy and frequently.

I vote for the stock C/R or slightly under (the .010 topped pistons).

Get a set of Mahle Pistons and Mahle rings.

Check it all, I'd have the machine shop check the rods out thourally while you're there, especially the small end.

A compression test should reveal if the scoring in the #8 hole is the culprit.

J

[JeepSJ]

Interesting turn here...things may not be as bad as I had thought. Changed the oil today. Pulled out that Lucas high-tbn diesel oil and put in some Rotella (non-synthetic). Things are much quieter and after a short drive the blow-by is less. I'm definitely going to do more diagnosis before I start tearing things apart. I'm going to drive it for a few days and see if things settle down with the new oil.

[redbird2]

"The plan - pull it, strip it, get it bored, throw in new pistons and rings, and put it all back together using existing bearings, etc."

You really don't plan on taking the engine apart and reusing the bearings?
I know it sounds good to save that 100-125 but you don't want to pull the thing again or worse yet lose a good block and crank for a tank and half fuel.

I agree with john8662 have the machine shop check those rods wrist pin ends had to have mine rebushed when build my siginture truck engine.

think about it carefully before you possible shoot your self in the foot to save a buck today

good luck

[JeepSJ]

Well, she sure rattled good when she was cold this morning, but a lot of the noise is now gone. Oil pressure is much better as well. Engine just sounds healthier with the new oil. I'm just going to keep driving it and monitor things and see what happens.

[ronniejoe]

18:1 C/R isn't well suited for a daily driver, it's more suited for an engine that'll pull heavy and frequently.

Can you provide some evidence to support this assertion?

My experience says there is no difference in suitability for daily driving with 18:1 verses 21:1. My Suburban is a "daily driver" as well as a tow vehicle.

There are lots of "daily driver" 18:1 engines out there. They work fine and give you the advantage of improved reliability.

[john8662]

18:1 leads to smokey starts, which are unacceptable for a city driver. Cold starting with standard glow times (even in warm weather) leads to smokey starts.

Some people this may not bother (it's a diesel right?), but for me it does.

Another observation so far comparing two 18:1 engines that I currently operate is that the engine with the KD pistons in it starts harder than the engine with just the topped pistons. By starting harder, I'm noticing more smoke, and not a smooth run till they all get to firing.

Both using STD glow times, one is mechanically injected, the other EFI, the MFI engine starts better (which is odd).

I attibute the harder starting to one engine to the KD pistons.

This is primarily due to the combustion bowl on the piston in where the heat on the piston is retained.

With a stock type piston, heat is retained in the recession in the piston, helping maintain proper firing.

If I had to do it again, I'd do a 20:1 with all the goodies.

J

[ronniejoe]

If you don't adjust glow time, of course it will start harder. Mine starts great with no smoke on most occasions. Even extreme cold this past winter only produced a brief puff of smoke. With programmed longer glow times, I don't even need to use my manual over ride any more.

I would look elsewhere for the difference in starting besides the piston differences...

[More Power]

I agree with RJ. Assuming everything else is OK (compression, injection system, timing set, etc.), longer glow times allow an 18:1 engine to start as well as a 21.x:1 engine - at least down to an overnight low temp that really requires using the block heater anyway.

Jim

[Robyn]

I have heard mention of the intake air heaters.
I know the Dodge cummins used/uses these.
Would this sort of thing help the 18:1 engines start up and run better on a cold light off ???

Just a thought

Robyn

[ronniejoe]

With proper glow time, they start up and run as well as a stock compression engine on cold light off. No other help needed.

[BiggR]

My brother's 18:1 motor starts great in even the coldest of temps, maybe just a puff of smoke, but not any worse than my stock compression motor!!