59FORD

oversized pistons are .50mm and 1.00mm

.001 inches is equal to 0.0254 millimeters

0.050 inch = 1.27 millimeter
.50 millimeter = .0196
1.00 millimeter = .0393
^^^^^^^^^^^^^^

I stand corrected!

My Cummins book is old and dirty, the . can't be seen without
magnification and a good wiping.

WOW thats a lotta wear, ain't it.


Sleeve it if you have too. The repair sleeve is about $35
A good machine shop maybe another $200.
I had 2 sleeves done a couple years ago, total cost was $250
and you could NOT tell it had been sleeved from above
or below.

These would be fair prices but,
$13,000 is stealing from the poor and giving to the $R$I$C$H.


59

Geico266

He is da man! And this is why this web site rocks. The goofy, slander, trash talking crapola is not allowed here. Guys who really know their stuff get a chance to express it without being stepped on.

It works.

Smkndzl

Like I posted , they have two oversized pistons.

.50 mm equals .0196 in.

1.0 mm equals .0393 in.

they dont make a 50mm or 100mm oversizes pistons

LVTony

If an engine is repaired with sleeves, does anti-cavitation additive have to be added to the coolant from then on?

Tony

AlpineRAM

The repair sleeve will not come into contact with the coolant, so only the standard specs for Cummins coolant remain applicable for the engine.

The repair sleeve has an advantage over the oversize bore because you can still choose the correckt deck heigth for the standard piston whereas the oversize piston has the shortest distance between the pin and the crown. This may lead to a slightly uneven compression between cylinders. The oversize piston (if used ) should be weighed and machined to get to the same weight as the other pistons to avoid vibrations.

I did my repair with an oversized #6 piston instead of sleeving it but in hindsight I think it would have been better to sleeve it because my #6 has a considerably lower deck heigth now. (I think that they do only make them that low to accomodate for the maximum block resurfacing you can do on these engines.

HTH

AlpineRAM

dieselfan

so 2 rebuilds is all we can get out of or cummins? i thought it was like 5?
i learn something new everyday, great site!

thanks, brian

AlpineRAM

Not quite - you can bore the stock block twice (.5mm and 1.0 mm over) and then bore it to accept the repair liner- that will give you stock bore. The liner can be bored to .5mm and 1.0 mm over if you like, after that it has to be pulled and a new liner can be installed. Repeat as often as you like. The problem is that you can only resurface the block twice... and there ain't too many undersize bearing sets for the crankshaft.

AlpineRAM

Raspy

And you might not have to bore it on the first re-build. The bore might be OK with honing and a set of rings. Depends on the mileage and what happened to make you tear it down.

Wetspirit

wannadiesel

That is very true. I recently helped a fellow DTR'r change his head gasket. At 315k the crosshatch was clearly visible and there was not enough of a ring ridge to catch your fingernail.

gmctd

Diesel fuel is a light oil, injected at the top of the compression stroke.

Gasoline fuel is part of the intake air charge, entering the cylinder at the top of the intake stroke, washing the intake valve-stem, washing the cylinder walls as the piston drops, completing the wash as the piston rises on the compression-stroke.

For that reason, gasoline engine pistons\rings\cylinders\valves wear very rapidly, where 100kmi may be the end of it's useful life

Even a long-stroke 6-cylinder gasser will exhibit deep cylinder wear ridges, where the Diesel cylinders can retain the oem hone marks to unbelievable mileage, with little ridge, due to excellent full stroke cylinder lubrication.

The B Cummins can be a million-mile engine, if proper scheduled maintenance procedures are adhered to.

AlpineRAM

Naturally the hole must be inspected before you decide to bore it or sleeve it. I think that this engine has it's head off already and there must be some marks or cuts making the dealter think it isn't just slapping in a new piston.... but maybe the dealer thinks about a whole lot of $$$ for his pockets first..

LVTony

Can they inspect the piston and cylinder wall well enough using a bore scope through the injector hole, or do they really need to take the head off?

I would guess they couldn't really look at the valve seats, though, so it's probably better to take the head off. Although, would it be true that if there's no damage visible on the piston crown that the valves should be okay?

Tony

AlpineRAM

IMO you can't really inspect this stuff good enough with a bore scope.
The only thing you'd see on the piston crown would look like that:


You won't see an eventual crack because it's dirty, or you can just guesstimate.
Maybe the rest of the piston looks like that:

If the scuffmarks are not too visible in the bad lighting you have with a bore scope you won't get any hint..

IMO the head comes off rather quickly and a headgasket ain't that expensive.

AlpineRAM

boostjunkie1

OMG------WOW----What did that come out of and what was the problem????

AlpineRAM

This was my #6 and I assume that I had a headgasket leak a little coolant in and a little oil in the coolant too. It got a bit crispy and needed to be bored .50mm over.

The crack at 12 o clock in the following picture is the reason why you need to clean the piston and have a really good look.



AlpineRAM