desertwalker62

hey everyone... had an old thread about driving with a blown headgasket... thought i did for a week before the teardown... i have a rebuilt engine and new head by oregon engine rebuilders... 45k on it... keith black piston 9.7:1, oversized valves, cam, high volume oil pump, weber 32/36, tri y header, flowmaster, no cat, marlin crawler tranny, new radiator, fan clutch, alternator, etc... many new parts...

drove well (rich, didn't have altitude jet pac for weber yet) for 45k after engine swap... couple weeks ago i noticed oil/coolant mix from crankcase breather hose an feared headgasket... sometimes i tow tool trailer, gets hot on a few steep grades but never pinned the needle... after pulling the head, gasket showed little sign of failure (however we have mix coming out the top, not so much milkshake in pan) but i was amazed to see chunks missing from first 2 piston and a sludge ring at top of cylinder... what's happening here? why did this happen? OERebuilders has a limited LIFETIME warranty... we'll see!

BigSwole

the Pleasures of a warranty. Have you contacted them yet?

desertwalker62

waiting for them to "get back to me..."

desertwalker62

called them again... right guy still not their, but apparently they have had this problem with MANY keith black pistons, and have started using rock pistons instead and "not as many" coming back... hmmm... more on warranty info later...

MudHippy

Improper engine break in procedure. And/or poor cylinder honing technique.

At 45k miles you should not still be seeing the honing pattern on the cylinder walls. Which tells me break in was not accomplished successfully. This could be for a number of reasons:

1. Honing was done with the wrong grit stones.
2. The micro-inch finish was too course.
3. The honing pattern cross-hatch angle was too steep/too shallow.
4. Synthetic oil was used before proper piston ring break in was achieved.
5. A proper break in procedure was not used.

I believe what you'll find when you remove the pistons will also verfiy that the above hypothesis is correct. Which will be apparent by significant scuffing on the skirts of the pistons.

Alternate hypothesis:

Running that filthy(literally)rich could very well have contributed to the failure by overloading the faces of the pistons with carbon deposits. Causing a loss of deck height requirement. Basically, carbon isn't compressable. If it builds up to a certain thickness it's going to cause clearance issues between the piston face and the cylinder head. Which, as well as raising the compression ratio will eventually cause damage to the pistons like you're seeing there.

But now that you mention it, it could also be a result of poor quality pistons. Or pistons being used in an engine that would not support them, for various reasons. Such as incorrect deck height requirement, or combustion chamber incompatability. AFAIK Keith Black is a reputable piston manufacturer, so that would suprise me.

It could also be for a combination of any of the reasons listed above.

1990yota-pickup

desertwalker, i just sent my spare 22re block to the machine shop here in Eastern NC

thermo clean block 95.00
bore and hone 125.00
turn crank 95.00
rebuild head plus part 265.00
engine kit 215.31
tax 8%
total $812.53

MudHippy

Edit: Those would be intake valves. So they would definitely be closed as the piston approached. Nevermind. Unless the valve timing was WAY off.

xxxtreme22r

take a good look at the valves. As MudHippy mentioned the clearances with those high compression pistons in the motor combined with the over sized valves/cam cannot be all that much. Add to the mix the carbon buildup from running rich. This is why it is so important that people run those weber's run them correctly and not let the motor run way lean or way rich, because this kinda stuff happens. If I had the engine come back to my shop I would not cover it knowing the engine was run rich. That is very apparent. And has nothing to do with the place that built the engine.

You will be lucky that ORE replaces that motor.

MudHippy

Well, maybe I was onto something there. The valves, even when closed, could have still been too close to contacting the piston on the compression stroke. Especially with the carbon build-up taking up the needed room for clearance.

xxxtreme22r

doubt that. but the exhaust stroke would have "issues".

MudHippy

Yeah, I guess that's a bit of a stretch.

scope103

Hard for me to tell from a small photograph, but that honing pattern looks a lot like what I saw on my own 3VZE at 157,000 miles.

Do you believe that the honing pattern should just completely disappear?

sam333

Detonation can cause piston breaking( alot of times the ring lands wil break) / melting. Do you have the EGR hooked up ? Do you know the actual compression ratio( after the new pistons and all machine work). Was the engine knocking anytime? Hows your timing? Hows the head gasket fire ring look on the bad cylinders( is it burnt or cracked)? The engine does not have to overheat to detonate( wont usually see it on your temp gauge). Cant tell alot from your pictures( too small).

MudHippy

Yes. They should be glazed up/shiny like a mirror ASAP. For the best piston ring seal. Don't feel bad for not knowing that. Alot of folks think that's a "good" sign, but it's not.

ZARTT

I am amazed at times at the bad information that gets posted on some of these forums.
When a bore is honed to its final size, the stone used, is chosen to match the material makeup of the ring pack. (soft, medium, hard, moly, chrome)
The pattern that is honed on the wall, is comprised of microscopic scratches that are by design, used to hold an oil film.
That film is used to lubricate, cool, and help seal the ring pack to the wall.
A bore that has a totally smooth surface is one where the rings have never seated, and will suffer from low compression, and excessive blow by.
I apologize for going into preach mode, but I just couldn't let that one pass.

Art.

hilandfrog

I think it comes down to what size we are calling micro scratches

I'm a picture kind of fella.




And this summation Shamelessly taken from google.

"When we refer to engine or cylinder break in, we are talking about the physical mating of the engine's piston rings to it's corresponding cylinder wall. That is, we want to physically wear the new piston rings into the cylinder wall until a compatible seal between the two is achieved."

Repo

BigSwole

so should you see the honing or not. Yall are confusing me

xxxtreme22r

I am also under the impression with only 45K on it, I think you should still see at least half the crosshatches left. The block should wear the ring down not the ring wear the wall down. Cyl wall glazing is a BAD thing.

ZARTT

Simply put.
For optimum performance, no matter what the mileage is, the bore should ALWAYS display a crosshatch pattern.

Art.

desertwalker62

SAM: there is no EGR hooked up, comp 9.7:1, made a valve lash adjustment to alleviate knocking or tapping sound around 30k, gasket looked way better than anticipated, but had couple dents (weird compression? minor blemishes) near 4th cylinder and possible crack split between 3rd and 4th cylinder... noticed once we started removing... damaged pistons #1 and #2... gasket looked pretty good, but we did have coolant / oil mixing blowing out breather... i have to drastically size my photos down to meet the websites sizing requirements.

also, wouldn't running rich cause lower temps in the combustion chamber and just blow out the extra fuel??? wouldn't all those deposit be from oil and water leaking into chamber at point of combustion? ie faulty head gasket?