jacksonrw

i will double check and thank you Mike for replying

Tom faxed over to the shop the specs for clearnace and even though they were faxed to the shop prior to the pistons being made....the shop didn't want to do anything with the block until the pistons AND rings were there to double check and verify.

That is why I do believe the shop when they say that either the rings or the coatings were incomaptible. they went to great lengths to dbl check what Tom was telling them

I will ask the shop what clearances they used when i talk to them today when I check on the next block they are prepping since the one I had was gaulded and ruined

Ski

How bad...will 101 clean it up? If so, save it.

jacksonrw

ok i will hold on to it
I left you a message at work
I am in Houston as well.

Lunch?

do you have any other numbers for Tom? As I am reviewing the emails from him when we were getting these made.....he wanted to get out from doing these anymore - but he did have another set which I would be glad to trade him and test to see what happened...

Mike Lindsey

There has been people running a straight billet piston in a Alusil bore without coating and having
decent luck although we certianly wouldn't advise it. With enough clearance, it may (or should
I say has shown to) work. It doesn't sound like a coating issue to us. Sounds more like a clerancre issue.
And there has been other history of persons using the same ones.

We didn't want to say much since this doesn't involve us, but at the same time would hate to see you
have this happen a second time. So here is something to think about or pass along to those involved.
They may already of used/known this information but maybe not.

Make sure they measure the bores cold when checking them through the boring/honing process. The heat
generated in the boring/honing makes the cylinders grow (can begin to simulate a up to temp engine) and
they must cool down first. Otherwise your to tight on the clearance.

I am going to guess those are 2614 forgings. Most companies don't seem to use a 4032 or equiv. J&E for example as big as they are don't. WISECO has few and won't build from 4032 unless you insist. Mahle will default to 2614 it seems unless you tell them 4032 equiv. (theirs is 124) If you tell Mahle your going to run over 18 psi, they won't make them out of 124.

4032 can run a much tighter clearance since they don't grow as much. You could run a looser clearance on them and not hurt anything. 2614 clearance needs to be about 3-4 times that of 4032. We vary depending on bore size and application. Someone reading a Porsche manual and boring for stock piston clearance while running a 2614 is going to stick them. No question about it.

Another issue is ring gap. Porsche says .008 to .016 I recall. We go with .015" on the top two on a 100mm build. If they
were to tight, as the ring grows, the gaps come together and you can kiss your cylinders good bye. Better
to gap on the larger side and error on the side of safety.

Good luck and if you need anything, let us know.

jacksonrw

Mike I had wished I had gone to you directly..
I have said that before unfortanetly

You guys have sold me a lot of things and nothing has ever ever failed
thank you

I have forwarded your comments to the machine shop

could the rings have caused this due to incompatability of material?

Mike Lindsey

I don't feel your going to get gauling in the piston because of just a ring material issue.
It will likely wear to fast, or not ever seal good with the improper selection. With the right gap, I think your also safe on your different materials. Our new 100mm rings for stock grooves for example are SS on top and cast on the 2nd. Same gaps on both are used.

The piston is much smaller at the top above and where the rings are on the piston. So even a tight piston clearance would be plenty loose up there. I suppose it could be .025" +/-. If you had a ring issue, look at the wear on the cylinders and see how high it goes up the cylinder walls. If the scoring is
all below what would be the bottom of the oil rings, (roughly a inch down) that should tell you more about if it's a likely piston or ring issue.

Tom M'Guinn

I opted not to use the Tom C pistons after receiving them, since I was not able to gain comfort from either Tom C or my machine shop re the material and coating and rings. Clearly they can be made to work, since many have used them, but I wanted to eliminate as many risks as possible when building the motor. If anyone is interested in a set of 105mm turbo pistons...

jacksonrw

guys I just got back from the machine shop and have the psiton heads with me and i will post pictures tonight

regarding where on the cylinder walls the galded scratches are found are all up and down the cylinder wall

In reality once the rings are compromised - foreign particles are present and contribute to the whole demise

The machine shop stands behind the adusil prep as well as the clearence specs

Dennis faerman spoke to his contacts at Total Seal and there is no aftermarket rings that are truly compatible with the adusil surface
additionally he believes that the coating could also been the problem because if the caoting is incompatible we have problems there as well

how many of those using tom's pistons use them in sleeved or bored?
if sleeved - any ring works without a doubt

but bored adusil takes more compatability with the cylinder wall materials into account

jacksonrw

pistons galded
no reply from Tom
more experts have weighed in with advise
Closing thread to keep things from getting ugly
PM with comments or questions