Cleaning New Cylinder and Pistons

[porschedude996]

What are your thoughts on cleaning new Maule assemblies? Other than clocking the rings, my new ones are spotless. Seems strange that if they needed to be cleaned, the rings would not have installed. Why increase the risk of breaking a ring?

[Classic 911]

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[porschedude996]

When I removed the pistons from cylinders I noticed that all the piston ring gaps were aligned.

[Flat6pac]

The rings move to where they want to be in minutes of running.
They’re never on the 120 when opening.
Bruce

[PeteKz]

Olde Porsche machinist I know says to just install Mahle out of the box (not other brands, which you should measure first). That's what I did. As Bruce noted, they will rotate around the piston in use anyway.

[porschedude996]

Thanks guys, I found the cylinders and pistons very clean, lightly oiled, and i’ll do the indexing the ring gaps at 10 and 2. I may check the ring gap on one piston and clean one assembly with clean alcohol and see how much foreign matter I find.

[mikedsilva]

That's interesting. I installed a new set of Mahle pistons and cylinders early this year. And they definitely required final cleaning.

[reclino]

I cleaned my new Mahle 3.4 liter pistons and cylinders, the pistons were pretty clean, the cylinders were black when run over with solvent on clean room wipes. I spent a lot of time cleaning the cylinders, final clean at 170 deg F with ATF fluid soaked clean wipe. Engine building rule, all parts are dirty, must clean everything, even new. No one will care more than you do.
Just looked back at my build threads, I cleaned the new 3.4 liter pistons and cylinders on page 17.
https://forums.pelicanparts.com/911-930-turbo-super-charging-forum/848849-barn-find-1986-911-turbo-17.html

I am not an engine builder, just a very careful guy working in his garage.

David
Performance EngiNerding

[AVI_8]

If I’d just spent several thousands on new pistons and cylinders I’d sure as hell be stripping them down to clean them, why not it’s only time, you’re not going to break a piston ring if you’re careful.

[porschedude996]

Originally Posted by AVI_8

If I’d just spent several thousands on new pistons and cylinders I’d sure as hell be stripping them down to clean them, why not it’s only time, you’re not going to break a piston ring if you’re careful.

When I was working aircraft, we would charge out a “jug” (Cylinder/Head/Piston) without even thinking of cleaning it. But I am cheerfully taking the advice of the group and disassembling and cleaning. Time is not that critical that I can’t spare 1/2 a day. I’m retired…

[AVI_8]

Well the way I see it, when you start an engine after a rebuild, especially when you’ve new P and C installed, there’s going to be some wear involving metal contact which is naturally going to break down causing micro swarf and that just going to happen as a natural breaking in process, hopefully mostly flushed after the first oil change, but why add to it by having any kind of swarf during the machining process of manufacture added to the engine oil.
Anything to reduce wear during initial break in is only a good thing.

[PeteKz]

reclino, thanks for your link to your other thread. My 3.2 Mahle Sport 3.2 P/C's were clean and oiled. I wiped out some of the oil just so they weren't so oily to handle. No dirt on the cloth. I'm wondering if you pushed the pistons/rings up and down in the cylinders at some point, thus starting to wear-in the surface of the cylinder and rings, creating the black stuff?

[reclino]

My pistons cylinders / rings were not assembled. All were separately bagged, looked like nice fresh clean parts. Fred Apgar had been advising me on my build. He had given me clear instructions on how he cleaned cylinders. I did my best to follow his method and document it. In one of these conversations with Fred regarding building my engine,.he stated that in contrast to other mechanics,(not an exact quote) good engine builders as they gain more and more skill over the years get slower and slower, double and triple check more items,.and clean more and more. These engines keep getting more and more expensive, simple mistakes can be very catastrophic and expensive.

[zztot]

Great information,…….
I am not builder but weak organizer.
Where can I buy wipes and IPA you mention?
Thanks for your posts.

[reclino]

Intex Cloth like rags. Big yellow box of 300 from Walmart, 91% isopropyl alcohol also from Walmart. These non woven paper towels are not advertising as clean, but they leave little to no visible lint behind. I had a small box of lint free lab wipes, I think I bought in Amazon. Charcoal lighter fluid is a other cheap clean solvent, it's refined enough pure hydrocarbon to evaporate with no smell.or taste in food it's good enough for me. I usually add 5% (small splash) ATF just so the parts dry with a thin oil film.

[zztot]

Thanks Reclino. Made Walmart trip.

[porschedude996]

I have a bit of Spacecraft experience and I know about cleaning surfaces. Lint free wipes are a must for cleaning things that need to be super clean. We, and i imply Largest Aerospace Company in the free world, didn’t use NASA Spec’s much. We had other imposed spec that were similar. I can’t get to those since i’m retired. But here is NASA’s rundown.

https://ntrs.nasa.gov/api/citations/20100002193/downloads/20100002193.pdf

IMHO, I can’t see the benefit of using a lint free. Paper towels will work, but the Blue Shop Towels available at Costco or most Auto Parts store are better. Soft particulate on a small scale will not matter. It either burns up in the cylinder, or gets scrubbing by the filter. Grit in the form of dirt or machining residue is the problem.

As far as a cleaning fluid, we bought Freon until it was band. Subsequent fluids sucked, but life goes on. We had a still and recycled pre-band Freon. It was amazing how little loss we had. But in the 60’s, 70’s, and 80’s cleaning facilities treated it like water and rather than distilling would toss it to grade.

I use Methyl Alcohol (Methanol) for most of my cleaning. Simple Green is my other go-to cleaner.

My approach is going to remove pistons, swishy-swishy in a bucket of Methanol and blow dry with dry/filtered shop air. Cylinders will be scrubbed with a wet towel and Methanol. If it looks too dirty on the towel i’ll degrease with Simple Green and then Methanol again. I think Methanol is better and is as cheap as Isopropyl Alcohol which has water in it (10-30% H2O), unless if you can find anything above 90% locally. Methanol is 99.85 and I buy it on amazon.

I think the critical part is changing the oil and filter very soon after first running and breaking it in. I plan on an hour or so. Filters are good, but nothing like washing small particles away the filter doesn’t catch on a freshly rebuilt engine.

[PeteKz]

Based on cleaning a few American blocks back from the machine shop, I don't think the solvent you use matters much. Good old soap and water works well too. The most important ingredient is liberal amounts of elbow grease. If you use soap and water (or Simple Green, etc.), be sure to immediately wipe everything down with some kind of oil, to stop flash rusting. That applies to aluminum cylinders too. If you wash them, oil them. Even though they may have a Nikasil coating, that coating has aluminum embedded in the matrix and below it. Unprotected aluminum also corrodes.