adrial

I used goetze rings from EBS (Engine Builders Supply) and I had no gap issues (no filing required)...

Mike Lindsey

Our experience with the Goetze rings when you install in a cylinder and take a measurement we see double or more the target ring gap. By the time they seat in, that's going to grow even further. A genuine Porsche Ring is going to be right on the money, but only if the bore is 100mm. You don't see that on a used engine. So that Porsche ring is going to have a larger then desired gap the larger the bore. One could argue using a Goetze ring would be like putting a used ring back in the engine in terms of gap, but the ring tension would be better, which is better then doing nothing.

So we had developed a ring set that would allow you to go as much as about .007" or .008" over the 100mm and still have enough material to gap them down to desired spec. The smaller your bore, the more you remove from the ring in the gapping process.

This allows the use of piston coatings, or having pistons made say .003" oversize for example without
going all the way to 100.5mm if your wanting to get your piston to bore clearance back where it should be. Or if your plans are to put your pistons back in as they are, and leave the bore alone, then at least you can start with the correct gap.

Yes, that requires extra effort. But we felt if your going to put in new rings, why not start with the correct gap, because neither the Porsche or Goetze ring is going to get you there unless you have a brand new block. Well, the Goetze never will.

Then, there is the material the rings are made from. The Goetze and Porsche 1st and 2nd are cast rings. Our top ring is SS which is as good as it gets. Don't recall the 2nd ring material and don't have
time to track that down.

Goetze = Install and not have to worry about gapping although they will be loose. Least $$
OEM = Install and not have to worry about gapping and have a tighter gap then the Goetze. Most $$
LR = Require file fitting, but can have a perfect gap, and a stronger ring for less $$ then
the Porsche, but more then the Goetze.

It's the same with our 104mm ring sets. I think they are good to .006" over 104mm.

Voith

Thanks for this explanation Mike. I will go with LR rings.

What is the case with OE engine bearings vs glyco?

When I replaced bearings on my bmw, they were color coded for size, so fitment of aftermarket bearings was not possible, since one crank has different sizes of bearings (colors).

Is porsche different and has strict sizing?

ether_joe

Sorry to resurrect an old post, but I thought I'd add a data point. I am rebuilding a 951 engine with a buddy and we just tried the Goetze rings a few days ago. Granted, the cylinders have been honed, but tolerances were WAY out of spec. Many of the rings were as much as 0.019" or more, and we had one that was > 0.025 . I believe maximum tolerance is 0.017 . We were pretty disappointed in the Goetze rings and have just bought a set of the LR ones.

Paulyy

Better then stating a new thread I looked at this exact thread when choosing piston rings also. Went with the LR rings, we gaped them to spec. Engine hasn't ran yet though.

dillon410021

I will most likely go with the LR rings as well. How hard are they to file and gap correctly as I have no experience doing that before.

David Floyd

Not hard, buy a ring file from jegs or similar place, file a little at a time measure ring in bore repeat to correct size

dillon410021

so do you just put the ring in the cylinder and measure the gap or install it on the piston, install and check gap?
thanks

David Floyd

Ring in cylinder to measure

FRporscheman

I am the buddy

The Goetze rings were a bummer. Our engine is tolerance group 1; I wondered if they would be in spec for tol group 0, but by my math, the largest circumference difference between groups 0 and 1 is less than 0.002", and most of the gaps were about 0.022".

Thanks to kev951 for cluing me into suspecting gap problems on those rings. I was about to just assume they were good out of the box.