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Maybe it's time to start looking for 968 pistons. Just saying.
Cheers
That's always an alternative, which we do. And amazingly, 968 pistons have gone down in price, instead of going up! (If a mistake on Porsche's part, they will certainly correct it, at the next monthly price increase.)
Requires a custom rod and some work to be able to use 968 head gaskets. (Or use Cometic....GFL with that!)
And someone who really understands how to deal with Alusil and can hold some seriously close tolerances. (Piston to wall clearance is .0007" and the current supply of 968 pistons are "fingerprints"...no two are the same! We end up measuring and fitting each piston to each bore.)
Once you go to all that trouble, might as well use one of our custom cranks (or a heavier "stockish" GTS crank) and make it a 5.8. (This requires a different custom rod, but you are already buying custom rods for the 968 pistons and the stock crank, anyway.)
Add in some GT cams, a 4R intake manifold, match port the early heads, and you've got something very, very special!
.....Guarantee that the GTS engine will sit in the corner, only going back into the car if someone wants the original serial number engine.
First off, I am very appreciative of all of your constructive dialog and recommendations. Thank You.
At the moment, I think it is best if I can find an oversized piston. I'll post a WTB thread to the wider RL to see if any parts hoarders are willing to sell one. It sounds unlikely, but it's worth a try at least.
The 968-piston route described above is likely more than I want to invest in this S4 engine. It was intended to be a stock motor to serve as a learning exercise, which it already has. I still have an early GTS motor that will need Head Gaskets, Drilled Pistons, 2R Rods, and all the stuff you replace while in that deep. That is where I would prioritize my investment.
I am curious if there are other solution routes I should consider. Are there existing aftermarket or custom piston solutions available?
Freisinger has no pistons but a new crankcase with pistons for 6.800,00 € plus VAT
92810190709 is the Nr. of the part
Hello
Unfortunately we can not help with oversize pistons.
However, we would have a factory new crankcase with piston 92810190709 at
euro 6800,00
Price plus 19% vat
Freisinger has no pistons but a new crankcase with pistons for 6.800,00 € plus VAT
92810190709 is the Nr. of the part
Hello
Unfortunately we can not help with oversize pistons.
However, we would have a factory new crankcase with piston 92810190709 at
euro 6800,00
Price plus 19% vat
It is interesting that the m28.21/22 engines are to be found for 2,000 + euros less.
It looks like Freisinger has a 917 motor available, so maybe you'd want to consider that. These 928 motor parts are expensive, so I'm sure it's not too much more.
(admittedly, I went to the Freisinger website to try and be helpful, and came away with that nonsense, above. Apologies)
I find it very frustrating that one can buy, from Porsche, virtually every single part (many of them "recreated" parts) to rebuild a 951 engine/vehicle, yet can not buy oversize pistons for a S4 or a GTS.
And oversize pistons are just one example of what is not available for our 928's;
very basic, yet very important manual transmission pieces are not being remade, just no longer available.
Last month, Mary (wife) finally was able to find an eighth set of standard size GTS piston rings, after a two month search!
Unfortunately, it's fairly obvious that Porsche doesn't give a **** about keeping 928's on the road, which are, without any doubt, one of the very best cars they have ever made
First off, I am very appreciative of all of your constructive dialog and recommendations. Thank You.
At the moment, I think it is best if I can find an oversized piston. I'll post a WTB thread to the wider RL to see if any parts hoarders are willing to sell one. It sounds unlikely, but it's worth a try at least.
The 968-piston route described above is likely more than I want to invest in this S4 engine. It was intended to be a stock motor to serve as a learning exercise, which it already has. I still have an early GTS motor that will need Head Gaskets, Drilled Pistons, 2R Rods, and all the stuff you replace while in that deep. That is where I would prioritize my investment.
I am curious if there are other solution routes I should consider. Are there existing aftermarket or custom piston solutions available?
There are alternatives but none of them will be less expensive than waiting for an oversized piston.
You're kind of at a standstill.
I found a set of iron sleeves for a couple of 5.0 blocks I have. That opens up a lot possibilities. But, not cheaper than waiting. I'm lucky I have a couple of shops nearby that have the experience and CNC machines to sleeve my blocks.
I just can't pay them enough to change over their sunnen machines from steel to alusil.
Not directly related to the topic and I hope of being excused by the OP, but Karsten, you are well informed on parts and services suppliiers in Germany and Europe in general. There are quite a few members from Europe for whom purchasing from the excellent sources in the U.S. is, er, “challenging”. Maybe you should start a thread on this.
09-20-2023 | 07:11 PM
