Black Arrow

Thats a nice link!
I`ll send him a email and ask if he got the 104mm turbo pistons!

btw, I`ve already sent a email to mahle regarding 104mm pistons, havent got any response from them yet.

Does Performance Developments got any homepage?

Ski

I've been in contact with Mahle North America. They have all the drawings, they could tool up to do a run, they would coat them with the Ferro Print Iron coating, standard and up to 2 oversizes - but they will only sell to them a vendor and not an individual. The ferro print coating is more of an environmental friendly process than the old process, ferroxxxxx - sorry can't remember what it's called at the moment, but the waste water from that early process does not meet standards of today. The ferro print process is used in the Cayenne I know, not sure what others.

Lets call Heritage and express interest is certian sets, maybe they will see the interest and get some sets.

Konstantin

here some infos

Konstantin,

These pistons are made from Mahle Racing Forging we developed with Mahle, we have only stock on 104.5mm bore. We have discuss the possibility of making a production of 104.0mm bore 16v turbo pistons, but currently we have no plan on going forward. Since most used 968 engine block at 104.00mm bore in road cars have taper and worn cylinder; installing a new piston into a unmachined engine is not a good idea. In addition, 104.00mm block from Porsche have several tolerance group according to final hone measurements, therefore, even 104.00mm pistons will not fit all 104.00mm engine block with different tolerance groups.
$2200/set of piston including high strength pins and rings, price reflects low production volumes. $400 to bore and hone your engine block to fit pistons. We must have your main-halves, Headgasket to be used, head studs to be used, all balance shaft covers....
FYI, we also have in stock the following:
Mahle 944 hi compression pistons 10.2:1 pistons 100.5mm 101mm
Mahle 944 conversion 2.5L to 2.8L NA piston 100.5mm
Mahle 951 8.75:1 2.5 to 2.8L turbo pistons 100.5mm (require 3.0L crank)
Mahle 951 8.0:1 2.5to 2.8L 100.5mm (coated) (require 3.0L crank)
Mahle 951 8.75:1 2.5L 100.5, 101mm pistons (require 3.0L crank)
Mahle 944S 2.5L 16v piston 100.5mm
Mahle 944 S2NA 104mm
HMR Custom 944 NA 100.00mm must sleeve block
HMR Custom 951 (any compression (from 7.5:1 to 9.0:1,turbo 100.00mm must sleeve block
HMR custom 951/968 3.0L 104+mm any compression 8v or 16v in a 2.5L block, sleeve required.
All above pistons in stock, custom piston machining available for valve pocket relief (additional cost)

Konstantin

you guys talk about FERROSTAN coating

for 2200 I can provide almost every piston you want This is from Mahle R&D in Germany
the original 968 Turbo s one cost 750 EUR each (about 850 US$)
They run in Nikasil and not alusil. I can coat the steel liners with Nihasil if you want. This si waht most F1 teams use today. Mahle Pistons on Nikasil liners.
Ther eis only one option which is even better but more expensive.
I plan to make a 16V Turbo engine with this new option tha usually is offered only to F1 teams
20 times less friction than what is common today.



Konstantin

Tom M'Guinn

This is exactly why I bought 104.5 Mahles from Andial. The chances of getting the piston to wall clearance correct without machining seemed remote, especially with a used block. Unless you want 16v pistons, as far as I know, Andial is still selling 104.5 8v turbo pistons from Mahle (with ferroprint, etc.), so no need for a special run unless you want 16v pistons or a different size.

Now, if we wanted to go for a run of 100.5 turbo pistons from Mahle, that could get interesting if we could get the cost down to something reasonable... Think of all the motors that could use one-over Mahle pistons...

Zero10

I think that's me we are talking about.
I have no other reason for the galling. I still have not found the cause. My best guess at this point is that the piston skirt coating was too thin at that spot.
What's weird, is that I as well had 142psi compression on all 4, and less than 2% leakdown, and yet part of the piston was being ground away onto the cylinder wall.

The information in this thread is most helpful! It would be nice to see some 104.5mm turbo pistons 16V or 8V, either would be fine. What is more important is that they need to work with the stock alusil bores.

Tom M'Guinn

Do you know what your piston to wall clearance was/is?

Konstantin

I can get you Mahle sleeves which you can use with the stock 100 mm 951 Pistons.
no need for oversize pistons

Konstantin

Ski

Konstantin, what is the price of those? Do these come with the machining tolerances needed?

Zero10

Tom, I don't know off hand, but my shop assured me that they were exactly to spec in that regard.
It was only 1 piston, the machines all should have been set the same for each cylinder, so if it was piston-wall clearance, I should see this on all 4, shouldn't I?

Ski

you always double check the pistons, machine each bore to the perspective piston, label the pistons to the bore. .001 should have been the tolerance but that should have been based on the measurement of each piston, which should have been underneath or measured 5mm above the bottom of the skirt.