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The pistons are Mahle Motorsport, Slipper skirt with Ferroprint Iron coating, top coating from Swain.
Trying to sit here and think how many engines we've done with Duffin: Blacky, Red, JAB car - twice and the spare block that went with the track car, Rhobs, Gators, the one I sold to Greg (mntman82 ?), and Cliffs down in Corpus. I think Jim did an NA for a guy in Corpus, just assembled the short block.
When we did the three group buys of pistons a long time ago, we had 6 sets done for the 2.8L i.e. moving the wrist pin location, the rest were all 100.5 and 101mm.
Thank you, they were. Jon Milledge got four sets and got 13 hp over his regular blueprinted build. He suspected the design of the top of the piston helping the combustion and the lighter weight for rotating mass but nothing really confirmed.
My dyno of the track car motor showed a better improvement even on a bad tune, but I had the slipper skirt pistons plus the custom lightweight set of gears and pulleys; so that 8-10 hp plus the 11-13 of the pistons and the track car should put out 365-370 for Keith the new owner at 17 psi on 104 octane. It was 358/351 last motor.
I had Lindsey build be a 3 liter motor in 2011 and wasn't a happy customer at all. I had over 40% blow by and they said the same thing to me about break-in, which my mechanic, who is a 944 specialist said is pure BS. I put 1500 miles on it when the leakdown was done. OP- feel free to PM me if you want my full story. Sorry to hear you're dealing with the same stuff I dealt with.
Sorry not meaning to hijack but these Mahle pistons are slightly different than the pistons now posted on Mahle's web site Dated Novemver 4, 2014 yes? Something you mentioned once about the coating change?
Quote from their site
MAHLE Motorsports Introduces
Porsche 944/968 PowerPak Plus Pistons
"Fletcher, NC… November 4, 2014 –As the main supplier to Porsche from original equipment to their Formula 1 race efforts, it’s no wonder MAHLE Motorsports pistons are in such high demand from the discerning Porsche enthusiast. Designed to the exacting standards that Porsche owners have come to expect from MAHLE, they are triple coated first with a phosphate dry film to protect the pin bores from galling. Next, MAHLE’s proprietary anti-friction Grafal® coating is applied to the 2618 alloy slipper skirt forgings and then finally, to withstand the higher cylinder temperatures and pressures associated with a highly tuned Porsche engine, the top ring grooves are hard anodized to protect against micro-welding.
MAHLE is the world's largest piston manufacturer, and is the leading piston liaison between upper level professional racing, OE and the specialty equipment automotive aftermarket. All parts are machined to exacting tolerances on MAHLE manufactured, application specific equipment with unmatched quality and consistency. The U.S. Motorsports division operates in Fletcher, NC. For more information, contact www.mahlemotorsports.com, or call toll free: 888-255-1942"
Originally Posted by Ski
The pistons are Mahle Motorsport, Slipper skirt with Ferroprint Iron coating, top coating from Swain.
Trying to sit here and think how many engines we've done with Duffin: Blacky, Red, JAB car - twice and the spare block that went with the track car, Rhobs, Gators, the one I sold to Greg (mntman82 ?), and Cliffs down in Corpus. I think Jim did an NA for a guy in Corpus, just assembled the short block.
When we did the three group buys of pistons a long time ago, we had 6 sets done for the 2.8L i.e. moving the wrist pin location, the rest were all 100.5 and 101mm.
Motor is out of the car, all cylinders are scored it still looks like they were not impregnated properly! Can also still see some crosshatching on the cylinders. Another thing the valve stem seals are falling off not installed properly and one is actually off. The crank pulley bolt was not tightened down properly to spec you could actually turn it with a 3/8 ratchet. Another issue noticed was the extrude hone manifold it looks like when the engine hit operating temperature chemicals that used to hone the manifold actually fell out into my cylinder walls you can see on the manifold where it fell from. I will upload pictures later tonight
WTF seriously?? Do they build these motors them selfs or outsource?
Grushy: Grafal coated pistons are not for alusil. Alusil new mahles are coated with phosphate gray base coating and ferroprint skirts. (factory used older now banned coating called ferrostan)
Sunnen AN-30 paste never touched your block. I did a writeup on how I redid my block with AN-30 since I also thought my cylinders are too shiny. Not even close to yours though.. https://rennlist.com/forums/944-turb...it-look-4.html Check out the shine, left is after AN-30, right before.
Motor is out of the car, all cylinders are scored it still looks like they were not impregnated properly! Can also still see some crosshatching on the cylinders. Another thing the valve stem seals are falling off not installed properly and one is actually off. The crank pulley bolt was not tightened down properly to spec you could actually turn it with a 3/8 ratchet. Another issue noticed was the extrude hone manifold it looks like when the engine hit operating temperature chemicals that used to hone the manifold actually fell out into my cylinder walls you can see on the manifold where it fell from. I will upload pictures later tonight
The cylinders don't actually get impregnated with anything. The proper honing process just exposes the silicon already there.
Eric (URG8B8) had a similar issue with an exrude honed intake very recently...you might compare notes with him...
The cylinders don't actually get impregnated with anything. The proper honing process just exposes the silicon already there. Eric (URG8B8) had a similar issue with an exrude honed intake very recently...you might compare notes with him...
I know me and Eric talk! And was told by some reputable shops it's called impregnated!anyways you guys still know what I mean
03-14-2015, 06:56 AM
