Mahle Pistons aren't forged....fact or fiction

Stanley I guess the reward is in the doing of it

4,523 posts · joined Mar 2003 · 8 Oct 2010, 11:15 am

#806545

I'm in the process of trying to locate 87mm forged pitons.
I've been looking at Nissan SR20 pistons which as luck would have it come in 87mm (1mm oversize from STD) and also have a 22mm gudgeon. Still haven't looked into deck height etc.
However these are expensive around $750 for a set (piston only).

Anyway due to the cost I thought I’d just look at Mahle forged pistons and while a lot of US sites give different part numbers for cast and forged one website I visited had this statement. Not sure if it's applicable to all sizes though.

Mahle / Cima pistons and cylinders kits have been the #1 builder’s choice for years. Made in Brazil by Mahle of Germany, these kits come with "So called Forged" pistons and extra thick cylinders for superior strength. Designed to perform even under the extreme pressures of Nitrous and turbo charging. all sets include pistons rings - piston pins and retaining clips.

Fact or fiction?

Additionally, I stumbled across another forum in the UK which said Mahle stopped making 87mm and 88mm forged pistons some years ago.

Cheers

Stanley

Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 · 8 Oct 2010, 11:46 am

#806547

I know I had a set of forged Mahle on my 1640 in the late 80's..............but I think they stopped making them.

I will speak with Pobjoy and see if he has any for you/or knows if the are still available.

HotRodMatt If it\'s old or rare - cut it!

3,616 posts · joined Sep 2002 · 8 Oct 2010, 2:38 pm

#806576

After Lowbug broke a Mahle piston a few years ago we looked at the metal and it certainly didn't looked forged. I took the metal to a metallurgist who examined the metal who confirmed that they are simply what he called "pressure cast". IE cast then rammed at the top while solidifying.

hellbugged 48's and straight cuts

5,080 posts · joined Apr 2003 · 8 Oct 2010, 3:25 pm

#806587

Nick and Dave discussed this in a thread not too long ago. I will look for it when not on the mobile

Stanley I guess the reward is in the doing of it

4,523 posts · joined Mar 2003 · 8 Oct 2010, 6:14 pm

#806607

Thanks Craig

I think the price says it all. Forging is actually a relitively expensive process when it comes to pistons because of the huge pressures involved and the resultant wear and tear on forging dies. A set of Mahle "forged" pistons and barrels is aroud $300 where as pretty much any forged piston only, from JE or Wiseco etc is around $150+ each.

I know there was a mob at the Jamboree who custom make pistons using forgings and CNC machine the piston to a spec for somewhere in between. Might look at this option.

bajachris88 The international telephone dialing code for Antarctica is 6

6,661 posts · joined Apr 2005 · 8 Oct 2010, 7:16 pm

#806618

a random old hotrodder said that back in the day you could go to repco or sumfin and they would have a listing of all the pistons available from a supplier without any brand labels, and you just pick based on a specific dimension your after etc, amount of rings and what other specs you can think of, pick one from the list then choose a conrod to suit.

Dunno if its tru though, he could have been crazy... customer's at pool shops sometimes come across as 'off with the fairies'...

No harm asking around though.

(ô_!_/ô) (ô_!_/ô)
69' baja: kombi box, thing spindles, irs, disc front, type 3 rear drums, 2 inch lift kit, 31x10 rears. 👍
New engine in process: 94mm p&bs, 74mm C/w chomol Crank, 35.5x39 SP heads, turbo. Wierd combo, hopeful torque monsta!

Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 · 8 Oct 2010, 7:19 pm

#806620

they probably aren't true "forged pistons" but Stan uses Mahle pistons in his supercharged 1916 running well over 300hp and very high boost.....no probs 👍

Stans supercharged VW 1600 drag bike and Suzuki Drag bike didn't have forged pistons..........with no failures. You probably suffered a lean out.

Stanley I guess the reward is in the doing of it

4,523 posts · joined Mar 2003 · 8 Oct 2010, 7:43 pm

#806630

Might still be a fuel issue then. All seemed ok until I upped the boost.

Mind you I haven't touched it since last weekend. I'll pull the plugs and do a comp check tomorrow.

Might even pull the engine while the rains set in. I can watch bathurst in the shed.