I thought this conversation was of merit enough to mention it here as it struck me as curious. I was speaking with a parts dealer in Germany about an item they had and the subject of pistons was brought up. When I mentioned Wiseco, Ross and the like, he gasped for air due to their 'poor metal quality'. He emplored me to use a superior alternative of some sort in Europe. Correct me if I am wrong, but I thought ALCOA aluminum supplied the T2618 aluminum to these piston manufacturers all over the world unless I am missing something? Is his claim nothing more than national pride and ignorance or does it have any merit?
National pride. There are great pistons made in several countries. Mahle makes a great piston, so does Wiseco and Cosworth just to name 2.
Its my understanding that TRW makes most of the forgings that are used by piston "manufacturers" worldwide, to the extent they are all pretty much the same. I believe Mahle makes some of the "Euro brands". Wiseco makes their own forgings, and I have had very good luck with them. I am a BIG advocate of proper reverse dome shape and squish, and Wiseco has accommodated me.
I'm currently having a Porsche engine restored (here in San Diego) and, FWIW, Mahle seems to be regarded as the best in that context.
This one is easy, Mahle. They make most of the Cosworth stuff, along with supplying just about every OEM out there and participating in pretty much all racing series.
Precision machining is what I concern myself with as most manufacturers use 1 of 2 alloys. Perfectly flat ring lands are extremely important if you want excellent ring seal. 2618 is very popular for power adder applications. Mahle commonly uses 4032 which is a bit more brittle but still great for a naturally aspirated/mild power adder engine.
4032 has higher silicon content, which means lower expansion, which means you can run a tighter clearance. Anyone have piston-wall clearance specs for modern Ferrari engines? I couldn't imagine OEM's running anything other than 4032 for NVH reasons even in high-output engines.
I think the arguement is that 4032 allows for tighter clearances but is a more brittle meaning they can crack. 2618 has a bit more 'give' and expands more, thus meaning one must run looser cold clearances.
I run Borgo pistons in my 2300S which was the brand Ferrari used in the same years and was told by the engine guy that the bores needed to be tapered as these pistons expanded more due to the higher aluminium content (don't get the logic there) Anyway, the car blows minimal smoke until it is warm and then perfect, like a lot of Ferrari V12s from that era
Borgo seems to do a lot of Alfa piston sets as well and is regarded as one of the best by the alfa crowd. Ditto on the Mahle pistons - very highly regarded with the porsche crowd, particularly the air heads. Mahle has been making very good quality pistons for porsches for 40+ years. I would think that piston quality including tolerances and thermal characteristics to be particularly important in an aircooled engine so probably a pretty good endorsement.
I had a set of forged JE pistons installed in a custom engine used in my daily driver. It's been almost 2 years and no problems. I have noticed that when cold there is a bit of piston slap until they fully expand.......me thinkest forged units expand more when heated therefore need more clearance when cold. Geffen
i'm re-doing my 308 engine and went with mahle. i believe mahle is the current supplier for Ferrari. (or at least one of their piston suppliers).
forged are not for the street esp early ones, look good though. More and thicker al makes for more expansion and weight always, good for nitro though. Stick w/stock if you can. The taper theory was good for airplanes in the 40's and easy to attain w/v 12's w/sunnen equiptment but not advisable nor required. Interesting discussion on a rainy afternoon though clay
There are only 5-6 forging blanks used by moist mfgs for this purpose. What is best is a function of what it is you are trying to achieve, and at what level of the food chain... OEM, new product ultra refined with warranties of 5yrs and 50k miles will be a different set of requirements for the engineering dept. than repop hot rod, limited production, "used for track only" parts..... So, what are YOU asking is at the best a non starter, as the answer for MB, Ferrari, BMW will be different that what I will ask JE when I have pistons made for our LM, or RS60 projects...additional factors will be flow bench and cam harmonics changes if other valvetrain items have been changed(8mm valve stems now 5-6mm)...it is a more complicated answer than one miught think... In general, I would agree with past poster CLAY DINO's opoinons.. ...
I just ordered JE pistons for my 400/TR engine (still talkign about the various options) and also just ordered 5mm stem valves (34mm,28.5mm heads) along with shim under stuff ot mauch the crazy big cams. BTW, JE says they have over 130 forgings to pick from.
I am working with John at omni-tech who does cosworth in Seattle and is building a set of CP pistons for my Lotus turbo project. http://www.cppistons.com/ anyone else used these guys?
Those are the pistons I prefer. Used them in my TT Z06 build (now sold) and previous TT SS build. A little pricey but an exceptionally nice piece.
FWIW, maybe a teeny bit off-topic, but does anyone remember the great steel strike of, was it 1985, 1986? IIRC a lot of F1 motor builders had big problems because they could not find decent pistons because the steel that was turned out specific for this was substandard, pistons failed all over, and they had to use older pistons or import pistons ???? I think it about killed Brian Hart and a few others. Anyone remember that?
I have use Wiseco for years. I find the service end is far better than any others I have tried. JE, Mahle, & Wiseco, all good stuff. FWIW by far Ferrea is the best valve company to deal with also.