Tippy

Connecting Rods Forged (nice)
Crank Forged (nice)
Pistons Cast (WTF) with "Graphal" coating to eliminate piston slap (noise)
Cams Hollow (nice)
Cylinder Walls Lokasil coated not nikasil like the GT3 (oh well)
Mass Air Meter Hot Film not hot wire as I thought (now I know)
Crankcase Has seperate Main Bearing support (I guess for strength)

Stupid $69k+ car has cast pistons, a 1986 mustang even had fored pistons!
Oh well, wouldnt trade for the world, unless turbo or GT3!

GT3 gets forged TITANIUM rods


Info from the shop repair manual under general

99firehawk

yeah but the pistons hold up just fine I Have neevr seen a piston fail on a 996/986 even on cars that huff more nitours then a raver

10 GT3

Well, you need to get out of 1986. How impressive is a 4.9l V8 that puts out (please nobody laugh) 200hp today? Technology progresses. Just because a piston is cast does not mean is weaker or any less tolerant of heat than a comparable forged piston. Did you know that all the GT Mustangs built since 1992 (93 model year on) have cast pistons? Even the high compression DOHC Cobras came with cast pistons. Ford only uses forged piston in forced induction engines today.

How about those MKIV Supra Turbos? Their short blocks are know for their strength. With a big turbo and fuel upgrades, there are hundreds of these cars pushing 600-1000 hp realiably without ever removing the head or touching the shortblock with only 3.0L of displacement. They have a strong cast iron block, a forged steel crank, forged rods and cast pistons. These pistons have repetitively tolerated 30 psi of boost and lived another day.

Castings have changed by improving the alloys used. Alloys with high silicon content provide excellent heat and expansion characteristics, so I would not complain about having cast pistons.

Tippy

Now that is funny

I have busted a many of pistons in other cars (dont worry people not a 996) that were cast due to supercharging. I had one motor lose every skirt off the pistons. I guess if Nitrous wont toast them (996), super/turbocharging should be easier on them.

99firehawk

should be but its all in the tune with fi, wet kits on p-cars work real well. Its never the rotoating assy that fails on pcars its usally valve train or fixed part failure

Tippy

Uh...umm...I am not a Engineer but that statement, I believe is false. Compressed billets of aluminum (forged) are stronger than cast aluminum, probably no matter what alloy you mix with the cast aluminum unless it is a heavier metal which you cant use for weight purposes.

And your point about Ford only using forged pistons on forced induction, that is my point, I want to put a super/turbocharger on my car someday. Yes I did know about the cast pistons in the Cobras and Mustangs, I lived around those cars.

I called the 996 stupid as a joke

ebaker

Mahle makes excellent cast pistons. The casting has some advantages in that you can form more complex shapes such as strengthing ribs on the skirts.

Tippy

Could'nt a 5-axis milling machine make a complex as you needed shape, especially for strengthening ribs on skirts?

I am just saying, take the most powerful internal combustion engine in the world; a top fuel dragster, they make over 8000 hp. There is no way a cast piston could withstand the pressure of the engine, hell, the engines melt pistons and rings almost every run anyways.

Anyways, the point of my thread was to inform people of what I think is cool technology in our engines but was disappointed by the fact we have cast pistons, I believe the GT3 and Turbos do though.

I got attacked for living in the '80s

fast1

I got attacked for living in the '80s

If you go up to a mother and tell her that her son is deficient in some way, don't be surprised if you walk away with a black eye. The same applies here. You just got your figurative black eye.

Adrian

http://www.mahle.com/C125705E004FDAF...LLL7P769STULEN
Ciao,
Adrian.

99firehawk

the cast pistons hold up for the life of the vechicle i have never seen or heard of an issue, you really cant expect the manufacturer to add cost to a product becasue oif what someone in the future may want to do with it

fast1

This is from the link referenced by Adrian.

Forged piston

Forged pistons for high loads
What has long been common in motor racing is increasingly being used in series-produced engines subject to high stresses: forged pistons. These have a finer micro structure than cast pistons with the same alloys. The production process results in greater stability in the lower temperature range. A further advantage is the opportunity for producing lower wall thicknesses – and hence reducing the weight. Boring or milling internal areas of the piston also helps reduce the weight.

Benjamin Choi

bud, i wouldn't even begin to go the route of comparing the carrera engine to a GT1 series engine. it'll humble your ride.