[Z06] Z06 Pistons....
10-19-2005, 11:52 AM
#4
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Because they are cast rather than forged. Not really a weak link on a street driven car but you may need to upgrade them for competition, or forced induction and/or NOS.
It seems silly they would be cast rather than forged in an engine that has such things as a forged Crank, and forged & heat treated Titanium Rods. However, my understanding, was that these were used instead of forged to save some weight and to eliminate cold start piston slap.
A good upgrade might be forged slugs with coated Titanium wrist pins (as used in NASCAR) to keep the weight down.
I wonder if the Performance Build Center would allow you to substitute those in during the build process. NOT!
It will be interesting to see IF the Blue Devil is ever produced with the rumored SC engine if they use forged pistons then.
It seems silly they would be cast rather than forged in an engine that has such things as a forged Crank, and forged & heat treated Titanium Rods. However, my understanding, was that these were used instead of forged to save some weight and to eliminate cold start piston slap.
A good upgrade might be forged slugs with coated Titanium wrist pins (as used in NASCAR) to keep the weight down.
I wonder if the Performance Build Center would allow you to substitute those in during the build process. NOT!
It will be interesting to see IF the Blue Devil is ever produced with the rumored SC engine if they use forged pistons then.
Last edited by DJWorm; 10-19-2005 at 11:55 AM.
10-19-2005, 07:47 PM
#5
Team Owner
Originally Posted by c5_from_jc
The weak link????? WHY???
$$$$$$$$$$$$ they build it to their spec not a tuner spec for SC and the like.
10-19-2005, 11:26 PM
#6
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St. Jude Donor '12-'13-'14-'15, '19
The pistons are made in Germany by Mahle, and are supposed to be up to the task or they wouldn't be there. Casting allows better geometry than a forged set can offer.
(paraphrased from a DH response)
(paraphrased from a DH response)
10-19-2005, 11:49 PM
#7
Team Owner
Cast pistons are quiet. Forged tend to suffer piston slap on cold start which is noisy. Judging from those bitching about noisy transmissions, they made the right choice. 
10-19-2005, 11:59 PM
#8
Burning Brakes
Forged slugs would be better from a strictly performance standpoint, but Mahle has been making cast pistons for BMWs for many years and I've never heard of failures. Maybe Chevy's saving forged ones as an upgrade in a couple of years, when it goes up to 550(?) HP 
10-20-2005, 12:31 AM
#9
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Cast pistons have better thermal control because they can have steel inserts and other thermal expansion control devices. For those that want NOx, oh well, that is your problem. If I was chief engineer on this motor program, I would never consider NOx a design requirement. This is not a drag race car, never will be, so who cares about how well it holds up with the automotive equivalant of steroids.
10-20-2005, 12:37 AM
#10
Le Mans Master
Originally Posted by ghoffman
Cast pistons have better thermal control because they can have steel inserts and other thermal expansion control devices. For those that want NOx, oh well, that is your problem. If I was chief engineer on this motor program, I would never consider NOx a design requirement. This is not a drag race car, never will be, so who cares about how well it holds up with the automotive equivalant of steroids.
10-20-2005, 01:32 AM
#11
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Originally Posted by ghoffman
Cast pistons have better thermal control because they can have steel inserts and other thermal expansion control devices. For those that want NOx, oh well, that is your problem. If I was chief engineer on this motor program, I would never consider NOx a design requirement. This is not a drag race car, never will be, so who cares about how well it holds up with the automotive equivalant of steroids.
10-20-2005, 04:36 PM
#12
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St. Jude Donor '09
Originally Posted by DJWorm
Because they are cast rather than forged. Not really a weak link on a street driven car but you may need to upgrade them for competition, or forced induction and/or NOS.
It seems silly they would be cast rather than forged in an engine that has such things as a forged Crank, and forged & heat treated Titanium Rods. However, my understanding, was that these were used instead of forged to save some weight and to eliminate cold start piston slap.
A good upgrade might be forged slugs with coated Titanium wrist pins (as used in NASCAR) to keep the weight down.
I wonder if the Performance Build Center would allow you to substitute those in during the build process. NOT!
It will be interesting to see IF the Blue Devil is ever produced with the rumored SC engine if they use forged pistons then.
It seems silly they would be cast rather than forged in an engine that has such things as a forged Crank, and forged & heat treated Titanium Rods. However, my understanding, was that these were used instead of forged to save some weight and to eliminate cold start piston slap.
A good upgrade might be forged slugs with coated Titanium wrist pins (as used in NASCAR) to keep the weight down.
I wonder if the Performance Build Center would allow you to substitute those in during the build process. NOT!
It will be interesting to see IF the Blue Devil is ever produced with the rumored SC engine if they use forged pistons then.
All really neat stuff, if you stick with street use as DJ has stated. Once you go with forced induction, forged 2618T6 Pistons are the ONLY way to go. They'll take 40 PSI boost no problem.
Jim
Last edited by Halltech; 10-21-2005 at 06:02 AM.
