996TT 3.8 pistons
#16
11-28-2008, 06:46 PM
Now that is craftsmanship, clean, nice port & polish.
CP Pistons make pistons and you can get great steel liners from Neil at Performance Developments.
I have a spare set of 102 mm pistons if you are interested. I have had just about every manufacturer of 102 mm pistons made. I'm now using 105.7 mm pistons.
Also be aware that many people sell 102 mm pistons as a 3.8 displacement. They are not. With a standard crank throw that is under 3.8L displacement. They just round out to 3.8L. You can get the correct size to get a true 3.8 displacement and have your liners honed accordingly.
I have a spare set of 102 mm pistons if you are interested. I have had just about every manufacturer of 102 mm pistons made. I'm now using 105.7 mm pistons.
Also be aware that many people sell 102 mm pistons as a 3.8 displacement. They are not. With a standard crank throw that is under 3.8L displacement. They just round out to 3.8L. You can get the correct size to get a true 3.8 displacement and have your liners honed accordingly.
#17
11-28-2008, 06:55 PM
The liners are steel ....... note the thickness. They were designed for the torque this motor will be generating. Generally, there is no need for this kind of thickness.
#18
11-28-2008, 10:41 PM
Join Date: Jan 2007
Location: Los Angeles, SFV
Posts: 276
Rep Power: 36 
liners
I don't understand about the thickness, don't they have to match the factory liners to fit in the block? Thanks for the input, CJ.
#19
11-29-2008, 03:32 AM
and it is a fast car, 60-130mph in 6.2 seconds with 2 shifts at close to 1 bar only.
#20
11-29-2008, 03:43 AM
Now with 3.8Liter...Is it bigger bore or bigger stroke?
According to Todd K...Stock sleeves and rods r the weakest parts on stock engine
BTW....Any idea where the cheapest place to get OEM parts or used OEM parts in a good condition?
According to Todd K...Stock sleeves and rods r the weakest parts on stock engine
BTW....Any idea where the cheapest place to get OEM parts or used OEM parts in a good condition?
#21
11-29-2008, 08:05 AM
As additional clarification, Porsche uses nickasil piston and lines which are very
light and appropriate for certain power/force applications involving limited rod/piston ratio's. Increase these forces past a certain point and forces exerted on the liners will distort the liners causing failure.
Last edited by cjv; 11-29-2008 at 09:12 AM.
#22
11-29-2008, 08:31 AM
The stock crank is 76.4 mm. If you add 4 mm's to the throw of the crank you pick up 2L gain in displacement . The difference in the two is the torque gained with the crank option.
The sleeves and rods are one of the weakest parts on the stock engine especially when you start playing with bore and stroke. The nikasel liners are really not strong enough for these applications. That is why in ultra high turbo applications the Mahle pistons are not commonly used. In addition, they do not lend themselves to easily adapting to increasing the lift and duration of your cams due to their limited dome relief cuts.
Note: Please do not confuse what I am saying with what Jean has said regarding Mahle. Jean is talking about a track race motor designed to run many continuous hours at ten tens. To do this they lower the power to attain far greater continuous longevity. The design of the motors are vastly different. The questions is, do you want all the power you can get for bursts or two to three laps or do you want all the power you can get for endurance type competition? In the later, your power is really limited by heat sink.
When you stroke the motor you need to either shorted you rod length or lower the centerline of your piston. In either case you are changing the rod/piston angle which puts additional pressure/forces on you piston liners. Again, you must design you liners for these additional forces. Especially with the stroker modification as the torque will increase dramatically. It will also kick in at a lot lower rpm range.
In KA's motor we designed 105.7 mm buckets with a 80.5 mm crank. This was coupled with one of a kind single lobe custom designed intake and exhaust cams. We should see well over 1000 foot pounds of torque at around 1200 rwhp @ 1.3 bar. The motor internals (including the heads/gaskets/o-ringing/studs) is designed for well over 1.3 bar and with the GT42R turbo's it will be more than up to the task.
Last edited by cjv; 11-29-2008 at 09:00 AM.
#23
11-29-2008, 09:42 AM
It can be either. Most people go to the bigger bore because it is cheaper along with not having to change rod length or piston centerline. This is required due to deck height. The stock 3.6 uses 100 mm pistons. People add 2 mm to the size of the piston for approximately .2L gain. Not a full .2L gain. Rules as well as Porsche Racing have recently changed in this regard which has allowed for true 4.0L's in racing.
The stock crank is 76.4 mm. If you add 4 mm's to the throw of the crank you pick up 2L gain in displacement . The difference in the two is the torque gained with the crank option.
The sleeves and rods are one of the weakest parts on the stock engine especially when you start playing with bore and stroke. The nikasel liners are really not strong enough for these applications. That is why in ultra high turbo applications the Mahle pistons are not commonly used. In addition, they do not lend themselves to easily adapting to increasing the lift and duration of your cams due to their limited dome relief cuts.
Note: Please do not confuse what I am saying with what Jean has said regarding Mahle. Jean is talking about a track race motor designed to run many continuous hours at ten tens. To do this they lower the power to attain far greater continuous longevity. The design of the motors are vastly different. The questions is, do you want all the power you can get for bursts or two to three laps or do you want all the power you can get for endurance type competition? In the later, your power is really limited by heat sink.
When you stroke the motor you need to either shorted you rod length or lower the centerline of your piston. In either case you are changing the rod/piston angle which puts additional pressure/forces on you piston liners. Again, you must design you liners for these additional forces. Especially with the stroker modification as the torque will increase dramatically. It will also kick in at a lot lower rpm range.
In KA's motor we designed 105.7 mm buckets with a 80.5 mm crank. This was coupled with one of a kind single lobe custom designed intake and exhaust cams. We should see well over 1000 foot pounds of torque at around 1200 rwhp @ 1.3 bar. The motor internals (including the heads/gaskets/o-ringing/studs) is designed for well over 1.3 bar and with the GT42R turbo's it will be more than up to the task.
The stock crank is 76.4 mm. If you add 4 mm's to the throw of the crank you pick up 2L gain in displacement . The difference in the two is the torque gained with the crank option.
The sleeves and rods are one of the weakest parts on the stock engine especially when you start playing with bore and stroke. The nikasel liners are really not strong enough for these applications. That is why in ultra high turbo applications the Mahle pistons are not commonly used. In addition, they do not lend themselves to easily adapting to increasing the lift and duration of your cams due to their limited dome relief cuts.
Note: Please do not confuse what I am saying with what Jean has said regarding Mahle. Jean is talking about a track race motor designed to run many continuous hours at ten tens. To do this they lower the power to attain far greater continuous longevity. The design of the motors are vastly different. The questions is, do you want all the power you can get for bursts or two to three laps or do you want all the power you can get for endurance type competition? In the later, your power is really limited by heat sink.
When you stroke the motor you need to either shorted you rod length or lower the centerline of your piston. In either case you are changing the rod/piston angle which puts additional pressure/forces on you piston liners. Again, you must design you liners for these additional forces. Especially with the stroker modification as the torque will increase dramatically. It will also kick in at a lot lower rpm range.
In KA's motor we designed 105.7 mm buckets with a 80.5 mm crank. This was coupled with one of a kind single lobe custom designed intake and exhaust cams. We should see well over 1000 foot pounds of torque at around 1200 rwhp @ 1.3 bar. The motor internals (including the heads/gaskets/o-ringing/studs) is designed for well over 1.3 bar and with the GT42R turbo's it will be more than up to the task.
BTW...Who is KA's ?
#24
11-29-2008, 05:49 PM
Last edited by cjv; 11-29-2008 at 07:06 PM.
#26
02-22-2009, 09:23 AM
Here is a picture of the "perfect bore" set up per rapidtransit's post...
Pm or email me for details...
rhonda@fvd.us
__________________
FVD Brombacher - USA
Contact me directly to get the latest FVD forum member discount!
Rhonda Roxburgh
+1-954-571-2050 x 1
rhonda.roxburgh@fvd.net
Visit our online shop for an extensive selection of tuning and original parts www.fvd.net
FVD Brombacher - USA
Contact me directly to get the latest FVD forum member discount!
Rhonda Roxburgh
+1-954-571-2050 x 1
rhonda.roxburgh@fvd.net
Visit our online shop for an extensive selection of tuning and original parts www.fvd.net
#27
02-22-2009, 10:12 AM
It can be either. Most people go to the bigger bore because it is cheaper along with not having to change rod length or piston centerline. This is required due to deck height. The stock 3.6 uses 100 mm pistons. People add 2 mm to the size of the piston for approximately .2L gain. Not a full .2L gain. Rules as well as Porsche Racing have recently changed in this regard which has allowed for true 4.0L's in racing.
The stock crank is 76.4 mm. If you add 4 mm's to the throw of the crank you pick up 2L gain in displacement . The difference in the two is the torque gained with the crank option.
The sleeves and rods are one of the weakest parts on the stock engine especially when you start playing with bore and stroke. The nikasel liners are really not strong enough for these applications. That is why in ultra high turbo applications the Mahle pistons are not commonly used. In addition, they do not lend themselves to easily adapting to increasing the lift and duration of your cams due to their limited dome relief cuts.
Note: Please do not confuse what I am saying with what Jean has said regarding Mahle. Jean is talking about a track race motor designed to run many continuous hours at ten tens. To do this they lower the power to attain far greater continuous longevity. The design of the motors are vastly different. The questions is, do you want all the power you can get for bursts or two to three laps or do you want all the power you can get for endurance type competition? In the later, your power is really limited by heat sink.
When you stroke the motor you need to either shorted you rod length or lower the centerline of your piston. In either case you are changing the rod/piston angle which puts additional pressure/forces on you piston liners. Again, you must design you liners for these additional forces. Especially with the stroker modification as the torque will increase dramatically. It will also kick in at a lot lower rpm range.
In KA's motor we designed 105.7 mm buckets with a 80.5 mm crank. This was coupled with one of a kind single lobe custom designed intake and exhaust cams. We should see well over 1000 foot pounds of torque at around 1200 rwhp @ 1.3 bar. The motor internals (including the heads/gaskets/o-ringing/studs) is designed for well over 1.3 bar and with the GT42R turbo's it will be more than up to the task.
The stock crank is 76.4 mm. If you add 4 mm's to the throw of the crank you pick up 2L gain in displacement . The difference in the two is the torque gained with the crank option.
The sleeves and rods are one of the weakest parts on the stock engine especially when you start playing with bore and stroke. The nikasel liners are really not strong enough for these applications. That is why in ultra high turbo applications the Mahle pistons are not commonly used. In addition, they do not lend themselves to easily adapting to increasing the lift and duration of your cams due to their limited dome relief cuts.
Note: Please do not confuse what I am saying with what Jean has said regarding Mahle. Jean is talking about a track race motor designed to run many continuous hours at ten tens. To do this they lower the power to attain far greater continuous longevity. The design of the motors are vastly different. The questions is, do you want all the power you can get for bursts or two to three laps or do you want all the power you can get for endurance type competition? In the later, your power is really limited by heat sink.
When you stroke the motor you need to either shorted you rod length or lower the centerline of your piston. In either case you are changing the rod/piston angle which puts additional pressure/forces on you piston liners. Again, you must design you liners for these additional forces. Especially with the stroker modification as the torque will increase dramatically. It will also kick in at a lot lower rpm range.
In KA's motor we designed 105.7 mm buckets with a 80.5 mm crank. This was coupled with one of a kind single lobe custom designed intake and exhaust cams. We should see well over 1000 foot pounds of torque at around 1200 rwhp @ 1.3 bar. The motor internals (including the heads/gaskets/o-ringing/studs) is designed for well over 1.3 bar and with the GT42R turbo's it will be more than up to the task.
#28
02-22-2009, 10:34 AM
Registered User
Join Date: Jan 2006
Location: MPLS, MN USA
Age: 63
Posts: 5,710
Rep Power: 464
Ka
Killer Angel is the name of Chad's "996 Turbo project"
He has gone so deep and to such high level of specs that most
of the tuners that he has worked with have learned something from
the project. We all look forward to the car on the street!
Last edited by WOODTSTER; 02-22-2009 at 10:35 AM. Reason: spelling of angel
#30
02-22-2009, 05:40 PM
CP Pistons make pistons and you can get great steel liners from Neil at Performance Developments.
I have a spare set of 102 mm pistons if you are interested. I have had just about every manufacturer of 102 mm pistons made. I'm now using 105.7 mm pistons.
Also be aware that many people sell 102 mm pistons as a 3.8 displacement. They are not. With a standard crank throw that is under 3.8L displacement. They just round out to 3.8L. You can get the correct size to get a true 3.8 displacement and have your liners honed accordingly.
I have a spare set of 102 mm pistons if you are interested. I have had just about every manufacturer of 102 mm pistons made. I'm now using 105.7 mm pistons.
Also be aware that many people sell 102 mm pistons as a 3.8 displacement. They are not. With a standard crank throw that is under 3.8L displacement. They just round out to 3.8L. You can get the correct size to get a true 3.8 displacement and have your liners honed accordingly.