I'm looking to upgrade with higher strength Millenia rods and lower compression pistons to allow more boost. Wiseco forged pistons are a good option, lots of great info already posted on Vitera pistons as a low cost option with somewhere around 8:1 comp. This little exercise is looking at readily available B20 pistons.
Others have pointed out that the B20 piston has the correct pin diameter for the Millenia rods, and I think there are members who have done this swap for NA. I have a question on the use of B20 pistons turbo pistons with Millenia Rods for a low compression setup. Pricier than the Vitera pistons, but perhaps less than custom pistons and may be available off-the-shelf.
The B20 pistons for this example - although there are several suppliers - are the Manley Platinum Series, forged 2618 alloy, with floating pins, a 11.9 cc dish, and 84.5 mm. The B20 pistons have a compression height of 30 mm (1.181") vs. stock KLDE pistons with a compression height of 29 mm (1.142") (or 28.75mm in some references, verification here would be great!!).
The Millenia rod specs I have pulled from old threads is 5.4' length, 21mm small ends, full-floating, versus 5.427-inch and 20mm for stock.
The deck height with stock KLDE rods and pistons is 0.013" (I think, not verified from a shop manual reference). Add 0.027" for the Millenia rods (5.427 - 5.4), then subtract 0.039" for the difference between the compression height of the B20 and KLDE pistons (1.181"-1.142") and the remaining deck height above the piston top is 0.001", or diddly squat.
KL03 head chamber volume is 39cc, stroke is 2.921". Compressed head gasket is 0.026". Plugging the all info for the KLDE/Millenia Rod/Manley B20 turbo piston into the Summit Racing compression calculator tool,
http://www.summitracing.com/expertad...ion-calculator
comes up with a grand total of 8.6:1 compression ratio, or a nice happy number for a turbo while not killing it when not on boost. For comparison, STIs run 8.2, Evos 8.8.
Putting it out there to see what the issues may and see if anyone else has taken this to the next step.
I will get the ball rolling with some of the obvious stuff:
- may create interference engine, valve relief for a B20 may be all wrong for a KL
- the 0.001" piston clearance from the deck seems sketchy.
- The connecting rod/KLDE piston compression height/deck height numbers above may be off
- the piston wrist pin offsets may be wrong
Thanks!
Others have pointed out that the B20 piston has the correct pin diameter for the Millenia rods, and I think there are members who have done this swap for NA. I have a question on the use of B20 pistons turbo pistons with Millenia Rods for a low compression setup. Pricier than the Vitera pistons, but perhaps less than custom pistons and may be available off-the-shelf.
The B20 pistons for this example - although there are several suppliers - are the Manley Platinum Series, forged 2618 alloy, with floating pins, a 11.9 cc dish, and 84.5 mm. The B20 pistons have a compression height of 30 mm (1.181") vs. stock KLDE pistons with a compression height of 29 mm (1.142") (or 28.75mm in some references, verification here would be great!!).
The Millenia rod specs I have pulled from old threads is 5.4' length, 21mm small ends, full-floating, versus 5.427-inch and 20mm for stock.
The deck height with stock KLDE rods and pistons is 0.013" (I think, not verified from a shop manual reference). Add 0.027" for the Millenia rods (5.427 - 5.4), then subtract 0.039" for the difference between the compression height of the B20 and KLDE pistons (1.181"-1.142") and the remaining deck height above the piston top is 0.001", or diddly squat.
KL03 head chamber volume is 39cc, stroke is 2.921". Compressed head gasket is 0.026". Plugging the all info for the KLDE/Millenia Rod/Manley B20 turbo piston into the Summit Racing compression calculator tool,
http://www.summitracing.com/expertad...ion-calculator
comes up with a grand total of 8.6:1 compression ratio, or a nice happy number for a turbo while not killing it when not on boost. For comparison, STIs run 8.2, Evos 8.8.
Putting it out there to see what the issues may and see if anyone else has taken this to the next step.
I will get the ball rolling with some of the obvious stuff:
- may create interference engine, valve relief for a B20 may be all wrong for a KL
- the 0.001" piston clearance from the deck seems sketchy.
- The connecting rod/KLDE piston compression height/deck height numbers above may be off
- the piston wrist pin offsets may be wrong
Thanks!
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