Piston specs - Minimum Top Land width?

[Thuppu]

What is the minimum forged piston(Alloy 2618) top land width you can use in a turbo application for 600-800hp?

Area F:

[Thuppu]

Anyone? Any thoughts?

[Billman]

have you seen this?

http://www.cft-motortec.de/kolben.php

[Thuppu]

Yes, I have sen that. Interesting comparison but it doesn't answer the question though.

[Jamo]

It's not something you normally specify with pistons, normally it's the compression height. I'd leave that calculation to the piston vendor personally.

[Thuppu]

Yes, of course. Just tinking loud if milling down a kit of pistons..?

[Jamo]

That has been done with stock pistons and used to good effect, was a popular mod in the early days but you reduce the squish this way so it's not as good as properly designed pistons.

Audiman old green S2 ran these I believe

[Thuppu]

...milling down a kit of forged pistons to fit a stroker build(like I say'd, just thinking loud here ). If used 159mm rods I could reduce the piston dome and fit perfect squish. Reduced dome would mean higher CR = good for E85. Would need to mill 3,3mm off. The squish would then be 0,8mm.

[Jamo]

Won't work with 159mm rods, compression height reduction isn't enough to bring down the CR to a sane level. If you use stock pistons in a stroker your CR is something like 10.6
I have the calculations somewhere but I know it won't work.

Stroker = custom pistons

[Thuppu]

They are not stock pistons, the dome on these pistons are -21cc, so CR is quite low with 155mm rods.

[Billman]

Sten Parner sells 158mm rods. What is zour Pin size?

[Thuppu]

22mm

Edit. 158mm SPM seems to be for 23mm pin.

[Thuppu]

Stroker = custom pistons

These are custom pistons for stroker with 155mm rods. Bought them new, never used. Calculated that the CR is quite low though, close to 8.0.

The idea was to get higher CR(close to 10 would be ok for e85) and longer rods suitable for higher rpm's. But I have no idea how thin the Top Land can be on a forged turbo piston aiming for high power..? Propably have to ask from the manufacturer.

[Billman]

22mm

Edit. 158mm SPM seems to be for 23mm pin.

Yes I got these.

[Thuppu]

The top land is 8,3mm thick on the squish area between the valve pockets, and otherwise it's 7,7mm thick. My friend here have the feeling the -3,3mm is too much to take off.