4age 18 -> 20mm piston pin

[bmak]

I'm just after some info on what people have done previously to enlarge and bush to suit a 20mm pin.

Is it OK to just use the bush that's for the later rods and still have enough rod end left?

Or should it be enlarged the bare minimum with a custom bush to suit.

And what the reliability of doing it either way? Looks like there is enough meat there to be safe.

[too_quick]

So you want smallport 20mm pin rods to go into bigport 18mm pistons ?

[bmak]

no sorry i mean a 20mm pin into the smaller bigport rod

[Munki]

I have heard of pistons being modified to suit from the 18mm bigport to 20mm fully floating pin to use the later rods/wrist pin.

[Munki]

opps im too slow

dont know if that will work the other way around...

the 20mm are floating 18mm are semi-floating. i wouldnt trust extra bushings that need to be press fitted into the piston.

[Chrisso]

PM FeralMR2 - He's got smallport pistons in his bigport (AW11). I can't find the threads, but it's not uncommon. Requires a little bit of simple machining to fit.

[oldeskewltoy]

Do you know there is a high compression piston for the "smaller"/earlier rod??

[Drifty Midship]

I have some 20mm small end bushes my engine builder did not use that I need to get rid of.

[bmak]

PM FeralMR2 - He's got smallport pistons in his bigport (AW11). I can't find the threads, but it's not uncommon. Requires a little bit of simple machining to fit.

Thanx for that but looks like he used a small port rod.

Do you know there is a high compression piston for the "smaller"/earlier rod??

Yes

I have some 20mm small end bushes my engine builder did not use that I need to get rid of.

Could you measure up the outside for me? And let me know the price