9 replies to this topic

[Chappb]

Just a quick one really although it might sound like a stupid question........
do all aftermarket pistons have the standard size gudgeon pin holes? i.e would i be able to put aftermarket pistons on standard A+ rods or do i have to buy aftermarket rods too? thanks in advance.

[mini13]

most do, unless the are somthing totally different like 18mm.

std pins are 0.81"

[Guess-Works.com]

Those pistons which are designed for the mini will have the correct gudgeon pin diameter, however those pistons which are designed for other manufacturers may well have a different size...

I don't think there is a standard size..

Well, for a start the gudgeon pin for 1275s is different to those for a 998.

[Chappb]

So if i were to buy pistons with floating pins, would i be right in saying that i need rods specifically for floating pins?

[Guess-Works.com]

In general, pistons which have a floating pin will either come with a bush which will need pressing into the rod, or will need a bush making, as the pin will be smaller than the hole in the standard rod. Eg Omega pistons. This is the case for big bore engines.

Some 998 pistons and rods already use a floating pin.

[Chappb]

I've being looking at the H-Beam rods that Specialist Components do, if i got MED Omega die cast pistons with the short pins would they go straight onto the Specialist Components rods?

[mini13]

std pins are a sliding fit in the SC rods which are bushed, the omegas probably come with spirolocks for retaining the pin, in which case the two will go together ok.

[Chappb]

std pins are a sliding fit in the SC rods which are bushed, the omegas probably come with spirolocks for retaining the pin, in which case the two will go together ok.

I thought omegas had their short 'floating' pins held in the piston by two circlips?

[mini13]

basically the same thing,

[Chappb]

basically the same thing,

Righty O, thanks again guys