YOREVOL

engine for sale on ebay, seller states that by fitting 2.9 pistons the compression has been lowered. apparently 2.9 pistons sit 1mm lower.
can anyone confirm this.

tabetha

If you're referring to a 2.8 cologne being fitted with 2.9 pistons, pretty sure they can't, but not 100%.
tabetha

pabloXR

The 2.9 pistons do fit in the 2.8 block. It's my engine....Everyone said they dont fit but if you look in the haynes manuel you will see that the bores are the same size the difference is in the stroke. The 2.9 pistons have a far deeper bowl that the 2.8 which helped to lower the compression.

I even have a build thread on it for when we bought the 2.9 engine and swapped out the pistons.

pabloXR

This is the 2.9 block we bought



2.9 pistons fitted in 2.8 block



Original 2.8 pistons

tabetha

As I said not 100% sure, the reason for that is I think the best thing to do with any 2.8/2.9 is weigh them in.
tabetha

pabloXR

Uhhh.....can't argue with that, although I found that the blocks make good anchors for ships Oh and the heads weigh 4 stone a pair

MrEngineerdat

can the 2.8 pistons be used in the 2.9 for high compression n/a?
or will the valves clash?