I've salvaged a 4.6 RR V8 but it turned out to have a cracked block and needing 3 replacement pistons. Repacement liner block from Turner Engineering, and I've mangaged to get 3 pistons off ebay to go with the ones I had already...

Bloody typical, they're not a 'pefect' match. Ideally as other knowledgeable people have suggested I'd be best to buy new... but I'm broke !!!

It turns out 5 pistons have D23 M6 stamped on the face, but 3 pistons are slightly different shape below the face / next to the pin; these have either Y37 M6 or Z29A M6 stamped on the face.

Dish shape and everything else is the same, so figure the CR to be equal - I suspect either a different batch or manufacturer.

Max 3g variance in weight between them all with rods, pins, and rings.

I figure if I needed to repair a piston, 1 wouldn't match, so aside from best practice, any known reason why I can't / shouldn't use these 3 ??

I really don't want to bugger up a grands worth of new block... help !??!

Thanks

Jon

I'd not risk it - buy a new set

v8tuner sells 4.6 pistons for £37 each with no rings

Sounds risky to me too. It MIGHT be alright but if it's isn't you'll feel like a right plonker.

Order 3 of the same spec as your other serviceable 5 and be skint, but be happy

find a feindly machinist / engineer or a smartarse in a shed somewhere and ask if the 3 heavier ones can be milled to the same weight as as the other 3

That's the wierd thing, they are the same weight.

The range of 1181 to 1185g is between all the different kind - even the same batch have a few gram difference ?!

I've picked up a set from eBay; so will have to wait and see of their condition. Seems to risky to chance a mix match !