Do not purchase these pistons and connecting rods, they do not fit properly. .Wossner sold them to me as a "set" I tried to return them and they said there is not warrantable because the bearing caps had been removed, and are deemed used. How on earth are you supposed to know they dont fit properly unless you install them?? After installing two piston and rod assemblies I tried to rotate the engine over to install the final two rods only to find they hit the block. I contacted Wossner Germany directly and they weren't even aware of the issue. Which basically tells me they have never even test fitted them into a block or run them in an engine to assure they fit properly. I returned them to Wossner at their request and my expense of another $250.00. They then informed me they are not warrantable because they were "used" and are sending the rods back to me and would not give me a refund. This is why I have an issue with Wossner. PEC did not sell me the rods, Wossner did, If I purchased the rods from PEC then I would have been seeking a return refund from PEC but I didn't, I purchased them from Wossner. Total POS company in my opinion. " Wossner Research and Development" What a joke. Stand behind the products you sell under your name they are sold as a matched set. Other brands such as Supertech and ZRP, CP Carillo are all know to fit without issues.

 

Here is the Wossner Direct link proving they are sold as a matched kit, with no mention on the page that you must machine additional knotches into the bottom of the cylinder walls. The only document warning of additional machining "may" be required is in the install instructions. Buyer beware
https://www.wossnerpistons.co.uk/pro...n-rod-package/
here is their generic cover your azz pec install instructions.
https://www.wossnerpistons.co.uk/wp-...tructions2.pdf

 

With all due respect, it says right there on the product page you linked, under the listing for connecting rods:
"In order to fit this product, your engine block will require additional machining to ensure clearance."

Also, I'm not an experienced engine builder, but if I see in the instructions: "On some engines it may be necessary to machine clearance notches in the block for the connecting rod big ends." I'm budgeting for machine work to fit that product.

 

That is for the EP kit, not the Cooper S kit, the only mention that you may have to cut knotches is in the generic install guide for all ARP rods, which is like I said, a generic Cover your azz document putting all the onus on the installer in case of failure

 

You do know its the same engine block, yeah? Some of the externals are slightly different, but it's the same basic engine.