Marcelo Rattin

Hello how are you? I need a change of sleeves and pistons a Porsche 944 turbo 1986. The problem is that I see that the sleeves (Darton) are for sale is for measures from 101.6 to 106 and the pistons of Porsche 944 turbo measure 100 or 100.5 (Wossner pistons) . Would they work? I appreciate if you can explain me. Sorry for my english lol

rlm328

There are 2 different sleeves you can get the 2.5 liter is 101.6 mm to 104 mm and one for the 3 liter 101.6 mm to 106 mm. The sleeve comes with a bore of 3.985 in or 101.2 mm, the standard 2.5 liter bore is 100 mm. Darton sends the liners to fit US piston sized bores, i.e. inches. You may as well go with a larger piston and get more displacement. You will need a competent machine shop to install the sleeves and they will bore the sleeves to match your pistons. You will need to contact the piston maker and tell him your bore size and material it is made of so that they can recommend the proper gap between the piston and the piston cylinder wall.

Marcelo Rattin

Thanks for the explanation. Do you know where I can buy 101 mm pistons?

Marcelo Rattin

101 or bigger...

rlm328

Any of the piston manufacturers, JE, Mahle Arias, Wossner. Any of them can make you a piston just contact them with what you want.

Marcelo Rattin

The thing is that i only found 100.5 or 101 mm... I do not understand why is it to hard to find pistons that work propertly with the sleeves sold in the market...

steven74

When the sleeves are installed, the stock pistons will no longer be suitable as the sleeves are usually a ductile iron whereas the factory pistons and their common over sizes of 100.5 and 101 mm are designed to be used with the factory alusil bores and they often contain an iron or similar coating on the pistons for use with the alusil bores. Once the sleeves are installed, you will not need nor be able to use the factory style pistons and must buy a suitable piston for use in an iron sleeved bore. As Bob suggested, there are many piston manufactures to choose from. I have a sleeved block and run a 4.030 inch small block chevy application piston in the block, which roughly comes out to a little over 102 mm. I hope this clarifies the piston and sleeve choices.

Steven

MAGK944

If you want to fit the Darton, or any other ductile iron sleeves, you will have to use aftermarket pistons. Question is why do you specifically want the Darton sleeves? Iirc there are other sleeves that allow you to use the stock 100mm pistons.