Herman A

Are there any AluSil/Silumal cylinder liner castings available on the market with larger dimensions than the MSI/KS 84x106x160 mm liners? If not; can the same material be bougt somewhere as rods with larger OD than 106 mm?

slate blue

What do you want to do? I can't see any purpose, can you expand a little and maybe there is something that can be achieved. If it is about liners, you wouldn't bother trying to replace the alusil, if you wanted to go an alloy liner route you would just Nicasil them and save yourself some grief.

Greg

Herman A

Big bore blocks need big diameter liners and AluSil is superior to almost all other materials and cylinder surfaces used today. A well treated Porsche V8 has low oil consumption small blow-by after many 100.000 of km's and that can not be acheived with anything else than low friction between cylinders, rings and pistons. AluSil is not a surface treatment to be replaced but the liners are solid AluSil. However, the finishing an AluSil bore is somewhat more complicated than finishing a cast iron bore. Furthermore alu pistons and alu liners is the optimal combination from thermal point-of-view, e g clearance can be kept small.

Vilhuer

How you plan on installing them? Still leave original tower intact or remove it completely? I think you can't go much bigger than 106mm if you keep original tower or there wouldn't be enough block left to keep liner in place.

If you plan on removing towers and adding wet alusil liners then it could be possible to get couple of worn 944 S2 blocks and make liners from their towers.

James Bailey

NOPE .... since the block has no "removable liners" they are not made as replacements. And the few who have machined out the cylinders have opted to use steel liners so they can buy pistons at a reasonable price. Far easier to get displacement with stroke.

Herman A

Old liners which form parts of the block need to be removed by machining. Bottom seats for new liners need also to be machined and possibly also the block at the head plane. If the later will be nescessary depends on the selected bore size and if there need to be additional supports of the liners at this interface.

A long stroke crank will be nescessary to build the largest possible volume engine. If large enough diameter Alusil liner material can be obtained, the bore can be sized to use remachined stock pistons (possibly) which then require Ferrostan or similar coating. Otherwise custom made pistons are not too expensive.

Steel liners is certainly an option. Without having made a detailed survey, there are likely plenty of standard items which can be remachined to fit and pistons without coating can then be used. New liners can also be machined from a proper steel but the advantage with low friction and small piston clearance can in this case not be obtained.

Vilhuer

Its unlikely correct Alusil material exists in kind of shape which can be used to make towers from scratch. Only 944 S2 and 968 blocks have enough wide cylinder towers for much beyond 104mm bore and even they are limited to something like 106-107mm.