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As was described in another thread https://rennlist.com/forums/928-foru...-1993-gts.html I have started the tear down of the 93 GTS engine due to a heavy oil consumption of about 1 quart per 100 miles. Pete DeJong is doing most of the work at his place in South Carolina so Kevin Berez and I visited Pete today to take a look at the engine and discuss next steps. When Pete split the block and removed the crankshaft to get a look at things we saw below picture. As this is my first GTS engine, my question is: Has this engine been sleeved or is this normal in a GTS block? We did check with a magnet and they aren't steel. The sleeve is about 2.5mm thick and the car had stock 100mm pistons. Sleeved or normal GTS?
Back in the day when no one knew why the GTS's burned what we consider normal, it was thought that the rings & cylinder walls were not compatible. Several local shops were known to sleeve the blocks in attempts to cure but failed to notice that the piston oil drain back holes were not drilled through or were willing to experiment with them to solve the problem 1st. Ali Kilinc of German Precision Motors in Dallas showed me the 1st GTS he solved the oil issue back in 1996 and his knowledge and my exposure to 928's spurred me to start my search for a 928, and also got involved with German Precision Motors in 1998.
A little more information. I had received a stack of invoices from Reeves Porsche when I bought the car so sent through them all last night. One dated July 2001 mentions TBF and engine work authorized by PCNA under warranty. The particular line item of interest is part #928-101-907-KX, PET shows 928-101-907-08 as new crankcase with pistons, not sure what the KX means unless it is a sleeved crankcase. It also got a new crankshaft and rods per the invoice. I will post copies when I get home this afternoon.
928 101 907 KX is the part # for an exchange crankcase with pistons for GTS, in the exchange (ATK) section of PET. Note there are 2 exchange part numbers, FX and KX, the former for a 92810190708 crankcase, and KX for 92810190708/11 crankcase. I don't know what the difference is.
It was me who first discovered these linered GTS engines on Rennlist by virtue of having the last ever factory supplied complete warranty replacement GTS 5-spd engine in my car. Look tor the posts and you will also see the Porsche supplied experimental pistons, which look a lot more like a 968 piston rather than a 928 GTS piston. The oil return holes were drilled, but only 2 out of four on each side.
Kolbenschmidt would happily sell you an alusil liner to press in and bore/hone to correct size. Even better, there is a company in the UK, which would happily supply you a aluminium liner, which is already nikasil plated and can be honed to size too.
It was me who first discovered these linered GTS engines on Rennlist by virtue of having the last ever factory supplied complete warranty replacement GTS 5-spd engine in my car. Look tor the posts and you will also see the Porsche supplied experimental pistons, which look a lot more like a 968 piston rather than a 928 GTS piston. The oil return holes were drilled, but only 2 out of four on each side.
Kolbenschmidt would happily sell you an alusil liner to press in and bore/hone to correct size. Even better, there is a company in the UK, which would happily supply you a aluminium liner, which is already nikasil plated and can be honed to size too.
I've asked Kevin to post a picture of one of the pistons.
It was me who first discovered these linered GTS engines on Rennlist by virtue of having the last ever factory supplied complete warranty replacement GTS 5-spd engine in my car. Look tor the posts and you will also see the Porsche supplied experimental pistons, which look a lot more like a 968 piston rather than a 928 GTS piston. The oil return holes were drilled, but only 2 out of four on each side.
Kolbenschmidt would happily sell you an alusil liner to press in and bore/hone to correct size. Even better, there is a company in the UK, which would happily supply you a aluminium liner, which is already nikasil plated and can be honed to size too.
Anyone know how to get some of these Alusil sleeves, in the US? Or even direct contact information in the UK or Europe?
I took apart another GTS engine, yesterday, with a cracked cylinder from a leaking head gasket. (Getting to be really common, guys!) It sure would be nice to weld up the crack and fit a Alusil sleeve, instead of fitting steel sleeves.
Anyone know how to get some of these Alusil sleeves, in the US? Or even direct contact information in the UK or Europe?
I took apart another GTS engine, yesterday, with a cracked cylinder from a leaking head gasket. (Getting to be really common, guys!) It sure would be nice to weld up the crack and fit a Alusil sleeve, instead of fitting steel sleeves.
Anyone?
Someone should make a billet block for these cars. I doubt the demand would be very high though. I'm probably one of the few that has a machine that could make one, but it would still be nice for "someone else" to make it and cure these issues.
Anyone know how to get some of these Alusil sleeves, in the US? Or even direct contact information in the UK or Europe?
I took apart another GTS engine, yesterday, with a cracked cylinder from a leaking head gasket. (Getting to be really common, guys!) It sure would be nice to weld up the crack and fit a Alusil sleeve, instead of fitting steel sleeves.
Anyone?
Paging Kevin Wilson. He's been hot on the trail and I believe has had some success.
01-13-2019, 09:57 PM
93 GTS Engine - Sleeved or normal?
