I'm restoring a 1994 Porsche 968 and pulled the engine out yesterday. I found that a bit of the cylinder head assembly has at some point (been...) broken off & someone has tried to glue it back together.
It's a frustrating part - it's a camshaft bearing cap except it isn't! On the Porsche 4 pot twin-cam the final bearing cap (back end of the engine, other end from where the cams are driven) is shaped as a camshaft bearing cap (it's interchangable with the front cap, which does hold the cam) but it doesn't actually hold the cam shafts, as they stop after the final valves on cylinder 4. Because the whole cylinder head & bearing caps assembly are machined as one Porsche doesn't sell the caps separately, as normally they need to match the seats in the cylinder head. So, even though it's not a bearing cap, it's still not available seperately from Porsche. I doubt that makes much sense but maybe a picture will make it clearer...
As you can see at the end of the photo, a chunk of the cap has broken away and was laying in the cylinder head...
Ideally I'm going to try and get hold of a replacement from a breakers but that might not be particularly easy or cheap, so if I'm unsuccessful, I'm wondering about getting it repaired. I have a decent MIG set (and bu&&er all skill) but I think that if it is fixable, it's a job for someone who has experience of TIGing cast aluminium. As I say it's not actually a bearing or structrural, it's really just blocking a hole that would let the oil out and a surface for the timing cover gasket to sit on. It's not clear from the picture but the broken off bit is a perfect fit in the break - nothing is missing.
I'd appreciate your wisdom!
It's a frustrating part - it's a camshaft bearing cap except it isn't! On the Porsche 4 pot twin-cam the final bearing cap (back end of the engine, other end from where the cams are driven) is shaped as a camshaft bearing cap (it's interchangable with the front cap, which does hold the cam) but it doesn't actually hold the cam shafts, as they stop after the final valves on cylinder 4. Because the whole cylinder head & bearing caps assembly are machined as one Porsche doesn't sell the caps separately, as normally they need to match the seats in the cylinder head. So, even though it's not a bearing cap, it's still not available seperately from Porsche. I doubt that makes much sense but maybe a picture will make it clearer...
As you can see at the end of the photo, a chunk of the cap has broken away and was laying in the cylinder head...
Ideally I'm going to try and get hold of a replacement from a breakers but that might not be particularly easy or cheap, so if I'm unsuccessful, I'm wondering about getting it repaired. I have a decent MIG set (and bu&&er all skill) but I think that if it is fixable, it's a job for someone who has experience of TIGing cast aluminium. As I say it's not actually a bearing or structrural, it's really just blocking a hole that would let the oil out and a surface for the timing cover gasket to sit on. It's not clear from the picture but the broken off bit is a perfect fit in the break - nothing is missing.
I'd appreciate your wisdom!
