2 replies to this topic

[OBEY]

Need help identifying the cause of blown out gaskets. I fit a set of brand new permaseal exhaust gaskets and did the bolts up nice and tight. I started the car with new headers I installed and its so loud from exhaust leak it sounds like it has no exhaust system at all. I removed the headers to find the bottom of the gaskets has been blown out between the 2 metal sheets on both gaskets. The holden exhaust ports are obviously the rounded rectangles and the new headers are just circles that are larger than the exhaust ports. Should I use a different type of gasket or sealing agent? I ran a straight edge to check if the heads or headers were warped but they both appear straight.

 

Circles on headers are larger than the engines exhaust ports

Both metal sheet sides is fine but I peeled them apart to find the inside section blown out on the bottom. This happened on both gaskets

[koalasprint]

Try re-installing without the entire exhaust connected. Are you able to check for gaps around the headers when they are bolted up without gaskets, specifically around where the gaskets blew out?

Access is hard but try with a feeler gauge or sending a bright light up the headers. Best done in a dark garage.

If there are no leaks take the headers off off, use new gaskets and some exhaust silicone and bolt them back up. Use some copper grease on the threads to make sure they tighten OK. Re-torque after a couple of heat cycles. Check that the rest of the exhaust lines up and isn't putting pressure on the headers. If all of that fails then the exhaust gas temperatures must be too high and you'll need to get the engine tune sorted out.

 

(I know of some guys that don't run gaskets, just use the silicone, but I haven't tried this myself)

[OBEY]

Thanks that was the perfect advice I needed. Found the system to be fouling on the engine mount. I'm going to switch over to using copper rtv and see how that works instead because its cheaper than gaskets and has plenty of good press online with sealing.