13-06-2018, 04:46 PM
Hi,
A few engines back I took a lot of care to get both the block and aluminium head machined flat, reassembled dry and torqued down. The gasket blew very quickly and I was not amused. I read on here about Loctite 5990 (is that what others are calling coppaslip on here? That's something else) and reassembling that engine, with the slightly used gasket coated in 5990, well torqued gave a gas, oil and water tight seal. Since when I've used nothing else.
When I was in industry we did have problems when asbestos jointing was finally banned in the 1990's. The replacement gasketing materials weren't as forgiving as CAF. The new material isn't as resilient as asbestos, it doesn't spring back after it's compressed taking up a permanent set and the expansion and contraction from heating can reduce the clamping pressure. Correct tightening and following up were vital parts to avoid a blow out.
My advice follows others on here; 5990 and regularly keep torqueing to 20lbft until the nuts no longer rotate.
Dave
A few engines back I took a lot of care to get both the block and aluminium head machined flat, reassembled dry and torqued down. The gasket blew very quickly and I was not amused. I read on here about Loctite 5990 (is that what others are calling coppaslip on here? That's something else) and reassembling that engine, with the slightly used gasket coated in 5990, well torqued gave a gas, oil and water tight seal. Since when I've used nothing else.
When I was in industry we did have problems when asbestos jointing was finally banned in the 1990's. The replacement gasketing materials weren't as forgiving as CAF. The new material isn't as resilient as asbestos, it doesn't spring back after it's compressed taking up a permanent set and the expansion and contraction from heating can reduce the clamping pressure. Correct tightening and following up were vital parts to avoid a blow out.
My advice follows others on here; 5990 and regularly keep torqueing to 20lbft until the nuts no longer rotate.
Dave