From Lotus Internet List
Mon, 19 Oct 1998

Dave Peters wrote:
I obtained some rubber cam cover gaskets from JAE for our "Commemorative " Esprit. In spite of sticking them to the "head" with contact adhesive, and using Hylomar on the cover side, they didn't take long to extrude. Does anyone have a better plan?

Tim Engel replied:
The neoprene gaskets are a big improvement over the OEM units. The only real problem is they don't come with installation instructions. If you do it wrong, they squirt right out... as you experienced.

Install them dry. It's the only way they work. ANY sealant goop or oil residue just makes them slippery and they squirt out of the joint as it's tightened down. Make sure both the head and the cam cover mating surfaces are clean and dry. Wipe them down with brake/carb cleaner. Then install the neoprene gasket dry. That's harder to do on the lower edge of the exhaust cam carrier. Unless you get all the oil residue out of the cam gallery, it just keeps running across the sealing flange.

The neoprene gaskets are the opposite of the stock units. The stock gaskets come flat and are so stiff it's hard to get them to conform while you're fitting the cover and inserting the bolts. Frustrating. The neoprene gaskets are so limp they just flop all over the place and keep falling out of position while you're fitting the cover. Also frustrating.

The trick is to tack the gasket into position with a series of 2 inch long pieces of electrical tape. You need to remove the tape after the cover is installed, so don't overlap much of the gasket. You're just trying to lightly tack the gasket in place, so 1/8 to 3/16 inch (3 to 4 mm) overlap is more than enough. Then rub the tail of the tape down onto the side of the cam carrier. There are a series of flat machined pads around the perimeter that work well for taping the gasket down.

Install the cam cover and it's bolts and lightly torque it down. Remove the tape tabs by peeling them out of the joint gently. Don't just jerk on them and pull the gasket out of position. Then torque the bolts to spec in a series of even steps. The gasket should stay in place. If it looks like it's coming out of the joint, back off on the torque a bit and push the gasket back into the joint. Then hold it while you tighten the nearest bolt. If necessary, proceed around the perimeter holding the gasket in the joint with one hand while tightening the nearest bolt. Tighten the bolts progressively in several small torque steps.

There's no gasket dressing to dry, so technically you should be able to start the engine immediately. However, I usually let it set over night to let the gasket creep or squish into position. Then re-torque the bolts, start it up and inspect for leaks.

Now the bad part. If it does leak, the gasket will get slicked up with oil in the area of the leak. Simply tightening the cover won't suffice since the slippery gasket now has great potential to just squirt out of the joint under pressure. Remove it. Clean the mating metal surfaces and the gasket with solvent (brake/carb cleaner) and do it all over.

I haven't had nearly as much trouble with the neoprene gaskets as I've had with the stock units. The grief has been with sealants and with holding the limp noodle in position during installation, not with leaks. Once I learned to install them dry and to tape them into position first, they've been easier to deal with and more reliable then the stock gaskets.