Real Gaskets brand silicone gaskets?

[440Magnum]

Anyone ever used Real Gaskets Tennessee brand silicone gaskets? I'm still in my 40+ -year ongoing battle to find valve cover gaskets that last more than a couple of years in a big-block Mopar with stock factory high-performance manifolds that sit about an eigth inch from the passenger's side valve cover, and cook the gasket to crispy critters. I've had decent luck since switching to cast aluminum valve covers and Moroso rubber-over-metal gaskets, but I did have one of them fail recently. I've also taken to sliding a strip of header wrap insulation between the manifold and the valve cover, so that helps too.

The Real gaskets are pure silicone rubber . The upside is that they're good to 400F and are reusable, soft enough to mold into the as-cast gasket surface that old cylinder heads always had. Downside is that they are pretty squishy and require very low torque (20 in-lb), and probably loctite on the bolts.

I'm going to experiment with them, but was just curious if anyone here had tried them before. Apparently they're a big supplier for general aviation, with lots of rocker box and valve cover gaskets for Lycomings, Continentals, Jacobs radials, all the way up to P&W and Wright radials.

For those who aren't familiar with the upswept BBM performance exhaust manifold and how close it is to the valve cover, pics with OEM and cast aluminum valve covers:

 

[SubieRubyRoo]

Kind of an around the block method, but have you looked into something like TechLine Coatings' header coating? You can blast the manifolds, spray this stuff on and then cook the manifold at 500*F for an hour, and it will keep much more heat inside the manifold, likely saving your gaskets. It's extremely similar to SwainTech, Calico, etc... but you can DIY this and save some cash. I think the size that will do one pair of headers is still only around $50.

TechLine Coatings

 

[440Magnum]

Originally Posted by SubieRubyRoo
Kind of an around the block method, but have you looked into something like TechLine Coatings' header coating? You can blast the manifolds, spray this stuff on and then cook the manifold at 500*F for an hour, and it will keep much more heat inside the manifold, likely saving your gaskets. It's extremely similar to SwainTech, Calico, etc... but you can DIY this and save some cash. I think the size that will do one pair of headers is still only around $50.

TechLine Coatings



I've thought about it, but the problem isn't really enough of a problem to warrant it. Next time I have the manifolds off the engine for some other reason anyway, I've thought about having them extrude-honed and then coated.

 

[maxdustington]

Originally Posted by SubieRubyRoo
Kind of an around the block method, but have you looked into something like TechLine Coatings' header coating? You can blast the manifolds, spray this stuff on and then cook the manifold at 500*F for an hour, and it will keep much more heat inside the manifold, likely saving your gaskets. It's extremely similar to SwainTech, Calico, etc... but you can DIY this and save some cash. I think the size that will do one pair of headers is still only around $50.

TechLine Coatings
That's awesome, my oven only goes to 450.

You should probably get them coated, that's pretty extreme. How did cork gaskets survive?

 

[440Magnum]

Originally Posted by maxdustington

How did cork gaskets survive?


In a word: poorly!

Actually, cork gaskets are kinda amazing given that its hard to imagine them working AT ALL, let alone for years. My experience was that they would last a couple of years under most circumstances, maybe a little longer. Coated rubber worked better, the absolute longest I ever got was using straight Permatex Great Stuff with no gasket. But its a pain to remove the covers when they're basically glued on, the scraping away the old Permatex is horrible, etc. I'd rather leave them uncoated and just change gaskets every couple of years, but it looks like the Real Gaskets might last a lot longer if I can hit the torque spec on the nose.

To be honest, back in the day most people probably put headers on these engines. The factory manifolds are among the best factory manifolds of the era, but guys that bought the HiPo engine option probably went straight for even more power as soon as the warranty was up. And that wasn't 100k miles in 1969, either! People were also a lot more tolerant of small oil leaks then than now. Gasket materials were poor, and the manufacturers didn't even bother to put machined gasket surfaces on the heads for valve covers.