The finish required for a Cometic gasket is nothing exotic, any quality machine shop can and does finish heads to the Cometic spec as normal practice.
I've had many people claim that their Felpro's didn't leak, they don't know what their looking for, it's as plain as the headline in Sunday's paper if you know what you looking at.
The finish on an Eddy head is fine for Cometics but, who installs Eddy heads out of the box without doing a fine trueing cut first anyhow? Not in our shop.
If you have any doubts about the finish on the block or heads, just spay a couple of light coats of Coppercoat on both sides of the gaskets before you install them. Quality distributors of Cometic gaskets will supply you gaskets specific to your bore size and allow the correct amount of clearence to the gasket bore. This may range from .030 for most applications to as much as .100 for some heads which are known to move around more.
They offer gaskets in the catalog in about 10 different thickness' to achieve correct compression ratios and quench, actually a qualified distributor can order about 30 different sizes by using different combinations of center cores and sometimes even going to a 5 or 7 layer gasket for specific applications.
Cometic uses many new and very effect materials for many different sealing duties, Chemically Foamed Viton rubber over aluminum in various thickness'. This material has a 80% recovery rate and requires No Silicone to seal and can usually be re-used in most applications. Great for timing covers, oil pans, water pumps, intakes etc. Their Aramid fiber is again available in many thickness' up to .188 the perfect sealer for quality cast Valve covers, carburetor base and metering block/bowl gaskets.
Every engine we build get's Cometic gaskets top to bottom, the right materials for each application. We now even offer a complete engine kit with all our tested and proven gaskets for BB and SB, many of which we have developed with Cometic and some exclusive to only us. Our intake gaskets for BB are available in 4 port sizes, SB come in 3 sizes for various head port sizes and without all the extra holes for crossovers. Our exclusive line of Aramid fiber carb gaskets WILL NOT STICK EVER. BG and Holley have a "Non-Stick" gasket, what a joke, our's are NEVER Stick.
Nothing worse than a brand new engine that pukes oil, silicone ozzing out of the front cover, chunks floating around in the pan plugging everything up.
They've now come up with a 3 layer Stainless Steel MLS Header gasket, several thickness', if your burn these out you need new headers.
It's 2007, try some gaskets that were designed with modern materials and technology, this old paper and silicone sealing of engines is as obsolete as a crank hanging out from your front bumper.
Did you know that we can have a custom Aramid Fiber or AFM (Aluminum foamed material) gasket made in 5 days or less working from an old gasket or even a rubbing and in most cases for only an additional $15.00 set up fee?
Quality product, custom gaskets, modern materials Made in the USA, what more could you want?
