Failing Headgaskets

[john in illinois]

I have an AER engine with Snyder 5.5 and had nothing but problems with the silicone gaskets. I switched to a Best Gasket Graphtite sprayed with copper coat and it has been trouble free for probably 15,000 miles.

I also had to surface the head the first time I took it off. Also as mentioned start the engine and idle until hot and retorque when it cools. Don't drive it before the first retorque.

John

 

[Tom Wesenberg]

I'm with Greg on the gasket. I only use the copper gasket sprayed with Copper Coat on both sides. Larry B. also recommends the copper head gasket. As Dave mentioned, be sure to fit it to both the head and bock to see that the fire ring area is covered (compressed my metal from the head and block on both sides.

 

[Bob Johnson]

Bob,

Thanks for sharing your experience. It makes sense and will keep the torque wrench in the car. How much torque did you use? When yours failed was it in the area between the cylinders and center water passage? Seems like a weak place in the gasket. I wonder if using the modern silicone coated composite gasket is worth the hassle or if going with the copper one would be better.

I used 55-60 ft-lbs. The failure was either center front of cylinder #3 or right between #3 and #4.

Bob

 

[tbirdtbird]

"Don't drive it before the first retorque."

AMEN! or the second either

 

[ctvpa]

I blew a head gasket 480 miles on a pro rebuild. I am running a high compression head. I called Snyders and asked for the 'High Compression Silicone Gaskets'. His answer was "I work here and won't sell you one" He told me to use a model B head gasket.

 

[Growley bear]

Straight Edge should be long enough to cover entire length of cylinder head or block. A length of monofilament fishing line used on a clean surface is as good or better than a steel tool. It is very inexpensive, easily obtainable, easy to store, and very accurate and easy to use.
Chet

Checked both head and block with a 12 inch machinists straight edge. Both are flat and true. No light coming in under ruler and cannot get a .001 feeler guage under straightedge anywhere.