speedtigger

iTrader: (16)

When port matching my Edelbrock Performer RPM intake to match my CNC ported Texas Speed LS6 heads I found that the intake ports needed to be enlarged substantially to match. In fact, I enlarged them to the point where the o-ring type seal gaskets were no longer viable.

I thought I left the metal around the inside of the rubber O-ring seal gaskets thick enough so that they could still support the pressure of the vacuum in the intake tract. When I started to re-assemble my engine after replacing the lifters, I found out I was mistaken. When installing the new O-ring gaskets I noticed that several intake ports had started to collapse around the O-ring area.

As a solution, I filled the O-ring pockets with JB-Weld and I will be running the paper gaskets. I believe this will solve the problem.

So, If you are going to be running CNC ported heads, be aware of this when you port match. If you cut the metal too thin around the O-ring seal, it can suck that area of the metal right in to the port. This could end in a simple vacuum leak or in your engine snacking on a piece of aluminum.

GNCLONE

JB Weld is awesome - I wish it came in 55 gallon drums!

speedtigger

iTrader: (16)

Back when I was into porting cylinder heads and fuel injection intakes regularly, I would buy quart containers of a product called Plastic Mastic. It had characteristics nearly identical to JB Weld, but thicker. It is probably available by the gallon too.

speedtigger

iTrader: (16)

Just for the knowledge base, it takes about 6 to 7 ounces of JB to fill the O-ring grooves.