Engine: Exhaust Crossover

[Stu Duglee]

How do you correctly block or limit this exhaust/heat crossover on the intake manifold?I've had a few vapor lock issues during the cooking heat of summer & just looking to cool the carb base a bit.I have a set of metal gaskets with one having a small hole(1/2") & the other is normal,just wondering if they are correct or do I need 2 with the small hole?Or do you block them altogether....questions,questions,questions...Thanks[ATTACH=CONFIG]23162[ATTACH=CONFIG]23161

[Tom Bredehoft]

I put a piece of shim stainless on each side, no holes, found later half a cup of water in there. I drilled a 1/4 inch hole in each piece of stainless, haven't had it apart since, but it seems to work OK.

[BobPalma]

Sit tight, Stu. Jon Myer discusses this at length in the May Turning Wheels Co-Operator, coming to a mail box near you within two weeks. BP

[rusty nut garage]

I use brass shim stock. I cut a piece for each side large enough to completely cover the port. Make the piece just large enough to be sandwiched by the intake manifold gasket.

How do you correctly block or limit this exhaust/heat crossover on the intake manifold?I've had a few vapor lock issues during the cooking heat of summer & just looking to cool the carb base a bit.I have a set of metal gaskets with one having a small hole(1/2") & the other is normal,just wondering if they are correct or do I need 2 with the small hole?Or do you block them altogether....questions,questions,questions...Thanks[ATTACH=CONFIG]23162[ATTACH=CONFIG]23161

[Jerry Forrester]

If I was in Canada I don't think I would block the intake exhaust ports. Us good ole boys down south always do.
Rather than blocking the exhaust/intake ports to help prevent vapor lock, I would install a fuel return line back to the tank.

[over50]

I took out the heat riser valve. That seems to work pretty good to cut down exhaust flow thru the crossover.
Norm

[StudeRich]

If you have the Factory Correct Head Pipes, removing the heat riser will cause a misfit to the exhaust manifold.
The best method if you really want it gone and are not concerned with slow or never warming up the Carb. Choke in Winter, then you remove the butterfly and shaft and drill and tap the shaft holes and plug with Allen screws.

Stu the Gaskets you have on the shelf are somewhat rare Avanti R2 to restrict the flow and control Carb. heat. The open one goes on the Left where it will not matter after you blocked the exhaust flow from the heat riser, if in place on the Right.

[ROADRACELARK]

A visit to your local exhaust shop and purchasing 2 exhaust pipe flanges will solve the fitment issue. If you don't have the welding equipment, have the shop weld them together. Just to be on the safe side, take pipe flange gasket, or the pipe itself, to ensure the correct size. Hope this helps.

Dan Miller
Auburn, GA

[Stu Duglee]

Thanks all...I live in the southern coastal area of B.C. so we don't get much winter just rain,so the heat riser has been removed & a correct size spacer was installed to make up the gap so my pipe flange fits the exh. manifold. A return line will be installed soon & anything else I can do, I will... Thanks again

[SScopelli]

Call Lee Silverstone in Canada. 519-485-1966. When I did the dual in SS and rid the crossover he had the proper filler for the bypass valve and it still only used 3 gaskets on the right side. Also I believe they sell the Intake Gasket with that blocked out.