blocking exhaust passage 430cid intake???

What do I need to buy to block the exhaust ports that go through the intake on a 430 motor and where I can buy them?

Are they actual plugs or a special gasket or both?

I believe this mod will keep thing a little cooler.

 

An easy way to block the heat crossovers is to plug the round hole in the heads, a 3/4 inch freeze plug works great for this.
It's easier if you slightly flare the opening before putting the plugs in. Jim Burek

 

Hi Jim,

That sounds simple enough. I assume it can be done without taking the heads off the engine?
I would stuff rags into the outlets on the head and grind a small bevel on the outer edges of the crossover ports before tapping in the freeze plugs.

Thanks for your help.

 

I block my exhaust crossover with a simple set of freeze plugs, and some loctite to ensure a tight fit. FYI--- the size is actually 18MM, 3/4 is a touch too big and the don't fit quite right. 18MM plugs should be availabe at any good engine shop! Good luck

 

Thanks for your advice. Someone was telling me that blocking these causes problems with exhaust gas flows but I find that hard to believe.

Did you notice any change in smoothness?

 

I couldn't say there was difference since I changed a few other variables as well. but I will say this, MY intake manifold is cool to the touch when the car is at 160. And last year, the manifold was so hot the paint cracked off and burned all along the exhaust crossover path. In my opinion it wwas worth the $1.62 price :Brow:

 

That 430 heat passage that goes up into the carb is nuts. What were they thinking???? Blocked mine years ago with a metal plate (goes under carb) made for that purpose. Mr. Gasket used to sell it.
The better way would be to do it at the head though to help the intake run cooler.

Tony, what color is your Riv?

Bruce

 

Hi Bruce,

I have a 66 and my son has the 69

They're both a different mettalic green (not original) Mine is a Ford color called Everglade and the 69 id an Audi color.

See them on my website which is at the bottom of my posts.

 

Same size plug (18mm) for the 350??????????????????????

 

Can someone give me a quick a walk through on this? Not sure where the holes are to be honest.

Thanks,
Danny