Carb base gasket

Hey folks, I rebuilt the Carter AFB on my '66 the other day and it turned out very well. Unfortunately when I removed the carb the base gasket(s) tore and were not reusable. The rebuild kit came with three base gaskets - one was a standard square bore with open center, one was a four-hole square bore, and one was a four-hole that also followed the heat crossover around the front of the intake manifold (under the carb - you know...). The only one that sealed completely was the gasket that included the heat crossover. The car runs just fine with that base gasket on there but it created two issues. One, I have read where it was not intended for the exhaust gasses to be in direct contact with the carb base as it is with the current (and only) gasket in place, and two is that the ports at the base of the primaries that are supposed to create vaccum for the hot-air choke system are allowed to pull air directly from the exhaust crossover (bad) and nothing is being pulled through the choke spring housing.

After all this, what do I do for a base gasket? I don't plan to drive the car in below freezing temps so blocking off the exhaust crossover is just fine with me. The local auto parts stores (all two of them, small town) only have standard square bore gaskets that don't extend far enough to the sides to completely seal off the exhaust crossover.

Thoughts, ideas, suggestions? TIA!

Brett

 

Block the holes.

 

Ummmmm, great. I want to block the holes or at least the exhaust crossover but don't have a gasket big enough to do it. After talking with my father just a few moments ago we surmised that all I need is an aluminum/steel plate in the shape of the gasket I have now minus the crossover opening. Then I should be able to use just about any standard gasket on top of that which I do have.

Now to get or make the plate...

 

Block the holes in the manifold with some set screws. The aluminum plate will get eaten away in short order from the exhaust gases.

 

I just did this repair on my 66 Skylark.

Bought a steel plate from CARS, with gasket and then used gasket that came with the rebuild kit for between the carb and steel plate. (Thin steel plate I might add).

There is a guy on ebay that also sells the plate and gasket for around $16.00.

I tried blocking off the heat passages, but managed to run the tap in too far on one side, so I went the plate route.

Please either block off the heat passages or put a plate on as the gases will most definately eat the AFB up.

 

Russ Martin sells them. Pretty sure they are stainless.
http://cgi.ebay.com/ebaymotors/Buick-364-401-425-carburetor-heat-shield-gasket-57-66_W0QQitemZ110386264300QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item19b388b8ec&_trksid=p3911.c0.m14&_trkparms=65%3A1|66%3A2|39%3A1

 

Yes, perfect! Thanks for the link as that is exactly what I was looking for. Two more questions, does it mater that the plate is an "open" design versus a 4-hole and, two, it sounds like in the ad that the carb sits directly on the plate itself. Doesn't there need to be another gasket between the plate and carb?

Tom, I obviously wasn't following your "plug the holes" with a tap and plugs comment - my mistake. I would rather leave the manifold alone go the plate route myself.

Many thanks!

 

I haven't run the car more than 20 minutes since the rebuild an only up and down the local road to make final adjustments. The carb is fine and the car is a project, not a daily driver, so if it sits for a while that's OK with us.

:beer

 

Just one gasket. It goes against the carb.
Your best bet is to phone Russ and order the gasket that way. His eBay prices are generally a bit higher to cover fees.

 

Glad I just saw this, I had the ebay add pulled up was ready to order. He's not that far away from me either.

With all your '66's I'm sure you'll be seeing more questions from me.

 

Personally, I always keep the heat under the carb for drivability and mileage.... You need a heavy base gasket with the crossover in it,,,, next the shield,,, then the paper gasket,,,, the best shield is a stainless one, thicker is better,,,on my cars with the 3 barrels, I have made adapter/shield plates of 3/8 hot rolled steel..... they will not flex and adapt the carb to the intake also.... you have some ''wiggle room'' here......

 

Well, I got the gasket from Russ Martin. I called him directly and wound up paying more for the gasket than the listed price on ebay. On the up side it is exactly what I needed and it is on the car and running well - even the choke is operating perfectly. I mounted the carb directly to the plate and it seems to be sealing just fine. So far so good!