When reinstalling the carb on a 65 GS 401 do you use a gasket on the manifold and then the stainless steel baffel and then the carb, or do you use two gaskets, one on each side of the baffel? Seems like a single gasket should do the trick, and then the carb bottom would support the baffel from exhaust gas pressures pushing up. Any help appreciated.
I use the thick , heat resistant,type gasket first, then the metal shield and then a thin heat resistant gasket....
Buick put the gasket on the manifold, and the ss plate against the carb. That method transfers the most heat to the carb.
Thanks Guys, I think I will go with the factory arrangement. I have a 401 sitting on the floor of my garage and it has the original stainless steel baffel, but I couldn't tell if there was another gasket on top of it as I got the engine without the carb. I did notice that the original baffel was eaten through by the exhaust gases which means they need to be changed occationally. My guess is every three or four years, or some number of miles?
That is why the plate goes against the carb. Exhaust gases eat up the plate instead of the base of the carb. I put a new one on 3 years ago, but with the little driving I do, it will probably last for a really long time.
Trick,,,,,,, use the old one for a pattern and make one from stainless about .075 thick.... lasts longer and prevents fuel boiling...
There's a guy in Detroit who's making them from thicker stainless. Don't know his name, but everyonce in a while he'll put them on ebay. You might contact Russ Martin, Centerville Auto Repair, in California to see if he's handling them. Russ goes by the handle of Buick Rodder on ebay.
Will you have a vacuum leak with the thin stainless gasket against the carb base? I have the same question on my 67 GS400.
These thicker stainless plates that Paul B. makes are the way to go. Some years ago I sent him an OE steel as the pattern for the '66-7 Qjet.
If the original steel baffle is eroding, I'd be looking at the heat riser valve; or looking for one side of a dual exhaust system being restricted. Too much exhaust flow across the intake manifold will destroy stuff in a hurry.
Update: The burned out baffle was on a spare motor and I was looking at it to see what the original looked like. I don't think the passages are blocked and the heat riser is basically MIA on my running engine. Wanting a part that fit correctly (not all reproduction parts are accurate copies!) I ordered a NOS baffle from CARS, paid extra for it. Much to my surprise it was not a GM stainless part, but a galvanized reproduction. Might be a new old replacement part, but not NOS. Anyway, I wanted to get the vehicle running so I went ahead and installed the CARS part. I will get a stainless reproduction soon so I don't damage the pristine bottom of my AFB. Happy Thanksgiving to all.
I should have used one that is made out of real stainless steel, much more resistant to rust and corrosion, but I was in a hurry. I will be getting a SS replacement soon. So, no I wasn't happy witht he CARS part.
As mentioned, Russ Martin sells the repo. I believe these are the thicker stainless ones made by Paul Bowser: http://cgi.ebay.com/ebaymotors/Buic...r_Truck_Parts_Accessories?hash=item19b4898ece Or go directly to the source (Paul)..... Listed as being 0.045" stainless: http://buicknailheads.com/newparts.htm
Russ does have the AFB ones on his website here: http://www.centervilleautorepair.com/buickparts1.html But you're right, he doesn't presently have them listed on his eBay pageso No:
Incidently.... There is also an aluminum plug on the bottom of the intake that will often corrode leak, and cause grief. It is located right in the center where the exhaust crossovers meet, and it looks like a big freeze plug. You have to take the intake off and flip it over to see it. This can be blown out and you would never know it. I learned this the hard way some years ago.... Erik
Expecting to take delivery of my heat shield from Rocking B Nailhead Parts today. Hope some is home to revieve it...otherwise gotta wait another day and pick it up at the dang post officeray:
