I recently went from a manual choke back to an automatic, and "It's Baaaaaack!" :rant: My 350 likes to leak exhaust from around the choke coil tub, and it's driving me crazy. About every 4 months, I get to replace the gasket. Several times now, I've tried: hammering/tapping the "tub" mounting surfaces flat, hammering/tapping the tub to match the manifold surface, using various hi-temp gasket pookies, various amounts of torque on the bolts, etc, but all to no avail. After awhile, it starts leaking...the only way I could stop it was to use a piece of 1/4" steel plate, when I had a manual choke. This is on a '70 GS350-spec engine, with manifolds and 2 1/4" exhaust pipes w/ walker turbo mufflers. ALSO: Where can I buy the choke gasket? I'm tired of cutting them out....
No, the best was the Hi-Temp Copper Permatex (RTV?), but after a few months, everything gets blown out. When we put the steel plate on, I just put a solid piece of gasket material under it, no cutout hole in the middle. When I took off the 1/4" steel plate to put the automatic choke back on, the gasket material in the middle was completely gone, the only thing left was the usual layer of soot. uzzled:
See if you can get some sheet copper. I think you can sometimes find that at Home Depot. You will need to use your well as a template to make a new gasket from copper. I have done this and it works great. Usually the copper is soft enough to form a good gasket and you can cut it with a utility knife but will take several tries to penetrate all the way through. If you can not find the copper, look for some lead roof flashing material.
Good call George...you can also find the copper sheets at art stores. They sell them in different guages.
um.... is this supposed to be open to exhaust gasses? I thought it was seperate but just there to hold heat. nate
I've seen Buick 350 intakes that have that area wide open to exhaust , and some that have a floor in the bottom so exhaust don't leak.
I believe 70 intakes were sealed from the exhaust gases, but 71 and up had a removable plate/tub for the choke coil.
the 70 2bbl and 71 4bbl i've seen were sealed from the exhaust gasses. both had a removeable plate above the tub but the tub was cast into the intake. Nate
correct....in the 71 and later intakes, the casting was not there anymore....which allowed for lots of exhaust leaks.
So that means I NEED to go back to the 'yard and find a '70 or '71 manifold! And while I'm at it, gasket match it to the heads, and might as well pull the heads and port them, and heck, while I'm that deep, why not go for a bigger cam......wait a minute! :spank: Nahhh, I'd rather stay married! :bglasses: You guys almost had me started there, think I'll go find some copper tomorrow...:beer
Working on your car is much cheaper than another woman!:Brow: Also much cheaper than a divorce? Can you drive half of a Buick?:beer
You can also find the copper at most good machine shops.... they call it shim stock. I use this to make water pump gaskets for the small block chevy's that like to blow the paper gaskets out. I usually make two and stack them.....never had a leak from them. Mike
