Hi, I've got a '65 Buick Skylark cast iron 4bbl intake manifold. I bought a Quick Fuel SL-450-VS carb. Since the bolt patterns are different I have to use an adapter in between. The intake manifold has a groove for exhaust gas to heat the carb. The adapter I bought from eBay isn't long enough to cover the groove, hence exhaust gas may leak into the engine bay. I checked other adapters available on eBay but from this aspect all of them looks the same. Has anybody encountered with this problem? What's the solution?
probably not but if you flip the adapter around , any dif ? one of the older adapers might have more coverage ? i have an old Eelco brand i think , not sure of dimensions . i'll check . maybe just fill in the heat crossover slot ? or plug source ?
I believe you have the Holly / Edelbrock adapter plate there. If you google carburetor adapter plates look at the Quadrajet plate it is square up front.
Easy to make a metal plate. I have made many. Find thin steel at hardware, metal fab shops (like AC and Heating shops, body shops, etc.) Use the gasket that fits the base of the carb correctly, and if you have the one that fits the intake pad, use that first to make the plate outer dimensions, and stud/bolt holes, then lay the proper carb base gasket on you metal plate and locate the ports. After, check it for fit and fine adjust. Hole saws, and 2x8 are helpful for drilling the bores. Fine metal file to chamfer all the edges.
I'm running the 1/4" thick base gasket, tapped the exhaust holes, cut the heads off 2 bolts and JB welded them in the threads, works great, I'm running an edelbrock 500 on my 300.
Go the metal plate route with 3 layers of Aluminum foil for a gasket , or fill it with ciramic epoxy. The plate &foil deal is cheap, the epoxy is not.
At each end of the slot, tap and install 1/4" NPT pipe plugs. Then your gasket between manifold and adapter should be fine.
Thanks for all the help. I ended up with a custom made aluminium adapter. Funny thing is that it was cheaper than the ones I bought from ebay. I’m still wondering why Buick thought in the ‘60s that the carb should be heated. Isn’t this contradicting with nowaday’s trend to keep the carb as cool and isolated as possible?
Originally the nailhead thermostat was 160F, in colder climates a hotter 'stat was put in during winter months. The "carb heat" helped the fuel better mix with air than collecting on the plenum surfaces. Later fuels being more volatile, and current fuels with any methanol make "heated" carb or intakes troublesome for good fuel/air component over the wide operating range. Plugging the passages under the carb and blocking the exhaust flow through intakes helps make the cars run better. One might have a little "cold natured" after first starting, but most cars are over that and warmed up enough within the first mile to run well without the heat (and even a choke). Current systems want a cooler and denser fuel air charge as part of efficiency and power. Science and data over years is how we got to this point and changed that focus.
Under the right conditions, the carb could actually ice up. That is why there is carb heat. Even happens with throttle bodies. Humidity in the air is where the ice comes from.
