Carb spacer info needed . . .

I'm trying to fit a modern Carter carb onto a manifold made to accept an original '63 era Carter carb on it (327 Corvette manifold) and am going to have to use a spacer to make the match-up.

The spacer is the open plenum type, just a square hole, like this one:

http://images.oreillyauto.com/parts/img/large/mrg/6005.jpg

I've heard that this style spacer can cause problems because the fuel mix isn't directed right into the holes in the manifold, but rather sort of floats around in the open chamber before vacuum takes over and the mix get's sucked into the manifold.

Also heard that this style spacer tends to result in the fuel mixture de-atomizing and pooling as a liquid.

Anyone successfully running an open style spacer? Any problems? And info/comments/etc.?

Kind of worried about the potential problem . . .

Thanks !

Best bet is always going to be to try and match the carb spacer to the layout of the intake manifold. A spacer like the one you linked would be a good match for something like an edelbrock torquer intake that already has an open plenum. I'd assume your current intake has a 4 hole carb mounting, if it's factory, so that's what I'd use for a spacer. Prevents the issues you mentioned while also keeping intake velocity up. Jegs and Summit are going to have piles of various spacers and adapter/spacers.

If you have a coolant passage in the intake, and it runs close to the carb mounting, don't get a metal spacer. Go with a composite of some type. Aluminum can transfer too much heat from the intake manifold to the carb, and particularly with a Carter, it can make your float bowl too warm. Not so much of an issue with Holley's that have the bowls hanging off the side.

-Hans

hhaase,

GREAT info, thanks ! Never considered the material that the spacer was made of. I had a thought this afternoon, the spacer that I've been going to use is made of aluminum, open plenum and 0.5" thick. If this style wouldn't work well, is was going to grab up some urethane mix at the local department store, fill the open void and drill four holes into it. An alternative would be to melt down a plastic toy of three (or a mess of plastic milk jugs) and pour that instead.

After reading your post regarding heat transfer, and one I determine just how much of a spacer is needed, I was thinking of grabbing up a sample floor vinyl floor tile piece or two, laminate them together or just use the one depending on the needed thickness, drill for the mounting holes and manifold/carb holes, and use that instead of the aluminum spacer.

Might be easier than pouring urethane and would be MUCH better at not transferring heat from the manifold to the carb, of course I have yet checked to see if vinyl is fuel proof.

There are TONS of spacers of all types available, but I'm gonna TRY to work with what I have and see if I can't make it work with help from you guys and a some crap lying around the house . . .

I'm normally all for doing crazy things, but if it degrades and starts dumping crumbs down the intake, you're looking at an engine. And this is for a part that will be seeing wide temp swings, plus near constant exposure to fuel. For a $20 part I'd just buy a ready made spacer.

-Hans

Wood is actually a pretty good carb spacer material. If that feels a little too GRM for you then make it out of phenolic.

I'll try wood then, easier and more available down my cellar. Maybe a thin skim of JB Weld around each hole to prevent the fuel/air mix from seeping into the wood.