carb spacers, big small material, i want to work out what i want to run what are the benifits of different spacings, has anybody bothered to play about ive herd that you could gain hp by getting the carb spacing just right? bigger=better? please discuss and give me some views on the matter

 

each car is different, go to the track with several different ones and see what the car likes.

 

My thoughts on Material is simple: Phenolic or wood. Leave the aluminum and sheetmetal stack ones on the shelf. The rational is simple, you are trying to get the heat of the intake manifold away from the carb. Aluminum is a terrific conductor of heat, so nix that, and the sheetmetal/gasket packs are just too prone to vac leaks, so scrap that as well. That only leaves the phenolic and wood ones.

How tall...that's a loaded question because, like the fellow just said, every motor is different. I like 1" on dual plane manifolds if I have enough room under to the hood to do it (sometimes, you just don't have any room to move the carb up without hitting the bottom of the hood). I would go at least 1/2". On a 3rd gen with a stock hood, you may be S.O.L. on putting any kind of spacer under the carb. (Make a couple of clay spikes on the top of your air cleaner, close the hood, then take a peek and see if any of them touched the underside of the hood...that will tell you if you have room to go up with a spacer.)

The shape of the spacer varies. I have had the best luck with the 4-hole variety, though some motors respond well to the open plenum type (1 Big hole under the carb) especially if the manifiold has a divided plenum.

 

Yea, you really have to buy an assortment and try them out.
From what i've heard, an open one has a tendancy to SLOW the mixture down, and a 4 hole one has a tendancy to SPEED the mixture up. So if you're having problems with fuel puddling in the intake, it's usually moving too fast and hits the floor and comes out of the intake charge - so you'd use an open one in that case. And so on and so on. Trial and error.

 

hey guys thanx for that, thats real interesting sonix, i always thought about keeping it open to aid the plenum in getting the mixture in the right dirrection helping airflow, say for instants you have particles at the front of carb and its got to get to the back of the engine it can already flow that way before getting to the manifold - if that makes sense? hard to describe what i was thinking!!!!

 

Yea, that makes some sense too. Like I said, xxx may have worked great for Joe, but yyy worked better for Mike, etc etc. Purely guesswork. You really need to get a couple guys together and go in on buying a set of 5-6 of them, different heights and styles (4 hole, open, etc). Also rent a dyno for 3 hrs. Try each one on each car, every combo you can think of, and write down which one worked best for each person. Then leave the ones that didn't work best on your shelf to collect dust (or return it if they have a good return policy) and buy up the ones you need