Carb Spacers.......worth the trouble?

[Just 6T9 CHGR]

Since I added a drop base to my factory aircleaner to clear my hood pad, I figured I might inquire about adding a ½" or so carb spacer.......

1.  Worth the trouble?

2.   4 holes or wide open?

This would be for my 750 vac secondary Holley on top of my Eddy CH4B manifold.

Thanks!

[firefighter3931]

Hey Chris, carb spacers are basicly a tuning tool. A 4hole will increase signal to the boosters and make the engine "feel" more responsive off idle. An open spacer is for increasing plenum volume which increaes top end power.

Spacers are "combination specific" so it really depends what you're looking for. If you want a sharper throttle resonse, then the 4hole is the way to go. The CH4B that you've got is a really descent manifold that makes very good top end power because it moves a lot of air. On a combo like yours. increased plenum volume really isn't an issue. That being said, the 4-hole would be my choice to increase idle vaccum and sharpen throttle response.

Fwiw, i recommended a 4 hole to Mike (Brightyellowrtse) and he really liked how much the throttle response improved with that upgrade. There were other tweaks done to the low compression 400 "smogger" but it was transformed from a slug into a tire frier.    Mike is also running a vacuum secondary holley carb.

Ron

[Just 6T9 CHGR]

Thanks for the input Ron. 
 
Any goodness to this thing?


Its a heat dissipater/spacer thats ½"

Is ½" worth it or does it have to be 1"?

[firefighter3931]

No experience with that heat dissipating setup...looks kinda funky, lol. I've used the composite spacers which also serve as an insulator for the carb. I haven't tried a 1/2in but the 1in works very well. Put it this way....it won't hurt and "should" help.

Ron

[Chryco Psycho]

an open spacer may help in youyr case seeing as you are using a dual plane intake & allowing some crossover usually helps

[firefighter3931]

an open spacer may help in youyr case seeing as you are using a dual plane intake & allowing some crossover usually helps

The ch4b allready has a milled divider so an open spacer will only serve to increase plenum volume....the crossover allready exists in the original design. 

What specificly are you looking for Chris ? Increased throttle response or more top end power ? In most cases the open spacer helps with a dual plane because it allows for crossover as Neil said, but the ch4b with it's divided center and generous runners is an exception to the rule.

Ron

[Just 6T9 CHGR]

Looking for a little more crispness.   I think the 4 hole would be the way to go.

Its going to be down the road in the season though.  Cant wait to install & try out my FBO dizzy & ign kit.
Im sure that will make a nice improvement as well.....

Thanks for the ideas/info

[firefighter3931]

Looking for a little more crispness.   I think the 4 hole would be the way to go.

In that case i would agree with the 4-hole. 

Ron

[Ghoste]

I had one of those multi layer insulator spacer setups and I didn't like it very well.  It seemed to cause a lot of whistling and vacuum leaks.  SPend the money on a one piece composite, it's worth it.

[Silver R/T]

phenolic spacers do help

[4402tuff4u]

I purchased a 1" thick phenolic spacer from Summit for my Weigand intake manifold for my 440 as per Chryco's suggestion. I guess it also acts as a heat barrier to isolate the heat from the carburetor. Can't wait to run the engine period! Hope hood clearance wont be a problem. The machinist said he can plane the 1" phenolic spacer down to a custom thickness if the hood is a problem.

[Just 6T9 CHGR]

If you are planning on using a stock air cleaner than hood clearance will be a problem

Thats why I had to use a Ferd Motorsport air cleaner drop base under my factory one to stop hitting my hood pad.

[4402tuff4u]

If you are planning on using a stock air cleaner than hood clearance will be a problem

Thats why I had to use a Ferd Motorsport air cleaner drop base under my factory one to stop hitting my hood pad.

Yes I'm going to run the stock air cleaner. You think I will still have a problem even without a hood pad? Where did you buy the drop base - on line? I just learned this morning that my Weigand intake heat cross over chamber in the manifold will have to be shaved down, cause it's hitting the INDY valley pan plate. I'm not using the heat cross over anyhow.   

[Just 6T9 CHGR]

You'll probably be fine without a hood pad.
Im running a Edelbrock CH4B manifold which is pretty much an aluminum version of the cast iron factory one (flows better though) and it hits the hood pad.

I heard about this trick a while back on Moparts from I think 471magnum, but never persued it.

You can get them on ebay and I think Summit sells them.
I got mine on the cheap on ebay used for $10....the lid was dented but I didnt care, just wanted the base!

Heres one that lists the part # as well.....
M-9600-A302

http://cgi.ebay.com/ebaymotors/NEW-FORD-MOTORSPORT-13-INCH-AIR-CLEANER-LOW-PROFILE_W0QQcmdZViewItemQQcategoryZ43946QQitemZ8049113397QQrdZ1QQsspagenameZWDVW