Barry Grant or Wilson Carb Spacer?

[1985 CCX]

Please advise of your experience:

I am going to add a 1" carb spacer to the plant this winter. I am considering a 4 hole Barry Grant aluminum or a Wilson tapered 4 hole. I am not sure if the Wilson, with its taper, would allow improved laminar flow over the BG which is very 90 degree? I am also going to throw in a K&N Stubstack to help even further. I am looking for more in the low to mid range power hence the 4 chamber versus open plenum. Correct?

Thoughts?
Experiences?
Warnings?

Thanks guys.................Jeff

[blykins]

Use the Wilson or use an HVH Super Sucker.

Of course the above really depend on what your engine combo is. Dual plane intakes sometimes gain more from an open spacer. Some others gain more from a 4-hole.

I would try either one of the above....and this may sound stupid, but try them upside-down too.

[Roscoe]

Barry Grant suggested I switch from a 1/2" open spacer to a 1" 4 hole one. However, this was based on their analysis of my dyno sheet.

Roscoe

[wtm442]

Jeff - Will you have enough clearance between the air cleaner and the hood after the changes?

[CobraEd]

The concept of anti-reversion makes sense to me. When that intake valve slams closed at high rpm, the reversion wave can go back up thru the carburator instead of resonating in the intake manifold and actually causing an increase in flow velocity at the other ports. This is the essence of designing a well "tuned" intake manifold. It is not only about flow. This plate helps keep the resonence in the manifold, and not backing up into the carb. Webers have a haze of fuel/air mixture over them at high speed because there is no tuned plenum manifold to use the reversion for increased power. So when the intake valve slams shut, the reversion goes back out the carb bore and caused a gas haze. That is why Webers are bad for top end rpm horsepower.

http://www.magnafuel.com/products/ac...ates/index.htm

.

[1985 CCX]

Warren

Already checked, I placed a 1.25" block of wood on the top of the air cleaner, it was close so the 1" should be fine.

Good thinking!

Jeff

[DAVID GAGNARD]

On my 331 stroker, approx. 472hp, the spacer with the four tapered holes was good for 16 hp and about the same torque over an open spacer, it has a single plane (Victor Jr.) intake...........

David

[vector1]

now that's some good information

[shark]

Jeff, I experimented with all of the above and found that the "open" spacer (birch wood - to help alleviate heat soak) worked best on my dual plane manifold. I tried alloy, phenolic?? & wood. Also, make sure that whatever configuration you use clears the butterflies - full open-closed. Not all butterflies and hole spacer sizes are equal. Ask me how I know....

Regards,... sharkey

[DAVID GAGNARD]

Originally Posted by shark

Jeff, I experimented with all of the above and found that the "open" spacer (birch wood - to help alleviate heat soak) worked best on my dual plane manifold. I tried alloy, phenolic?? & wood. Also, make sure that whatever configuration you use clears the butterflies - full open-closed. Not all butterflies and hole spacer sizes are equal. Ask me how I know....

Regards,... sharkey

Good point, different engine/intake/carb setups may or may not gain by using a certain type spacer.....only real way to tell is try different ones on a dyno...........

Used to be a dyno shop almost within hearing of my house, saw the owner dyno a 600hp race motor, spent 2 days with different combos.... one carb liked one certain spacer and another carb like a totally different spacer........


As a general rule of thumb, single plane manifolds will do better with a 4-hole spacer and dual plane manifolds wil do better with a open spacer.......very general rules.......

David