Heat spacer or Carb spacer

[Twinibeam66]

Dang you did a good job Joe-JDC they look great ! And i have 1 haha, Falcon67  let me know how the 2 inch super sucker does when you get it, like i need to spend some more money ?? Cant buy enough to keep this 390-416 going  haha

Thanks everybody

[plovett]

As has been said, no two engine combinations are identical and it is difficult to predict what spacer will work best.   That said,  I have found that spacers typically add hp compared to no spacer.  That is in addition the insulating affect between the intake manifold and carburetor.  In general, for most street or street/strip applications,  I think a 4 hole spacer, as tall as you can fit, works the best.  That is, if you are not going to dyno or track test different spacers.  I've never tried a Supersucker, but it is tapered 4 hole spacer. 

I believe in using up all the available height between the carb and hood with a combination of spacers and air filter elements.

I have a 1" cloverleaf spacer and a 3-1/2x14" air filter on my 428.

JMO,

paulie

[Twinibeam66]

Thanks plovett i will remember that i should have plenty of room , going in 66 Truck

[Drew Pojedinec]

The 66 can fit a 2 inch spacer with a performer rpm if you have a drop base filter.

[plovett]

I use an L-88 air cleaner base (Chevy!).   Probably the best thing Chevrolet ever made.    It drops the filter way down.  I don't remember the actual height drop now, but it is a lot. 

Anyhoo, with the tall hood of a truck, it isn't nearly as much of an issue.

JMO,

paulie

[machoneman]

I use an L-88 air cleaner base (Chevy!).   Probably the best thing Chevrolet ever made.    It drops the filter way down.  I don't remember the actual height drop now, but it is a lot. 

Anyhoo, with the tall hood of a truck, it isn't nearly as much of an issue.

JMO,

paulie

We used to think and were told by a pretty savvy shop long ago that the L-88 drop base was 'good' even for a full race engine.

Wrong!

The ideal best base is one totally flat all across the top edge of the carb and actual track testing proved this with a scooped hood. Yet, I would not hesitate to use one if fitment was the issue with a streeter that needs a stock hood. Interesting too is that today, decades later, many vendors offer different height 14" bases pretty cheap so one can dial up any height one needs. 

[My427stang]

I use an L-88 air cleaner base (Chevy!).   Probably the best thing Chevrolet ever made.    It drops the filter way down.  I don't remember the actual height drop now, but it is a lot. 

Anyhoo, with the tall hood of a truck, it isn't nearly as much of an issue.

JMO,

paulie

We used to think and were told by a pretty savvy shop long ago that the L-88 drop base was 'good' even for a full race engine.

Wrong!

The ideal best base is one totally flat all across the top edge of the carb and actual track testing proved this with a scooped hood. Yet, I would not hesitate to use one if fitment was the issue wiht a stretetr or even a racer that needs a stock hood. Interesting too is that today, decades later, many vendors offer different height 14" bases pretty cheap so one can dial up any height one needs.

I like a flat base with a tall filter.  Of course you can't always get there, but minimal drop is best for power and metering

[Twinibeam66]

Thanks Drew Pojedinec  thats good to know, thanks for the help everybody

[Drew Pojedinec]

Anyhoo, with the tall hood of a truck, it isn't nearly as much of an issue.
paulie

My experience with trucks isn't the hood, it is the engine set back far enough to interfere with the firewall/hood interface/lip.  At least with a full size 14inch filter.  Totally dependent on the filter housing.
Being that my trucks have always been daily drivers, I view heat insulation of the carb as being more important than airfilter size/flow as I'm typically motoring along at 2200rpms.

[plovett]

I use an L-88 air cleaner base (Chevy!).   Probably the best thing Chevrolet ever made.    It drops the filter way down.  I don't remember the actual height drop now, but it is a lot. 

Anyhoo, with the tall hood of a truck, it isn't nearly as much of an issue.

JMO,

paulie

We used to think and were told by a pretty savvy shop long ago that the L-88 drop base was 'good' even for a full race engine.

Wrong!

The ideal best base is one totally flat all across the top edge of the carb and actual track testing proved this with a scooped hood. Yet, I would not hesitate to use one if fitment was the issue wiht a stretetr or even a racer that needs a stock hood. Interesting too is that today, decades later, many vendors offer different height 14" bases pretty cheap so one can dial up any height one needs.

I like a flat base with a tall filter.  Of course you can't always get there, but minimal drop is best for power and metering

Sure.  If you have the space, then all that makes sense. 

A '67 Cougar with a 428 and no scoop. doesn't have the space to make the ideal induction tract.  I'd rather have a drop base with a 4" filter than a flat base with a 2" filter.  I have experimented with different base, spacer, and filter combos.

JMO,

paulie

[Twinibeam66]

Ok Thanks Drew Pojedinec  my breather is a Ford Motorsports im thinking its 12 inches but might be 14. But anyway i will check that really appreciate it.

[allrightmike]

Joe, without a dyno test could you predict which of your spacers shown or not shown would yield a gain on a 427 low riser Comp 282S, modified plenum & port matched street master, iron heads bigger valves, 10.5 compression, efi, shorty cast headers. Quite a list I know.

Mike.

[GerryP]

You would probably do well to use either an open or tapered spacer, Mike.  The reason being that the intake you're using has a pretty small plenum and the two mentioned spacers will add plenum volume.  A regular open spacer is cheaper than the tapered spacer, so I would try that one first.

A four-hole spacer is cheap enough that you could also pick one of those up.  Again, spacers seem oblivious to expertise and can surprise you.

[Joe-JDC]

A lot of what folks experience in increased horsepower, is not the design of the spacer so much as the added plenum area and that allows the engine to draw from a larger area.  Because of the larger area, the carb signal is increased, and everything starts working better, making more horsepower.  I have actually increased spacer height to 4.00" on a 600 hp engine, and it kept increasing to that point.  Any spacer that increases the velocity directly under the venturi will change the torque curve some, and should help with horsepower.  On a dual plane intake, the divider is a turbulence inducer with an open spacer, and anything you can do to reduce that with a spacer will help, and increasing the height above the divider will aid higher rpm horsepower.  Cutting down the divider does not always help, and causes loss of low rpm torque.  In a race environment where low rpm is not needed, the cut down divider MAY help with horsepower production, but in my dyno testing, it causes a difficult tuning issue in most cases.  As for what spacer to use, I like a super sucker in most cases, whether 1" or 2", they work.  On the Streetmaster, a lot depends on what has been done to the plenum, and if it has been gasket matched.  The better the manifold works, the less spacer needed.  Joe-JDC

[cjshaker]

A lot of what folks experience in increased horsepower, is not the design of the spacer so much as the added plenum area and that allows the engine to draw from a larger area.  Because of the larger area, the carb signal is increased, and everything starts working better, making more horsepower.  I have actually increased spacer height to 4.00" on a 600 hp engine, and it kept increasing to that point.

Which is one reason why tunnel rams work so good at producing power, and why everyone should have them on their engines. 

It's well proven that directing airflow into the carb helps all along the curve. A drop base certainly doesn't help in that area, but sometimes you just don't have a choice. And any time you can get outside air into the engine, rather than super-heated engine compartment air, is going to produce noticeable effects. Anyone who notices how much better their car runs on a cool day is seeing that effect.