2" air filter element or 3" element?
Thread Starter
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
2" air filter element or 3" element?
Hi, folks,
I have a 1980 'vette, L48 engine, Edelbrock 2101 intake manifold, block-hugger headers and 2 1/2" dual exhaust, Magnaflow mufflers,Holley 600 vacuum secondary carb, no-name dropped base air cleaner with 3" element, and stock hood. I have about 1" of clearance between the top of the air cleaner and the hood. I would like to experiment with carb spacers, for insulating the carb from engine heat and more low end torque/throttle response (I have a 3.07 diff ratio and a th350 trans, I need all the low end grunt I can get) I can probably get away with a 1" spacer, but if I wanted to install a 2" spacer, the only way I can see to get the clearance is to use a 2" air filter element.
1.) Will a 1", 4-hole, phenolic spacer make any improvement in performance, even if not noticeable? (little things add up)
2.) Same question for a 2" spacer, but combined with a 2" filter element. I.E. Will the 2" spacer starve my engine for air, and if so, will the 2" spacer make up for it? How about if I use one of those air cleaner tops with the filter element built in to it?
I realize this is all a buncha theoretical bullflop, but I would appreciate anybody's input, positve or negative, shoot, you can even call me names if you want!!
Scott
I have a 1980 'vette, L48 engine, Edelbrock 2101 intake manifold, block-hugger headers and 2 1/2" dual exhaust, Magnaflow mufflers,Holley 600 vacuum secondary carb, no-name dropped base air cleaner with 3" element, and stock hood. I have about 1" of clearance between the top of the air cleaner and the hood. I would like to experiment with carb spacers, for insulating the carb from engine heat and more low end torque/throttle response (I have a 3.07 diff ratio and a th350 trans, I need all the low end grunt I can get) I can probably get away with a 1" spacer, but if I wanted to install a 2" spacer, the only way I can see to get the clearance is to use a 2" air filter element.
1.) Will a 1", 4-hole, phenolic spacer make any improvement in performance, even if not noticeable? (little things add up)
2.) Same question for a 2" spacer, but combined with a 2" filter element. I.E. Will the 2" spacer starve my engine for air, and if so, will the 2" spacer make up for it? How about if I use one of those air cleaner tops with the filter element built in to it?
I realize this is all a buncha theoretical bullflop, but I would appreciate anybody's input, positve or negative, shoot, you can even call me names if you want!!
Scott
Tech Contributor
Joined: Jun 2004
Posts: 20,905
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Hi, folks,
I have a 1980 'vette, L48 engine, Edelbrock 2101 intake manifold, block-hugger headers and 2 1/2" dual exhaust, Magnaflow mufflers,Holley 600 vacuum secondary carb, no-name dropped base air cleaner with 3" element, and stock hood. I have about 1" of clearance between the top of the air cleaner and the hood. I would like to experiment with carb spacers, for insulating the carb from engine heat and more low end torque/throttle response (I have a 3.07 diff ratio and a th350 trans, I need all the low end grunt I can get) I can probably get away with a 1" spacer, but if I wanted to install a 2" spacer, the only way I can see to get the clearance is to use a 2" air filter element.
1.) Will a 1", 4-hole, phenolic spacer make any improvement in performance, even if not noticeable? (little things add up)
2.) Same question for a 2" spacer, but combined with a 2" filter element. I.E. Will the 2" spacer starve my engine for air, and if so, will the 2" spacer make up for it? How about if I use one of those air cleaner tops with the filter element built in to it?
I realize this is all a buncha theoretical bullflop, but I would appreciate anybody's input, positve or negative, shoot, you can even call me names if you want!!
Scott
I have a 1980 'vette, L48 engine, Edelbrock 2101 intake manifold, block-hugger headers and 2 1/2" dual exhaust, Magnaflow mufflers,Holley 600 vacuum secondary carb, no-name dropped base air cleaner with 3" element, and stock hood. I have about 1" of clearance between the top of the air cleaner and the hood. I would like to experiment with carb spacers, for insulating the carb from engine heat and more low end torque/throttle response (I have a 3.07 diff ratio and a th350 trans, I need all the low end grunt I can get) I can probably get away with a 1" spacer, but if I wanted to install a 2" spacer, the only way I can see to get the clearance is to use a 2" air filter element.
1.) Will a 1", 4-hole, phenolic spacer make any improvement in performance, even if not noticeable? (little things add up)
2.) Same question for a 2" spacer, but combined with a 2" filter element. I.E. Will the 2" spacer starve my engine for air, and if so, will the 2" spacer make up for it? How about if I use one of those air cleaner tops with the filter element built in to it?
I realize this is all a buncha theoretical bullflop, but I would appreciate anybody's input, positve or negative, shoot, you can even call me names if you want!!
Scott
On item #2 you could install a vacuum tap in the air filter base and hook it to a vacuum gauge. That would allow you to compare the flow capability (or relative restriction) of the air filter combinations.
Thread Starter
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I think I am going to try a 1", 4-hole, phenolic spacer to try to keep the carb cool. I have noticed that after extended running, (on the highway for an hour, for instance) it runs rough.
Scott
Scott
Thread Starter
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I would like to hear some opinions on the following spacers. Some of them seem a little, well, strange.
This one just screams snake oil, it's like a vacuum leak looking for a place to happen.
http://www.summitracing.com/parts/MRG-98/
I like this one, the material has a great insulation value, and it's pretty cheap.
http://www.summitracing.com/parts/EDL-8723/
I think I am going to go with a 1/2" spacer, I don't think it will have much of an effect on power, but I wish to insulate the carb from engine heat, plus, it's an excuse to screw around with the 'vette.
Scott
This one just screams snake oil, it's like a vacuum leak looking for a place to happen.
http://www.summitracing.com/parts/MRG-98/
I like this one, the material has a great insulation value, and it's pretty cheap.
http://www.summitracing.com/parts/EDL-8723/
I think I am going to go with a 1/2" spacer, I don't think it will have much of an effect on power, but I wish to insulate the carb from engine heat, plus, it's an excuse to screw around with the 'vette.
Scott
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
A 1", 4-hole spacer on a dual-plane manifold will show measurable but relatively small torque increases. Anything taller isn't worth it.
I'd stick with a 3" or taller element for sure - I've watched a 2" choke a relatively mild 350 on the chassis dyno.
I can't imagine you're getting fuel boil on the highway...?
I'd stick with a 3" or taller element for sure - I've watched a 2" choke a relatively mild 350 on the chassis dyno.
I can't imagine you're getting fuel boil on the highway...?
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
I have a 1" solid pot metal spacer. The whole center is open. I can't tell if it does any good. But then again it has not decreased any power either. If you do place a spacer on it, you will need to adjust your carb. again. I had it laying in the tool box from years ago, I figured one day what the heck.
Drifting
Joined: Mar 2011
Posts: 1,886
Likes: 9
A carb spacer will probably take away power at low RPM's, and might add it at higher RPM's. It will make a 2 plane manifold act more like a single plane manifold. I don't think it would help with the grunt off the line at all.
Try to use a thin (maybe 1/2") spacer with some insulating properties (phenolic, etc), without having to use a smaller air cleaner.
Try to use a thin (maybe 1/2") spacer with some insulating properties (phenolic, etc), without having to use a smaller air cleaner.
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Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
An open-plenum spacer on a dual-plane will have that impact - but a 4-hole acts like a runner extension and does improve low-end torque slightly.
Burning Brakes
Joined: Aug 2006
Posts: 1,155
Likes: 0
From: San Diego California
A carb spacer will probably take away power at low RPM's, and might add it at higher RPM's. It will make a 2 plane manifold act more like a single plane manifold. I don't think it would help with the grunt off the line at all.
Try to use a thin (maybe 1/2") spacer with some insulating properties (phenolic, etc), without having to use a smaller air cleaner.
Try to use a thin (maybe 1/2") spacer with some insulating properties (phenolic, etc), without having to use a smaller air cleaner.
Carb spacers are ordinarily used to slightly increase power at high RPM- not what you're looking for.
There are insulating gaskets to help limit heat transfer from the manifold to the carb- and they are pretty thin.
If you want some more off the line performance, without a huge cost, swap your rear end gears for 3:55 or 3:73's, and forget about carb spacers.
