Performer air gap vs performer
Le Mans Master
Joined: Aug 2008
Posts: 5,578
Likes: 61
From: Austin TX
I hear ya. I too doubt there's much of a difference, I'm just thinking with the engine at speed you get airflow underneath the manifold and it helps cool it..some. Good idea on the wood spacer. I wish I had the space for one..don't think I do.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,352
From: Santa Ana CA
I'm going to have to disagree with this.
The air gap manifold has the advantage of not having hot oil splash the bottom of the plenum. Unless you can get a temp gun underneath the manifold, you can't really measure a temp difference of the plenum floor.
As with everything, it's all incremental. H-pipes, X-pipes, Air Gap manifolds.. they all add up and the car will run better.
The air gap manifold has the advantage of not having hot oil splash the bottom of the plenum. Unless you can get a temp gun underneath the manifold, you can't really measure a temp difference of the plenum floor.
As with everything, it's all incremental. H-pipes, X-pipes, Air Gap manifolds.. they all add up and the car will run better.
I use the RPM with the crossover blocked off, and I have a lifter valley splash shield. I also have a 1/2" open spacer. All are port matched and the inside of the RPM has been "massaged" and this probably outflows an Air Gap.
When CarCraft ran the RPM and Air Gap manifolds on the same engine, IIRC the difference was about 3 hp at the top end. Block off the heat riser and cut down the plenum (maybe killing a bit of lower end torque) the difference is probably nil.
The RPM and Air Gap are reported to be the same height.
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,352
From: Santa Ana CA
I also run a flat hold down screw, not a wing nut.
Be really careful when making intake changes and using a stud in the carb. for holding the air cleaner on. You do not want that hole in the middle of the hood. I use lightly balled up wads of aluminum foil for checking clearances when making changes.
Be really careful when making intake changes and using a stud in the carb. for holding the air cleaner on. You do not want that hole in the middle of the hood. I use lightly balled up wads of aluminum foil for checking clearances when making changes.
Le Mans Master
Joined: Aug 2008
Posts: 5,578
Likes: 61
From: Austin TX
Are you sure that this difference isn't more due to the exhaust crossover present in the Performer RPM rather than the hot oil?
I use the RPM with the crossover blocked off, and I have a lifter valley splash shield. I also have a 1/2" open spacer. All are port matched and the inside of the RPM has been "massaged" and this probably outflows an Air Gap.
When CarCraft ran the RPM and Air Gap manifolds on the same engine, IIRC the difference was about 3 hp at the top end. Block off the heat riser and cut down the plenum (maybe killing a bit of lower end torque) the difference is probably nil.
The RPM and Air Gap are reported to be the same height.
I use the RPM with the crossover blocked off, and I have a lifter valley splash shield. I also have a 1/2" open spacer. All are port matched and the inside of the RPM has been "massaged" and this probably outflows an Air Gap.
When CarCraft ran the RPM and Air Gap manifolds on the same engine, IIRC the difference was about 3 hp at the top end. Block off the heat riser and cut down the plenum (maybe killing a bit of lower end torque) the difference is probably nil.
The RPM and Air Gap are reported to be the same height.
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
Le Mans Master
Joined: Mar 2005
Posts: 6,776
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From: Troutman NC
Racer
Joined: Sep 2008
Posts: 454
Likes: 7
From: SB County CA
Don't forget about body mounts when making hood fitment comparisons...aluminum vs rubber/poly and/or condition of rubber/poly. My '68 with new poly body mounts, RPM Air Gap, PJ III (Dominator dimensions) and 3" element on a flat base are about 1.75" above my '68 small block hood lines (have a '67 BB scoop)...so an early small block hood would work with an Air Gap intake if a drop base is used, but I'd say 2" drop base on poly or up to 3" on aluminum or aged body mounts...
Note: the PJ III uses a 1/4" throttle body spacer
Note: the PJ III uses a 1/4" throttle body spacer
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Pro
Joined: Jun 2006
Posts: 575
Likes: 3
From: Tampa / Ft. Myers FL
'69 with a 383, air gap and Quick Fuel 750, poly mounts. I have only test fitted the stock S/B hood (since the car is not finished yet) I have only about 1/2 inch (maybe) above the carb without an air filter... I picked up a stock small block hood at the Kissimmee NCRS show to play around with and make a testbed hood similar to a Z06 hood and keep it as low profile as possible. So, LONG answer to part two of your question; no, an air gap will not fit under your stock S/B hood (with an air cleaner)
Le Mans Master
Joined: Mar 2005
Posts: 6,776
Likes: 2
From: Troutman NC
'69 with a 383, air gap and Quick Fuel 750, poly mounts. I have only test fitted the stock S/B hood (since the car is not finished yet) I have only about 1/2 inch (maybe) above the carb without an air filter... I picked up a stock small block hood at the Kissimmee NCRS show to play around with and make a testbed hood similar to a Z06 hood and keep it as low profile as possible. So, LONG answer to part two of your question; no, an air gap will not fit under your stock S/B hood (with an air cleaner)
Racer
Joined: Sep 2008
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From: SB County CA
Drifting
Joined: Jul 2004
Posts: 1,695
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From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
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St. Jude Donor '07
It has been a while since I have posted these pics. Maybe they will help out.
Assuming the GM aluminum intake is an aluminum version of the cast iron intake. The air gap shown is the Performer air gap. It is on my car now. The Performer RPM is the tallest and I believe the Performer Air Gap RPM is the same height. ( not shown ) I think the Performer was a copy of the original LT-1 aluminum intake.
Assuming the GM aluminum intake is an aluminum version of the cast iron intake. The air gap shown is the Performer air gap. It is on my car now. The Performer RPM is the tallest and I believe the Performer Air Gap RPM is the same height. ( not shown ) I think the Performer was a copy of the original LT-1 aluminum intake.
Le Mans Master
Joined: Mar 2005
Posts: 6,776
Likes: 2
From: Troutman NC
Energy poly mounts, RPM Air Gap, Proform 3 inch AC with whatever drop that is, I just had a bunch of teeth pulled this morning so im couch bound for today or I would measure the Air Cleaner drop
Le Mans Master
Joined: May 2008
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2022 C3 of the Year Finalist - Modified
The communication in some threads can drive a guy crazy.....and every word means something. Truth is that Edelbrock makes a Performer intake, a Performer Air Gap intake, a Performer RPM intakes AND a Performer RPM Air Gap. That is FOUR different intakes.
I believe both RPM's, the regular RPM and the Air Gap RPM are advertised at exactly same height. Check the Edelbrock website.
The photos above can fool you, but the highest one is a Performer RPM, the Air Gap shown is a standard Performer Air Gap, NOT a Performer RPM Air Gap.
I believe both RPM's, the regular RPM and the Air Gap RPM are advertised at exactly same height. Check the Edelbrock website.
The photos above can fool you, but the highest one is a Performer RPM, the Air Gap shown is a standard Performer Air Gap, NOT a Performer RPM Air Gap.
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
the R.P.M air gap on my car does take a while to warm up. as far as power difference? i think there is some difference. a lot of people say they notice no difference, normally those are people who don't tune for the new part. you need to optimize your combination for best results.
Drifting
Joined: Jul 2004
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From: Kissimmee fl
Finalist 2021 C3 of the Year - Modified
2017 C3 of Year Finalist
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St. Jude Donor '07
I agree. If you read what I wrote, nowhere does it say that it is anything but a performer. I stated the performer RPM air gap is NOT shown. The Performer air gap is actually 1/8th of an inch taller than the Performer.
Last edited by c69vete; Dec 11, 2014 at 11:25 PM.
Le Mans Master
Joined: Oct 2010
Posts: 6,900
Likes: 833
From: melbourne florida
2023 C3 of the Year Finalist - Modified
It has been a while since I have posted these pics. Maybe they will help out.
Assuming the GM aluminum intake is an aluminum version of the cast iron intake. The air gap shown is the Performer air gap. It is on my car now. The Performer RPM is the tallest and I believe the Performer Air Gap RPM is the same height. ( not shown ) I think the Performer was a copy of the original LT-1 aluminum intake.
Assuming the GM aluminum intake is an aluminum version of the cast iron intake. The air gap shown is the Performer air gap. It is on my car now. The Performer RPM is the tallest and I believe the Performer Air Gap RPM is the same height. ( not shown ) I think the Performer was a copy of the original LT-1 aluminum intake.
Thread Starter
Drifting
Joined: Jun 2006
Posts: 1,912
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From: Schaumburg (Chicago) Illinois
ok, based on info from another thread I am going Performer. If I am looking at the pictures correctly it seems that it will be 7/16 inch taller than stock (assuming my stock 68 327 intake is the same height. That has to work because I could get a 1 inch drop if I must.
Melting Slicks
Joined: Jan 2003
Posts: 2,165
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From: Where are the Smoky Mountain Cruisers? Not Correctly Restored Stingray
http://www.hotrod.com/how-to/engine/...manifold-test/
Pricey, but the composite seems to be an interesting option. To bad the link didn't run the duel plane intake.
Pricey, but the composite seems to be an interesting option. To bad the link didn't run the duel plane intake.