What a Phenolic Improvement!
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
Likes: 0
What a Phenolic Improvement!
Decided to try a 1/2" phenolic 4-hole spacer to see if it would make a big difference in keeping the Holley cool and stop the percolating and gas smell in the garage. It was a lot cooler outside, but after a 45 minute cruise, the carb was cold to the touch. I let it sit for 10-15 minutes and felt it again, since the engine heat would have really saturated things by then. Still cool. Before this, it would get so hot you couldn't touch the carb! Very Kool!!
Got the kit from Summit (Summit brand) for $27 (included the spacer, two gaskets, new studs, nuts & washers).
:party:
Got the kit from Summit (Summit brand) for $27 (included the spacer, two gaskets, new studs, nuts & washers).
:party:
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Re: What a Phenolic Improvement! (killervette666)
I have this same problem of fuel boiling out of the carb. I have been waiting for someone with positive results from a spacer. I think I have room for only a 1/4 inch spacer but would like a 1/2. Is it a 4 hole spacer or open plenum spacer
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: What a Phenolic Improvement! (Barry's70LT1)
Question - is the exhaust crossover blocked off in the intake manifold? Also, do you have the heat riser in the rt. hand exhaust manifold and does it work? Gas boiling out is a common symptom of the exh crossover open and/or the heat riser partialy shut. Glad the spacer fixed the problem.
Race Director
Joined: Feb 1999
Posts: 19,659
Likes: 34
From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
Re: What a Phenolic Improvement! (bigvette1)
I have been thinking about getting one of the Air Gap manifolds. Wouldn't this take care of this too?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Re: What a Phenolic Improvement! (Eddie 70)
My AFR heads have no crossover in them and I am running headers so I have no exhaust near the intake. The Air gap intakes will help this but they still have the heat from the intake manifold that transfers to the carb, but it is far less due to the intake sitting in the air. Maybe some Air Gap users can answer this better.
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
Likes: 0
Re: What a Phenolic Improvement! (Gordonm)
Is it a 4 hole spacer or open plenum spacer
When searching for one of these, I ran into some phenolic head to manifold insulators. Anybody ever try these?
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Melting Slicks
Joined: Oct 2001
Posts: 2,065
Likes: 1,395
From: Halifax, Nova Scotia, Canada
Re: What a Phenolic Improvement! (killervette666)
They are inexpensive and should work on any carb.
I don't remember if it is a 4 hole or open. It's been on there for about 10 years.
I also run headers, and have the exh. cross over partially blocked. (Restricted).
Also a picture of the spacer installed.
I don't remember if it is a 4 hole or open. It's been on there for about 10 years.
I also run headers, and have the exh. cross over partially blocked. (Restricted).
Also a picture of the spacer installed.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Re: What a Phenolic Improvement! (Eddie 70)
Eddie 70
IMO - The air gap is a marketing scheme. It basic physics. Some materials have rapid heat X-fer. Iron, copper, aluminum. that's why they used for cooking. You heat an area of the metal and it all nearly reaches a consistant temp.
I have run tall single planes for years with the "air gap"
Just playing around on a running motor and using a IR point and readout the thermal surface temp and the intake right under the carb of my running motor was within 10 degrees of where it attached to the head. I would atribute the temp difference more to the vaporizing gas than the colder air flow accounting for the temp difference. Aluminum is a very good heat conductor. So :bs
I had gas boiling many years ago an went with an open 1/2 wood carb thermal spacer. They do work better as a thermal barrier than Phenolic.
[Modified by gkull, 12:45 PM 11/24/2003]
IMO - The air gap is a marketing scheme. It basic physics. Some materials have rapid heat X-fer. Iron, copper, aluminum. that's why they used for cooking. You heat an area of the metal and it all nearly reaches a consistant temp.
I have run tall single planes for years with the "air gap"
Just playing around on a running motor and using a IR point and readout the thermal surface temp and the intake right under the carb of my running motor was within 10 degrees of where it attached to the head. I would atribute the temp difference more to the vaporizing gas than the colder air flow accounting for the temp difference. Aluminum is a very good heat conductor. So :bs
I had gas boiling many years ago an went with an open 1/2 wood carb thermal spacer. They do work better as a thermal barrier than Phenolic.
[Modified by gkull, 12:45 PM 11/24/2003]
Burning Brakes
Joined: Oct 2002
Posts: 1,228
Likes: 6
From: lancaster ma
Re: What a Phenolic Improvement! (Chris69)
This sounds like exactly what I need. The gas smell after driving makes me nervous. I usually leave the car outside for awhile or leave the door open.
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
Likes: 0
Re: What a Phenolic Improvement! (adamdinat)
:smash:
Well... the weather has warmed up around here the last couple days and guess what.... The insulator is no longer doing its thing.... Guess I jumped the gun thinking it would cure the percolation problem, but the cold weather tricked me. The carb is still cool when I first shut it down, but after about 30 minutes it's once again very hot to the touch. And, of course, the gas odors are back. The insulator itself is also hot as hell! $27 bucks down the drain?
Maybe I'll try one of those big ugly heat shields to see if that helps keep the heat off the carb. Anyone tried those things?
Well... the weather has warmed up around here the last couple days and guess what.... The insulator is no longer doing its thing.... Guess I jumped the gun thinking it would cure the percolation problem, but the cold weather tricked me. The carb is still cool when I first shut it down, but after about 30 minutes it's once again very hot to the touch. And, of course, the gas odors are back. The insulator itself is also hot as hell! $27 bucks down the drain?
Maybe I'll try one of those big ugly heat shields to see if that helps keep the heat off the carb. Anyone tried those things?
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Re: What a Phenolic Improvement! (Chris69)
only to use as a base to seal to hood scoop, i need to make sure i'm on the
same page as others, PHENOLIC is the hard plastic spacers (yes/no) i think of
plywood being in the composite group the plastic spacers helped me ,but the wood seamed to do better, maybe need both, ?????
same page as others, PHENOLIC is the hard plastic spacers (yes/no) i think of
plywood being in the composite group the plastic spacers helped me ,but the wood seamed to do better, maybe need both, ?????
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
Re: What a Phenolic Improvement! (comp)
I have a 1/2 inch wood spacer that has completely solved my perculating carb. I have a RPM Air gap.
It used to be so bad you could hear the gas boiling after shutting the car down.
Now the carb stays cool and it never percolates!
Wood rocks
It used to be so bad you could hear the gas boiling after shutting the car down.
Now the carb stays cool and it never percolates!
Wood rocks
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Re: What a Phenolic Improvement! (427V8)
glad to hear, i haven't used a new Edelbrock air-gap yet, plan on a build for
truck (to tow trailer) 383,vortec's with pocket work, air-gap perf. , small hyd.
roller, Q-jet, high 3 to low 4 rear gear , and 200r4 trans.
truck (to tow trailer) 383,vortec's with pocket work, air-gap perf. , small hyd.
roller, Q-jet, high 3 to low 4 rear gear , and 200r4 trans.
Thread Starter
Burning Brakes
Joined: Jul 2000
Posts: 1,118
Likes: 0
Re: What a Phenolic Improvement! (comp)
only to use as a base to seal to hood scoop, i need to make sure i'm on the
same page as others, PHENOLIC is the hard plastic spacers (yes/no) i think of
plywood being in the composite group the plastic spacers helped me ,but the wood seamed to do better, maybe need both, ?????
same page as others, PHENOLIC is the hard plastic spacers (yes/no) i think of
plywood being in the composite group the plastic spacers helped me ,but the wood seamed to do better, maybe need both, ?????
Hey... if you use two wooden spacers, would it sound like a motor? Wooden - Wooden... :lolg: :lolg: :lolg:
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Re: What a Phenolic Improvement! (Chris69)
good one, hope not like a saw, got other one from lars, he probably has forgot more than i know,. is there a way to hunt for just 1 subject in the forums??? thanks.