Phenolic spacer - The 1947 - Present Chevrolet & GMC Truck Message Board Network

7tee · 04-02-2015, 06:47 AM

After rebuilding the carb yesterday I decided to install the 1" spacer due to percolating. I surely hope it lives up to all the hype...

**twouvakind** · 04-02-2015, 06:59 AM

We all support better performance tweaks but that fuel line should really be addressed.

7tee · 04-02-2015, 07:04 AM

Quote:

Originally Posted by twouvakind

We all support better performance tweaks but that fuel line should really be addressed.

Ordering hard line today, thanks...

Swar · 04-02-2015, 09:20 AM

It should help. Hard to see in the picture, but I've got 2" aluminum spacers.
I definitely noticed an improvement, and the phenolic spacer should help even more with heat soak.
As for the rubber fuel line, I've been running them for years without issue. Hard lines do look better though.

**michael bustamante** · 04-02-2015, 11:18 AM

how can you tell if you need to use a spacer? i have the same carb on my build with a street avenger intake but havent started the motor yet.

Swar · 04-02-2015, 11:24 AM

From my experience, you only need them if you're having a heat soak problem/vapor lock, or need more room around the carb(s).

Longhorn 70 · 04-02-2015, 11:31 AM

Being I live in AZ and the temps are high in the summer I have run a 1" phenolic spacer on my carbs for years. I have found it helps on restarts. There were times the engine would crank slowly after running then sitting. The fuel was boiling out of the carb and down into the manifold.

**RenoKeene** · 04-02-2015, 11:43 AM

Laminated wooden spacers have always worked well for heat soak / vapor lock.

**michael bustamante** · 04-02-2015, 12:36 PM

i live in a hot environment too. if the gas seems to be coming out the bottom of the carb after stopping the truck could that mean i have percolating also? new gaskets

Tillik · 04-02-2015, 01:06 PM

percolating? My truck is hard to start at times and my fuel was bubbling in the clear fuel filter last summer. Is that effect considered Percolating? If so, going to pick up a spacer for my carb.

enaberif · 04-02-2015, 01:28 PM

Quote:

Originally Posted by Tillik

percolating? My truck is hard to start at times and my fuel was bubbling in the clear fuel filter last summer. Is that effect considered Percolating? If so, going to pick up a spacer for my carb.

Percolating usually happens within the carb as the heat from the engine gets absorbed by the carb.

If you see the fuel bubbling in your fuel filter then it should be removed from heat sources.

geezer#99 · 04-02-2015, 01:37 PM

For any carbs like the eddelbrock or a quadrajet I use a wood or phenolic spacer.
For carbs like the holley with the float bowls hanging on either end I use a heat plate to deflect the heat away from the bowls.
Post #5 in this link has a heat plate.
http://www.hotrodders.com/forum/carb...ld-123374.html

leftybass209 · 04-02-2015, 02:14 PM

What hype are you hoping it lives up to, reducing heat soak or power adder? I'm just kidding about the power adder thing, I've just been running across that a lot lately on FB. As a tool to reduce heat soak it's pretty effective in my experience.

7tee · 04-02-2015, 04:09 PM

Well I'll have to say, so far so good. The clear fuel filter is not bubbling (due to siphoning into the carb) and no gas boiling over down to the butterflies.

At least something has gone like it should...

Longhorn 70 · 04-02-2015, 04:34 PM

Quote:

Originally Posted by geezer#99

For any carbs like the eddelbrock or a quadrajet I use a wood or phenolic spacer.
For carbs like the holley with the float bowls hanging on either end I use a heat plate to deflect the heat away from the bowls.
Post #5 in this link has a heat plate.
http://www.hotrodders.com/forum/carb...ld-123374.html

If the heat plate had a 3" round 05" deep indentation on the rear panel it'd make a good coffee warmer. Of course you'd have to stop, get out, open the hood to take a sip. j/k

Does fuel with alcohol evaporate or boil at a lower point? Could that also add to the issue?

7tee · 04-02-2015, 06:31 PM

Quote:

Originally Posted by Longhorn 70

If the heat plate had a 3" round 05" deep indentation on the rear panel it'd make a good coffee warmer. Of course you'd have to stop, get out, open the hood to take a sip. j/k

Does fuel with alcohol evaporate or boil at a lower point? Could that also add to the issue?

IMO it's boil at a lower point...

MagmaJct · 04-04-2015, 10:20 AM

I have some experience with fuel percolation.

More so on my '74 VW. Today's fuels have a lower vapor (boiling?) point than they did in the 70s. Hot restarts are a hassle requiring me to hold the pedal to the floor and crank for several seconds, followed by throttle feathering until it'll idle on its own.

I've tried a lower float level, but it causes drivability problems under light acceleration. The "correct" float level will lead to fuel drip from the main nozzle. There are no phenolic spacers available for old aircooled VWs.

I'd imagine the problem is less severe in our old Chevys. The carburetor is larger, and so's the engine room. Some Chevys used a heat shield to block radiant heat coming up from the intake area. Does anyone know which models had these?

--Mike

geezer#99 · 04-04-2015, 11:47 AM

Only the holley equipped chevy's had heat plates. Z28 302 was one.
Even though they don't make a spacer for a vw doesn't mean you can't make one. First one I used I made out of wood. Wood is the best insulator!

04-02-2015, 06:47 AM	#1
7tee Registered User Join Date: Mar 2015 Location: Fletcher, N.C. Posts: 309	Phenolic spacer After rebuilding the carb yesterday I decided to install the 1" spacer due to percolating. I surely hope it lives up to all the hype... Attached Images

04-02-2015, 06:59 AM	#2
twouvakind Senior Member Join Date: Dec 2011 Location: South Carolina Posts: 2,662	Re: Phenolic spacer We all support better performance tweaks but that fuel line should really be addressed.

04-02-2015, 09:20 AM	#4
Swar Registered User Join Date: May 2014 Location: Matamoras, PA Posts: 397	Re: Phenolic spacer It should help. Hard to see in the picture, but I've got 2" aluminum spacers. I definitely noticed an improvement, and the phenolic spacer should help even more with heat soak. As for the rubber fuel line, I've been running them for years without issue. Hard lines do look better though. Attached Images

04-02-2015, 11:24 AM	#6
Swar Registered User Join Date: May 2014 Location: Matamoras, PA Posts: 397	Re: Phenolic spacer From my experience, you only need them if you're having a heat soak problem/vapor lock, or need more room around the carb(s).

04-02-2015, 11:31 AM	#7
Longhorn 70 Registered User Join Date: Dec 2012 Location: Chandler AZ Posts: 1,149	Re: Phenolic spacer Being I live in AZ and the temps are high in the summer I have run a 1" phenolic spacer on my carbs for years. I have found it helps on restarts. There were times the engine would crank slowly after running then sitting. The fuel was boiling out of the carb and down into the manifold. Attached Images __________________ 1970 Longhorn, Front Disc, 350/4 bolt, 882 heads, HEI, Edelbrock, 700R4, HO-52/4.11. 1996 Corvette, Collector Roadster, LT4, 396, 450RWHP, 6sp, 4.11/Dana44/posi 5 point roll bar And let us not grow weary of doing good, for in due season we will reap, if we do not give up. Gal 6:9

04-02-2015, 11:18 AM	#5
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,862	Re: Phenolic spacer how can you tell if you need to use a spacer? i have the same carb on my build with a street avenger intake but havent started the motor yet. __________________ 1967custom

04-02-2015, 11:43 AM	#8
RenoKeene Florida Edition Join Date: Oct 2010 Location: Fruitland Park, FL Posts: 4,029	Re: Phenolic spacer Laminated wooden spacers have always worked well for heat soak / vapor lock. __________________ 70 GMC Short Stepside "Rose"-An American Beauty: Factory 402/TH400, AM/FM, AC, Tilt, Tach, Buckets, Posi, PS, PB, 3-5 Drop, Complete Resto-Rod 67 C-20 Slant Back Wrecker "Mad Max" 67 C-10 Ratrod "Step-N-Wolf" 71 Serro Scotty Sportsman camper "Scotty" 97 LT1 Z28 "The Hornet" Link to more pics of "Rose" http://67-72chevytrucks.com/vboard/a...p?albumid=1684 Check out my "Cheap Tricks" thread and add to it if you can, lots of good info there. http://67-72chevytrucks.com/vboard/s...d.php?t=489394

04-02-2015, 12:36 PM	#9
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,862	Re: Phenolic spacer i live in a hot environment too. if the gas seems to be coming out the bottom of the carb after stopping the truck could that mean i have percolating also? new gaskets __________________ 1967custom

04-02-2015, 01:06 PM	#10
Tillik Registered User Join Date: Sep 2012 Location: Layton, Utah Posts: 186	Re: Phenolic spacer percolating? My truck is hard to start at times and my fuel was bubbling in the clear fuel filter last summer. Is that effect considered Percolating? If so, going to pick up a spacer for my carb. __________________ James B. 1967 Chevy Fleetside Shortbed 4X2 (Black & Beautiful) 1971 Chevy Fleetside Shortbed 4X4 (White & Rough)

04-02-2015, 01:37 PM	#12
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,736	Re: Phenolic spacer For any carbs like the eddelbrock or a quadrajet I use a wood or phenolic spacer. For carbs like the holley with the float bowls hanging on either end I use a heat plate to deflect the heat away from the bowls. Post #5 in this link has a heat plate. http://www.hotrodders.com/forum/carb...ld-123374.html

04-02-2015, 02:14 PM	#13
leftybass209 Registered User Join Date: Feb 2011 Location: Modesto, CA Posts: 2,189	Re: Phenolic spacer What hype are you hoping it lives up to, reducing heat soak or power adder? I'm just kidding about the power adder thing, I've just been running across that a lot lately on FB. As a tool to reduce heat soak it's pretty effective in my experience.

04-02-2015, 04:09 PM	#14
7tee Registered User Join Date: Mar 2015 Location: Fletcher, N.C. Posts: 309	Re: Phenolic spacer Well I'll have to say, so far so good. The clear fuel filter is not bubbling (due to siphoning into the carb) and no gas boiling over down to the butterflies. At least something has gone like it should...

04-04-2015, 10:20 AM	#17
MagmaJct Registered User Join Date: May 2008 Location: Mesa, AZ Posts: 281	Re: Phenolic spacer I have some experience with fuel percolation. More so on my '74 VW. Today's fuels have a lower vapor (boiling?) point than they did in the 70s. Hot restarts are a hassle requiring me to hold the pedal to the floor and crank for several seconds, followed by throttle feathering until it'll idle on its own. I've tried a lower float level, but it causes drivability problems under light acceleration. The "correct" float level will lead to fuel drip from the main nozzle. There are no phenolic spacers available for old aircooled VWs. I'd imagine the problem is less severe in our old Chevys. The carburetor is larger, and so's the engine room. Some Chevys used a heat shield to block radiant heat coming up from the intake area. Does anyone know which models had these? --Mike __________________ I own 3 classic vehicles. 1971 LWB C10 Deluxe. 1974 VW Super Beetle. 1971 VW Fastback. The C10 and the Super Beetle run, the Fastback is just not there yet! Please visit my Super Beetle and Fastback profile on TheSamba.

04-04-2015, 11:47 AM	#18
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,736	Re: Phenolic spacer Only the holley equipped chevy's had heat plates. Z28 302 was one. Even though they don't make a spacer for a vw doesn't mean you can't make one. First one I used I made out of wood. Wood is the best insulator!



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