Carb heat shield . . . anyone try this?

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1974DartSwinger

1974DartSwinger

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Its about time I do something about this annoying vapor lock issue thats been cursing my '66 Barracuda. Its a total pain to start after sitting overnight (bowls must be boiling dry) and if it sits for 5 - 10 min, hard start again. If sits for a little longer she starts up fine. If I pour a shot glass of fuel down the carb she fires up on the first crank too.

Anyways, I figured I'd give this a shot. If the spacer and fuel line heat wrap dont work then Im thinking about putting in an inline fuel pump with a switch, use it as a primer pump just for starting. I've heard of a few local people having good luck doing that.

Anyways, anyone buy this kit before?


http://www.jegs.com/i/Mr-Gasket/720/3710/10002/-1?parentProductId=743789

Cheers!
 
Is it the original carb? Aftermarket? What's the model #? Is it the stock cast iron intake manifold?

Carters/Edelbrock's are known for having the bowls dry up when sitting, even just overnight. It may not be a vapor lock problem (ie, fuel getting too hot), it just has to do with the bowl vents allowing the fuel to slowly evaporate. Depending on the model of the carb, there may be a way to dial back the bowl vents a bit to keep the fuel from evaporating so easily.

And if that is the problem, the heat shield won't help you either.

The only thing is that wouldn't effect the 5-10 minute start issue, although that could be a number of things-timing, carb tuning, etc.
 
The engine is a '74 360 block/heads with a '66 273 commando 4bbl cast intake and 4bbl carter AFB 4120S. It has the divorced choke (keeping as original as possible) so I can't plug the exhaust cross over.

I'm pretty darn sure I'm having fuel boil/perk vapor lock issues. The car runs fine otherwise, it has a very very slight lean surge while cruising around 60-70. Its just a real pain to start, thats about it. have to crank her for at least 10-15 sec to even get a sputter and it usually takes 2 or 3 tries and lots of pumping to get her to finally catch and stay running (and NO i'm not flooding her . . . )

The annoying thing is that carter AFB 4120 is a weirdo, it doesn't have the regular Carter AVS/Eddy bolt pattern so I cant just go get a phenolic spacer off the shelf, was considering making a wood one lol . . . my buddy did that once and it worked fine. I'm thinking the carb heat shield would be worth trying for now.
 
1974DartSwinger said:
....................carter AFB 4120 is a weirdo, it doesn't have the regular Carter AVS/Eddy bolt pattern so I cant just go get a phenolic spacer off the shelf, .....................
Click to expand...

Of course it's standard!!!! The older AFBs just had the 'narrow' bolt pattern, most common Holleys had the 'wide' pattern, and many adapters/ spacers have BOTH bolt patterns, like the one below:

2


This one is a little expensive, but if you Google some, you'll find a cheaper one

http://www.jegs.com/i/Trans-Dapt/969/2446/10002/-1?parentProductId=1068336
 
I use that kit on all my engines. Well one like it. I use the Mr. Gasket one with the open center. I like all the layers. I can use how ever many I need to add or decrease hood clearance. And it really helps to keep heat out of the carb. I to had heat problems when I just had a thin gasket. Carb really got hot after shut down. Now it is much cooler!
 
Just use the Edelbrock 2732 part. It won't raise the carb as much, and that makes the choke / linkage easier.

Part of your problem maybe the fuel pump / plumbing. Just a tiny air leak (crack) on the suction side rubber hoses can let the line from the tank to the pump leak back in to the tank - losing prime.

A tired fuel pump can leak back through the check valves too.

If either of those things happen, it will be hard to start after sitting. It will take a lot of cranking to suck the fuel to the pump.

Add the insulator. Check all of the lines, from the tank to the pump.

B.
 
I ran one of these when I had a Carter carb on my old 340, worked great:

http://www.jegs.com/i/Edelbrock/350/9266/10002/-1

The fuel would still boil out over night but it solve the embarrising no start issue when I would stop and get gas or get ready to leave a car show. It is specially made for the boil over problem that todays fuels cause.
 
Yep,
I have used that one. Now I have gone to the stackable type, as my LD4B intake is taller than the performer I had been running. And clearance is an issue for me. I just use two gaskets and one plate out of the kit. Much thinner than the Edelbrock one, and still seems to block the heat really well.


340sFastback said:
I ran one of these when I had a Carter carb on my old 340, worked great:

http://www.jegs.com/i/Edelbrock/350/9266/10002/-1

The fuel would still boil out over night but it solve the embarrising no start issue when I would stop and get gas or get ready to leave a car show. It is specially made for the boil over problem that todays fuels cause.
Click to expand...
 
if you got some skills you can simply cut your own heat shield - i used to make one out of aluminium (simple to cut and bend) and it works great, about 160 F under the shield on top of the intake and only about 70 F above the shield at the carb bowl.
 
Here's the thing. If the fuel was boiling in the bowls, the fuel in the bowls would be gone shortly after shutdown (less than half an hour or so). So, that could explain it being hard to start a little after shut down. But, it wouldn't get any better if it sat longer, because the bowls would still be empty.

But, if the car starts fine after sitting longer than that, then the bowls obviously aren't empty, and the engine would have already been cooling down. So, if it starts fine after half an hour or more, but won't start the next morning, the bowls are either leaking, or the fuel is evaporating, not boiling.

If its hard to start after 5 or 10 minutes, but starts fine after the engine cools a little, then you're probably running rich. If it does start fine after half an hour or more, then you're not boiling your fuel. And, if it won't start again the next morning, you're either leaking, or evaporating the fuel in the bowls.
 
Does the heat shield go over or under the gasket to manifold area?
I have a performer 600cfm carb, then the 2732 performer adapter and then the gasket to the manifold (per the instructions) yet I need a heat shield due to hot start.
thanks!
 
340sFastback said:
I ran one of these when I had a Carter carb on my old 340, worked great:

http://www.jegs.com/i/Edelbrock/350/9266/10002/-1

The fuel would still boil out over night but it solve the embarrising no start issue when I would stop and get gas or get ready to leave a car show. It is specially made for the boil over problem that todays fuels cause.
Click to expand...

I bought one of these for my 1965. Wrong bolt pattern. My 1965 carb bolt pattern is approx. 4 1/4" wide. The holes on this part are approx. 5 1/4" center to center.

I also tried SCE 352.
http://www.summitracing.com/parts/sce-352
Good looking part for a great price, but same problem.

I think the Trans Dapt 2446 would fit since it fits both the Holley bolt patter as well as the narrower early Carter pattern. But it's not cheap.
http://www.summitracing.com/parts/trd-2446

Still looking for something affordable that fits the early pattern.
 
Had one on this engine. The multi layer Mr.Gasket insulater. And "yes" to the electric fuel pump switched for hot starts. Used that method on 2 of my cars and just installed it on my driver now for the embarrising "Hot" starts.
 

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Darter6 said:
Had one on this engine. The multi layer Mr.Gasket insulater. And "yes" to the electric fuel pump switched for hot starts. Used that method on 2 of my cars and just installed it on my driver now for the embarrising "Hot" starts.
Click to expand...

Is this the Mr. Gasket setup you're talking about?

http://www.speedwaymotors.com/Mr-Ga...or-Plate-Holley-AFB-Carbs-1-4-Inch,61743.html

Does it do the job? I was skeptical that anything with aluminum in it would insulate as well as a 100% non-metallic spacer.
 
604 said:
Yep,
I have used that one. Now I have gone to the stackable type, as my LD4B intake is taller than the performer I had been running. And clearance is an issue for me. I just use two gaskets and one plate out of the kit. Much thinner than the Edelbrock one, and still seems to block the heat really well.
Click to expand...


I don't like the stackable type "heat shield". The ones where you stack thin gaskets and aluminum plates. They allow for too much variation in height when you are installing them and you can break ears off of your carb base. I used them once and ended up cracking an ear off of my carburetor base.

I use a 5/16" thick carb gasket which won't let that happen.
 
If you want a heat shield why not use a thin sheet of stainless steel, it has less than a tenth of the thermal conductivity of aluminum.
 
65 dart,Though the picture from speedway doesn't show the large aluminum plate/shield(Much like 805's homemade one) that may be it. You layer it with the fiber gaskets between each thin aluminum spacer. maybe a stack of 3-5 of each .
Yes you have to be careful as to not overtighten. Also any auto part store should carry the 4 hole dual bolt pattern fiber spacer that is about 3/8'' thick. I got mine from a Carquest store. That will help.
 
I'm with drive 48 Cool Carb works great. I started using them on my 383 Barracuda when we started having oxygenated fuel year round. If you let the car sit for a couple of hours it wouldn't start without cranking it for a long time.
 
Darter6 said:
65 dart,Though the picture from speedway doesn't show the large aluminum plate/shield(Much like 805's homemade one) that may be it. You layer it with the fiber gaskets between each thin aluminum spacer. maybe a stack of 3-5 of each .
Yes you have to be careful as to not overtighten. Also any auto part store should carry the 4 hole dual bolt pattern fiber spacer that is about 3/8'' thick. I got mine from a Carquest store. That will help.
Click to expand...

Stacking plates and gaskets like this will allow the carb to "****" while tightening it down and you may break an ear off of your base plate. I've done it before, that's why I use a 5/16" thick gasket with spacers that will not let it **** like just stacking thin metal plates and gaskets. :violent1:

YOU'VE BEEN WARNED! :rambo:

If you try this and break your carb, don't come back here whining..... :sad2: :-({|=
 
Darter6 said:
65 dart,Though the picture from speedway doesn't show the large aluminum plate/shield(Much like 805's homemade one) that may be it. You layer it with the fiber gaskets between each thin aluminum spacer. maybe a stack of 3-5 of each .
Yes you have to be careful as to not overtighten. Also any auto part store should carry the 4 hole dual bolt pattern fiber spacer that is about 3/8'' thick. I got mine from a Carquest store. That will help.
Click to expand...

thats what i did, used a thin gasket between the intake and shield, then the thick gasket between the shield and carb. my carb went from to hot to touch to warm.

I sw the post above about stainless, very interesting!
 
My 69 Super Bee w/6pack had the exact same symptoms so bad that during the summer the former owner would change out the ballast resistor and it would work for a while. What he didn't realise was by the time he went and got the resistor everything had cooled down to where it would start right up.
When I bought the car and found over 1/2 doz "good" ballast resistors I thought Oh Chit what now??
Any way to make a long story short since I installed a MSD (multi strike ignition) ignition dist, box and coil. It always starts right up now.
Hope this helps.
Good luck
 
i realize the gas we buy today is junk, but I have to wonder how many times it is a simple carb adjustment or issue. ???????
carb work has eliminated these problems so far, points ignition cars?????
 
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