Carburetor spacer.

[celticwarlock]

I am looking into putting a carb spacer on my motor ('69 440, stock, in a '69 NY, with a Holley 650 on it). Heat soak is causing fuel-related hot starting issues, and I have heard that a spacer may help significantly. I am willing to try one, but how tall should it be? Should it be an open, a 4-hole, or a combination spacer? I am not expecting an increase in power anywhere, but if it makes any sort of difference, I'd like to make the best choice I can. After a lot of reading on the subject at various sites and getting no clear answer, I figured it is best to consult the gurus here, especially since this will be installed on a C-body. I suspect that much of what I read regarding a boost in HP will not apply in my case, given the nature of my set-up. This is primarily for insulating carb from engine heat, but if one particular design has any additional benefits that I would notice, so much the better.

 

[C Body Bob]

A half inch 4 hole spacer with a wide heat insulator works well on a stock engine. I also have found there is a difference in fuel. Try a tank from a different store. They don't all have the same mix of ethanol.

 

[celticwarlock]

A half inch 4 hole spacer with a wide heat insulator works well on a stock engine. I also have found there is a difference in fuel. Try a tank from a different store. They don't all have the same mix of ethanol.

I have tried a variety, but have not noticed a difference with regard to this issue. Will a 1" 4-hole spacer be too much?

 

[jrm]

I would use an open design so any plenum can feed off it, phenolic or plastic would be better at not absorbing heat, they also make a thin metal plate that bolts under the carb and runs the length of the carb to keep the heat from rising to the bowls directly
Also insulate your fuel line going to the carb from the motor as well as any filter.
hope this helps

 

[C Body Bob]

I have tried a variety, but have not noticed a difference with regard to this issue. Will a 1" 4-hole spacer be too much?

Every car is different, but I think that too high. And it may cause throttle linkage & kick down linkage issues.

 

[celticwarlock]

Every car is different, but I think that too high. And it may cause throttle linkage & kick down linkage issues.

All of that could be remedied easily enough. If it was of any benefit, I would go up to 1", but that is what I need help determining. I would like to make an improvement outside of the heat soak issue, if that is possible.

 

[C Body Bob]

You can try a 1 incher, but I think the heat sheild is your friend along with the 1/2 incher. All of that with the 3 gaskets is going to be pretty high. I believe Summit & Jeggs sells this pre packaged. You may need to trim the shield to clear stuff. Make sure your return springs aren't binding or too tight

 

[celticwarlock]

I think I will use the Play-Doh test to check for hood clearance and see how much of a gap there is to begin with. Maybe 1" will not be possible anyway, which would make the decision easier.

 

[C Body Bob]

I would try just the heat shield by its self. Those things work pretty good.

 

[WorkerBee]

I would try just the heat shield by its self. Those things work pretty good.

x2

Insulating/wrapping the fuel line helps to.

 

[1978 NYB]

Go with the heat shield. You need to shield the fuel bowls on that Holley. Jeg's and Summit sells them.

 

[livininharrow]

I am looking into putting a carb spacer on my motor ('69 440, stock, in a '69 NY, with a Holley 650 on it). Heat soak is causing fuel-related hot starting issues, and I have heard that a spacer may help significantly. I am willing to try one, but how tall should it be? Should it be an open, a 4-hole, or a combination spacer? I am not expecting an increase in power anywhere, but if it makes any sort of difference, I'd like to make the best choice I can. After a lot of reading on the subject at various sites and getting no clear answer, I figured it is best to consult the gurus here, especially since this will be installed on a C-body. I suspect that much of what I read regarding a boost in HP will not apply in my case, given the nature of my set-up. This is primarily for insulating carb from engine heat, but if one particular design has any additional benefits that I would notice, so much the better.

a half inch phenolic open hole spacer should be fine. if you are worried about hood clearance which you should not then I just take a loose ball of tin foil and put it on top of the breather and close the hood slowly. it will crush down and stay there for measurement purposes.

 

[celticwarlock]

That's what I use the Play-Doh for, but the aluminum foil is an excellent idea. I think I will go with the heat shield and trim it where necessary. Thank you for all the sound suggestions.

 

[cbarge]

You are on the right track thinking about the carb spacer.
I had posted this in a few other threads and I hope it helps you.
I,too had a 66 300 that had heat soak issues.
This is what I did.
1)Removed intake,blocked the heat crossover.
Big Blocks love to build heat and this area can be the main culprit of heat soak.
You may want to go manual or electric choke since the factory choke will not work since it relies on the heat from the intake to work.

2)Wrap insulation in tin foil and place atop the turkey pan intake gasket tin.(Typically the factory installed this but after 40 years it is toast) .
This also blocks heat and also reduces any engine noise.

3) Used the Edelbrock 1/2 open face spacer kit. Clears hood,no fussing with the throttle cable/kickdown linkage.

4) Used heat sheathing on fuel line. make sure fuel line is NOT touching any part of the engine to attract heat (i.e valve cover,etc).

With a heat laser gun,before the work,the carb was hot at around 250/265 degrees F when the thermostat is open,engine warmed up
After the work was done,base of carb was down to 106 degrees F!!
Go the extra mile,pull the intake and block the heat crossover.
Eight bolts and B/RB intakes are dry--no coolant to deal with.
Did mine in one afternoon.

 

[celticwarlock]

I drive this car in cold weather, so I'd like to keep the heat crossover (though when it is time to change the intake, I can revisit the issue). In the meantime, I will seek to employ what you have suggested.

 

[68Bigred]

I finally got around to blocking the crossover, huge difference! I was having idle issues when hot.

 

[Snotty]

Clearance issue are also going to involve your air cleaner. I attempted to put a spacer on my '70; with a dual-snorkel air-cleaner the hood would not close.