secondaries hitting intake

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burdar

Owen's Dad
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I have a brand new Edelbrock Thunder series carb #1806 and a new Air Gap intake. I'm 99.9% sure these carbs are supposed to bolt right on to this intake without a spacer right?

I just mounted the carb to see what linkage adjustments I have to make. I noticed the secondaries weren't opening all the way. I took the carb off and they opened just fine. The secondaries are hitting the inside of the intake. I know aftermarket parts will need work to fit but I wasn't expecting this.
 
Darren, I had to have the seconday ports of my intake enlarged for my Edelbrock carb. Sounds like you need the same thing done too. Mike
 
The thin gasket that came with the carb. I tried it with and without the gasket.
 
X2 A heat shield gasket will lift it a 1/2 inch and on these Edelbrockit's a must do from what I have learned . X2 1968FormulaS340
 
What gasket are you using under the carb?
 
Who's Darwin? Are you getting forgetful in your old age Mike. Lol

Did you have the machine shop do it or just clearance it yourself?
 
You need the heat insulator gasket. It's 1/4" thick.
 
Darwin, I had to have the seconday ports of my intake enlarged for my Edelbrock carb. Sounds like you need the same thing done too. Mike
You could be right Mike, seems I have seen a few opened up a bit (enlarged ) =D>
 
I'm using the thin gasket that came with the carb. I wasn't going to run a phenolic since the Air Gap design is supposed to insulate the carb from excessive heat.
 
Who's Darwin? Are you getting forgetful in your old age Mike. Lol

Did you have the machine shop do it or just clearance it yourself?

Sorry, LOL Woody did it at Radar's shop. Yep, I'm getting old.
 
You don't have to run a phenolic spacer. Just listen to everyone else and do it wrong. That intake is DESIGNED for that carburetor, but you must use the right gasket. Why in the world they don't include the right one I'll never know, but they don't. The gasket you need is a simple, 1/4" insulator gasket. There is no need to grind on anything because they are designed to work together. Millions of people run that combination and don't grind a thing. If you find yourself grinding something, you're doing it wrong.
 
Yep! These carbs hold the fuel to close to the intake, and it is a must do to use the gasket RustyRatRod is talking about, got to keep the heat off the base plate... I don't know way they don't ether Rob :-?
 
You don't have to run a phenolic spacer. Just listen to everyone else and do it wrong. That intake is DESIGNED for that carburetor, but you must use the right gasket. Why in the world they don't include the right one I'll never know, but they don't. The gasket you need is a simple, 1/4" insulator gasket. There is no need to grind on anything because they are designed to work together. Millions of people run that combination and don't grind a thing. If you find yourself grinding something, you're doing it wrong.

Sorry Rusty, Didn't notice the Air Gap intake. If your cab secondaries are larger than the intake, the obvious thing to do is enlarge the hole if a gasket or spacer won't cure the problem. tmm
 
Yep! These carbs hold the fuel to close to the intake, and it is a must do to use the gasket RustyRatRod is talking about, got to keep the heat off the base plate... I don't know way they don't ether Rob :-?

Yep, and the reason they don't include it is probably because they would have to charge another 15 bucks for thier manifolds.:D
 
Mike, that's when I would use an adapter.
 
I'll pick up a thick gasket and give it a try then. If it's required with that intake they should mention it in the instructions. It says nothing about requiring that gasket. I hope the gasket is slightly larger then the intake opening or the secondaries are going to hang up on that too.

I was aware the phenolic gaskets were a must on the traditional intakes but thought the AirGap would work fine without it...guess not. Thanks for the help. I'll check back in and let you know how it works.
 
Edelbrock RPM Air Gap. The secondaries look like they are the same size as the intake opening. Maybe the bolt holes were drilled slightly off or the opening shifted a little.

These were bought from Summit so they shouldn't be counterfeit knockoffs.
 
The secondaries are probably hitting the center divider. With the thick gasket it should clear fine.
 
I wanted to see what Edelbrock had to say about this. They said the thick gasket is NOT required but it is a good idea to use it even on the AIR GAP intake. They also said the intake must not have been machined correctly because the carb should be a bolt-on deal.

I need to figure out where the interference is and Edelbrock will do the machining for free. First, I'm going to pick up a thick gasket and see if there is still a clearance issue.
 
Have you tried bolting the carb on loosely?Open secondaries and move carb slightly so secondaries aren,t catching...bolt down snug.:D
 
I wanted to see what Edelbrock had to say about this. They said the thick gasket is NOT required but it is a good idea to use it even on the AIR GAP intake. They also said the intake must not have been machined correctly because the carb should be a bolt-on deal.

I need to figure out where the interference is and Edelbrock will do the machining for free. First, I'm going to pick up a thick gasket and see if there is still a clearance issue.

That' a first time hearing this for me on one of their intakes. Heads, that's another story. Makes me wonder all the more if Edelbrock's claim if being made in USA is really true.
 
I've been talking with customer service the last two days and have sent them some pictures of the problem. They want me to send in the intake and carb so they can have a look at them. They said sometimes the 1408's will clip the center divider a little bit. This is a different story though. It looks like something shifted when this intake was cast.

I tried spacing the carb up off the intake with washers. With the carb spaced, the secondaries cleared but not by much. It would probably work running the thick gasket but I'll feel more comfortable having Edelbrock look at it.
 
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