Thermoquad question

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RogerK

RogerK

Roger Kizer
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OK,
I just repaired my TQ's warped bowl with the bowl from a donor carb. Pretty straight forward. Its a 9014 carb from a 1974 400 cid CA AT car. Trying to gain some fuel economy I just swapped the secondary jets from 5143 to 5137, the rods from 2005 to 2103 and left the 4098 primary jets in place.

I have a pretty stock 318 V8, cast iron stock intake with the EGR blocked off, stock 904 tranny and 7 1/4 rear. The car ran great and I was getting 18 MPG before the bowl warped.

The question is how much of a difference is there running a big block carb instead of a small block carb? Does the 1 3/8 bore for the small block carb make that big of a difference over the 1 1/2 bore for the big block?
 
Dispite the larger primary bore size, mileage shouldn't be effected IF you can tune the carb back to the same state as the smaller primary carb. Throttle response will dip a little bit between the 2 carbs.
 
rumblefish360 said:
Dispite the larger primary bore size, mileage shouldn't be effected IF you can tune the carb back to the same state as the smaller primary carb. Throttle response will dip a little bit between the 2 carbs.
Click to expand...

The carb I have with its stock jets and rods match with a earler model for a 340, the only difference being the bore size. The throttle response I have is a little flat with the bigger bore.

Good info, thanks.
 
Your welcome. Try a ever so slightly richer mixture. It should help ever so sligtly but it may not clear up the flat feel you have due to the loss of velocity with the bigger bore primary.
 
It will require some tuning, and some learning if you're not real familiar with them. I put the larger one on my 318 and pulled half my hair out before I got it to work the way I wanted. It screams now. I do however have a larger cam and headers, so that might make some difference.

I was determined to use it, as I have not used one in the past. Everybody said put a holley on it which made me even more determined LOL.
 
badsport said:
It will require some tuning, and some learning if you're not real familiar with them. I put the larger one on my 318 and pulled half my hair out before I got it to work the way I wanted. It screams now. I do however have a larger cam and headers, so that might make some difference.

I was determined to use it, as I have not used one in the past. Everybody said put a holley on it which made me even more determined LOL.
Click to expand...

Glad to hear you got it tuned. It was worth it too wasn't it? The TQ is head and shoulders above anything a Holley can do on the street when it's right.
 
Well, a lot of my problem was garbage in the tank, I took that out and reconditioned it this winter and blew the line out real good. Then of course I had to disassemble the carb again and clean it out, and discovered that I had messed the gasket up around the wells. All that aside it runs and tunes now much better. I have about 50 bucks in it, and like I said it runs like a scalded dog.

As for me I will pick up a few more when I find them on the cheap, if they are the non smoggers, rebuild them for future use.

I have one I picked up from a 340 that is next on the list for rebuild. Again it will be a 50 dollar carb. I don't think a person can go wrong with a TQ. I will be looking at swap meets for a 9801 this summer.

All in all I am glad I learned it and used it.
 
If you can find the Superquads, they are about the best ones. They were the later competition series. They were made in the 80s. 9800S is the phord and chebbie and 9801S is the Mopar. They are both the same except the throttle linkage. I would look for either. All you need for the 9800S is the Mopar linkage adapter. I have two of the 9800S carburetors. Always lookin for more.
 
This is all good info. The more I look into them the more I like them. It keeps my MoPar all MoPar and it runs better than the new Eddy carb I have now. If anyone has a small block TQ to sell cheap I would be interested.
 
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