What to do with the carb ??

-
M

MoparFan

Well-Known Member
Joined
Jan 30, 2005
Messages
147
Reaction score
0
Location
Montreal south shore
Hi,
I have two questions.

First, I have two ThermoQuad carb one 9243s and one 9108s. The 9108s is supposed to de around 750cfm and is primary have a diameter of 1.5" . The 9243s has smaller primary, 1.37" in diameter.
Does anyone knows what would be the cfm of the 9243s?

Secondly, I have a tired (around 90psi compression) 318 in my Dart. I will install headers (Hedmann, Hookers...not expensive one) soon, because the whole exhaust is all crap (single cheapo fitting) anyway. I also have a single plane Holly Street Dominator intake. So...should I keep the 2bbl setup, until I rebuild/change the engine or I could put one of these 2 carbs and it will run great?

Thanks :thumblef:
 
With 90psi cranking pressure nothing you do is going to make it rn great till you rebuild it.
 
AdamR said:
With 90psi cranking pressure nothing you do is going to make it rn great till you rebuild it.
Click to expand...

Yep sadly I knew that... :sad2: But what I am looking for is, with the engine as it is, will I improve something with a 4bbl setup with one of these carb?
I remember having read somewhere that using header tend to lean the mixture, so I tought maybe I should go 4bbl even if the engine is in bad shape.
I will change or rebuild the engine this ummer or next year...I had to face reality, it would be better to be sitting decently in a slowly running Dart, then a having a powerfull Dart and no decent interior :D

Also, anyone has any info on the TQ 9243s?
 
There were 2 different thermoquads. The only difference was the size of the primary bores. The large bore was supposed to be 850 cfm. I would have to guess that the smaller one was around 750 cfm. I will tell you that putting a single plane intake on a stock tired 318 will turn it into a real stone. If you feel the need for a 4bbl, a factory 4bbl intake or a edelbrock Performer (not performer rpm or airgap), would make for a MUCH better running car. Save the single plane and the big thermoquad for that new motor (if you're gonna rebuild it anyway, do a 360). That 318 with only headers will like one of the 2 above intakes and that smaller carb. Trust me.

don
 
1968FormulaS340 said:
No point in a carb swap. Get a good long block or rebuild first. Don't wast your money on a dead horse.
Click to expand...


I agree under 100 psi is tired,

I would double check that the exhaust flapper is open on the passenger
side exhaust manifold,
and for less money, get duals off the stock manifolds.

You will notice a difference even with a 2bbl. :)

Works fine for me.Before I rebuilt my 318, to replace my tired 273;
i had the dual exhaust installed, using Dynomax Super Turbo mufflers.

Great mufflers, not as loud as Flowmasters,but still have a nice sound.

If your heart is set on a 4bbl on a 318 i suggest a slightly bigger cam,
when you finally rebuild the engine.

The stock cam is not enough to make use of a 4bbl.

I am using a Mopar Performance .430/.450 lift cam,and the recommended
springs to match.

I love the setup.
 
You must log in or register to reply here.
-

Back
Top