Started new engine!

[mpro69rr]

I'm not too sure the current Demon (which is not very Quadrajet like) is well suited for a big cammed 383. Just speculating.

When I was researching the new demon it said it was on the principle of a quadrajet. This is the street demon, not like the old demons, which they still have.

 

[RemCharger]

Pic of the carb? And the cam specs if you can find them?

 

[mpro69rr]

Pic of the carb? And the cam specs if you can find them?

Carb I have at https://www.holley.com/products/fuel_systems/carburetors/street/parts/1904

The cam specs are:
Intake hyd - .544
Exhaust hyd - .541
Duration intake - 236
Duration exhaust - 242

 

[BSB67]

It's not a spreadbore carb

At least not in the conventional sense, I think. Will it work on a square bore intake? Maybe not.

 

[BSB67]

Carb I have at https://www.holley.com/products/fuel_systems/carburetors/street/parts/1904

The cam specs are:
Intake hyd - .544
Exhaust hyd - .541
Duration intake - 236
Duration exhaust - 242

Thanks. We know what carb you have.

What is the cam overlap and seat timing?

 

[mpro69rr]

Thanks. We know what carb you have.

What is the cam overlap and seat timing?

Hmmm, I don't see that on the paper I have.

 

[RemCharger]

I didn't see where the intake was posted

 

[mpro69rr]

I didn't see where the intake was posted

Edelbrock performer RPM
Performer RPM heads too

 

[BSB67]

Edelbrock RPM

Well, that answers that question.

 

[RemCharger]

OK. Just wondering about the 3 bbl carb thing. carb gasket was checked that theres no overhang/ decent throttle bore alignment etc..Throttle opens fully..
But yeah Id call that a Thermoquad.

 

[mpro69rr]

OK. Just wondering about the 3 bbl carb thing. carb gasket was checked that theres no overhang/ decent throttle bore alignment etc..Throttle opens fully..
But yeah Id call that a Thermoquad.

Yes, I checked all those things when I installed the carb. One thing I haven't checked yet was vacuum leaks. I'll have to check that.

 

[BSB67]

OK. Just wondering about the 3 bbl carb thing. carb gasket was checked that theres no overhang/ decent throttle bore alignment etc..Throttle opens fully..
But yeah Id call that a Thermoquad.

Considering its basically a square bore carb, how is it not more like an AVS?

 

[RemCharger]

Considering its basically a square bore carb, how is it not more like an AVS?

The plastic main body is primarily a T-Quad attribute.. Looks like they just crunched the 2 big secondary blades together into 1 flap. Making it closer to a square bore.

 

[khryslerkid]

Backfires through carb. Carb issue???

Still think it's timing issue. Triple check firing order.

It might have been asked before but what rockers are you using? Could be settings are too tight and holding an exhaust valve open.

 

[MoparLeo]

Modern take on a Carter Thermo-quad carb (Factory Mopar Performance carbs ) Excellent by the way. Many times incorrect linkage setups on aftermarket carbs. A look at your linkage, manifold, spacer, carb with Pictures would help a lot. If you are having trouble with that, ask for someone with a cell phone camera to help you out.

 

[mpro69rr]

Backfires through carb. Carb issue???

Still think it's timing issue. Triple check firing order.

It might have been asked before but what rockers are you using? Could be settings are too tight and holding an exhaust valve open.

Yes, checked the firing orders several times. Not sure on the rockers, probably should put that on the list of things to check.

 

[mpro69rr]

Modern take on a Carter Thermo-quad carb (Factory Mopar Performance carbs ) Excellent by the way. Many times incorrect linkage setups on aftermarket carbs. A look at your linkage, manifold, spacer, carb with Pictures would help a lot. If you are having trouble with that, ask for someone with a cell phone camera to help you out.

I'll Take some pics when I get home from work tonight.

 

[BSB67]

The plastic main body is primarily a T-Quad attribute.. Looks like they just crunched the 2 big secondary blades together into 1 flap. Making it closer to a square bore.

And the secondaries are 1 3/4", like a large square bore Holley

 

[BSB67]

Backfires through carb. Carb issue???

Still think it's timing issue. Triple check firing order.

It might have been asked before but what rockers are you using? Could be settings are too tight and holding an exhaust valve open.

Right. A true backfire would likely still be timing.

 

[mpro69rr]

Right. A true backfire would likely still be timing.

I'm thinking its timing, I did the initial but not full yet, so I'm going to get that done.