750 Mighty Demon on my 340?

-
jimbo

jimbo

Well-Known Member
Joined
Jan 2, 2008
Messages
344
Reaction score
13
Location
Seattle/Tacoma
I am running a 550 Edelbrock now and it does fine. I'm curious about what a difference in performance I can expect and is it worth the $700 for the carb and all the do dads that go with it.
BTW 2.02-1.60 valves, ported heads,and 480-287 camshaft.
 
I'm not a fan of Demon carbs,they can be very tempermental ran one on my previous duster and it took some time to get it to perform correctly,by the time i had it running good i sold the car..i'm running a Quick fuel technology carb now its hand down the best carb i've ever used..little pricey but not to bad at $650.00...
 
I'd go w/ a 650 for a 340. Save the 750's for the big blocks or if you stroke it someday to 416. It's a little overkill for your combo (IMO). Bigger is not always (rarely) better in this case...

Don @ FBO recommended a 650 for my 340 and it's got 11.1 compression, ported heads 2.02/1/60's, .508 Purple cam and an Eddy RPM intake. They'll get one set up just right for your car.
 
Beatnik said:
I'd go w/ a 650 for a 340. Save the 750's for the big blocks or if you stroke it someday to 416. It's a little overkill for your combo (IMO). Bigger is not always (rarely) better in this case...

Don @ FBO recommended a 650 for my 340 and it's got 11.1 compression, ported heads 2.02/1/60's, .508 Purple cam and an Eddy RPM intake. They'll get one set up just right for your car.
Click to expand...
So I will be better off installing this unit on my new .030 HP 383 with the 906 heads, hemi grind comp cam and 727 auto? The carb on the 340 is only 550 cfm.
 
The Demon I had lasted 2 weeks on my 360 before I ripped it off and threw it in the corner and then sold it at the Portland swapmeet for dirt cheap.

They are one of the smoothest carbs I have ever played with but the quality is crap and you have to retune it everytime you drive the car and that is after 2 rebuild kits.
Go with a bigger Eddy or a Holley but I would say if it aint broke...

If you want a spiffy new carb I would jump on the one that KSP has for sale.
 
The 340 came stock with an 850 CFM unit. Is this true???? If so a 750 would do just fine, besides it's already on the shelf with the box collecting dust. This is not a commuter car, I plan to do a little bracket racing this year once I get it tuned.
 
a 750 will run fine on a 340 if its tuned good...

I think for the money that carb the guy above is selling would be a decent deal for sure.. nothing wrong with a 650 dbl pumper..
 
Hmmm, I love all my Holleys for the last 25 years but this winter I got a Demon 650 race carb-with removable boosters-for just $315 from Jeff Gordon racing school-1 year old and with E-bay you never know what you get. This was one of the better deals.

I love my Demon now. A few things are nicer, using a steel fuel line and the fittings on the float bowls are much larger and easier to get a good grip on. The base plate linkage has 2 positions to open the secondary's, just need to switch links. The idle discharge holes are the 1 3/4 base plate type, so if ever I want the put a 1 3/4 base plate on it, all that needs to be done is a little grinding.

The float blow screw threads are hel-coil already and the adjuster screw for the level is easier to tighten than a Holley.

Was able to get it to shine with just a little bit of metal polish-yeah it does nothing for it but it looks great, almost like chrome.

Running it on a Mopar 318 with M.P. high swirl 360 heads and a little cam from Mike Jones-220 @ .050. I needed to open the IFR to .033 and reduce the IAB to .67 and jet it DOWN to 68 all 4 corners. Thought the stock 70 jets were fine till it warmed up here, then I found it was too rich. Using a RPM intake with the exhaust heat open-its still freezing here in MI at night time.


PS..Demon air bleeds stink, too small, the Holley air bleeds screw right in and are much nicer, only thing I found thats better.

shiny (Small).jpg
 
You must log in or register to reply here.
-

Back
Top