340/ 650 too small???

[Pentastar Pete]

I have a 73 Challenger 340. bored .60 over. Stock heads, 484 lift cam, stock mopar ign. / silver box. 727 auto trans w/ shift kit.  Rear: 3.91 sure grip.   
I have a Demon 650 carb.
In the 1/4, my best time is 14.2 at 95mph w/ both street and slicks.
I thought it should in the 13's..... Some guys are saying it's unde-carbed...
Any ideas?
Thanks

[sleepychallenger]

interesting, my 383 is running a 625 CFM and seems to run really well with that size carb

[Chryco Psycho]

yes it is too small IMO , the later 340s had a 750 TQ earlier had the 6 pack , this may not be the whole problem though , tuning could get you a long way

[Pentastar Pete]

Thats what I thought... But I wanted to hear it from the pro's...
Thanks for the input......

[GoodysGotaCuda]

I have a 73 Challenger 340. bored .60 over. Stock heads, 484 lift cam, stock mopar ign. / silver box. 727 auto trans w/ shift kit.  Rear: 3.91 sure grip.   
I have a Demon 650 carb.
In the 1/4, my best time is 14.2 at 95mph w/ both street and slicks.
I thought it should in the 13's..... Some guys are saying it's unde-carbed...
Any ideas?
Thanks

I have a 318 with a 650 avs carb, about same cam, stock 360 j-heads, +.030, same ratio and a 3500stall. I've ran a 14.0 was my best, i have a feeling i need more as well..

[Pentastar Pete]

As soon as I get some $$$$,  I'm going for the 750..... Then I'll be test running it at Island. But, that won't happen until spring.....
Hey, GGC, If you get the carb before I do, let me know how you like it....
Thanks.............
 

[Alice]

Seriously I'd stick with the 650 and work with the tuning. What demon is it... road, speed or mighty? I have a similar combo that loves it's 650 mech secondaries.
 I have heard of issues with plugged internal passages with demon carbs causing problems.

[GoodysGotaCuda]

Ya brought this thread back from September 2007 

[Alice]

Ya brought this thread back from September 2007 

well, it was a good year. Shall I pour you a glass?

[Ck[FIN]]

Properly tuned 650 demon with camshaft under .500 lift cam will be enough with those stock heads. Make sure everything else is right before you change the carb.


I have run my 360 (0.060 over) with 600cfm holley vacuum pretty well. 13.8s 1/4mile 3330lbs car 3.23 rear end 727 trans. I have about 0.500lift, stock j-heads with stiffer valve springs. air gap intake.

[moper]

BG uses wet flowed ratings... If it were tested apples to apples with the 750 Holley HP (which is dry flow tested) it would flow closer to 730cfm. The MP 484 needs decent static compression to run really well, and it sounds like you have no stall convertor... With a 28" tire and 3.91s, the engine may feel sluggish. I think the carb is fine. Bigger one will only slow it down. but I agree it should be faster. I'd say get a cylider pressure reading to seee if the engine is doing what it should. (I know, old thread, but the i figured I'd answer it anyway...lol

[71chally416]

What kind of 60 ft time does it do?