SAY IT AINT SO!!!!!!!!!!
11-14-2003, 06:28 PM
#1
Drifting
Thread Starter
Member Since: Nov 2003
Location: chicago IL
Posts: 1,410
Likes: 0
Received 0 Likes
on
0 Posts
SAY IT AINT SO!!!!!!!!!!
We running a 750 cfm Speed demon carb with a performer RPM intake on an otherwise stock L-82, BUT our carb is running FILTHY RICH, we called around and a bunch of people said that it is WAY TO BIG, i want to know if its possible to run the 750 without getting a supercharger or changing the rotating assembly, wer planning on getting cam and lifter kit as well as port matching the heads. ANY HELP WILL BE APRRECIATED :confused: :D
11-14-2003, 06:49 PM
#2
Racer
Member Since: Apr 2003
Location: Katy TX
Posts: 349
Likes: 0
Received 0 Likes
on
0 Posts
Re: SAY IT AINT SO!!!!!!!!!! (killervette666)
A 750 Demon is like a 850 Holley. Your carb is too big for a stock 350. You should be running a 650 or so. You can try to change the jets to 73/83 and maybe the power valve as well.
[Modified by bhmyers, 11:49 PM 11/14/2003]
[Modified by bhmyers, 11:49 PM 11/14/2003]
11-14-2003, 08:43 PM
#3
Drifting
Thread Starter
Member Since: Nov 2003
Location: chicago IL
Posts: 1,410
Likes: 0
Received 0 Likes
on
0 Posts
Re: SAY IT AINT SO!!!!!!!!!! (bhmyers)
Were thinking of trading it in for a 625 Road Demon.. Wat do you think, will it provide enough power if we change cam/port heads? :confused:
11-14-2003, 09:12 PM
#4
Melting Slicks
Re: SAY IT AINT SO!!!!!!!!!! (bhmyers)
A 750 Demon is like a 850 Holley. Your carb is too big for a stock 350. You should be running a 650 or so. You can try to change the jets to 73/83 and maybe the power valve as well.
Given a choice i'd rather go with the carb with the big holes.
11-14-2003, 09:36 PM
#5
Safety Car
Member Since: Feb 1999
Location: Fountain Hills AZ
Posts: 3,625
Likes: 0
Received 10 Likes
on
10 Posts
Re: SAY IT AINT SO!!!!!!!!!! (killervette666)
Under what conditions is it running rich? Idle? Cruise? WOT? While a 750 is more than a stock L-82 needs, it's not grossly over-carbing. Speed Demons are jetted more for a modified engine than for a stock smog motor so some adjustments may be needed. If the over-rich condition is just at idle, the solution could be as simple as adjusting idle mixture.
11-14-2003, 09:46 PM
#6
Drifting
Thread Starter
Member Since: Nov 2003
Location: chicago IL
Posts: 1,410
Likes: 0
Received 0 Likes
on
0 Posts
Re: SAY IT AINT SO!!!!!!!!!! (Vetterodder)
It running rich at all RPMs,are q-jets really 850? i find that hard to beliveve, would it be worth goin to 625 road demon?
11-14-2003, 10:00 PM
#7
Racer
Member Since: Apr 2003
Location: Point Pleasant NJ
Posts: 486
Likes: 0
Received 0 Likes
on
0 Posts
Re: SAY IT AINT SO!!!!!!!!!! (killervette666)
Didnt lars just make a post on this very subject. Let me go look and I will link you to it.
Indeed Lars strikes again... good luck
http://forums.corvetteforum.com/zerothread?id=688640
[Modified by Spook, 10:01 PM 11/14/2003]
Indeed Lars strikes again... good luck
http://forums.corvetteforum.com/zerothread?id=688640
[Modified by Spook, 10:01 PM 11/14/2003]
11-14-2003, 10:09 PM
#8
Race Director
Re: SAY IT AINT SO!!!!!!!!!! (Spook)
Quadrajets and square bore (Holleys) should not be compared on CFM's. Taks a look at the quads primary venturies, very small comapred to a Holley. You would need a much bigger ( CFM wise ) quadrajet to replace a 750 Holley. :D
11-15-2003, 05:17 AM
#9
Le Mans Master
Re: SAY IT AINT SO!!!!!!!!!! (killervette666)
I hear this a lot.. "My carbs too rich"!... There is a difference between too rich(too much fuel to air ratio) and too much of the correct mixture. An incorrectly set up 200cfm carb can flood an engine and run so rich the engine will smoke black and foul plugs. Even a correctlly set carb that is too big shouln't do that. Granted, it may not perform to it's potential but it should run ok except maybe at WOT. I think you have a carb tuning issue. I don't know anything about the Demon carbs but they are still a carburetors and the same rules apply..
