Chevelles.com banner

Status
Not open for further replies.
1 - 9 of 9 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
i have a 72 chevelle with a 350 and HEI.i have a edelbrock performer intake, and a performer carb #1407(750 cfm, manual choke), i have the plugs gapped at 0.055, and and the timing advanced to about 4 degrees ATDC. i have a summit racing fuel line w/-6 an fittings, and a spectre clear view fuel filter. anyways to make a long story short, on hard excelleration, or when i floor it, it will either stall completely, bog down, or back fire. the bogging occurs also when i first start the car, and haven't warmed it enough. why is this doing this???? i also have crappy fuel miliage. help me please!!!! thanks in advance

mike
 

·
Registered
Joined
·
4,973 Posts
Put more timing in it and curve it to come in earlier. If you have the '72 dist. in it, its set for smog specs. Not good. Get a curve kit and change it. Change to an electric choke (there is a kit for this) and set it properly. This will prevent the bogging while cold. You'll be amazed at the differences these changes will make in driveability.

OOOOPPPPS sorry, didn't notice the edelbrock carb. on my previous post. Thanks Joe.....

[This message has been edited by d1_bradley (edited 05-13-99).]

[This message has been edited by d1_bradley (edited 05-13-99).]
 

·
Registered
Joined
·
1,747 Posts
Timing set to 4deg ATDC? If this is true the timing is retarded not advanced. It should be at least 4deg BTDC.

------------------
Steve Strasemeier (70SS)
 

·
Registered
Joined
·
35 Posts
Edelbrock Performer Series carbs don't have power valves. Cruise and power modes are controlled by the Step-up piston.
 

·
Registered
Joined
·
22 Posts
Sounds like you have too much carb for you motor, or if you are still using the stock calibration, you are way rich. I think a 600 CFM would work much better.
I would change your primary and secondary jets at least 2 sizes smaller and then see if you still have problems.
I agree with Steve S, check your timing.
You should be at 34-36 degree total at 3000 rpm.
The only time I have seen a back fire through one of these carbs is when the timing is off. Your plug gap may be to wide, try .045. This is what most people run with a HEI and MSD box. If you need more info on the carb, email me.

Brian

[This message has been edited by Brian n az (edited 05-12-99).]
 

·
Registered
Joined
·
19 Posts
Need to know if this is a brand new carb or a used carb. The difference would be that a new carb should runs fairly well, even without being tuned, on a near to moderately stock engine. If this is the case, then concentrate on either timing or a vacuum leak.
If the carb is used (gas been sitting in it for over a year), then it could be timing or carb related.
You need to bring some of the hardware back to normal op conditions first (regap plugs to .045 - large gaps cause hard starting). Then start with the idle circuit, and tune that in. Once you have the engine idling correctly proceed with off-idle and driveabilily. Once it seems to operate correctly at off-idle speeds, then tune the accel area (which by this time, might already be tuned in).
 

·
Registered
Joined
·
158 Posts
I agree with Brian, you have too much carb for your application. I have a stock 350/300hp with and Edelbrock #1405 (600cfm) which I installed fairly recently. My problem was the opposite, the stock setup was too lean for my application so I richened it up by going two stages richer on the rods, primary and secondary jets and she runs like a champ now. Since Edelbrock doesn't make a 650 you have to improvise. don't bother trying to return the carb, because it will be a NIGHTMARE - trust me, been there done that! Take Brians advice and go 2 stages leaner on your rods and jets. You will need the following parts to do this:
Primary Jets - #1431 (.107)
Secondary Jets - #1429 (.101)
Rods - #1445 (065x047)

They are very easy to change out yourself.
Also like Joe said you did not blow any power valves, cuz Edelbrocks don't have that problem like Holley does.

If you need help email me...I've been down this road and thanks to some help from folks here I got it fixed pretty quickly.


------------------
 

·
Registered
Joined
·
25 Posts
Discussion Starter #8
a couple of things i forgot to mention.the carb is brand new, the timing is 4 degrees btdc. also i have an air pocket in the fuel filter, how do i get this out???? could this be the cause??? if i am running rich, what will my plugs look like? after running it for a few days the #1 adn #7cylinder plugs smelled,and looked like that were sitting in gas(flooded?) thanks for the help

mike

[This message has been edited by 7duecemalibu (edited 05-13-99).]
 

·
Registered
Joined
·
158 Posts
If your plugs have fuel on them, that's a sure tell sign your running way too rich. How do the other plugs look?
 
1 - 9 of 9 Posts
Status
Not open for further replies.
Top