351C timing problem?

[automart]

I have a 1970 351C Mach I that I am almost to the end of a 3 year restoration. The car will not start unless I move the timing up to where it is too high, if I drive it, it starts to ping so I retard the timing to where it suppose to be. After it cools off (say the next day) I have to do the same thing to get it started. I have the MSD distributer just installed out of the box. The car is running extremely rich. I have a newer Holley 780 and a stock 4V intake with a small cam, 4 speed transmission.

Any help would be appreciated.

Thanks,
Ronnie

 

[ForceFed70]

Same problem when hot and cold? You say it's running rich, have you tried adjusting the idle mixture?

 

[bnickel]

need to recurve the dizzy so you can get the correct total timing with less initial timing. you may also want to re jet the carb at the same time as well, the riche condition of the carb may be requiring more timing to get the fuel mixture burned, however it won't be so bad as you describe. either way the dizzy needs to be recurved

 

[automart]

I have no idea what the "dizzy" is. The distributer was suppose to be a drop in, I don't remember reading anything

The car will not start cold without advancing the timing. It hits like it's going to start but only when I advance the timing will it start.

I have a couple of issues, I have tried the air/fuel adjusting but it doesn't effect the motor too much. I may have a vaccuum leak at the rear of the intake (there is oil around the oil sending unit, but it is not the unit leaking) I have a Torker purchased that should be here any day now.

 

[ratio411]

Did you rebuild the engine?

 

[automart]

Yes, the motor is newly reubuilt along with everything else. Getting close to the end and tired of spending $$$$$

 

[D.Hearne]

Your oil leak at the rear isn't a vacuum leak. And as for the pinging problem, are you trying to run this 11 to 1 motor on 87 octane fuel and a small cam ? That would explain a lot there, if so. This motor needs 93 octane premium at a minimum, and likely more octane to advance the timing where it'll put out and quit pinging.

 

[ForceFed70]

These engines are really forgiving when it comes to timing at idle. You should be able to get it to start with anywhere from 0* to 20* initial timing.

I don't think the problem is the actual timing. I think that adjusting the timing makes the symptoms better.

What are your plugs gapped to? Have you tried bypassing the MSD?

 

[automart]

no, I'm doing the 93 with octane booster. Your right, 11:1 compression. Sounded great before I had the exhause put on. It still sounds good, I just prefer the straight headers, too bad it's against the law. I've done the magnaflow with the X pipe.

 

[automart]

Bottlefed,

I have installed 3 sets of plugs gapped at 32? and the car is not ready for the road yet. I had the carb rebuilt which seemed to help (it set for 3 years)
I still don't know what the "Dizzy" is. I have the MSD dist and regular coil.

 

[bnickel]

Bottlefed,

I have installed 3 sets of plugs gapped at 32? and the car is not ready for the road yet. I had the carb rebuilt which seemed to help (it set for 3 years)
I still don't know what the "Dizzy" is. I have the MSD dist and regular coil.

dizzy is short for distributor. very common around here i'm surprised you didn't know what it is but also apologize that my use of the word confused you.

 

[automart]

THanks, I know now! So I assume the way to go is to advance the distributer, I hope I can find the instructions.

 

[BIGJUNE]

I think you need to redrop ur distributor it sounds like ur a tooth or two off.

 

[automart]

I received my intake yesterday so I'll do that and see what happens.

Does anyone know approx what size jets on a 780 to use for a 351 C, stock with a medium cam?

Thanks in advance!

 

[D.Hearne]

You've likely got a list #3310 carb? Not a 780 but a 750. Primary jets are 72's. If that's what's there, go with them. If your car's not driveable, leave that till you can. You cannot accurately jet the carb idling in the driveway.