Newly rebuilt 351W problems

[Texasdoc]

Thanks for everyone's help! Simple things first. I had a bad plug. Replaced and gapped to .45 (up from .35). Now it runs smoothly and idles at 850! Runs well with a little hesitation when the secondaries open. Gonna try to open the secondaries a touch to get a little fuel going thru the transfer circuit. Right now they are closed. Before it was idling at 1300 with a square slot.

Now I gotta work on the advance. Stock Proform advance is 24 degrees but it doesn't start advancing until 3000 and isn't all-in at 5000. My car is 2200 pounds. I read that I need to start at 1500rpm and be all in at 3000-3500. Base timing set at 14. Distributor's mechanical advaince is 24 for a total of 38. Not sure what the vacuum advance amount is. Is there a case of too much advance? What should the (base + mechanical + vacuum) maximum timing be?

[DAVID GAGNARD]

I'm not familiar with the Proform distributor, but all distributors have springs in them that determine how fast or slow the advance comes in....sounds like yours has some very heavy springs or corrosion that is slowing down the mechanical advance.....you want your advance to start coming in around 1500rpms and all in by 2500 to 3000 rpms, sounds like you need to change the springs.......

A little tip for checking for a grounding problem, wait till after dark, then open the hood and start the car,if you have spark jumping from a cracked coil or bad plug wire, you'll see it right off.........

David

[Tommy]

It seems like every mechanical misfortune has been encountered by someone on this forum at some time or another. And many of them are willing to share their knowledge. Cool place!

[Clois Harlan]

I had Keith Craft build me a 351 Windsor Engine stroked to 408 and we tried the ProForm Distributor and ended up swapping it out for a MSD for some of the same symptoms you are mentioning. I also used a 750 Quick Fuel Carb and couldnt' be happier. The Proform distributor is almost all GM except for the drive gear and the machined part of the shaft. What we found was that there was significant play in the distributor causing fluxuations in rpms. My vote is for a good Ford Distributor or a MSD and a QF Carb.

Clois Harlan

[CHANMADD]

I would think that you are sucking air somewhere. The proform dizzy also should have adjustable vacuum advance adjusted by using a small Allen key up the vacuum advance hose connector on the dizzy. There is no way I would use an msd in preference. You replaced the intake , could be a leaky gasket or........power valve......or carb...

[Mike_I]

Originally Posted by Texasdoc

I flattened 3 cam lobes on a tappet cam on initial startup. Yes, the idle was high before the cam change but it wasn't running long enough to tune. That was when I went to the roller conversion kit. Looked and sprayed everywhere looking for a vacuum leak.

Hello, do you know what caused the wipe out of the 3 lobes on the previous camshaft? Could the cam timing have been off or the vavles adjusted improperly? If so, you could have bent some valves and/or pushrods with the old camshaft that could be causing the problem you are having now. Another possibility is that you have the valve lash too tight and when the lifters pump up the vavles are not closing completely. Hope this helps. Good luck with everything.

-Mike

[Caprimaniac]

It did sound as your carb butterflies/ bearings/ shafts were "off" and leaking to give too high an idle. Well, you did get that sorted.

To get the advance in earlier, you can try remove one spring, pull one spring to a greater length (have to take it out) to trick the dizzy to see a lighter spring or to get- in one way or another- a lighter spring or two in there.

I guess you should have full advance in around 3000/3200.

You might wanna set total advance to about 34- 36 deg. There might be a way to adjust that in your dizzy. 38, by the way, is not totally out of order.

[Wbulk]

This is an article on setting up your dist. advance. This is a Ford dist. but the concepts are the same.

Dist. Advance Re-curve