Which aftermarket distributor to buy, 351C 4V

[TommyK]

This one that actually does what it says it does.

https://www.summitracing.com/int/parts/mef-100016/overview/?cm_mmc=pla-google-_-shopping-_-srese1-_-race-gas

Good luck at the show.

 

[Stanglover]

This one that actually does what it says it does.

https://www.summitracing.com/int/parts/mef-100016/overview/?cm_mmc=pla-google-_-shopping-_-srese1-_-race-gas

Good luck at the show.

Thanks, I will have fun if nothing else. Freakin' HOT here this weekend!

 

[Stanglover]

I'm continuing MY experience of learning how to recurve a remanufactured factory distributor.

To recap, I have used the experience and advice of many fellow members and learned a lot in the process, so thanks to one and all for that.

What I had done was to resize a slot to an L10, .410" which is 20* on the crank (from a chart) then I used a Mr.Gasket 925D spring on one side and a lighter spring on the other. The initial timing was set at 14* at 800 rpm, manual trans, and with 18"Hg vacuum on the manifold. I use the timed port on the Holley 670. The Vacuum canister is set to about 3-4* giving me a total of 37-38* @ 3000rpm. It ran quite well at this, but needed tweaking a bit more, Little or no pinging on acceleration. I am now using a Pertronix Ignitor II and coil, having ditched the Ignitor III

Yesterday, I got at it again. My intent was to pull the top of the distributor down and add a nylon sleeve to the post to cut the crank degrees down to about 18 then add 2* to the initial. Same numbers just a bit more umph!

What I found was that I had screwed up!! I had the 925D spring on what I now know to be the right side, but a lighter spring on the left.

From the pictures that I got from Cardone, the heavier spring should be on the left, indexed by the rotor slot. So, I installed a factory heavy spring, put it all back together leaving the sleeve off for now.

When fired it up and put the timing light on it, the initial setting had dropped 2* to 12. I readjusted that to 14, reset the idle and took it out for a test. It pulled like train without doing anything else, but it sounded different!! I think now I can still play around with it as it was not as responsive on take-off. I did not get an rpm reading yet as I live in town and can't rev an engine too much.

More later when I get to play with it some more.

Geoff.

EDIT: I think I missed mentioning that Cardone's tech sent me several springs. The "left" were heavier, but not as heavy as the original factory ones. The "right" were about the same as the factory light spring. The picture is not very clear to be honest and the type looks different to 351 C dizzy, but the set-up is the same. Also note the plastic sleeve on the post used as an alternative to welding and re-cutting the slot, or to adjust the amount of crank degrees.

Hope that clears up any misunderstanding.

 

[Stanglover]

Here is the picture link from Cardone showing left and right springs.

Last time I tried to post this, I lost everything and had to start over, hence I'm posting it separately.

 

[Stanglover]

Saturday's update;

I went to a small car show today, more for the drive than the show, but to take a third place home ain't a bad day either.

With the factory heavy spring on the correct side!! it ran very strong other than a couple of times at low speed in 4th gear, it coughed just one time on acceleration. So when I got home I bumped up the initial timing to 16*, then took it out again for a hard run. I could run it all the way to 5500 on each shift with no pinging at all. Even at lower speed in 4th and mashing it, same thing , no pinging. So far I'm happy. I did notice two things though, it was a bit harder to start hot, but the engine was noticeably cooler when I pulled into the garage and shut it off. Before I needed a fan blowing on the engine to cool it before closing the door.

I plan on one more tweak and to record the curve over the rpm range before I call it a day and also to double check my work. I'll post that up later.

Geoff.

 

[Stanglover]

Sunday's up-date.

The first thing I did today was to change the plugs from Autolite 25's to 24's with a .040" gap. As I run a Pertroinx Flamethrower II coil and module, I can run up to .010" bigger gap than recommended, which is .035". I chose the middle ground.

Next I took another look at those picture I got from Cardone. Realizing that they are not the same type, they are for a 6 cylinder dizzy, I decided to re-think the whole thing with regards to which weight goes where. As I know that both the weights are the same, 13gm with the same number stamped on them, I switched the springs. That part is easy, the hard part is getting that stupid little clip on the vacuum advance arm. I lost a half dozen!! (** Oh! I see one in the pictures, didn't see it when I was leaning over the front, I'll get it later I guess**)Then I came up with a plan and used a piece of paper towel, pierced a small hole and put it over the post. That way the clip was not going fall inside again. Problem solved.

With it all back together, I took the car out for a 30 mile run. The settings were; 16* initial + 20* crank + 4* vacuum advance with Autolite 24 plugs on 91 octane Shell gas. The springs on it are the heavy original factory and a Mr. Gasket 925D. The thing screamed, but that low speed issue was still there. From 40 mph, 2000rpm, it bogged slightly then pinged up to 50 mph and from then it just took off. (This issue returned, was it because I changed the plugs?) These engines as we know are designed for high rpm's and it showed.

At the 15 mile turn around point, I adjusted the timing roughly to knock it back a few degrees. The pining stopped and the hesitation was  less. On arriving home, I pulled a plug, definitely better color, not so lean. Then re-set the timing with the light to 14 *. I think that is the sweet spot. Later next week I am taking it to a mechanic I met who is a Ford guy. The object is to run it through the rpm range and see exactly where and when it all happens. Can't do that at home in town.

The pictures are; springs on supposed correct sides, springs on opposite side, A Cardone Select new distributor with a slot welded for 20*, but opposite the rotor slot. Does it matter??

Oops they loaded in reverse order.

 

[Stanglover]

This will pretty much sum up this timing ordeal.

 After a minor tweak to the tension of the heavy spring, still lose, but less than before, I came to the conclusion that as MY distributor has equal size and number weights, it doesn't matter which side the light or heavy spring is on or the relationship to the rotor. That has nothing to do with the timing, just the control of the advance.

So here is what I settled on. 14* initial plus 20* mechanical plus about 6* on the vacuum, still to be double checked. I get no pinging whatsoever with these numbers and curve. Power comes on strong and smooth as far as the distributor is concerned, but I think I can get a bit more by changing the carb pump cam to get a bit earlier shot. I'll leave that to my carb guy though. The plug read looks good with a light tan/brown on the Autolite 24's

Also to recap my motor, it is a 1971 351C 4V 4 speed with a 3.25:1 open dif. The motor has KB 148 13cc dished Hyper pistons, zero deck. Melling MTF 2 cam with .486 and .512 lift. Pretty tame really, but I have fun with it and can actually afford to run it in Ontario, Canada.

Thanks for all the interest and great comments. I've learned a lot and plenty more to learn in the future. This is what makes this hobby fun and much more enjoyable knowing that great help is only a post away.

The End.

Geoff.