Distributor for EFI Chrysler 440

You must mean the first link in the quote below from December 12th in this thread 
 

You said you read it back then and thanked the guy who posted the link 

There's plenty of conflicting info in that thread

My source that told me the dizzy shafts are the same also told me that the distributor clamp is different sizes, based on whether it's made for use with the collar. The collar clamp is longer, and the shorter clamp is too short to use with a collar. But maybe that only applies to small blocks, if all big blocks had the same dizzy & used a collar, regardless of rotation.

Is there anybody else out there with a dual 440 setup who can verify that they both have collars? Or verify that that was the norm for all marine 440's?

Since my last post, I had an elderly gentleman who's apparently been around Chrysler marine parts for decades. He looked up part numbers and advised me that the distributor I have in hand that came with my engine is an automotive distributor (Part #2875362), as I suspected. Part numbers for the Prestolite marine distributor a 440 should have are 2875894 for the points distributor, and 4142730 for the later electronic distributor.

But the more puzzling thing he told me is that there's only one marine 440 distributor and one shaft length. He said the reverse rotation setup—although it uses a collar, just like the small block—doesn't take a longer-shaft distributor. The small block isn't the same, apparently. The small block collar sets the dizzy out far enough that it can't engage the oil pump drive w/o a longer shaft. He also told me that the 440 collar sets the dizzy out 3/4". Again, how that makes any sense, I don't understand. If you look at the small block collar, the outside of it is about 5/8" thick. But the inside of it is machined out, so the distributor offset is much less. Apparently either the big block collar is substantially different, or he isn't aware that the collar doesn't push the dizzy out as much as it might otherwise appear. Potentially it could be machined that way, I suppose. I just can't verify that. And it makes me wonder why Chrysler didn't make the small block collar the same way.

If the big block reverse rotation engine with a collar takes the same dizzy with the same shaft length as a standard rotation setup, then I don't have a problem with the Edelbrock dizzy. Hooray! In a few days I'll have one of those big block collars in my hand and I can answer that question myself.

I think you got it straight.

I suppose that's why the oil pump drive shaft rises on the reverse rotation setup, but not the standard rotation setup?

Doesn't change the fact that my distributor is supposed to be set up for reverse rotation, but didn't come with a collar. I did manage to find and order a big block collar from a marine parts supplier today. Man on the phone said it was the last one they have. I'm holding my breath to see whether it's a real collar or an inventory mistake.

The Edelbrock guy kinda hinted today that they use an MSD or MSD-derived distributor. I think I'm down to the fact that the main question left is how easily you can swap out a distributor shaft for a longer one in an "Edelbrock" EFI distributor.

Of course I understand why they can't say it will work in a marine application. They haven't done the design, testing, and certification to stand behind that representation. Pesky lawyers would take a bite out of them if they strayed from that script & someone lost an eyeball. But that doesn't mean someone else can't make it happen in a one-off situation…safely.

And thanks for the the info & pointers. It's all very helpful.

You're worried about whether the distributor can rotate backwards, you don't need to worry because it rotates CCW on your 440 big block whether it's standard rotation or reverse rotation.

Kinda like  the 318 like you have in the other boat, only the distributor rotates CW regardless of the engine rotation.in the small block LM engines and CCW in the big blocks regardless of engine rotation

It's just a triggering device for the black magic box in the Edelbrock injection kit.

Maybe MSD can help you after all if you talk to them

And if I was Edelbrock why would I want to tell you that a system designed for automotive use and not USCG approved or advertised for marine use, that you want to modify for your use will or will not work?

You seem to understand the reason for the collar being to absorb upward thrust due to the reverse cut cam and oil pump drive gears. The reverse cut gears keep the distributor and oil pump going in the same direction as on a normal rotation engine like mentioned earlier.

As far as Harry's goes........somebody here on the forum did some business with them this past summer or so, buying an oil pump intermediate shaft of the right length for his RR 318. If I remember right it was used but at least they had the part.

I can probably dig up that thread 

It's not as inherently accurate, but to reduce parts & simplify installation, the Edelbrock system takes that reading from the distributor. I don't know what magic parts & programming that make that happen, but unless it's a super-easy swap, I'm not sure a different brand dizzy  would be an easy solution. I am sure it's probably pricey, since you'd effectively have to buy 2 whole distributors to make that happen. Figuring out how to make Edelbrock's dizzy work with just an extra part or two just sounds cheaper.

So if it's as simple as talking the Pertronix folks out of a longer shaft (and collar?) that would fit seamlessly into an Edelbrock body, along with the rest of the factory Edelbrock parts, shazam! That would be a welcome solution. When I spoke to the Edelbrock people, they didn't know much about longer dizzy shafts, which is pretty understandable, since the marine crowd isn't on their radar.

Using my best redneck engineering research tools (a screwdriver & eyeballs), I took the collar off the small block distributor and put it on the 440. Diameter-wise, it fits just fine, both on the 440 distributor, and down in the distributor hole in the 440 block. So, obviously Chrysler had a one-size-fits-all approach to the diameters. So far, so good. And my eyeballs tell me the distributor shaft diameter and flat-machined portion at the end are all the same size. So it's going to engage with the oil pump drive shaft just fine. So far, so good.

But…

…with the collar on, the 440 distributor shaft doesn't engage in the oil pump drive shaft/gear. So there's a length issue. The collar is machined with an offset, such that it appears to jack up the distributor 5/8" but because of the offset, it's only half that length, or 5/16". (Those are measurements taken with a degree of accuracy that would drive a machinist to drink, but they're close enough to be helpful for the immediate purposes.) But that's enough to prevent engagement.

It also appears that small block & big block collars must be different lengths. I didn't measure exactly, but it appeared to me that the small block collar, although the correct diameter, didn't extend down into the block far enough to reach the oil pump gear. If it can't do that, it's useless. Maybe it has to do with deck height, too, as a 440 is a "raised-block" big block. Can't verify that, though, as I don't have a plain "B" block around anywhere. But, I imagine a big block collar would be just fine. Anybody have a spare anywhere? Or know a source? Pretty sure that's not an item in current production.

So that raises a few questions:

1) Does anybody out there have a reverse rotation 440 with a collar?

2) Does anybody know whether reverse rotation distributors had a longer shaft, whether large or small block?

3) If #2 is true, is it the same for the big blocks?

4) How difficult would it be to buy a new distributor & swap out the shaft for a longer one?

I'm sure there are other pertinent questions. To review, the purpose here isn't just to find a 440 distributor. I'm trying to figure out what, if any modifications, are necessary to fit a collar to the Edelbrock Pro-Flo 4 EFI distributor so it can run backwards w/o self-destructing. If that can be done, their system can be used in a reverse rotation installation.

I took a pic of my distributors, but I couldn't figure out how to post it here. Hmm.

It's pretty much what Gary showed (on lots of them the side windows and enclosed back were optional)

CC called it a convertible top in their brochures from back then.

Thomas