Sprint Distributor Roll/Split Pins and Advance Springs

[Graham.Fountain]

Does anyone have the dimensions or part number for the split/roll pin that holds the drive gear on to the bottom of the 44D4 distributor drive shaft?

Also, does anyone need any springs for a 41589 for the cost of p&p?

I have a new set, a set that has done only a few tens of miles, and at least one set that have gone a bit further, but still seem to be fine. These are the two fairly light springs that look the same and are both in play from 0 degrees advance to the 9 degree limit - that's 9 at the distributor, not the crankshaft.

They are all surplus, as the advance stops on my two 41589s look to have been modified to give rather more than 9 degrees – about 13 for one and 15 for the other. I think they are modified not worn, because both are quite good, except for the wear in the roll pin on one – hence the above question —, but they do have semicircular faces where both my 41655s are flat. Yet again, I got them off a guy who rallied a Sprint in the 80s.

So, rather than disassemble and build up the stops to the right levels with weld, etc., I'm fitting a pair of the asymmetric 41655 springs to both, to let them advance normally to about 9 (the thinner of the 41655 springs being about equal to the two thinner yet 41589 springs), when the fatter, longer of the 41655 springs comes into play and limits the advance rate above that.

Graham

[xvivalve]

It's a roll pin Graham, part number 516514

[Graham.Fountain]

I don't seem to get anywhere on the part number. You got any dimensions for them, Alun? Looks like 1/8th by 3/4 to me. But I can't measure it properly till I get it out, and I don't want to do that till I know I can get a replacement.

And, if I didn't say before, thanks for the flinger.

Graham

[GrahamFountain]

I got one with the new gear drive I bought, so now I know it's 1/8th x 3/4" - £3.50 for 50 on eBay.

Graham

[xvivalve]

That's good to know; I'll stop the futile exercise of trying to remove the one from this dizzy which has been sitting outside for 20 years then!

[GrahamFountain]

The one I took out, came out broken.

It was like that when I found it.

If the seven-penny ones off eBay are any good, I'll let you know.

Graham

[GrahamFountain]

The 2 oz pack of 1/8th x 3/4" roll pins arrived, and I've just used one to reattach the not great drive gear to the not great distributor. I'll be knocking it out again, but at 7p each, even I'm not bothered.

And, considering I didn't do anything about the shimming under the (what I assume is a) Nylon bearing at the top of the main shaft, the results are truly excellent.

It's cured all the play in the drive, bar for a few thou of vertical play that a thicker shim would fix - though as the helical drive from the jack shaft pushes the main shaft up, so the vertical bearing surface is betwixt the drive gear and the big tab washer above it, I don't think I should be worried about a few thou of slack there.

So I'm looking at my second-best distributor, which is only that because of the play in the roll pin - it looks like it's a bit broken too - and thinking it would suddenly become the best if I put a new pin in it. The only other difference between it and the currently best one, which is in the Dolomite, is that it only gives a maximum advance of 24 degrees at the crank - probably from about 5000 rpm and up -, and the one in the car gives 26 degrees - probably from about 5600 or so.

That last bit makes me wonder, now I know how to control it with the secondary spring, where I want max advance in relation to peak torque and peak power?

Graham

[GrahamFountain]

I just knocked the roll pin out of the second best dizy and, interestingly, it measures 3.15mm in the middle against the 3.35mm of the one that came with the new drive gear and one out of the bag of 1/8" ones. It may also be interesting that it's slack in the smaller of the holes in the gear drive, though it needed a thump with a drift to get it out of the shaft. It also appears to have been only about 18mm long before it was driven to distraction.

The question is whether it's original, or if it's been replaced with a 3x18mm one, or if they were originally 3mm, or Lucas used a 3mm instead of a 1/8th" one when they threw the parts together?

One of the 1/8th" ones has gone in, with the new drive gear, without much bother, and thats fixed all the play there was, rotational and vertical. I do have a few concerns I'm putting a new drive gear against a used jack shaft, but needs sometimes must and all that.

Graham