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1956 100BN2 Distributor Problem

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Martinld123

Martinld123

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I am starting to think that I have too much end play where my drive gear attaches to my distributor. There is a fiber washer but there is still about 2 mm of up and down free play. I am wondering if adding more fiber washers would help me get a more stable run on acceleration and even idling for that matter. Any thoughts on this, Marty.
 
2 Mm is too much movement. I would take the shaft out of the body and check wheater there's anything left of the washer that sits underneath the baseplate to keep it clear of the body.
 
johnea said:
2 Mm is too much movement. I would take the shaft out of the body and check wheater there's anything left of the washer that sits underneath the baseplate to keep it clear of the body.
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Thanks for responding. The 1/2 to 1 mm fiber washer is in good shape and just as it should be. I believe someone might have put on a new drive shaft and did not have it pushed up tight where it belonged when they drilled the hole for the pin. I have an oil light washer that I thought I might put there but worry about it seizing up so maybe I will put in a couple new fiber washers instead. I have heard stories of shaft seizing up and doing big time damage if too tight. I think you are right and I need to remove free play so timing is consistent. Thanks Marty
 
The amount of free movement (up and down) has no effect on the timing unless the pin holding the shaft has rotational movement. You need that 1-2mm movement to avoid the seizing that you have mentioned. You either have 4 cambers on the shaft (4 cylinder cars) or 6 cambers. The camber opens and closes the points as it rotates. Slack acceleration is more likely to be the advance of the distributor rather than any play in the shaft.
 
andrewss said:
The amount of free movement (up and down) has no effect on the timing unless the pin holding the shaft has rotational movement. You need that 1-2mm movement to avoid the seizing that you have mentioned. You either have 4 cambers on the shaft (4 cylinder cars) or 6 cambers. The camber opens and closes the points as it rotates. Slack acceleration is more likely to be the advance of the distributor rather than any play in the shaft.
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The problem seems to be that on acceleration the distributor advances as it jumps up from the 2 mm free play. As the shaft moves up it rotates causing an advance? Everything I have read it should be up against the fiber washer with very little free play. Getting a consistent run is hard and makes me think this free play might be answer. Still up in the air. Bevel gears would advance the distributor as it moves up, no, yes?? Thanks Marty
 
I don't know the factory spec for the stock dizzy (couldn't find it in the Bentley Book) but I run a Mallory dual point and their set-up instructions call for .025 end float. Don't know for sure that they are comparable but if they are, your 2mm (about .079) would be about 1/16" too much. After I drilled mine, I found I had to use two thrust washers to get .021, and that was at least 15k miles ago. I don't think at .020-.025 there would be much rotational change from the heilical gears, but at .080 there might be a small change affecting timing.
Dave
 
red57 said:
I don't know the factory spec for the stock dizzy (couldn't find it in the Bentley Book) but I run a Mallory dual point and their set-up instructions call for .025 end float. Don't know for sure that they are comparable but if they are, your 2mm (about .079) would be about 1/16" too much. After I drilled mine, I found I had to use two thrust washers to get .021, and that was at least 15k miles ago. I don't think at .020-.025 there would be much rotational change from the heilical gears, but at .080 there might be a small change affecting timing.
Dave
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Dave,
I think this would be an easy fix for me to try. What I have on there now is a fiber washer but have not been able to find a similar washer. When you say thrust washer are you talking oil light or fiber? I have not been able to find any fiber washers yet. Do you have a source for what you are using? Nothing at Moss. Thanks Marty
 
Marty,
I think they are just regular hardened steel thrust washers from the auto parts store - visually I'd guess around .020 thick. It's been a long time since I looked at a Healey dist. closely but I don't remember a fiber washer and it seems to me a fiber washer might wear fairly rapidly - at any rate I have steel ones on the Mallory (I'm talking about between the tach drive gear and bottom of the housing - have no idea what is on the top side, inside the dist., might be oil lite up there because there isn't a regular oil flow like the bottom sees).
Dave
 
Marty, I still think your problem lies inside the distributor: the washer under the baseplate - almost like a spacer - should be about 3 mm. It brings your contact breaker and rotor arm just that bit higher up in the dizzy. Filling up the play between the housing and the drive with washers might cause binding of the dizzy to the driveshaft in the engine block.
 
Marty--

2 mm seems like a lot to me as well though end play is not nearly as critical as side play--in my experience any wobble n the distributor will make for lousy performance with points, though a solid state unit such as a pertronix or the Mallory Unilite that I have in my car will tolerate more.

I would call Jeff at Advanced Distributors--ask him what he thinks and follow his advice.
 
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