G80S 1956 timing side bush stake pin and bush query

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56G80S
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G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

At last found time to remove the bush. Neill's book says press out. I actually found a socket the right size, heated the case to spit hot and drove it out very carefully with a socket just smaller than the bore of the bush, a tube down through that to help keep things central and a longer steel tube to reach the top of the driving socket. Belt and braces. Once it was moving, remove the inside socket and just drive out.

Neill says the pin will come out too - not mine! It's still jammed in there and I can't see a way to get it out, there's nothing to get hold of.

Plus, I've had a new bush "in stock" for years. Took it out of the paper and there's no scroll in it like the original. There's also no recess for a pin (have to get the pint out before I do anything about that with a needle file. Dimensions appear spot on except the hole in the bush, the one between the camwheel bushes opposite the one for the pump plunger, is a tad larger and the perimeter facing inwards is a little relieved. As there's none of the drillings etc. there for a cylinder wall lubrication "jet" at the crankcase / barrel interface I guess this isn't important?

I see an order to Kettering on the horizon.

Johnny B
Mick D
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Re: G80S 1956 timing side bush stake pin and bush query

Post by Mick D »

Hi Johnny

I wouldn't stress over getting the pin out, just groove the new bush to coincide, the best way would be to get someone experienced in milling to cut it for you with a suitably sized end mill.

Who will be line reaming the bush for you? they should be able to sort the groove and fit the bush too ;)

Not sure about the missing scroll, did AMC ever fit plain bushes? are those currently available scrolled? presumably the scroll is to keep the oil in the crank case.

Regards Mick
56G80S
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Re: G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

Cheers Mick. I'm going to try and do the drive side bearings by the book, into the case first, rather than as some have done here. That will make things more straightforward when getting line reaming done.

There's a chap in the village who I expect would do this for me.

Hoping for someone to come along with the answers to the questions you raise about the bush that I have!

Johnny B
56G80S
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Re: G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

Hi All

Giving this a bump. Alan at AMOC Spares will take a look at what's in stock at Kettering before I order but it would be good to know from others about the scrolling on the timing side bush. I hope someone other than Mick D has a view.

Johnny B
56G80S
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Re: G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

Alan at AMOC Spares has provided info as promised and I should be able to take it from here (wasn't that a wartime radio show with Jimmy Edwards?).

Johnny B
56G80S
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Re: G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

Update - Alan @ Kettering made every effort to help but I find that the engineer in the village (after presentation of liquid encouragement) will cut a scroll for me and put in the relief point for a stake pin. Discussion with him also raised a stake pin extraction possibility, which I will carry out.

He was, though, hesitant about line reaming the bush. I think when I collect the bush I need to have the extract from the Army manual with me to confirm the tolerances (taking into account Ken de Groome's comments) and go back with the two crankcase halves with the new bearings / bush fitted AND the crankshaft as he wanted to measure the axle himself.

Could get there!

Johnny B
56G80S
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Re: G80S 1956 timing side bush stake pin and bush query

Post by 56G80S »

Latest is that I finally got round to to looking at the Matchless engine again. The engineer in the village has simply been too busy to cut the scroll. He had measured the "new" bush bore against the used one and said that he there wasn't that much difference. I have now bought another bush, with scroll.

On testing the three bushes on the new axle itself, I can feel a difference between the used bush and the new scroll bush with the latter a bit tighter and of course it will tighten more once fitted in the crankcase. This bears out the received knowledge that the harder surface may get more worn than the softer one? There was quite a bit of play before I split the crankcases. However, the non scroll unused bush is a close sliding fit on the axle.

I've carefully used a set of needle files to notch the O/D of the new scroll bush to match the in situ stake pin. I'll follow the Ken Bryant directions to heat the crankcase to spit hot but plan to draw the bush in with threaded rod and spacers rather than drive it in.

Thoughts welcome.

JohnnyB
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