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Dommy rocker spindles wear.

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Dommy rocker spindles wear.

Posted by robert_tuck at September 03. 2017

One of my inlet spindles is loose in the head and is set further in so does not engage well with the plate. What is the normal fix for wear in the head bore?.

Re: Dommy rocker spindles wear.

Posted by anna jeannette Dixon at September 03. 2017

Hello Robert   Well this is the first sign of poor oil feed to your cylinder head rocker feed   the right option you now have is to remove the cylinder and replace it with another  or have the all the spindle holes milled out to have an interference fit  for bronze bushing, with oil hole in it and then fit with new thackery washers   and get the oil ways blown through including the drain hole on the inlet side next to the valve springs  has shown on my photo  below  I do hope this fixes your problem    have a nice time we wish you well  so good luck yours   anna j 

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Re: Dommy rocker spindles wear.

Posted by david_evans at September 03. 2017

How loose is it Robert? If it is just loose enough to slide inwards and no more loose than that, you could consider a careful application of loctite with a small spacer inboard of the spindle to prevent the spindle disengaging from the end plate. If it is really floating around then boring and sleeving may be a solution.

If as Anna says the oil feed has been poor, the rocker may have seized on the spindle then the spindle will have been rotating in the head.

If a spindle say 0.002" larger in diameter will hold position then chrome plating would be another solution. I would think that your rocker would be worn large enough to deal with a spindle a couple of thou bigger

Re: Dommy rocker spindles wear.

Posted by robert_tuck at September 03. 2017

Yes David thats the way I was thinking, there is at least 2 thou wear in the outer bore  ,dont know if the inner is as bad ,if not then may do a real bodge with a strip of feeler plus locktite ,and a washer in the inner bore to get the side plate to engage.  Could copper plate the ends of the spindle as its not supposed to rotate.

Re: Dommy rocker spindles wear.

Posted by david_evans at September 03. 2017

I think the loctite should be good enough to deal with a few thou. the feeler gauge is a bodge too far in my opinion.

Re: Dommy rocker spindles wear.

Posted by ian_cordes at September 04. 2017

I have used the RGM modified plates, as I found that a couple of the locating tabs on the standard plates had broken off, allowing the spindles to turn. A good, if slightly pricey, solution, which should take up the end play on your spindle, provided it is not already worn.

Re: Dommy rocker spindles wear.

Posted by david_evans at September 04. 2017

Radial play is what you really need to deal with here and I suppose the RGM solution will do that. Worth a try with loctite first as it's easily accessible and cheap

Re: Dommy rocker spindles wear.

Posted by john_holmes at September 04. 2017

Never had much luck with locitite on a steel part in aluminium, the bond does not last long, guessing the different expansion rates with heat break the bond after a few heat cycles. Copper plating is a lot cheaper that hard chroming and is used to recover worn bearing housings but plating the OD of the bearing, and the RGM locking plates sound good too.

Re: Dommy rocker spindles wear.

Posted by anna jeannette Dixon at September 04. 2017

Hello these Spindel locators are not going to help worn rocker spindle holes may guesstimate is the others are getting worn to it's not going to be cheap the do the right good job or find another good cylinder head  So cheap fixes are Not the answer here  Bit the bullet get a good long lasting job done!    Yours   Anna J

Re: Dommy rocker spindles wear.

Posted by robert_tuck at September 05. 2017

You are right Anna,no decision will be made till I know the extent of the problem.  Luckily I have a good engineer who will do a proper job if thats needed. He is so good that whatever the problem is no disscusion is ever needed , I just give him the parts and pay later!. The RGM fix sounds a bit heath robinson but is not that exspensive, anyone tried it?.

Re: Dommy rocker spindles wear.

Posted by ian_cordes at September 05. 2017

Robert. If you read back through the posts here you will see that I have fitted the RGM kit to my 650SS motor. It is not at all Heath Robinson, and positively prevents the spindles from turning. However it is not a cure for wear in the head, if that is what the problem is. Personally, I would try a new spindle first; you never know....

Re: Dommy rocker spindles wear.

Posted by matt crighton at September 29. 2017

hello all, I have the same problem with my 650SS head. All 4 spindles are loose in the head but are a great fit in their  respective rockers, no play at all. I was looking at the bush option but will now give the RGM fix a try as its the far cheaper option. Thanks for the tip.

Re: Dommy rocker spindles wear.

Posted by anna jeannette Dixon at September 29. 2017

Hello Well the original plates were made to do the same job  but get flattened from heavy hand owners  just try and take the two plate apart  and push the tags of the inside plate  out  so they then fit right  Rocker Wear Is from LACK OF LUBRICATION and block up drain ways  or oil feeders tracks inside the head   pipe cleaners will clean these out,   disassemble the rockers and spindles and make sure you get all 8 Thackery washers out    then fit back the spindle and then get a suitable touch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this     yours  anna j

Re: Dommy rocker spindles wear.

Posted by robert_tuck at October 07. 2017

I have bought the RGM kit and will report back on how it does.  In the meantime I have a conumdrum,  which way does the flat on the rocker shaft face?  Norton plumstead book says one way and Dunstalls tuning guide says the other ,can't both be right ,or can they?.  99 with low pressure feed and scrolled shafts.

Re: Dommy rocker spindles wear.

Posted by richard_hudson1 at October 07. 2017

Previously anna jeannette Dixon wrote:

Hello Well the original plates were made to do the same job  but get flattened from heavy hand owners  just try and take the two plate apart  and push the tags of the inside plate  out  so they then fit right  Rocker Wear Is from LACK OF LUBRICATION and block up drain ways  or oil feeders tracks inside the head   pipe cleaners will clean these out,   disassemble the rockers and spindles and make sure you get all 8 Thackery washers out    then fit back the spindle and then get a suitable touch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this     yours  anna j

Anna, My 57 Dommie head only has 4 Thackery washers, where do the others fit?

 

Re: Dommy rocker spindles wear.

Posted by anna jeannette Dixon at October 07. 2017
Previously richard_hudson1 wrote:

Previously anna jeannette Dixon wrote:

Hello Well the original plates were made to do the same job  but get flattened from heavy hand owners  just try and take the two plate apart  and push the tags of the inside plate  out  so they then fit right  Rocker Wear Is from LACK OF LUBRICATION and block up drain ways  or oil feeders tracks inside the head   pipe cleaners will clean these out,   disassemble the rockers and spindles and make sure you get all 8 Thackery washers out    then fit back the spindle and then get a suitable touch so you can see inside the rocker housing and see if there is any up and down movement the shaft should be stiff to fit inside there holes now do have fun with this     yours  anna j

Anna, My 57 Dommie head only has 4 Thackery washers, where do the others fit?

 

Hello  NO  there should be 4 Thackery washers and 4 thin  washers  yours anna j

Re: Dommy rocker spindles wear.

Posted by robert_tuck at October 09. 2017

I have purchased and fitted the RGM kit,  But only to the exhaust rockers as thats where the wear appears. It seems to do the job and I immediately noticed a change in the tappet clearance. The existing rocker plate bolts 1/4" BSW  now appear to be a bit short and vulnerable to stripping so I will make up some longer ones. The kit insructions could do with a bit more clarity for the beginner mechanic. I will look next at the Atlas but as thats a pressure feed system I would hope for less wear.

Re: Dommy rocker spindles wear.

Posted by robert_tuck at October 30. 2017

The RGM kit is working well  ,really easy to fit.  Have not found a source for some longer whitworth end plate bolts  ,I think 3/4" long would be ideal  and plated or stainless . Nookys Nuts don't list them.

Re: Dommy rocker spindles wear.

Posted by Lance Crossley at October 30. 2017

Previously robert_tuck wrote:

The RGM kit is working well  ,really easy to fit.  Have not found a source for some longer whitworth end plate bolts  ,I think 3/4" long would be ideal  and plated or stainless . Nookys Nuts don't list them.

Hi, Robert.

I used Dave Middleton Stainless 37 years ago when I was refurbishing my 650SS, now D Middleton and Son. More recently I needed a one-off pair of studs and contacted them about providing them. They quoted from my dimensions and description and supplied following my confirmation, and, like my original experience, they were very quick. Probably not the cheapest way to source your bolts but it would provide a solution.

http://stainlessmiddleton.co.uk/

Email: sales@stainlessmiddleton.co.uk
Tel: 01924 470 807
Fax: 01924 470 764

Re: Dommy rocker spindles wear.

Posted by Fritz Wettstein at October 31. 2017

This is also a good source for stainless hardware: http://www.polished-stainless.com/
They also have lots of BSC ¼"

Fritz

Re: Dommy rocker spindles wear.

Posted by paul_standeven at October 31. 2017

When I got my bike, a previous owner had bushed the rocker spindle bores on my Dominator head, because the rocker spindle bosses in the head were badly flogged out.  Unfortunately, the spindles were a loose sliding fit in these bronze bushes.  After consideration, I got the spindles hard chromed and ground.  The grinder was not accurate enough, and couldn't make them the size I wanted - they should be 0.001" to 0.0015" interference fit

After a lot of messing around, I found that the spindles could be matched to a rocker, and give a just acceptable sliding fit.  More messing about, and a friend with a lathe polished each spindle end so that it was an exact fit in the respective bush in the head.

This was a very prolonged solution to the problems in my head.  It might have been cheaper and quicker just to find another head.... But it's fixed now.  When the bike is run in, I will know whether it really is sorted.

Paul

 

Previously robert_tuck wrote:

One of my inlet spindles is loose in the head and is set further in so does not engage well with the plate. What is the normal fix for wear in the head bore?.

Re: Dommy rocker spindles wear.

Posted by robert_tuck at November 01. 2017

Thats very interesting Paul, sounds like I dodged a bullet there. Seems like the best all round solution would be for someone to supply a set of oversize and a tad longer spindles and have it all bored out to suit.

Re: Dommy rocker spindles wear.

Posted by paul_standeven at November 01. 2017

Bear it in mind that the rockers are hardened steel, so if you want to enlarge the bores, they will have  to be ground or honed.  Given that your bike is a '50s machine, you will either have to get a spiral groove cut in the spindles, or upgrade the whole lubrication system to '60s spec with 6-start worm gears, and open out all the oil ways in the cases and cover.

My machine had an oil feed taken from the timing cover to the rockers, for increased oil feed upstairs (remember, lack of oil is the cause of the rocker bores flogging out...).  That meant too much oil up stairs, and a loss of oil pressure to the big ends.  The over-feed to the valve gear was dealt with by fitting oil seals on the valve guides, which then had too little, and they became sticky.

Hey ho.  My solution was to follow a recommendation from Norton - if your valve gear is not getting enough oil, fit the oil tank union from a 250 or 350 unit twin, which is almost the same, but with a smaller through-drilling.  (Actually, what I did was make a disc with the right hole size drilled in it, and silver-solder that to my oil tank union). That forces more of the oil returning to the tank to the valve gear.  Next time I run the bike, I will take valve covers off and see if I get sprayed with oil....

Paul

 

Previously robert_tuck wrote:

Thats very interesting Paul, sounds like I dodged a bullet there. Seems like the best all round solution would be for someone to supply a set of oversize and a tad longer spindles and have it all bored out to suit.

Re: Dommy rocker spindles wear.

Posted by robert_tuck at November 02. 2017

Hi Paul, I have dealt with the undersupply of oil by introducing a brass jet in the return union, orriginally I sized this to match the jubilee fitting but soon found this to be too much and have drilled out the jet in stages till happy.

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