27 J engine rebuild/ cam roller stud washers

[Martin Pettingell]

After discovering a cracked fly wheel (T&O did a great job rebuilding the flywheel set up) and then a badly repaired sprocket shaft outer race, see my earlier post on April 28th, the bottom end of my 27 J engine is back together. Its taken a year to get those problems resolved but now I am starting to see some light at the end of the tunnel.

I have seen a picture of a newly restored J JD engine with the cam cover off and there appeared to be fitted a couple of fibre washers on the end of the cam and roller studs. I cant find reference to this in my parts book and neither can I now trace the picture. I cant see how you could measure any end play on those studs once the cam case and cover are fitted so I am not sure whether I need them and if so what the dimensions and or material might be?

I'd be grateful for any information about his - even if its to be told I don't need anything.

Thanks

Martin
in the UK
MAP_4259_7855.jpgMAP_4253_7849.jpg

[Steve Swan]

Martin, i can't give a thorough answer right now, but i was asking these same questions in my resto/build page and also John Brookes brought up the same concern in his 20F resto page. going from memory, basically the lifter arm stud takes a very thin bronze shim i made on the lathe, and the came stud takes a thicker fiber washer. for both you want enough clearance so the lifter arms are able to drop by their own weight, and for the cam so it can't walk back and forth on the stud. your paper gasket of gear cover (not gear case) should be .015" and you have to take into account that gasket thickness in how thick your fiber washer needs to be. again, i am going from memory, all my notes on this are in my email files and are documented in my resto thread and also by John. hope this helps, i can post more, just not now.

[Martin Pettingell]

Steve,
That’s great thanks. As and when you get a chance I’d sure appreciate the further information stored in you files. At least I know now that it needs something in there.
Regards
Martin

[pfindlay]

Here are some exerpts from ch. 11 of Motorcycles & Sidecars (1920) that mention the washers in question:

When New Gears Have Been Fitted
7. If all new gears have been filed, or only another secondary, or another pinion gear, it will, of course, be necessary to retime the motor according to piston position.

If another pinion gear has been fitted, time the breather valve first. Turn the motor until the front piston is on top center; then place the breather valve in the bushing so that the port is open from 1/16 to 3/32 inch. Place the valve in the bushing in such a position that the port will gradually open if the motor is turned in the direction that it runs, and again closes when the piston reaches bottom center.

After the breather valve has been properly timed, see whether or not the mark on the breather gear is in line with the “U” mark in the crankcase when the mark of the pinion gear is in line with the secondary and roller arm studs. If the mark of the breather gear does not line up right, another wider mark can be ground into the, gear, after which the original mark can be ground off.

8. If another secondary gear, or another pinion gear, or both have been fitted, turn the motor until the front piston is between 3/4 inch and 9/16 inch before bottom center. Place the secondary gear on the stud so that the opening side of the front exhaust cam is just starting to lift the valve. The exhaust valves should open within these limits, and close when the pistons are between 1/32 inch to 3/32 inch past top center. It will not be necessary to time the rear exhaust valve or either inlet valve, because these caws are mounted on the same gear with the front exhaust cam, and cams are machined together.

After timing the secondary gear, see that the marks line up properly and turn the exhaust valve spring covers in place.

9. If no 1/64 inch thick fibre washer was placed ruder the roller arms, place one on top of them. Place a 1/64 inch thick fibre washer on the cam end of the relief lever stud,
and place a 1/32 inch thick fibre washer on the drive case end of the stud. Put the stud in position and fit the drive case temporarily with two screws. Test the roller arms and relief lever stud to see that neither is clamped tight sideways, and that. there is not over 1/64 inch end play. If the roller arms or stud are too tight, entirely remove or file off the 1/64 inch thick washers as may be necessary. If any part has sufficient play to allow the fitting of another fibre washer, do so. The roller arms and relief lever stud are good fits when they have no end play and are perfectly free ...

... 18. After the gears and ignition unit have been properly fitted, place the gear stud collar and split rings on the intermediate gear studs and again clamp the motor in the vise by clamping the front cylinder. Put the 1/8 inch thick fibre washer on the secondary gear stud and lay a straight edge across the drive case next to the stud to see whether or not the fibre washer is too thick or too thin. If the washer is too thick, file it off as may be necessary, or if another 1/64 inch thick washer can be put on the
stud without clamping the secondary gear when the drivecase cover is fitted, put it on.

19. Pour one-half pint of good engine oil over the gears, and fit the drivecase cover after making sure that the paper cover gasket is O.K. If another gasket must be fitted, scrape off every bit of the old gasket and shellac, and shellac the new gasket to the cover only. To soften the paper gasket and to prevent it, from sticking on the drive
case, give the gasket a film of oil after it has been shellacked to the cover. Use Yankee screw driver EK-325 to turn the screws in place.

[Martin Pettingell]

That’s good further information thank you. Who is the author of ‘motorcycles and side cars’ ?
I imagine it’s long out of print but worth looking out for a copy
Thanks
Martin

[Steve Swan]

Very good info, i couldn't say better but do not think you can arbitrarily set the shim thickness to those instructions. Shim thickness must be measured and fited accodingly, and the thickness of gasket for gear cover must be taken into account at least that is what men more experienced than me told me and that is also my experience.

[Steve Swan]

After discovering a cracked fly wheel (T&O did a great job rebuilding the flywheel set up) and then a badly repaired sprocket shaft outer race, see my earlier post on April 28th, the bottom end of my 27 J engine is back together. Its taken a year to get those problems resolved but now I am starting to see some light at the end of the tunnel.

I have seen a picture of a newly restored J JD engine with the cam cover off and there appeared to be fitted a couple of fibre washers on the end of the cam and roller studs. I cant find reference to this in my parts book and neither can I now trace the picture. I cant see how you could measure any end play on those studs once the cam case and cover are fitted so I am not sure whether I need them and if so what the dimensions and or material might be?

I'd be grateful for any information about his - even if its to be told I don't need anything.

Thanks

Martin
in the UK
[ATTACH=CONFIG]22470[/ATTACH][ATTACH=CONFIG]22471[/ATTACH]

Martin, did T&O do the fitting of pinion shaft to bronze pinion bushing?

[exeric]

I think that you can find that at Antique Motorcycle Works on ebay.

https://www.ebay.com/str/tomsamwresa...cat=2350035012

[pfindlay]

That’s good further information thank you. Who is the author of ‘motorcycles and side cars’ ?
I imagine it’s long out of print but worth looking out for a copy
Thanks
Martin

The author is Victor W Page. You can view it online here:
https://babel.hathitrust.org/cgi/pt?...view=1up;seq=9

Peter

[TechNoir]

Ok folks here are my comments.

The book mentioned above is great and I have posted about it previously. There is a very high quality copy of it here:

http://www.sidecar.com/links3.asp

It is bookmarked and divided into sections by chapter, a pdf per chapter.

As mentioned by Steve this question has been raised previously by first Steve and then me. Steve went with fibre washers and after some deliberation I went with bronze washers. Either should be fine.

I recommend that you read first Steve's thread about this on Yahoo Groups and then the discussion on my build thread which has comments from several people about the pro's and con's of various materials including bronze, fibre and some others.

John

[Martin Pettingell]

Thanks all.
Steve, T&O did not fit the pinion bushing for me. I kept the cases here in the UK to work on while they built the fly wheel assembly. I found an expert machinist who was able to sort out my sprocket bearing race , fit the pinion bush and align the two.
I will look out for the thread on the Yahoo group site but have struggled to get on it recently. I was going to post this enquiry there as well but gave up after the third attempt
John, thanks also. I have a picture of where I need to go wth this now.
Martin

[Steve Swan]

Thanks all.
Steve, T&O did not fit the pinion bushing for me. I kept the cases here in the UK to work on while they built the fly wheel assembly. I found an expert machinist who was able to sort out my sprocket bearing race , fit the pinion bush and align the two.
I will look out for the thread on the Yahoo group site but have struggled to get on it recently. I was going to post this enquiry there as well but gave up after the third attempt
John, thanks also. I have a picture of where I need to go wth this now.
Martin

i sent you a PM.