Author Topic: EW engine is completely ******ed ! (HELP!)  (Read 9605 times)

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Offline davebarkshire

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EW engine is completely ******ed ! (HELP!)
« on: 19 Mar 2009 at 21:06 »
The 1926 EW has had its engine stripped and the insides are not pretty. This explains the clunking sounds and the oil problems.

The crank is in a bad state (middle section aligning pegs etc) and the rear cylinder has been bored out too much. Also, the oil pump is missing the cog wheel that is driven by the worm.

HELP!  :cry:

If any of you have any of these parts in your dark and dusty sheds or know of anyone who does, please let me know.

We're looking for

1) A crank or even just the middle web section in good condition.
2) A rear cylinder.
3) The oil pump cog wheel that is driven by the worm drive.

Thanks in advance dave@barkshire.co.uk

Offline Doug

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #1 on: 22 Mar 2009 at 21:38 »
Dave,

Sorry to here the crank is knackered, but not surprised. They are not very robust, and the center web is so flimsy they get up to all sorts of wear and will even break if you indulge in prolonged high RPM. Essentially the same crank was used through the 1936 250/350cc ‘gutless wonders’ with a simpler spray-tube and splash oiling verses the drilled and pressure system as used on the EW. You might be able to find one of those in good shape and drill it for the EW oiling system. However I took a pair 1935 250cc engines down searching for a crank for my 1931 350cc, and both had center webs that had been carved up by the big end rollers. To think they used much the same crankshaft in some light 500cc machines!

You would do better to find another whole crank assembly of matching components. Douglas assembled the cranks, pinned the crank pin joints, and ground the main bearing journals between centers to final size and truth. You may find just replacing the center section from another engine that the crankshaft does not run true enough. If it is just a matter of the alignment pins holding things out of skew, then temporarily leave the pins out. Knock the crank into alignment and bore the alignment holes out for slightly oversize pins. You will probably have to use a micro-boring bar, as I doubt a reamer is going to cut very accurately into such a miss-matched hole. Anyway, what I am getting at is they are not perfectly interchangeable components. They may be close enough, and if you can get the main journals to indicate within 0.002” then for an EW you are probably quite good enough. The bearing bores in the crankcase (and probably the joint face) were done in a (worn?) turret/capstan lathe and I have not found them to be precisely opposed. This is why Douglas likely used a narrow ball race on the timing side and a self-aligning double row ball on the drive side; so that it would have a little give! 

Options for replacements are more limited here in the USA, where Dougies are not as common. So in the end I started a project to make a new crank for my 1931 350cc. This is not quite as hard as it first seems, though you do need a good size lathe. The hardest part is machining the center web. Even this is not so difficult if you make a fixture like that shown mounted to the lathe faceplate (see further on.) The fancy gold color was a failed experiment using titanium nitride plasma coating to increase the wear resistance. At the low processing temperature required to avoid drawing the temper out of the alloy steel, the adhesion was marginal.

-Doug



New turned blank from billet for the timing side. The flat is for a timed rotary breather not used on the earlier EW.


Ditto for the flywheel side.


The fixture for turning the center web.


From left to right, 350EW, A31, and new from billet. The yellow color is TiN plasma coating.


Old and the new drive side.


Original drive side, showing 'repair' with braze. Must have done wonders for the heat treatment. Note new crank is not drilled in the center of the main shaft to save weight like the original. Road license tax is no longer an issue!


More amateur repairs to the center web with braze. Also thread has been re-chased to a slightly smaller size.


Why folk braze the crank. The red arrows show where the big end rollers have worn into the face of the center web. The location of the arrow is about where you find the deepest wear, due to perhaps the way the crank flexes under load, and it is furthest away from a fresh supply of oil. With these later cranks, the oiling is by a spray bar over the crank, and the oil impacting and entering via the side of the connecting rod via the groove seen at the left-hand edge. The inner bearing race has already been removed.


The 'bits'. Note the alignment pin pattern is reversed, so that you can not install the center web backwards.


And the assembly, less crank pin races. This crank was destroyed attempting to use too aggressive a press fit for the crank pin races. So I will have to start over.



« Last Edit: 14 Oct 2018 at 17:25 by Doug »

Offline Edin

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #2 on: 23 Mar 2009 at 18:33 »
Hej Dave
I was thinking to answer you with warning against use a middle section from a foreign crankshaft, to repair your
own EW 350,-  when "DOUGH" answer,- warning against the same.
I can help you with an 350 crankshaft from early 1930 (same as EW whitout drillet oilsystem) in good condition
or an EW crankshaft 350 in fair condition,- and an rear cylinder in good condition ca. 62,0 mm
The problem is that thise part was planning  to swap with part I need in my own project.
If you are interestet,- I need : Front or rearhub condition not importent. Handlebar and footbord
Regards Edin DK

Offline sidecar willy

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #3 on: 26 Mar 2009 at 10:37 »
I think I can help you with the oil pump gear. I have a spare 250 Comet engine that is in a bit of a state and as such not opened it up yet...but almost certainly there will be a gear contained within. If the Comet bits are the same you are welcome to have it.

I am not at home currently and will not be home until early April...but will remove the timing cover when I get back and you can have the gear.

in an earlier request you were asking if there was a Douglas engineer that could help you with your engine...did you manage to find anyone?

I am based in Scotland.

your aye
bill

Offline davebarkshire

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #4 on: 26 Mar 2009 at 10:53 »
Thanks to everyone who has responded.

I have sent a PM to those who have sent me messages.

I was lucky enough to have been rescued by Henry Body and he has kindly taken me under his wing and has been working on the poor old EW. He thinks that he's managed to fix the crank so optimism is rising. Stuart Lister was kind enough to offer an oil pump part and we're hoping that it is the correct part as there is more than one oil system but we live in hope. Henry is looking for a rear cylinder and will be asking around at a meeting this week.

I'll keep you all informed of progress.

Regards - Dave

Offline Doug

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #5 on: 26 Mar 2009 at 13:52 »
Bill,

The oil pump used in the 250 Comet is a different system than that use on the EW350, and the worm and worm gear are not interchangeable. There are some pictures of the EW350 system here -

http://www.douglasmotorcycles.net/index.php/topic,1002.0.html

- to compare against your engine.

-Doug

Offline davebarkshire

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #6 on: 26 Mar 2009 at 14:39 »
The oil pump giblet has just arrived on the door mat (Thanks Stuart!)

I have attached a picture to the posting.


« Last Edit: 26 Mar 2009 at 21:49 by Dave »

Offline davebarkshire

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #7 on: 05 Apr 2009 at 08:19 »
Eureka!

I picked up the EW yesterday and it is running very nicely. There were quite a few things wrong which would have taken me a lifetime of pain and trial to rectify myself and it now runs sweetly with a good burble from the exhaust. The next stage is to get it MOT'd and I'm not sure how the tester will respond to the brakes which have new linings but the lever does touch the bar when pulled in (is this normal?). I'll probably not be able to make the cavalcade this year but am hoping to take the EW to the Isle of Wight for the VMCC scurry and maybe also the VMCC Scrumpi Run. I'll take some new photos of it in its newly aquired magnificence and will post the link then they're ready to view.  :D

Offline Chris

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #8 on: 05 Apr 2009 at 13:50 »
Hi Dave
    You should not need to bring the lever back to the handlebar. It sounds as though you need to do some internal adjustment to the screws that adjust the relationship between the band brake with the drum. The lining needs to be as close as possible to the brake drum all round without rubbing. You should then be able to get the brake fully on before the lever reaches the handlebar.   Chris.

Offline Stuart Lister

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #9 on: 06 Apr 2009 at 10:03 »
Congratulations Dave. Considering that your first post was only two weeks ago, this is a remarkable achievement. Enjoy.

How did you fix the crank?

Stuart.

Offline davebarkshire

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #10 on: 06 Apr 2009 at 10:40 »
Stuart,

I can't claim any of the credit, all of which goes to Henry Body who bored out the holes for the pins and put in over sized pins to sort the crank. It seems that this is a common problem because people don't tighten up the cranks properly and they often become wrecked this way.

Henry also identified a long list of other problems which he has sorted which included.... no engine breather, broken mag pickup ring, leaky HT leads, incorrect magneto drive fixing, clutch friction material too thick, clutch thrust washer too thick.... etc. This would all have taken me the rest of my life to sort out on my own!

The EW runs like a swiss watch now and starts very easily. I have just be putting the rubber studs in the new foot boards and tightened the front brake cable which when 'ping' so my cable making skills can be exercised in the garage this evening. I also now have the correct throttle/choke lever with the bolt which goes through the handlebar.

If all goes well I'll be posting some photos within the week.  :D


Offline davebarkshire

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Re: EW engine is completely ******ed ! (HELP!)
« Reply #11 on: 07 Apr 2009 at 09:17 »
Inevitably, I have been asked by some members whether Henry might consider taking on any other projects and I did ask Henry whether he was taking on projects at the moment. He told me that he doesn’t usually take on work and that mine was a ‘one off’ (very lucky me!). Henry has many projects of his own and is also at an age when his health has to be taken into consideration. Although he is still a sprinting champion, he’s having trouble renewing his racing licence due to his age and the regulations. I get the impression that there are some people in the Douglas community who may take on occasional jobs but they are unlikely to do it for people who they don’t know so if you are looking for some help then I can only suggest that you make yourself better known in the club and attend some events and this way you may be able to connect with some experts who may be about to help you on your way.