Jump to content
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble
Strawberry Orange Banana Lime Leaf Slate Sky Blueberry Grape Watermelon Chocolate Marble

Featured Posts

Russell Newbery  DM2, year of manufacture unknown, Engine No. 22B (or E) 1392.


This engine would at first sight seem to be equipped with a hand start mechanism right down to and including the starting handle. However there is no connection to the engine and the decompressors seem to have been disabled. The latter would imply that this is how the engine was built rather than a component failure.


The engine is fitted with a Lucas starter motor and has been an entirely reliable starter in all conditions.


My question are (1) Has anyone come across an engine set up thus?

                           (2) Has anyone reinstated the hand start?

                           (3) How much grief is involved in getting at the mechanism?


I would add that I have the experience to address the problem and a machine shop to back it up but forewarned is forearmed.

 

 

 

Share this post


Link to post
Share on other sites

Do you know what is disconnected between the starting handle and the crankshaft. If it's like the Listers there will be a chain drive down to a ratchet wheel and a couple of sprung pawls mounted to the crankshaft, arranged so that at rest they engage in the ratchet wheel, but when the engine is rotating at any speed centrifugal force throws them out of engagement. How much (if any) of this mechanism is still in situ?

Likewise for the decompressor there should be a shaft running through the heads (might be in two pieces) with cams on which hold the exhaust valves open when the shaft is rotated.

If you are going to tackle this yourself it would be best to take a look at a working example to see how it is all configured.

Share this post


Link to post
Share on other sites
2 minutes ago, David Mack said:

  and a couple of sprung pawls mounted to the crankshaft, arranged so that at rest they engage in the ratchet wheel, but when the engine is rotating at any speed centrifugal force throws them out of engagement

I assume my DM2 was like this, but the previous owner had disconnected it all "as when on tick over, the speed was not enough to completely dis-engage them, and the ticking WILL DRIVE YOU MAD!!!" - that's what he said anyway! It's a bit of a noisy (but nice noisy) engine anyway, so I'm not sure how much ticking would be heard. I'm also told that Schwartzeneger like fitness is required to hand start from cold in winter.

Share this post


Link to post
Share on other sites

Thank you David Mack and Mike Tee for your interest. I suspect David is right about it being a chain drive. Alas all I have here is the RN "Spare Parts List" which has a useful "sectional arrangement drawing" save that it does not include the hand start system. Sadly I am of an age and "locked down" 40 odd miles from the engine and despite having done pretty much the length of the country on the boat without it missing a beat it is surprising how much detail I didn't take in.


Add to that I am using a pair of hands and eyes attached to an Arts Graduate, (willing enough and learning but still very green), to get anything done.

Remote problem solving reminds me of an early computer programming exercise. The object was to instruct a person to safely cross the road by following instructions from people who are unsighted. "Take one step forward, are you at the kerb?"-  No. "Take one step forward, are you at the kerb?"-  Yes. "Look right and left, are there any vehicles within 50ft of you?" etc.  After much faffing around and no success at crossing the road one person in desperation looked out of the window to find out what was going wrong.

There was indeed a vehicle within 50ft. --- it was PARKED . . .


The definition of stupid might be doing the same thing more than once and expecting a different outcome. In this case running out of diesel -- TWICE in a month. Unfortunately  winding the engine over to bleed the system would see to have either killed the battery or the starter solenoid or both. Hence my interest in reinstating the hand start  if only to provide an alternate way of turning the engine over.

 

I take the point about "ticking" pawls, maybe it could modifed to take a spragg clutch.


Eventually I will get to the boat always 'sposing I dodge this wretched virus and things may then become easier. In the mean time is there any source of drawings for these engines? Also does anyone happen to know the part number for  the Lucas starter solenoid? The part numbers I have been given are not producing any  useful results.

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.