Twin Engine Indentity

[Tony Fearn]

Julian,

Here is a photo of the dynamo casing as it should be.

Dynamo for Julian.jpg

Also have a look through Marcel's saga at;- http://jowett.net/forum/viewtopic.php?f ... &start=195

The photos didn't come up in your latest post.

Tony.

[julian]

Thanks for the photo & the link - lots of information there - I'll have a good look through it all!

The photos are on the Google drive: https://drive.google.com/folderview?id= ... sp=sharing

[julian]

I drained the oil out of the engine today which removed any doubt I might have had about stripping the engine down- there were many small metal pieces of metal in the bottom of the sump plug. Also I've noticed a lot of end play on the crank shaft.

I'd appreciate some advice on best sequence for stripping the engine and also the best position to mount the engine whilst carrying out the work.

I'm also not sure how to remove the valves - I have a spring compressor for conventional cylinder heads, but it's not much use in this case!

Any help & guidance greatly appreciated.

Julian

[george garside]

valve removal is dead easy. all you need is 2 spanners and a screw driver. Removal is by slackening both the bottom nut and the locknut with spanners and unscrewing the valve with large screwdiver ( which is also used for valve grinding)

Removal of the flywheel can be difficult a and an extracter can be used . However there is less risk of cracking the flywheel if 2 large wooden wedges are used between flywheel and crankcase and driven in with sledge hammer. Wedges about 18'' long 2" tapering to zero
george ,

[Andrew Henshall]

Can I tell the tale of removing the flywheel from the end of the crankshaft on my 1936 7 hp? The engine was purchased partially disassembled, in a very rusty state, with lots of important parts missing, but it was clear that whoever had tried to dismantle it had struggled and failed to remove the flywheel from the taper on the end of the crank. There were very heavy witness marks on the edge of the flywheel were someone had tried (unsuccessfully) to knock it off with a sledge hammer. I thought of wedging it off against the crankcase, but thought it likely to crack the delicate crankcase, so I tackled it a different way. I made a puller that used the two existing tapped holes in the flywheel meant for this purpose, and a high tensile fine thread push bolt with a brass pad that pushed against the end of the crankshaft. I actually used a very high torque on the push bolt, but it failed to move the flywheel. I then struck the end of the bolt while the puller load was on in an attempt to "break" the joint on the taper free, but nothing happened. I then soaked the area in diesel for a week and tried again, and still nothing happened. I then heated the area with a soft flame, let it cool and tried again, still no luck.

At this stage I realised that I needed to get serious, so I bought a 20 tonne hydraulic press with a fully adjustable platform! The press turned what had been a bit of a struggle into a simple job; the flywheel came loose on the taper with a very loud "BANG" at about 6 tonne load. My recommendation to you is to take the engine to a workshop that has a large hydraulic press and get them to help you push the flywheel off the end of the crank without putting load on the crankcase in any way.

20T Press.JPG

I've also used my new press to push the pistons out of the rusted bores, etc, etc. A very useful piece of equipment.

Cheers,

Andrew

[julian]

Thanks, George - valves removed and cleaned up.

Interesting story, Andrew. I may well take your advise as I am expecting to have to have some work carried out on the bottom end (as witnessed by the pieces of metal in the sump plug) & the engineering firm could look at this after removing the flywheel.

Julian

[Jack]

Thanks, George - valves removed and cleaned up.

Interesting story, Andrew. I may well take your advise as I am expecting to have to have some work carried out on the bottom end (as witnessed by the pieces of metal in the sump plug) & the engineering firm could look at this after removing the flywheel.

Julian

Julian, where are you based? If you are local to us we have a press that I am sure you could use for a few minutes if it helps, there may be many members in your area with similar facilities that we could suggest who would help you out and may have experience of this type of engine and can give you some advice on the rebuild.

Jack.

[julian]

Hi Jack

Many thanks for the offer, but I am in the north of England near Skipton, Yorkshire - I am going to try the local garage once I get the clutch out - hopefully they can also help with removing the big nut.

Pictures of cleaned up head & valves & metal bits from oil drain plug.

[Andrew Henshall]

My recommendation to you is to take the engine to a workshop that has a large hydraulic press and get them to help you push the flywheel off the end of the crank without putting load on the crankcase in any way.

Julian, when you come to use the press to push the flywheel off the end of the crank, make sure that the flywheel is well supported on the platform and the crankcase does not see any of the load: see my red highlighted sentence above.

By the way, I did a calculation of the load that my well-engineered puller was applying to the end of the crank at the maximum torque I managed to apply, and it came to about 2 tonne (even with lubrication on the thread) which is why the flywheel didn't even look like moving!

Cheers,

Andrew

[julian]

Thanks for the warning, Andrew

At the moment though I am struggling to get the clutch assembly off the flywheel. I've removed the 6 set screws (any idea why these are slotted screws & not hex head bolts?) applied release oil around the edge and tried shocking it loose with hammer & piece of hard wood, but to no avail. Have I missed something or do I need to hit it a bit harder?

Julian

[Tony Fearn]

Hello Julian.

Now that you've removed ALL of the screws holding the back-plate, don't stand behind it when you have another go with the mallet - don't use a metal hammer on the back-plate, the piece of wood idea is good. There are 6 strong springs within the assembly, and if it lets go, the back-plate and spinning member could shoot off at a rate of knots.
I would replace three of the screws with a couple of turns each, so that when the back-plate loosens it doesn't jump off.
Perhaps judicious use of a blow lamp around the starter ring before trying the mallet again might just give you the 2 thou you'll need.

https://jowettnet/forum/download/file.p ... &mode=view

[julian]

Thanks for the warning, Tony - just as well it didn't come loose! I'll replace the screws loosely and try some heat as you suggest.

Thanks for the PM - I've replied.

Julian

[Tony Fearn]

Thanks for the PM Julian.
As to removal of the flywheel, I wrote this to Alan Bartlett in May 2007 as he was fettling his dad's car:-

Ian Priestly and I used the 'Braddock' technique George mentions to remove the much smaller crankshaft sprocket at the front of the engine of my 1927 Long two, and I was surprised that it worked. Shouldn't have been really because I.P. is a whizz at all things vintage and pre-war.

I haven't used the technique for flywheel removal though, only the 'puller method'. The large nut on the rear of the crankshaft is a 7/8 Whitworth size, the same size as the crankshaft sprocket retaining nut at the other end.

If I remember correctly, the 7/8" box or ring spanner won't fit over the clutch centering bearing on the back of the crankshaft. If it did, you would be able to prise it off whilst undoing the nut. If not then take care removing the bearing. It is a tight press fit on the shaft end, easily smashed and rather expensive to replace. (N.B. When rebuilding, make sure there are no burrs on the shaft end and offer the bearing to the shaft at 90 degrees before gently persuading it back into place using the inner ring of the ball race and a hollow drift.)

There is a keyway machined into the inside of the central boss of the flywheel which fits over a Woodruff key on the crankshaft end.

Another thing to watch for is that although most flywheels have the little arrow stamped on the rim to show Top Dead Centre (TDC), we have come across the odd one that when the arrow is visible at the top, the pistons are actually at Bottom Dead Centre (BDC)!

Back to the puller: - As well as the 6 clutch spring recesses on the inside of the flywheel, there are a couple of smaller holes drilled right through, one at either side of the central boss. These are drilled to take 1/2" Whitworth threads. To make a puller you will need a piece of 3/4" steel plate 6" x 3" and drill two holes 3 1/2" apart at their centres. The pair of holes should equidistant from the short ends, and on the centre line of the long axis. The holes need to be about 9/16" each.

Two 3 1/2" long pieces of 1/2" Whitworth screwed bar and nuts are also needed.

After removing the flywheel nut and washer, screw the screwed-bars into the 1/2" draw holes so that they just show through on the back side of the flywheel. Put the heavy iron plate over the bars and allow to rest on the crankshaft end. Put washers and the nuts on and tighten up each side a bit at a time. If you are lucky the flywheel might come off. If not, and making sure that there is a fair bit of tension on the plate, clout the centre of the plate with a lump hammer. If the flywheel doesn't come off at this stage, perhaps you'll be able to turn the nuts a bit more and clout it again. Heat from a blowlamp onto the central boss might also help as a last resort, but do this outside with a bucket of water or fire extinguisher handy.

When the flywheel finally comes off so will the puller with it, and together they will be very heavy so watch your toes.


It worked for me, and it's just another way of doing things, and perhaps a mite cheaper than purchasing a 10 ton press.

You'll have to make-up your own mind which method you use.

Tony.

[julian]

Thanks for all the information, Tony. I will proably give the puller a try and see how I get on.

Before that I had to remove the clutch! I hoisted the engine onto the bench and sat it fywheel up and ran release oil between the flywheel and clutch plate and carfully hammered round the plate with a raw hide hammer. Still it wasn't showing any signs of moving. I then removed the clutch operating levers and with a pin through the holes and a jemmy levering between the pin and the edge of the flywheel started to see some movement. Working round each lever postion in turn finally the plate sprung out (retained by the loosly fitting screws). I was then able to remove the clutch plate & pressure plate as show in photos.

[Tony Fearn]

Things are moving on with the clutch and fly-wheel.
I have just spoken with Julian and he tells me that he's sent off his subs to Mo and Bob, and is now a fully-fledged member of the Club, so:-

it's a "Welcome" from me and a 'Welcome' from ...............??

He's also coming over to Clayton le Moors tomorrow to have a chat.

Tony.