JAP 4/2 (Engine no. P15904UVX)

Bit more on the JAP, a few days ago I took the engine casing (2 parts) and fuel tank round to our metal finishing outfit for them to be stript of what paint was left and de rusted. I've not had this approach before but this cowling had some pretty inaccessible places.
Picked them up today and was quite pleased with the results, they actually zinc plated the parts as well. Obviously no plating has got in the tank but at least it's clean!
It has however revealed the surface corrosion scars now the surfaces are raw, all treatable with a primer/filler.
Most revealed are the dents in the fuel tank! Going to try and get some tools inside to minimise the amount of filler required.

Alan

Spent a bit of time today trying to remove some dents from the fuel tank using a piece of bar bent up to get inside. Not a total success but it did reduce the amount of filler required.
Also went over the engine casing filling the ex rust pits with filler finishing off with 120 grit to get it ready for some etch primer.
Cleaned up the petrol cap and discovered it's actually a brake fluid cap with those very words stamped on the top!
Anyone got a spare JAP petrol cap?

Alan

Coming along nicely Alan
RichieR

Thanks RichieR,
I put a photo up before of the starting handle boss that was broken during flywheel removal. I was guided to and example, with handle, on eBay but unfortunately I missed out by £3! (pig sick or what!)
Anyway I now have decided to manufacture something similar with handle but as this is my first engine that utilises a handle for starting I am unsure of the clearance between handle and starting boss?
I imagine it could be fairly 'loose' but a figure to aim for would be welcomed!

Alan

Tackled the starting handle boss today. Much chunkier than the original casting but thought that wouldn't be a hindrance.
I've left the bore for the handle undersize at the moment as I have not quite given up the possibility obtaining one, if all avenues fail I shall have to make a handle.
Has anyone got one that they could measure the 'throw' for me?
Bit more sanding and filling on the engine casing and tank and hopefully should be able to get some etch primer on soon.

Alan

It may be worth sending a photo of the broken casting to john@doubleboost.video he likes a welding challenge

Thanks Robostar5 will bear that in mind.
Fine morning so decided to get a coat of etch primer on the prepared parts.

Alan

Painting on hold again 'cause of the weather!
So I got on with the starting cranking dog.
Need to cut a slot in the opposite end for fixing (welding?) the handle to give a 6 inch throw.
I am thinking that the orientation of the slot relative to the engines timing should be that as the handle is pulled up the engine is on it's compression stroke with tdc achieved before the handle reaches tdc - does that sound about right?

Alan

Well having changed the design slightly and having a dry run (cranking) it seems ok but will not fix it together just in case mods are required!



When I got the engine all it had for a choke control was a bit of wire to operate it so no fine control at all. Try as I may I couldn't find any images of a choke lever or control of any kind so I had to fabricate what seems to operate ok. Choke lever can be left in any position as the top joint includes a friction washer. Up for full choke, down for off.



A question if I may? Upon removing the fitted pulley I couldn't find any form of retaining it on the shaft, no grubscrew - the pulley has no provision for fixing but when I pulled it off it would seem that it had been made a tight fit on the shaft using the key with a shim under it making it a semi interference fit. Not a tapered key.
Is that normal? I've not experienced it before.

Alan

Gone as far as I can, now held up for the engine casing and tank painting, come a long way - so close!
Been trying to source some sort of alternator/generator for it to drive with no luck so far so am considering using a car alternator, same model as my Astra. Bosch 100 amp bought secondhand as a spare I have been renovating it with new bearings and slip rings for possible use as I want to be able to load the engine.



Alan

Looks stunning Alan
RichieR

Looks good Alan, I bet you are keen to get it fully up and running. It would certainly be nice to get something for it to drive, if there is nothing else available, at least your car alternator would give it some load to work with.

I'm in the same situation as yourself, I'm running out of work I can continue with on the Scott generator set. I need some good weather, over an extended period, to allow me to undertake the top coat painting, before I can continue with the rebuild.

Here's to a good, warm and dry spring!

Neil.

Thanks guys, this one sort of pushed it's way ahead of the queue - it was only supposed to have an external clean to make it manageable and put it away for later!
Didn't have any luck locating a petrol tank cap, the one that came with it revealed after a clean up that it was in fact a brake fluid cap? although it fitted well enough.
Set it up and turned the centre out of it and using JB Weld stuck a brass disc in it. I was planning on soldering it in but the leather washer on the other side looked like it wouldn't survive being removed.
Not got a finished photo yet - as it's not finished!
It should look more the part than it did.

Alan

Assembled engine casing and tank this afternoon, main casing went on ok but the top cover really had to be pushed/heaved into position to enable bolts to be fitted! Had an old leather strap that was crying out to become fuel tank insulators/mountings, fixed to the band's with double sided tape once the screws were nipped up holds the tank nicely.
Cranks over well on the handle, all it needs (in theory!) is some petrol in the tank but I am a bit reluctant to have it bouncing around on the bench and as I have a sheet of 8mm steel on the way to mount it with new countershaft and alternator I shall hang on untill I at least have it bolted to it's new base.

Alan

Alan, that is looking really good, I especially like the paint finish you have achieved. I would be interested to know what the paint is you have used, the manufacturer and colour, also how you applied it, brush or spray?

Thanks,

Neil.

Thanks Neil, the engine itself had the bare cast iron etch primed and finished with satin black, both from aerosol tins.
Casing parts and tank were chemically cleaned and zinc plated. All the rust pitting was then filled, along with the dents in the tank, with P38. Once again etch primed and top coated using Arc Rite military camouflage paint. I used the semi gloss version as it is more forgiving!
The engine dates from 1940 and wasn't in military use but decided to use NATO Green as it wasn't a million miles away from it's original green.
This was sprayed on using a compressor fed touch up gun with a small amount of thinners added as it was quite cold when it was applied.
Looking forward to hearing it run!

Alan

Very nice!

Alan, many thanks for the information. I would have been interested in trying that military paint but I have already invested in a different supplier. I was hoping you had attempted brush painting and had achieved that finish, if you had I might have been persuaded to give it a go. I am now waiting for better weather before I can really make much more progress on the Scott. I did attempt to use my paint in the cooler temperatures we're currently experiencing but it did not flow off the brush very well, I'm hoping it will work better once the warmer weather arrives.

Neil.

What a cracking job on the engine. Very good indeed.
Andrew

Beautiful job. Well done.

Progress has not been good, material I ordered for the new engine base went missing delaying mounting the engine. Once that turned up I constructed an angle iron frame type chassis to take the engine/generator mounting plate.
Also going missing was my order for axle material for the wheels! This was eventually delivered after an over 2 weeks delay. Finally got the parts painted using hammerite
However we are now back on the project and have started assy, photos to follow (if I can lift it off the bench!)

Alan

An update! Finally got the engine, countershaft and alternator mounted on the new base assembly. Asked my son to pop round for help getting it off the bench as it so far weighs in at 200lbs managed to get it to ground level in one piece!
Today I was planning to fabricate some sort of handles to enable it to be moved around without pulling the exhaust apart but decided to give it it's first run.
I removed countershaft drive belt so it would be an unloaded engine, filled tank about 1/3 full and put in a dose of SAE 30 oil for some upper cylinder lubrication turned on the petrol tap and was rewarded with a bad leak out of the glass filter bowl incorporated in the on/off valve. It was too bad to attempt running the engine.
I had replaced the original disintegrated washer with what I thought was a nice O ring. I haven't been able to find a breakdown parts list of this unit so unsure what should be there?
Who might be able to supply one?



Alan

Alan,
What was the original washer like (apart from being disintegrated)? Can you see what material it was made from?
I would expect it to be made of cork or rubber or fibre, and square or rectangular in cross section.
I don't think an O ring would do the job. You may end up having to cut one out of rubber or cork sheet, or thick gasket material.

George.

I'm not sure the sediment filter on my Petter A1 had a washer?
Might be worth trying here .... http://www.guypartsandservice.co.uk/page10.html

George, I have just found a photo taken on dismantling, it was rubber and looks quite thin and square in section, I also remember it falling apart as I removed it!
I think the O ring I found and fitted was too fat and not get into the corner of where it needs to be.

Woodsman, I see they can supply a new sediment bowl, I didn't want to replace it so have asked if they can supply a seal for an original Wipac.
If not I will have a go at making one.

Alan