Petter A 1945 restoration

Having got this home from Ebay I firstly found this! saved a bit of work



This was the very first working outing with the new wheels and there's plenty of space and extremely easy loading.


For now this is put into storage until my A11 is finished but due to bad weather I decided to bring the magneto home to play with.

Next the Magneto..................

The magneto was a mess.

First the coupling was broken

Second the coil had failed.
Third the points were filthy and out of adjustment.
Fourth the coil cover copper contact was fitted upside down.
The biggest surprise was that the impulse was firing at 180 degrees out.
So it looks like a have a go hero had tried and failed miserably.
For the coil I used the Wipac CJ coil transplant.

Now fully cleaned and working.
I now routinely remove the spare stop button for spares.




I'm told that this is not the original unit for a Petter A and that it may be that someone fitted this to the original impulse unit 180 degrees out which makes sense.


https://www.youtube.com/shorts/P1xYzJTHjQ0?feature=share

The carburettor is a quite obscure Zenith 24U. Pictured here as removed untouched.






This comprises of three separate castings and no gaskets


Float bowl and jets


Upper body


Choke and air intake body














A steel choke flap

Strip and clean, nothing broken.






Better


Betterer


Betterest


Give me some deep Brunswick green!

I ordered stainless steel spring from China and stainless steel washer from Ebay. The engine had no washer on the contact face of the spring when I got it. I bought a 3/4" crank handle from SEP
I also replaced a rusty bolt with 8mm stainless steel rod through the shaft and final fixed it with loctite after painting.






The original handle is a mess and will got to scrap.

The barrel after cleaning.

I don't know why Petter felt the need for this breather but over the years it had been tightened so much that the aluminium had become imploded. I managed to bring it back to factory shape and of course over tightening is not a cure for oil leaks but there's monkeys everywhere.  


Aside from the exhaust valve being stuck the wear on both tells me they are original and lacked maintenance, extremely worn but my chances of finding replacement valves AND guides are nil or not cost effective. I know this engine didn't die from valve wear so I proceeded to lap them back in and clean. It will still work.


One done




I also had missing and bodged head bolts but I replaced the long ones by purchasing 2" long 3/8 BSF bolts and cutting the heads off. This was the cheapest option by far.




parts so far

Someone certainly got their money's worth out of those valves...

Looking good. Soon be up and running. Keep up the good work.
Andrew

This has been sidelined for a few weeks whilst I restored my mothers derelict garage to use as a storage and workshop unit.
Now continued..
The belt drum put up a fight so I had to destroy it to get the flywheel off.






The cowling will need a lot of attention














Something I found strange is this thick cylinder barrel shim

Shame you had to destroy the pulley but better than damaging the crankshaft!

Alan

Indeed yes Alan.

I neglected to show the fruit of my recent efforts






This 1952 A1 (on the right) is getting its first run tomorrow after a second rebuild. I'd been waiting to lacquer the paint to make it petrol resistant and that is now done. Hopefully just add fuel and go

I see you've got the most important tools in there... kettle and hammers!

Looks like another fine restoration in the making, ready to go on show in your new workshop come museum! With regard to the thick shim, could that be a compression plate for running on petrol/paraffin, in the same way as the Lister D had them on the head, although they had vaporisers as well?

Neil.

Can't have too many hammers  
Thanks Neil
All I know is that without the shim the piston would hit the head so its definitely necessary.
Today I cleaned the piston that I discovered is Hepolite and not Petters own.
I'm wondering if the shim was a work around for a none in house piston. 1945 there was very high demand for engines and possibly parts supply issues? total conjecture.




STD can be seen so not oversized and still in excellent condition with clean ring grooves and rings.


The engine is going back to the museum    tomorrow to await further assembly


The flywheel is very rough cast and was very hard to clean






Back to base

Now then Neil
Today I’ve discovered on reassembly that the shim actually prevents the piston crown reaching the top of the cylinder so now I’m not sure whether to leave as it was or remove it

I liked your theory and conjecture but now you have a conundrum! Do you leave it as it was when you took it apart and assume it worked that way, or do you remove it and see if runs well (better) without it being fitted. I suppose you could try taking a compression test with it fitted and removed, to judge what seems to be giving you a more reasonable reading. Sorry but I'm not that familiar with this model of engine to know if they did produce a paraffin version but would assume that would have been identified on the spec. plate, if there is one. Either way the shim looks to be of a manufacture's produced quality. Hopefully someone more knowledgeable about this model of Petter will be able to offer you better advice. Whatever you decide, as long as the piston does not contact the head, then if it runs, all should be well. It looks like you will be in a position to try fairly soon, good luck.

Neil

P.S. One final thought, I seem to remember reading somewhere that war time engines (bikes and cars) had their compression altered to be able to operate of the low octane Pool petrol available at the time. With the date of your engine, is this food for thought?

Thank you Neil. The consensus of opinion on Facebook is as you suggested and related to low octane fuel. There's nothing to be gained by removing it and increasing the stroke could cause an issue with any minor ridge at the top of the bore.

Pictures from today.

Yet again the tappets are impacted.

After a visit to the hobby lathe






Now I'm working on the cast iron cylinder head and repairs to the flywheel cowling.

Petter and Lister used thicker gaskets, sometimes two not steel spacer, your idea of different piston being to tall is likely.

Maryalice

We now know the piston is not too tall and stops short of the head by the thickness of the shim. An expensive item to make so I believe it was deliberate to reduce compression

Andy, I know there are available fuel tank sealers but do you consider your petrol proof lacquer you used would be any good inside a petrol tank?

Alan

No it’s only a paint finish it won’t fill pin holes and seal rust like PETSEAL

Thanks, I only asked as my JAP tank although sound is showing signs of light rusting again. I had it chemically cleaned and it was pristine inside. Having run the engine since, with an oily mix, I was hoping the residue would preserve the internals (it has been fully drained and vented)
Browsing over breakfast for tank sealers I didn't realise they were quite so well price, especially for a small tank!

Alan

For the lack of an alternative I have to use the original cylinder head despite two broken fins.

Same goes for the rotten flywheel cowling that I've rebuilt with glass cloth and resin.




Test fit

Moving along I now have a correctly fitting petrol tank having beaten it into submission. Some filling and paint to do then just the petrol pipe and a trolley to run.
I also need a screw on petrol tank cap as the original received a very big impact that caused the deformation originally.

I think I have a fuel cap for that tank.