What thread form?

Now that I've acquired my two Petter A1 engines...

Its time to dismantle and refurb them..

What generally are the spanner sizes needed to undo the various nuts and bolts?

What are the commonly used thread forms? In case I need to make new studs/ hex threaded spacers

I'd hazard a guess at being British, they are going to be Whitworth or BSF?

Thanks,

John

Hi John,

Ive noticed that some engines are both Whitworth and BSF, it can be a bit of a pain at times.

Are you going to restore both engines?

Are you going to show the engines?

If so , hows this for an idea, Restore 1 (the best one) and leave the other as it is. Then show both engines as a Before and After exhibet.

By the way, the flywheels are a complete bugger to get of, Ive never got one of without cracking it.

Paul

Rab,

Thanks for the reply.......

My orignal proposal was to restore at least one of the engines, making a good one from the two.

However, both need a mag/carb and exhaust..

One has a stud stuck in the head( I've removed all the nuts, but one ofthe studs appears to have 'siezed' to the cylinder head) the other has a stuck exhaust valve ( stuck open! )

So I guess its out with the thread gauges and time for a bit of technical guessing.....

That may be another option, sell of decent bits to get some pennys back for your next step.

I may have a carb in the shed, will have a look later and let you know, sorry i dont have a mag though.

The valves were prone to sticking on the A and A1, it wont take much to free them of. A wee bit wd 40 and crank the engine over to get them moving then just squirt some oil over them and they should free of. you may have to close the valve with a screw driver or something like that to start with but they do go in the end.

Try and tighten the stuck stud a fraction just to break the corrosin on the threads, then try and remove the stud.

Hope thats of use to you.

Paul

rab wrote:That may be another option, sell of decent bits to get some pennys back for your next step.

I may have a carb in the shed, will have a look later and let you know, sorry i dont have a mag though.

The valves were prone to sticking on the A and A1Paul

That would be great news if you have one to sell......

The valve issue isnt a big deal really...I think I can sort that without too much aggro..Removing the cylinder would be easier if the flywheel wasnt there..British spanners are a bit thin on the ground in my tool collection..

John

Chippie wrote:

rab wrote:That may be another option, sell of decent bits to get some pennys back for your next step.

I may have a carb in the shed, will have a look later and let you know, sorry i dont have a mag though.

The valves were prone to sticking on the A and A1Paul

That would be great news if you have one to sell......

The valve issue isnt a big deal really...I think I can sort that without too much aggro..Removing the cylinder would be easier if the flywheel wasnt there..British spanners are a bit thin on the ground in my tool collection..

John

No probs bud,

For Witworth spanners go down to the nearest car boot sale and have a ratch about in the tool buckets, you will be able to get all that you need for next to nothing. Watch out for named spanners, if you can get a whole set of say "Lister" they may be worth a wee bit money.
I got 2 Massy Ferguson spanners form the same bloke a few year ago for £1 i then walked away about ten yards, phoned a guy that was looking for this type he bought both of me for £120, Bargan or what.

Paul

Ask Mike about Whit spanners he got him self a brand new set at a good price
I still have my Snap on set since I was a lad
Jonesey

Chippie wrote:

rab wrote:That may be another option, sell of decent bits to get some pennies back for your next step.

I may have a carb in the shed, will have a look later and let you know, sorry i don't have a mag though.

The valves were prone to sticking on the A and A1Paul

That would be great news if you have one to sell......

The valve issue isn't a big deal really...I think I can sort that without too much aggro..Removing the cylinder would be easier if the flywheel wasn't there..British spanners are a bit thin on the ground in my tool collection..

John

Hi John,

I eventually found the carb in the shed, but unfortunately its the wrong type. The type i have is for a Petter a which is a Solex 26FV type.
I'm going up to a mates today so ill have a ratch about in his shed and see what i can find.

Paul

Paul,

Thanks for looking...

John

hi john...

if you looking for whitworth spanners,you can get them brand new from silverline,thay come in a lovely wallet as well so you don't lose them...
the other way is to go onto eBay,type in whitworth spanners and it comes up with loads of them,new and old.
the new ones aren't that expensive really....

good luck in your hunt...

regards..mike...

Thought I'd update this thread now I have my engine stripped...

The majority of bolts are 5/16 BSF, that would cover all the bolts used to attach things line the tin work and engine covers.
Cylinder head and cylinder fixings are 3/8 BSF..as are the big end bolts...

Finally, the thread in the end of the crankshaft(drive end that is) is 3/4 BSF.

A handy bit of info for anyone rebuilding one of these that doesnt know sizes.........

Chippie wrote:Thought I'd update this thread now I have my engine stripped...

The majority of bolts are 5/16 BSF, that would cover all the bolts used to attach things line the tin work and engine covers.
Cylinder head and cylinder fixings are 3/8 BSF..as are the big end bolts...

Finally, the thread in the end of the crankshaft(drive end that is) is 3/4 BSF.


A handy bit of info for anyone rebuilding one of these that doesn't know sizes.........

thanks for that john...will be handy for some of the members....

mike...