Brodie's Bastard BSA

If I can get away without making changes to the case I will. Just ordered some Evo base gaskets, see how close they are.

If I have to alter the case I may as well use a better head design.
 
Brodie said:
If I have to alter the case I may as well use a better head design.

yep, evo could be a good way to go. im liking this!
 
The more I look at this the more I think a Shovelhead would be the way to go. The rear cylinder appears to have enough meat on it that I could have holes driller where I need them to match up to the studs.

On the other hand, this engine has a stroke of 112mm. The Evo Sportster has a stroke of 96.83mm.
The M21 has a bore of 82mm. The 1200cc Evo Sporster has a bore of 88.85mm

So 112mm stroke and 88.85mm bore = 694cc
Who wouldn't want a 700 single with no starter motor! hmm maybe a lot of people.

So the 15~mm difference in stroke can be used to create an adapter plate for the different bolt patterns. Since two of the Evo bolts line up! (photo soon)

Here is a quick drawing to explain my idea.
 

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Brodie,
The Matchless 500 I learned to ride on had a decompressor lever to ease starting - wondered if something similar could be done in your case? If I remember correctly, it opened the exhaust valve just a tad when you were kicking the bike.
BTW, outstanding creativity on your part - I always liked the A10's too.
Pat
 
You are a braver man than I. You can still cut your losses and make a profit on parting it out.

Good luck mate
D
 
Dont really see the problem welding either cast iron or alloy?
We welded up a broken cast iron steering axle for forklifters size ++ in school. Used a bit of torch pre and post weld and stainless rod. No magic really, just easy with the heat and careful with the tempering.
As for cast alloy, whats he talking about? Its perfectly weldable!
Although adapter plate seems the way to go in this case..
Be sure to film your first few kicks! ;)
 
I'm with this guy. Welded the gear box on a Fate Root Heath pug mill cast iron gear box during rebuild and it's going strong. Rose bud tip pre and post. All good.
 
Ok so if I were to heat up the cast iron with a propane torch. Have it welded and the sick it in a bucket and cover it with sand, would that equate to a strong weld?

Sadly the evo bolts slightly overlap the m21 bolts. So it looks like unless I make two adaptor plates that won't work.

I can either weld up the shovelhead cylinder base to have it fit. Or weld up the stud holes in the BSA case and have new holes drilled to suit which ever top end I plan on using.

Anyone have experience with those hts2000 alloy "brazing/welding" rods. Will they hold well enough for a thread to be placed in it?
 
Brodie said:
Ok so if I were to heat up the cast iron with a propane torch. Have it welded and the sick it in a bucket and cover it with sand, would that equate to a strong weld?

Sadly the evo bolts slightly overlap the m21 bolts. So it looks like unless I make two adaptor plates that won't work.

I can either weld up the shovelhead cylinder base to have it fit. Or weld up the stud holes in the BSA case and have new holes drilled to suit which ever top end I plan on using.

Anyone have experience with those hts2000 alloy "brazing/welding" rods. Will they hold well enough for a thread to be placed in it?

No experience with those.
But brazing with pure zinc anodes will give you harder material to tap, though it will be more brittle as well.

I would suggest finding out which precise alloy was used for the cases, then select tig filler accordingly. Usually AlSi5 does the trick, though i would personally try to keep the original stud holes if they are fresh.
 
Flip the cylinder upside down and take a picture of both the cylinder and the case.

I am thinking you should modify the cylinder not the case if at all possible. You could fabricate a collar with two halves much like a Kawasaki exhaust flange but with 4 holes 2 overlapping like this: If you can plug the voids with lead just to seal (a tad proud for pinch) you might not need to weld anything.

mhk.jpg
 
So bear with me here as I am kind of just letting ideas flow from my brain.

I have been looking into every type of pushrod engine I can think of. BMW R models, VW Beetles, Harleys, every old Brit bike I can think of. Then it hits me, "Aren't the new Enfields pushrod?"
So after a quick look into the engine I have found that the top half of the cylinder has a casting around it yet the lower half does not. Here is a picture for an example.

royal-enfield-cylinder-piston-kit.jpg


The valve adjustment box is located on the lower end of the Enfield engine... so the cylinder sleave protrudes into it. They also have a bore in the range I need, 84mm-87mm. The stroke is at 90mm compared to the 112mm of the M21.
SO, If I cut the scrap cylinder in half and use that as the adapter I can keep the stock lower bolt location and just bolt the new Enfield stuff to the newly tapped holes in the "spacer" cylinder.


I think I might be onto something here.
 
Haha I only just watched the movie as inspiration. It nearly has me casting my own cylinder.

I am glad that I have possibly sorted out a solution that doesn't include welding on the case or being concerned about the strength of the weld on the cylinder.

I have ordered a base gasket and once it arrives I will be able to sort out if this can be done. After that I will order a cylinder and a head. Enfield parts are cheap.

Which leads to another question. Efi or carb?
 
I love posts like yours, Brodie - keep up the great work.
I read in a mid-sixties motorcycle magazine, one set of cylinders Burt Munro made for his Indian started out as water pipe (seamless?), with the fins sweated on (interference fit) - would something similar work for you?
I figured you had looked at getting a cylinder cast up, but pattern making is a lot of work for just one or two pieces and blessed expensive if you have to farm it out (don't know what you have for foundries down under, either).
Keep at it.
Pat
 
Thanks guys, getting there slowly.

A bloke at work had also mentioned Bert making a cylinder out of seamless water pipe and pressing cooling fins on. I am sure I could use this as a last resort. At the moment the Enfield cylinder seems to be the way to go. I am looking at getting a high compression piston and getting a machine shop to create the right height out of the two cylinders.

OK so I managed to score a NOS Lucas Magdyno. They are few and far between here in Aus, I asked Beachcomber to keep an eye out for me and he came up with the same results I was. So I bit the bullet and bought one from the US.

That should be arriving soon and will at leas complete the "spark" part a petrol engine needs to run.

I have also bought an Albion 4 Speed Gearbox which looks to be off an early 50s English Royal Enfield Bullet. The gap between 3 and 4 is decent so I should be able to set up 4th as a highway gear and have the other 3 for around town. Hopefully with the torque that the engine will produce the long gearing won't leave me searching for power in hills.

The seller of the gearbox doesn't seem to be the best at communication so I am still waiting to see if it has been posted or not.
 
Good score on the Mag and gearbox...I hope they arrive sooner than later. If the gearbox has the neutral finder you're going to like it. I sure wouldn't worry about torque...even with the lowly the side valve head, they could pull a house down. :D
 
Gearbox arrived today. Tucks in neat like I had hoped. Mag shouldn't be too far off. Maybe next week.

The RE base gasket should be here by then as well.

The gearbox needs a rebuild as the output shaft is bound to the input shaft. It also seems to have an issue shifting to 4th and there is a tiny rattle if I shake it.

As far as the frame goes. Looking at Goldy's build is helping me determine what lugs have been put on to the frame and what is stock.
Because I am building a single it looks like I will need to modify the frame to allow the bottom end to sit in the frame. The oil pump is stopping it and these frames come with a kink in them to allow clearance of the oil pump on singles.

Has anyone bought from "Royalmotorcycles" before? Their parts are a hell of a lot cheaper because of the conversion rate and they say they will ship international. Makes this build a hell of a lot quicker if I have access to more funds by saving on parts.
 

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