Brodie's Bastard BSA

Very, very interesting! I've a feeling that this is going to be a really impressive and unique machine.
 
I have found another two examples, but each with no information.
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All the info I can find is they used a shovelhead top end, most likely big twin, and a M20 lower.

My M21 lower might need a stroker cylinder.
Should be about 691cc, no idea on CR.
 
Good mornin sunshine

You need to do it with a iron head and blaze a new trail hoooha


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Horst Heller in Germany either built one or knows a lot about those hybrid motors. He's a member of the Jockey Journal
www.jockeyjournal.com
Great project!!!! I'm a big fan of BSA A7/10 frames. I built a 45 hybrid in the 90s. I still have a frame I got from Jack Wilson at Big D Cycle in Dallas.

Rider
 
thats fuckin awesome and funny my bsa goldstar came with a harley piston innit ,but i had never heard of the whole top end
i had to take the brand new harley piston out of mine tho it woont start :-X :D
its a wonder the bsa rod and crank can handle all the gobs of power a harley pissed-on puts out dontcha know ?!
 
Just a quick update.

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Also the shovelhead is so close
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Ironhead is a mile off
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Thanks to Hurco for the base gasket idea.
 
Shovel is pretty close. Could maybe slot the mounting holes to fit it? Bummer you can't get ahold of the guys who did your inspiration pic bikes
 
I asked my welder friend about welding cast iron and cast alloy.

His response was he can braise the iron and "Fuck that" for the alloy.

So Axtell make "ductile iron" cylinders. I wonder if it is worth finding one of them.
 
What's is there room to move the studs out a bit on the case?
 
Would have to move the studs in a bit. But the hole would end up elongated

My 2 plans involve finding a big bore cylinder with wider bolt pattern or running the flat head and using a 5 speed gearbox with small rear sprocket.

I would prefer the first. But I think building a plate to fit around the cylinder base and having that braised on, the correct bolt spacing drilled might be the go. Just worried about braise strength.
 
You could loctite in aluminum studs then machine new holes without welding. I've done that a bunch on different equipment. Never a bike (for full disclosure) but it should work all the same
 
the cast iron can be cast iron welded, but you need to find that guy ,a real qualified expert
,material can be added and built up .its an oxy-acetelyne process ,requires careful, even ,slow,hi temp preheat and slow cooldown in the oven as well
 
ok i see how the hole misses now.a slightly elongated hole is not a big issue as long as you can ad a heavy washer that will not distort
the other minor issue is to have the barrel clocked correctly and extra dowel or 2 would suffice
but those holes in the barrel are a basic very easy job for a qualified EXPERIENCED well know expert cast iron jockey
these guys are used to really broken shit,usually antique that cannot be replaced ,a nice clean easy to see barrel job like that , a walk in the park
 
Why not heat, nickel rod weld and bury in hot sand... loooks like it will all be under the jug so wont see the chiney weld.

I dont see threads so must have nuts backside no? maybe turn the jug just a few deg and fill the holes with lead leaving it a few thou proud topside to ease off with a file. Push rods wont mind a slight angle and tubes can be cussum fit with some leather seals soaked in hot wax.
 
nikel is for tempory "fixes" it aint no good the problem is the weld can easily be too hot which fucks with the carbon in the iron making a hard as spot, right where it needs to be, drilled agin :-[
i bet he could get it iron welded ,and faces machined for under 300 that would be money well spent
 
I'm still thinking modified aluminum cases. They are aluminum right? Much easier to work with than modding cast iron
 
hurco550 said:
I'm still thinking modified aluminum cases. They are aluminum right? Much easier to work with than modding cast iron
Click to expand...

nevrer to be a bsa agin :'( :'( by god you dont buggger as first wirst ,bah ! the barrels are expendable
 
Lol I have little morals when it comes to bikes. Even bsa. To me, better to be modified and ran than not touched and sitting. There is a line though. If it were a Vincent or something nah, but a modded thumper bsa... weld er up. Of course, my opinion only.
 
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