Jim's Speed Twin Build

Not really part of the speed twin look, but I just love those fishtails... :heart:

I thought that too but somehow I think Jim's build will be more Go and less Show.
Yeah... will be 750 kit with prolly an early 256 cam.... maybe more, but I'm hopin' for a daily rider as well as the old school look. I'll have the hardtail look... with a softail suspension.
 
Not really part of the speed twin look, but I just love those fishtails... :heart:

Hi Gary,
those fishtailed mufflers are replica "Brooklands Cans" which were developed for use at Brooklands racereack in the UK.
The "silencers" were developed to appease folks who built houses next to the track and then complained about the noise.
 
Utter total waste of time and energy, and who knows how many screws had been over-tightened because of his stupidity.

Or by the same token under tightened as they needed to be backed off a bit to stop at the same alignment!

And one more thing on electrical switches. I had a friend who was an electrician and one customer got very upset when after he was done wiring her house she found that some of the switches pointed up when lights were turn on and others pointed down. Thing is this was for lights on 3-way and 4-way switches controlling the lights from different points. Not sure if he ever managed to get her to understand that situation.
 
Um... been a day or two.... :rolleyes:

I've read from several knowledgeable folk here that the XS-1 cam gives a fair bit more mid-range grunt than the 447 cam. Not quiet a Shell#1, but pretty good none the less. Of course, I've no personal experience... but I do have a locked up XS-1 motor I been meanin' to tear down. Hmmm....

Turns out the cam is almost pristine.

PXL_20211117_232724851.jpg


Forum member @MrBultaco was kind enough to supply me with a 36T 447 cam that was a bit nicked up. Thanks Tom!! :)
Needed to press the 34T off the XS-1 cam and 36T off the 447 cam and swap 'em. So... Tool(ing) Time! :geek:

Drilled a half in. hole in a half in. steel plate and pressed in a half in. steel rod. Had to dress the rod a bit, but a nice press fit.

half inch plate.jpg


half inch rod.jpg


Made for a nice stable holder for the cams.
The teeth on the XS-1 sprocket split the TDC groove on the cam. The 447 sprocket lined up on a tooth. There's my reference point.

34T TDC mark.jpg


36T 447 mark.jpg


Time to press.

Aluminum tube.jpg


Both separated.

both apart.jpg



The backside of the sprocket has the punch mark for referencing against the head face. Counted 9 teeth from there and marked the tooth on the face up side.
With the aluminum tube sitting on the steel plate, I could rest the sprocket on it and slide the cam down the rod. This allowed me to see the pertinent marks for alignment. Once I was satisfied, I set a block of wood on the cam and gave it a few solid whacks with a hammer. Seated it "just enough" to flip it over and set it back in the Great Orange Beast.

realigning.jpg


Back together.jpg



Near as I can tell, I missed by about a degree. No worries, there's too many variables at this point.... head gasket thickness, cam chain length... and I still haven't compared the aftermarket 750 jugs with the stock ones to see if the height's the same. Once I get the motor back together I'll index the cam and see where I'm at. Might get lucky and hit it dead on the first time, but I suspect this is just try number one. :rolleyes:
Ready to install... Into the box with the 750 jugs for now until I decide which motor I'm gonna tear down.

Ready to install.jpg


This whole year has been nothing but remodeling the house (keep Sue happy :sneaky:), winding rotors and painting tins... with the odd bit done to the DT. Was nice to get back to the speed twin, even if it was just a simple job and an hour spent... I'm happy:D
 
I wonder if anyone makes an adjustable sprocket for the XS cam? I assume so, but never looked.
While I was reading up on swapping in the 256 cam I ran across a thread talking about an adjustable sprocket.
Iirc it was @grizld1 ... and as I recall, he didn't have nice things to say about it.
 
When I rebuilt my XS2 using a 447 crank and XS2 rods I used a megacycle adjustable cam sprocket for the 447 engine to match the sprocket on the 447 crank.
Con rods, pistons, and cam are XS2. Crank, cam chain and megacycle adjustable sprocket are 447.
 
Um... been a day or two.... :rolleyes:

I've read from several knowledgeable folk here that the XS-1 cam gives a fair bit more mid-range grunt than the 447 cam. Not quiet a Shell#1, but pretty good none the less. Of course, I've no personal experience... but I do have a locked up XS-1 motor I been meanin' to tear down. Hmmm....

Turns out the cam is almost pristine.

View attachment 202070

Forum member @MrBultaco was kind enough to supply me with a 36T 447 cam that was a bit nicked up. Thanks Tom!! :)
Needed to press the 34T off the XS-1 cam and 36T off the 447 cam and swap 'em. So... Tool(ing) Time! :geek:

Drilled a half in. hole in a half in. steel plate and pressed in a half in. steel rod. Had to dress the rod a bit, but a nice press fit.

View attachment 202072

View attachment 202073

Made for a nice stable holder for the cams.
The teeth on the XS-1 sprocket split the TDC groove on the cam. The 447 sprocket lined up on a tooth. There's my reference point.

View attachment 202074

View attachment 202075

Time to press.

View attachment 202076

Both separated.

View attachment 202077


The backside of the sprocket has the punch mark for referencing against the head face. Counted 9 teeth from there and marked the tooth on the face up side.
With the aluminum tube sitting on the steel plate, I could rest the sprocket on it and slide the cam down the rod. This allowed me to see the pertinent marks for alignment. Once I was satisfied, I set a block of wood on the cam and gave it a few solid whacks with a hammer. Seated it "just enough" to flip it over and set it back in the Great Orange Beast.

View attachment 202078

View attachment 202079


Near as I can tell, I missed by about a degree. No worries, there's too many variables at this point.... head gasket thickness, cam chain length... and I still haven't compared the aftermarket 750 jugs with the stock ones to see if the height's the same. Once I get the motor back together I'll index the cam and see where I'm at. Might get lucky and hit it dead on the first time, but I suspect this is just try number one. :rolleyes:
Ready to install... Into the box with the 750 jugs for now until I decide which motor I'm gonna tear down.

View attachment 202080

This whole year has been nothing but remodeling the house (keep Sue happy :sneaky:), winding rotors and painting tins... with the odd bit done to the DT. Was nice to get back to the speed twin, even if it was just a simple job and an hour spent... I'm happy:D

Good info, as always coming from Jim. Plans of doing the same thing when I get to that point of my 750 motor build, not so scary now seeing it done.
 
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