Misc: Everything Else Norvin 600 Build
- Thread starter davidd
- Start date
Hi Greg,
You should consider some expansion when hot.
A straight line bracket from the steering head to the cylinder head via the cross tube lug won't let the engine expand .
The Manx Norton head steady pictured above will obviously allow some expansion and if you look at other manufacturers head steadies you'll see that they are all designed that way.
I did make "articulated" front and rear head steadies for my Norvin twin, they only hold both heads in a lateral plane. Seems to work so far. I believe Ken Phelps doesn't use any head steady on his road going Norvin,
The alignment of the top of the engine versus an original Norton probably lends itself to more of a straight line "Push-pull" to the top of the headstock tube, so this is possibly a better thing........Who knows......I am happy to send pictures of the plates and templates and/or dimensions if anyone wants them, though I had to keep the gearbox as close to the engine as possible. When we got this engine/gearbox combo, the engine plates were to suit mounting in a Stock Vincent, and there was no provision for gearbox adjustment. I copied the original Norton rear plates, but kicked the gearbox around so the mounting points were on an angle rather than the originals which were near vertical. The lower hole is half inch and upper slot is 9/16, I guess it could have been made with a radius, but the amount of travel is quite small, and the ones on the original plates were exactly the same, so we just copied them. I am very tempted to make a threaded adjuster for each side which would help keep the gearbox aligned squarely and not hard to do. I am leaning toward making up an inlet manifold that keeps the carby more in the center of the frame rather than some fanciful one that passes under the left upper rail, as being "Up draft" it could cause issues with pooling of fuel in the manifold.
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Greg would love a copy of the comet plates as that is the stage I am at with my Norvin wideline Norton gear box.
Vincenttwin@gmail.com
Thanks
Peter Allen
Vincenttwin@gmail.com
Thanks
Peter Allen
Thats Fine Peter, Although I can't confirm that the wideline and slimline frames are the same at their attachment points. I have a replica Wideline frame here as well, but it has been made specifically for the chopped twin engine. Remember also I have fitted this up so that the engine and gearbox are as close as I can get because of the fairly short primary belt, and I think the shaft centers are a approximately 200 to 205 apart. With a standard Comet exhaust pipe installed in the head, I can put my fingers between the right front down tube and the exhaust pipe, so a good 25 to 30 mm gap. But to me the engine looks good sitting where it is, and with the gearbox neatly tucked in behind, I am very happy with it. I will post some pictures of the new alloy front plates which look very good as well, and they fit straight on..............How lucky is that.............
Hi Greg
The difference isn't between wideline and slimline, there are 3 different mounting types but they only concern the front mounts, singles have the front mount about 2" higher than the twins and the late twins had a 2nd mount almost at the bottom which lined up with the bottom front engine bolt, this is the type you have.
As you can imagine any front plates for an earlier twin or single frame will be very different.
I added a 2nd lower mount when I built my Norvin
The difference isn't between wideline and slimline, there are 3 different mounting types but they only concern the front mounts, singles have the front mount about 2" higher than the twins and the late twins had a 2nd mount almost at the bottom which lined up with the bottom front engine bolt, this is the type you have.
As you can imagine any front plates for an earlier twin or single frame will be very different.
I added a 2nd lower mount when I built my Norvin
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Great blog from a guy in the Uk who build a comet norvin , I like his way of mounting the engine.
Yes he did a nice job, though I don't want to cut anything off the engine like he did, and I was able to use the aft pair of lugs at the front of the frame to mount the engine at the front, I will get some more pictures on here to show you what I ended up with.
This thread needs a bump and I would like to ask a question or two...if I may. When and if you have a minute, could you tell me how wide that spacer is between the top lug of the gearbox and the drive side engine plate. 10 o'clock from the final drive sprocket. Is that a stock Commando sprocket or something with a different offset? Please and thank you.