Monstor 920cc sidecar Norton with 15:1 compression on Alky

Robet Hoods 920cc side car Norton with 15:1 compression on alky has been doing very well by winning races is New Zealand and beating some very high tuned BMWs (which they don't appreciate at all). So far this is the highest C.R. I've heard of for a Norton.

What else do you know about the engine internals? Is he running your rods and pistons? Does it have a 360-degree crankshaft?

More Pics more Pics! Please

Obviously, the exhaust headers and carburetors are too large to make any real power. lol

That is a beautifully engineered hunk of Norton. Looks mean.

Thanks for posting Jim

My good friend Don who got me into Norton's and Featherbed frames he went down the Triton way and built his own Triumph race engines, made his extra strong crank cases out of solid billets and made his own one piece Norton cranks for them, Don's way of thinking was the more compression the bigger the bang in performance (he was running 14:1), well he was right there he kept blowing his motors up and I said to him one day, "Don do you think you are running too high of compression" he said they ran great till that magic moment.
He use to take his race bike on a slim trailer towed by his old Shovel Head Harley it was a sight to be seen and always drew a crowd when he pulled up.

motorson said:

What else do you know about the engine internals? Is he running your rods and pistons? Does it have a 360-degree crankshaft?

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Yes it has a regular 360 crank with the long rods and light pistons.
He is only able to use that 15:1 C,R, because its on cool burning Methanol.

mean gene - Here's another pic I have. With all that compression the original Maney cylinder through bolts failed and so the cases broke. He had to get stronger reduced shank through bolts and new cases.

jseng1 said:

Yes it has a regular 360 crank with the long rods and light pistons.
He is only able to use that 15:1 C,R, because its on cool burning Methanol.

mean gene - Here's another pic I have. With all that compression the original Maney cylinder through bolts failed and so the cases broke. He had to get stronger reduced shank through bolts and new cases.

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Jim,
Any pictures of the other side showing the chair?
Thanks,
Mike

Sure is a purdy crank....

YING said:

Jim,
Any pictures of the other side showing the chair?
Thanks,
Mike

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Here's one I found.

About 100 races on that motor now.

Did he have to weld up the combustion chamber, essentially making it a bath tub sort of configuration, to get 15:1 CR?. With big valve heads and race cams (I'm assuming he has those), it's really difficult to keep enough valve-to-piston and valve-to-valve clearance and still get such a high CR in a 920. I suppose one could also get up there with a carefully fitted high dome piston, but it's not something I have encountered. We don't see much in the way of serious Norton builds for methanol fuel here in the states. I've seen some built for drag racing, as well as landspeed racing, that ran on methanol/nitro blends, but typically at lower CRs. Like the others here, I'd love to know more about the details.

Ken

100 races on the same motor is mind boggling to me. Small mind though, so it doesn't take much to get boggled. lol

There are a lot of myths about methanol. Phil Irving said in Tuning for Speed 'if methanol is run rich, it still gives good power'. And that is true, but most guys interpret that as meaning 'methanol should be run rich'. The reason methanol is good, is it hides-up the tuning errors. Getting the best out of methanol is as easy or as difficult as getting the best out ot petrol.
For a Commando engine on 9 to 1 compression, for petrol the recommended needle jet sizes are 0,106 and 0,107. For methanol in the same engine on 9 to 1 compression, the needle jet sizes are 0.116 and 0.117. If the engine was in the 12 to 1 compression which most guys would use the needle jet size would be 0.120 with very quick taper needles. If you are an idiot, you might believe that much more fuel in the mix, must create more power. What you rely on is that there is no 'quench effect'.
I have had a Triumph 650 motor running on methanol at 7 to 1 compression with E3134 race cams and megaphones, and it was quicker than any other I ever had running at 11 to 1 on Avgas or methanol. I sold the 650 motor to a friend who used in his sidecar. He had his first win with it, then blew it up.
The main thing with any fuel is that it is fully atomised and jetted lean enough to give best power. Methanol has unlimited antiknock, so it is possible to burn pistons and valves, before you know you are too lean. However you will usually detect a miss before you get that lean. Several things are inter-related - comp. ratio, ignition advance, type of exhaust system, jetting and knock rating. Also combustion chamber shape.
If my motor ever misses when I am riding the bike, I stop as soon as possible and fix it. Usually involves raising the needles. Mainj ets usually do not matter because they are always a bit too rich.

I could take him with the MK3.
I might have to remove the centre stand.

Glen

2014

WINNING SIDECAR WITH 98.5 HP AFTER 97 RACES

Robert Hood and passenger Mark Thompson won the New Zealand Classic Motorcycle Racing Register (NZMCRR) Post Classic Sidecar Championship in 2013, 2014 and 2015. JS 920cc lightweight pistons and longer rods. Maney cases and Barrels. One piece crank by Graham Martin in NZ. 36 mm Dellorto’s. 11.5:1 compression on methanol. 98.5 BHP at the back wheel.



“JS pistons and rings went in mid 2013. I have no record of any ring replacement since then. We did 17 races in 2013 on the new motor, 38 in 2014, 25 in 2015 and we’ve done 17 this year so far (2016). Plus practices and test days. We had the head off a few times over last Christmas and noticed no discernible piston wear. Our cylinder PSI cold after a head reconditioning was around 220 per side. Cheers Robert.”

jseng1 said:

Here's one I found.

About 100 races on that motor now.

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Thanks

worntorn said:

I could take him with the MK3.
I might have to remove the centre stand.

Glen

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You would also need to fit a racing headlight bulb!

Matchless said:

You would also need to fit a racing headlight bulb!

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And a passenger to even the odds.

What max revs get used with that motor ? I am surprised that it stays together, when it is pulling two people. It certainly seems to prove something about the crank and the crankcases and the rods..

lcrken said:

Did he have to weld up the combustion chamber, essentially making it a bath tub sort of configuration, to get 15:1 CR?. With big valve heads and race cams (I'm assuming he has those), it's really difficult to keep enough valve-to-piston and valve-to-valve clearance and still get such a high CR in a 920. I suppose one could also get up there with a carefully fitted high dome piston, but it's not something I have encountered. We don't see much in the way of serious Norton builds for methanol fuel here in the states. I've seen some built for drag racing, as well as landspeed racing, that ran on methanol/nitro blends, but typically at lower CRs. Like the others here, I'd love to know more about the details.

Ken

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He says its a Maney big valve head thats been milled and he's using a thinner head gasket. The pockets have been machined deeper so there is some massaging going on. With the 81mm domed pistons installed as normal you are already over 13:1 so I think 15:1 is possible. And yes Acrotrel things are probably stressed to the max.