Commando Interstate

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I recently purchased a 1972 matching numbers, disc braked Interstate. Have not previously owned a Norton.
Were all of this model fitted with the Combat engine. Number 203xxx
 

L.A.B.

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As far as we know, all '72 Interstates up to *211110* had the Combat engine.

*(when production of the Combat engine is supposed to have ended)
 
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Thank you for your response.
I am very much looking forward to life with the Norton.
 
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If they are still there (quite likely) we will replace. Thinking solid skirt. Do you have a recommendation.
I shoul have looked at the link first you have a recommendation. Thank you much appreciated.
 

Fast Eddie

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Talk to Andover Norton, I believe they are now doing very nice pistons.
Or... depending how much you wanna spend... check out JS Motorsports super light weight forged pistons and corresponding Carrillo rods...
 

L.A.B.

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I shoul have looked at the link first you have a recommendation.

I posted the link as it has a good example of the slotted piston. Norvil wouldn't necessarily be my first choice of supplier though.
 
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Appreciate all the advice as this is an area i have no knowledge in.
 
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Talk to Andover Norton, I believe they are now doing very nice pistons.
Or... depending how much you wanna spend... check out JS Motorsports super light weight forged pistons and corresponding Carrillo rods...
Do you see a need for Carillo rods for road riding.
Raced cars and used to road ride an R1 hard and am mechanically aware.
Combat will be cruising in the 70 to 90 mph range with occasional full accelleration use.
 
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if you do split the engine cases do not get talked into butchering them as per old britts inoa tech digest oil pick up mod.
 

Fast Eddie

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Do you see a need for Carillo rods for road riding.
Raced cars and used to road ride an R1 hard and am mechanically aware.
Combat will be cruising in the 70 to 90 mph range with occasional full accelleration use.

No there’s no ‘need’ for steel rods on a road bike. But the JS kit is a package, the longer rods seem to give certain benefits and the lighter pistons certainly do. I run them and think they’re fantastic. They’re not for everyone though. Check out his web site for details.
 
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No there’s no ‘need’ for steel rods on a road bike. But the JS kit is a package, the longer rods seem to give certain benefits and the lighter pistons certainly do. I run them and think they’re fantastic. They’re not for everyone though. Check out his web site for details.
Yes they look excellent.
I have used and benefited from longer rods in car racing.
 
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No there’s no ‘need’ for steel rods on a road bike. But the JS kit is a package, the longer rods seem to give certain benefits and the lighter pistons certainly do. I run them and think they’re fantastic. They’re not for everyone though. Check out his web site for details.
Do you think it makes sense to go a bit taller from the Combat gearing maybe even std Commando.
 
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You will lose on acceleration but gain more relaxed cruising, personal preference really.
 
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if you plan to ride it at 70+ MPH for very long stints than you for sure will want to go to a larger countershaft sprocket. IMHO a 21 is the the best all round compromise for mixed riding but if mostly above 75 MPH than a 22 might better option. a 19 at 70 = 4500 RPM and a 21 at 70MPH = 4000 RPM these numbers are an approximation.

Do y.ou think it makes sense to go a bit taller from the Combat gearing maybe even std Commando.
 

rvich

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Here we go...LOL. I have a Combat with a 19 tooth counter sprocket and I can't imagine cruising it between 70 and 90 MPH.

How much stuff can one swap out and still call it a Combat?

I'm considering a belt drive to improve the primary ratio, a different cam to give better mid-range torque, and I different head to improve the porting. Which sounds a lot like an 850. Anybody want to swap a Combat motor for a stock 850?
 
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