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Interstate Freshening

Classic Norton Commando Motorcycles.

Interstate Freshening

Postby swooshdave » Sun Mar 10, 2013 8:04 pm

Some of you remember the road trip my brother, dad and I made to Barber a couple years ago. My old Interstate had a hard time keep up. I was chin down trying to get up the slightest inclines. We knew the engine was tired, maybe a top end job was in line. And as they say, the rest of the story...

I started getting photos yesterday:
Image

Image
So far so good.

Image
Not too bad...

Image
Touch of blowby on the rings.

ImageImage
The bike is a 73. I thought the soft cams were later. It seems not. Surprised it ran at all.

So a top end job has now turned into a full rebuild. The head and barrel with be going to comnoz for his special care. Just a stock rebuild. But I bet it will run a wee better.

Any suggestions on which cam to go with? The stock cam? Something a little hotter? Don't want to get crazy.
If you see a post of mine and the image links are broken contact me and I'll do my best to fix them. Oh, and thanks Photobucket...
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Re: Interstate Freshening

Postby johnm » Sun Mar 10, 2013 10:20 pm

Make.
sure you replace or at least reface the cam followers

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Re: Interstate Freshening

Postby comnoz » Sun Mar 10, 2013 11:36 pm

That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim
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Re: Interstate Freshening

Postby rvich » Mon Mar 11, 2013 6:24 am

comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


I trust your eye, but please enlighten us as to how you can tell. If its from poor lubrication, what's up? Something plugged up, poor pressure or what?
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Re: Interstate Freshening

Postby comnoz » Mon Mar 11, 2013 7:25 am

The camshaft is not the style that was normally soft.

Loss of oil film strength is what likely destroyed this cam. Multi grade oils with VI additive or single grade oils from a poor base stock were common fair in the 80s and 90s and some are still around now. They broke down quickly in an air cooled motor and then it didn't matter whether the cam was hard or "soft". Jim
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Re: Interstate Freshening

Postby swooshdave » Mon Mar 11, 2013 8:03 am

comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


Who carries the Webcam and what do they approx. cost?
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Re: Interstate Freshening

Postby drones76 » Mon Mar 11, 2013 8:09 am

swooshdave wrote:
comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


Who carries the Webcam and what do they approx. cost?



http://www.webcamshafts.com/mobile/moto ... _twin.html
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1980 Honda Goldwing Interstate
1976 Honda CB 360 sold to fund #1 above
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Re: Interstate Freshening

Postby swooshdave » Mon Mar 11, 2013 8:16 am

drones76 wrote:
swooshdave wrote:
comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


Who carries the Webcam and what do they approx. cost?



http://www.webcamshafts.com/mobile/moto ... _twin.html


I just found that. I wonder if this cam would make a good core? :mrgreen:
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Re: Interstate Freshening

Postby comnoz » Mon Mar 11, 2013 8:16 am

swooshdave wrote:
comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


Who carries the Webcam and what do they approx. cost?


Send your cam to Webcam. They run around $375.00 on your core. Jim [Or send it and the followers to me and I will handle it]
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Re: Interstate Freshening

Postby comnoz » Mon Mar 11, 2013 8:18 am

I just found that. I wonder if this cam would make a good core? :mrgreen:[/quote]

As long as the bearing journals ,keyway or gear are not damaged they can repair it. Jim
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Re: Interstate Freshening

Postby swooshdave » Mon Mar 11, 2013 8:23 am

comnoz wrote:
swooshdave wrote:
comnoz wrote:That's not a soft cam. Just bad lube.

Webcam 12 grind. Jim


Who carries the Webcam and what do they approx. cost?


Send your cam to Webcam. They run around $375.00 on your core. Jim [Or send it and the followers to me and I will handle it]


Halfway tempted to send you the whole damn engine! :mrgreen:
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Re: Interstate Freshening

Postby rvich » Mon Mar 11, 2013 8:25 am

Kinda nice to have a doctor in the house!
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Re: Interstate Freshening

Postby comnoz » Mon Mar 11, 2013 8:29 am

Halfway tempted to send you the whole damn engine! :mrgreen:[/quote]

I will get it handled faster if you do the dis-assembly and re-assembly and just send me the parts. I am pretty slow when it comes to a complete build. Jim
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Re: Interstate Freshening

Postby mjfriesen » Mon Mar 11, 2013 10:58 am

This engine had well over 35K miles on it, and has never been apart. Most of the years I rode the bike a lot (late 90's and early 2000's) the speedo drive was broken more than not, so the 35K is just the odometer reading.

What is the expected life of a stock cam?

I certainly didnt skimp on the oil changes (if it sat for a couple of weeks it wet sumped, so time for an oil change!), and i dont recall seeing metal in the used oil. There obviously was some, so I probably just needed reading glasses sooner than I thought. :oops:

When i first saw the cam I was both relieved and sickened; relieved that I had a good explanation for the anemic performance, and sickened wondering what I should have done differently over the years. Maybe a dozen people here will tell me :wink:

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Re: Interstate Freshening

Postby comnoz » Mon Mar 11, 2013 11:28 am

I don't think there is a life expectancy for a cam. It all depends on the lube and use. Low speed and short trips is tough on a cam. Oil temp plays a big part- too hot or too cold causes cam problems.

I still think a lot of the cam problems were mainly the result of the poor oils that were common from the late 70s through the late 90s. Mono-grade oils were the only oils that were suitable for a Norton until hydrocracking and synthetics became common in the last 15 years. [except for a few specialty oils] Now multi-grades have an advantage- if they are from a good base stock and have not had the additive packages legislated out of them. IE motorcycle, or truck specific oils are best. Some racing oils are good but many have additive packages that are designed for short term use only.

I have hard cams here with 10,000 miles on them that look worse than yours.

I also have 2 cams from MK3 850s that have 70,000 miles on them and look perfect and they measure very soft.

So I guess you will have to ask someone who knows more about it than me. Jim
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