Why no mechanical solutions for the cam tensioners and oil pump?
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,414
Likes: 6,366
From: Honah Lee
I'm sorry, what now? As long as moving parts are contacting one another at a rate of thousands of times per minute, wear will NOT stop. What kind of engineer did you say you were?
Ooooh... sorry, a self-appointed know-it-all... my mistake.
ETA: And the hydraulics weren't a "smoke screen"; they were a superior and equal way to apply pressure compared to a spring.
Ooooh... sorry, a self-appointed know-it-all... my mistake.
ETA: And the hydraulics weren't a "smoke screen"; they were a superior and equal way to apply pressure compared to a spring.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
Last edited by Jackie Paper; Sep 14, 2018 at 07:46 AM.
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Joined: Aug 2014
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From: 40.2444° N, 75.6419° W
From what I've heard, the gear drives only work if a crankshaft has a minimal run out, .003", but factory spec is +-.012". I was talking about using the spring or hydraulic cct, but instead of a plastic shoe pressing on the chain, use a wheel so the friction would be insignificant.
Good to know there's an aftermarket oil pump with a screen out there, thanks I'll look into it
And I appreciate the explanation of why the cct' s failed to begin with, extra pressure. I've read the advice to check the wear on the shoe every 15k-20k mi, how much mileage can I expect to get from a hydraulic cct before I should check for wear?
Good to know there's an aftermarket oil pump with a screen out there, thanks I'll look into it
And I appreciate the explanation of why the cct' s failed to begin with, extra pressure. I've read the advice to check the wear on the shoe every 15k-20k mi, how much mileage can I expect to get from a hydraulic cct before I should check for wear?
Patent the idea , then invent it.
Cruiser
Joined: May 2017
Posts: 226
Likes: 37
From: Sault Ste Marie,Mi
What you fail to see is I am referring to the roller chain models. Your statement is true for the total link chain. It always rubs and wears. In fact, at maximum RPM at the speed limiter, it's moving fast enough to cavitate the oil and blast hunks out of tensioners. The roller chain only has outer links and they groove in and the rollers roll. Tensioner will last the life of motor or 10 years or so when they get brittle and can crack from hot oil embrittlement of the delrin.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
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Joined: Dec 2005
Posts: 19,859
Likes: 7,980
From: poway
What you fail to see is I am referring to the roller chain models. Your statement is true for the total link chain. It always rubs and wears. In fact, at maximum RPM at the speed limiter, it's moving fast enough to cavitate the oil and blast hunks out of tensioners. The roller chain only has outer links and they groove in and the rollers roll. Tensioner will last the life of motor or 10 years or so when they get brittle and can crack from hot oil embrittlement of the delrin.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
The idea that the oil is cavitating is very interesting.. It would explain the divots. I figured the tensioner was slapping the chain and causing micro fractures but the possibility of cavitation explains a lot. My bet it's a combination of spring pressure and silent chain construction that creates small chambers at the link where oil could cavitate..
I don think that the shoe is delrin. The delrin can't handle the temps. I figure it's some form of Ultem and probably not PEEK.
I don't think the inner hydraulic tensioner failure was the result of the silent chain from it's surface configuration but could be from the poor tolerances in manufacture. Chain may have had a tight spot. More than likely the hydraulic part tensioner failed as the same type of failure has been documented on roller chains.
One thing to remember is that autos are liquid / fan cooled so temps cam be controlled better. They probably don't see much above 240F.
Seasoned HDF Member
Joined: Apr 2015
Posts: 6,863
Likes: 3,727
From: St. Charles, MO
What you fail to see is I am referring to the roller chain models. Your statement is true for the total link chain. It always rubs and wears. In fact, at maximum RPM at the speed limiter, it's moving fast enough to cavitate the oil and blast hunks out of tensioners. The roller chain only has outer links and they groove in and the rollers roll. Tensioner will last the life of motor or 10 years or so when they get brittle and can crack from hot oil embrittlement of the delrin.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
You are correct that there is wear even with the roller rolling. However, it is almost unmeasurable other than the outer groove. Shoes in cars are hard rubber and last longer than the roller chains.
The first attachment is 90K on a roller chain. Second is 45K on a link. And third is Harley so-called upgrade which leaves the back chain link.
Seasoned HDF Member
Joined: Apr 2015
Posts: 6,863
Likes: 3,727
From: St. Charles, MO
The idea that the oil is cavitating is very interesting.. It would explain the divots. I figured the tensioner was slapping the chain and causing micro fractures but the possibility of cavitation explains a lot. My bet it's a combination of spring pressure and silent chain construction that creates small chambers at the link where oil could cavitate..
I don think that the shoe is delrin. The delrin can't handle the temps. I figure it's some form of Ultem and probably not PEEK.
I don't think the inner hydraulic tensioner failure was the result of the silent chain from it's surface configuration but could be from the poor tolerances in manufacture. Chain may have had a tight spot. More than likely the hydraulic part tensioner failed as the same type of failure has been documented on roller chains.
One thing to remember is that autos are liquid / fan cooled so temps cam be controlled better. They probably don't see much above 240F.
I don think that the shoe is delrin. The delrin can't handle the temps. I figure it's some form of Ultem and probably not PEEK.
I don't think the inner hydraulic tensioner failure was the result of the silent chain from it's surface configuration but could be from the poor tolerances in manufacture. Chain may have had a tight spot. More than likely the hydraulic part tensioner failed as the same type of failure has been documented on roller chains.
One thing to remember is that autos are liquid / fan cooled so temps cam be controlled better. They probably don't see much above 240F.
No.
(Not aimed at you, headlfow).
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,414
Likes: 6,366
From: Honah Lee
Think the link chain is referred to as a silent chain. First TC and up to around 2007 or 2008. After that, roller chain. Which is a roller spinning on an axle. Harley's part is cast in my opinion delrin. I worked in heat treating as part of my toolmaker apprenticeship years ago and we heat-treated delrin for special applications for periscope mask bearings slides. Delrin can take oil heat.
Last edited by Jackie Paper; Sep 14, 2018 at 07:46 AM.
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Stellar HDF Member
Joined: May 2015
Posts: 2,091
Likes: 304
From: mid Michigan
If a cooler is added to bike and the SE plate is set up with cam gears .001 inch it will last. This is on the silent on my bike , 30,000 miles later could not see any wear on the edge. Had cyco pads ready to go in but looks like the white SE pads will out last this build.