Henry's new 1000F CCT
Definitely in.........................
#22
06-24-2012, 04:16 AM
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Well done Henry :-)
As I said in my Skype message to you mate ...
I have only one concern with ANY tensioner that places load of the whole cam chain system all the time ? .
It was already said , that why did Honda in this case and actually any other OHC engine manufacturer not use a method like this ?
I believe there is a simple reason guys .
Cam chains are very very light and the guides are very fragile as well ...
My question about this new mod Henry is , does it load the system continually with that rather large spring?
( yes , I understand it is adjustable)
but.....
All the spring loaded systems that have ever been , use very very small load springs and those in the main , have to be locked off after tensioning(taking out the slack) so as to not continually load all the guides and chain while the engine is running ..
I feel it would be so simple for all the OHC manufacturers to do it this way if there were no nasty side effects? .
Your pics, that are great !, still make it a bit hard to see if this is the case mate ?
I take my hat off to you for your ingenuity , but I have reservations as to whether or not the cam chain and guide system will last if my concerns are founded? , and I mean for long periods of time! (more than the 1000 you have run her for so far ) without them failing under load eventually , if your mod leaves load on them ?
On a more positive note , maybe if I am correct in my thinking , replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
I would love to know a few more details mate :-)
As I said in my Skype message to you mate ...
I have only one concern with ANY tensioner that places load of the whole cam chain system all the time ? .
It was already said , that why did Honda in this case and actually any other OHC engine manufacturer not use a method like this ?
I believe there is a simple reason guys .
Cam chains are very very light and the guides are very fragile as well ...
My question about this new mod Henry is , does it load the system continually with that rather large spring?
( yes , I understand it is adjustable)
but.....
All the spring loaded systems that have ever been , use very very small load springs and those in the main , have to be locked off after tensioning(taking out the slack) so as to not continually load all the guides and chain while the engine is running ..
I feel it would be so simple for all the OHC manufacturers to do it this way if there were no nasty side effects? .
Your pics, that are great !, still make it a bit hard to see if this is the case mate ?
I take my hat off to you for your ingenuity , but I have reservations as to whether or not the cam chain and guide system will last if my concerns are founded? , and I mean for long periods of time! (more than the 1000 you have run her for so far ) without them failing under load eventually , if your mod leaves load on them ?
On a more positive note , maybe if I am correct in my thinking , replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
I would love to know a few more details mate :-)
#23
06-24-2012, 05:15 AM
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#24
06-24-2012, 02:05 PM
Well done Henry :-)
As I said in my Skype message to you mate ...
I have only one concern with ANY tensioner that places load of the whole cam chain system all the time ? .
It was already said , that why did Honda in this case and actually any other OHC engine manufacturer not use a method like this ?
I believe there is a simple reason guys .
Cam chains are very very light and the guides are very fragile as well ...
My question about this new mod Henry is , does it load the system continually with that rather large spring?
( yes , I understand it is adjustable)
but.....
All the spring loaded systems that have ever been , use very very small load springs and those in the main , have to be locked off after tensioning(taking out the slack) so as to not continually load all the guides and chain while the engine is running ..
I feel it would be so simple for all the OHC manufacturers to do it this way if there were no nasty side effects? .
Your pics, that are great !, still make it a bit hard to see if this is the case mate ?
I take my hat off to you for your ingenuity , but I have reservations as to whether or not the cam chain and guide system will last if my concerns are founded? , and I mean for long periods of time! (more than the 1000 you have run her for so far ) without them failing under load eventually , if your mod leaves load on them ?
On a more positive note , maybe if I am correct in my thinking , replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
I would love to know a few more details mate :-)
As I said in my Skype message to you mate ...
I have only one concern with ANY tensioner that places load of the whole cam chain system all the time ? .
It was already said , that why did Honda in this case and actually any other OHC engine manufacturer not use a method like this ?
I believe there is a simple reason guys .
Cam chains are very very light and the guides are very fragile as well ...
My question about this new mod Henry is , does it load the system continually with that rather large spring?
( yes , I understand it is adjustable)
but.....
All the spring loaded systems that have ever been , use very very small load springs and those in the main , have to be locked off after tensioning(taking out the slack) so as to not continually load all the guides and chain while the engine is running ..
I feel it would be so simple for all the OHC manufacturers to do it this way if there were no nasty side effects? .
Your pics, that are great !, still make it a bit hard to see if this is the case mate ?
I take my hat off to you for your ingenuity , but I have reservations as to whether or not the cam chain and guide system will last if my concerns are founded? , and I mean for long periods of time! (more than the 1000 you have run her for so far ) without them failing under load eventually , if your mod leaves load on them ?
On a more positive note , maybe if I am correct in my thinking , replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
I would love to know a few more details mate :-)
thanks for your detailed analysis. typically you and that aint a bad thing.
Firstly, the spring that I've used is experimental and only uses a fraction of the travel when in its operating position. The reason I used such a long spring is to give a good amount of travel to allow setting the chain on the cam sprockets without having to disconnect it. Secondly, when you actually se how much the chain tight spots move the tensioner arms as the chain moves with crank rotation is quite amazing. I don't think many people have ever run their engines with the cam cover off but you would be surprised. It's the same as a final drive chain. You get tight spots. Cam chains are no different.
If there were no allowance for these tight spots the chain and guides would wear very quickly.
You are right about the small springs used in the original CCT so that they do not excerpt too much pressure on the guide and chain but in this case the additional spring I have introduced works on the upper arm of the tensioner assembly and it is this addition the I believe reduces the vibration/noise produced by the tensioner as the top passive arm vibrates on the retaining pin.
By introducing some tension on this (and it only needs to be minimal) the play is eradicated, hence no vibration.
The additional tension on the chain seems to help but it is (I repeat) minimal!
I'm sure a smaller/weaker spring could be utilised. I will experiment but this is a prototype and you've got to start somewhere eh!
previous efforts to produce a manual CCT have always worried me as they fix the tension on the chain and have no give. I would not feel comfortable with this arrangement.
The additional tension on the chain however does seem to make the cams better synchronised.
If you ever run the engine without the top chain guide installed as I have done you can see the slack appearing between the cam sprockets and although it isn't very much, having the extra tension has made a subtle difference as I've said before. It's just a bit crisper, hard to put into words but you'd know what I mean if you did this conversion to your bike.
Anyway, thanks for your encouragement. I'll keep persevering and road testing. Any improvement is better than none and there's no way I'd go back to how it was before.
#25
06-24-2012, 08:29 PM
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No probs Henry, "detailed"? mate , that was my short version :-)
It sounds like you are at least well informed as to the potential issue of strain on the parts under load and that is a bloody good thing ...
I think the main issue that does bother me is that nearly all, if not all tensioners are locked off after tensioning ...
Honda in there wisdom , seemed to have a go at getting an automatic oil driven hydrolic one happening in our models , but as well all know , not with too much success..
and yes , I too have run a few different 4in line OHC engines with the cover off (what a fcvk ing mess with the revs up! lolol ) but yer , that slack seems to be a thing that they all do for reasons that I dare say are because the chains do run rather loose as a rule with manual tensioners that are locked off after tensioning ..
I am going to attack mine one day? , using a similar method to yours , but with perhaps one exception ... I would like to be able to release the spring to tension during periodic maintenance intervals , then lock the mechanism to stop further pressure on all the parts till the next adjustment ...Very similar to most of the existing manual tensioners ...
anyways ...thanks for the extra detail mate...
I will be keeping an ear open to see how you go over the next few mths .. :-)
It sounds like you are at least well informed as to the potential issue of strain on the parts under load and that is a bloody good thing ...
I think the main issue that does bother me is that nearly all, if not all tensioners are locked off after tensioning ...
Honda in there wisdom , seemed to have a go at getting an automatic oil driven hydrolic one happening in our models , but as well all know , not with too much success..
and yes , I too have run a few different 4in line OHC engines with the cover off (what a fcvk ing mess with the revs up! lolol ) but yer , that slack seems to be a thing that they all do for reasons that I dare say are because the chains do run rather loose as a rule with manual tensioners that are locked off after tensioning ..
I am going to attack mine one day? , using a similar method to yours , but with perhaps one exception ... I would like to be able to release the spring to tension during periodic maintenance intervals , then lock the mechanism to stop further pressure on all the parts till the next adjustment ...Very similar to most of the existing manual tensioners ...
anyways ...thanks for the extra detail mate...
I will be keeping an ear open to see how you go over the next few mths .. :-)
#26
06-25-2012, 12:20 AM
Quote HenryM Secondly, when you actually se how much the chain tight spots move the tensioner arms as the chain moves with crank rotation is quite amazing. I don't think many people have ever run their engines with the cam cover off but you would be surprised.
Couldn't agree more.
It's actually quite scary how much "lash" is in the chain - I can just imagine what it's doing at 10000 revs
Must be like hell in there.......
What tension strength does your spring have, our 'Enry - looks quite "beefy"....?
I wouldn't want to use one that's too strong when I get down to making one.....or too weak...
Thanks again for a great design.
Quote Classic replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
Steve I've replaced my camchain 3 times and my tensioner twice in the last 100000 K's.(the tensioner arm too) The noise is back within a couple of thousand K's at most - admittedly, a bit quieter for a while but it keeps coming back. I've just had the top off to do a cam cover gasket replacement - ran the engine just to see what Henry is saying with regard to "lash" and it's amazing. Not sure about the chain being fragile though - it has (I think) 7 links across the chain and while narrow, there seems to be a high level of strength there.........?
Couldn't agree more.
It's actually quite scary how much "lash" is in the chain - I can just imagine what it's doing at 10000 revs
Must be like hell in there.......What tension strength does your spring have, our 'Enry - looks quite "beefy"....?
I wouldn't want to use one that's too strong when I get down to making one.....or too weak...
Thanks again for a great design.
Quote Classic replacing the chain and guides a bit more often , but having a dead quiet engine would be worth it ??
Steve I've replaced my camchain 3 times and my tensioner twice in the last 100000 K's.(the tensioner arm too) The noise is back within a couple of thousand K's at most - admittedly, a bit quieter for a while but it keeps coming back. I've just had the top off to do a cam cover gasket replacement - ran the engine just to see what Henry is saying with regard to "lash" and it's amazing. Not sure about the chain being fragile though - it has (I think) 7 links across the chain and while narrow, there seems to be a high level of strength there.........?
#27
06-25-2012, 07:39 AM
Going back to the spring as both you and Stevo have mentioned it, although the spring looks beefy I am only using about the first 10mm of it's travel under compression so the force it's applying is not that great. Having said that by the time the force is directed to the upper arm which connects to the chain guide it's surprising how much additional pull that provides. I didn't get round to doing any measurements with spring balances or the like but just sent on sense of feel having had a certain amount of time to play with the assembly before finally mounting it.
I would certainly not recommend locking the tension in any way as Steve's suggesting. That negates the whole idea of providing tension but also allowing for tension variations in the chain its self. I maintain that the spring must be allowed to move as the chain rotates round the sprockets, tight spots and all.
As far as strength goes comparing a silent chain design to a normal drive chain, it's an interesting point. I wonder if data exists showing break strains for both types on a like for like (size for size) basis. While one has many links and small pins the other has two links but much larger pins.
I will still be replacing my cam chain at the same time/distance intervals that's for sure.
I would certainly not recommend locking the tension in any way as Steve's suggesting. That negates the whole idea of providing tension but also allowing for tension variations in the chain its self. I maintain that the spring must be allowed to move as the chain rotates round the sprockets, tight spots and all.
As far as strength goes comparing a silent chain design to a normal drive chain, it's an interesting point. I wonder if data exists showing break strains for both types on a like for like (size for size) basis. While one has many links and small pins the other has two links but much larger pins.
I will still be replacing my cam chain at the same time/distance intervals that's for sure.
#28
06-25-2012, 09:03 AM
I'm sure you see the reason for my concern, Henry, in that I don't want to put too much strain on the chain - just enough to stop the rattle - hard to tell what that would be though - if the spring isn't strong enough it won't stop the lash......s'pose it's trial and error for the most part.
And I agree, locking down the tensioner or the adjustable guide would defeat the object of having a spring in there to "ride" the chain - locking it down may cause irreparable damage, maybe even catastrophic malfunction and a broken chain - let's not even go there..........
May just be best to buy one from you..........
And I agree, locking down the tensioner or the adjustable guide would defeat the object of having a spring in there to "ride" the chain - locking it down may cause irreparable damage, maybe even catastrophic malfunction and a broken chain - let's not even go there..........
May just be best to buy one from you..........
#29
06-26-2012, 04:01 AM
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Steve I've replaced my camchain 3 times and my tensioner twice in the last 100000 K's.(the tensioner arm too) The noise is back within a couple of thousand K's at most - admittedly, a bit quieter for a while but it keeps coming back. I've just had the top off to do a cam cover gasket replacement - ran the engine just to see what Henry is saying with regard to "lash" and it's amazing. Not sure about the chain being fragile though - it has (I think) 7 links across the chain and while narrow, there seems to be a high level of strength there.........?
Are we suggesting that all the manufacturers are totally or partially wrong in there thinking ? ...
....or should we choose to think that at the least, they ALL have tested ALL there different engines!, to bloody near death ! in and while testing , to see what happens? with a some what simple " whack some constant load on the bastard to shut it up set up " ???
Logic tells me that ALL the Engine engineers are not quite that dumb guys ........lol
I still go with Henry's version ! :-) , but set , then lock the bugger! to stop stress getting too much for ALL the parts during the many hours of running time that they go through ....
Just my 2 cents worth :-) .... but hey , if anyone here? thinks that they are smarter than the hundreds of engine techs that have figured this **** out over the last 20 years and at least from several manufactures? ...hey go for it :-)
I think Henry is definitely on to something good !...... but om going with a cross of his thinking and plain old logic, driven from years of seeing what very smart dudes have been doing on many different 4 in line OHS engines from the factory ....
end rave .... lololol
Last edited by gotcbr; 09-19-2012 at 02:37 PM.
#30
06-26-2012, 12:44 PM
Once a mod, always a mod eh Steveo. I just so love your delivery mate.
I have no answer to your question. I'm just applying my own logic based on observation. Let's face it, if your cam chain breaks with what ever set up you've got you're going to be well and truly ****ed.
I'll keep on testing my theory against the historical wisdom of the countless engine techies. Sometimes ignorance has a point!
I have no answer to your question. I'm just applying my own logic based on observation. Let's face it, if your cam chain breaks with what ever set up you've got you're going to be well and truly ****ed.
I'll keep on testing my theory against the historical wisdom of the countless engine techies. Sometimes ignorance has a point!