CCT Problem Solved (100% guaranteed)

Where all the workshop knowledge lives together.
Post Reply
User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Thu Oct 26, 2006 10:22 am

I haven’t looked fully into this yet but although the spring on the front adjuster doesn’t get any lubrication this shouldn’t really make any real difference should it? After all it’s not a critical part like a bearing that needs a bath of oil to run on, it just goes backwards and forwards slightly.

So could it be a heat issue seeing as the front adjuster is at the top of the engine and has no bath of oil to cool it, possibly altering the springs ability to do its job or even changing its tensile if it gets too hot making it brittle and break?

Its obvious that the Honda springs aren’t up to the job but there is a conundrum I suppose and that is if Honda was to replace the spring with a stronger one this would put too much pressure on the cam chain and wear out the bearings resulting in the same devastation when the cam chain jumps off the gear due to cam bearing collapse.

So it seems that we are back to same choices of either replacing the springs every, what 6000 miles, which I feel is unacceptable, replacing with the solid screw type adjuster and either waiting for the cam bearings to collapse or setting it slack enough to avoid that and hoping that the chain doesn’t jump off the cam gears or maybe finding a spring that can stand the lack of lubrication and heat build up. But, and I haven’t checked this out yet, I think that a spring by definition is heat treated to a certain temperature to make it a spring so higher grades aren’t possible?
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Thu Oct 26, 2006 10:34 am

Now here's an intresting table, look at the maximum heat rating for normal high carbon spring steel springs, thats what our springs are made of and that isnt a very high temperature rating?

http://www.bristolspring.com/materials.html

Trouble is that when you change the material you change the spring's characteristic.
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Thu Oct 26, 2006 10:59 am

Now here’s a thought, we tend not to have a problem with valve springs breaking and they work 100 times harder than the CCT springs and I would say that they work under a similar type of load i.e. compression and extension. Wonder what grade of steel the original springs are?
Last edited by Walenut on Thu Oct 26, 2006 4:38 pm, edited 1 time in total.
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
Stormin Ben
Posts: 1234
Joined: Sun Dec 01, 2002 12:23 am
Location: Birmingham

Post by Stormin Ben » Thu Oct 26, 2006 2:51 pm

Interesting thoughts there mate,
My thought on this thorny subject is along the following lines

You don't want to start faffing about with changing spring types due to the reasons you've mentioned before
Therefore you accept that at some point the spring WILL fail
What you need to do is prevent a spring breaking from causing the cams to jump
To do this you need to make some way of stopping the plunger from coming all the way out when the spring snaps
I've got my hands on a duff CCT and will hopefully at some point get time to look into the workings with a view to making something

My initial thought is a bolt that goes down into the CCT but stops short of the plunger. This would then allow the plunger to retract enough to account for slack in the chain but not enough to allow it to jump
Also, this amount of slack would be audible so you'd know there was a problem

What do you think?
I've got an inferiority complex
But its not a very good one!

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Thu Oct 26, 2006 5:00 pm

Without actually seeing one of these in the flesh Ben I don’t know, I’d be interested to know where the spring usually breaks, if it’s in the same place all the time etc.

I’m going to have a better look at the cam set up because at the end of the day a timing belt is fully tensioned without the problems of cam bearing collapse, may be the chain and bearings could take the load from being tensioned by the manual type adjusters.

I am right in saying that the spring is a compression and tension type spring and not torsion spring only torsion springs are renowned for being unreliable?
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
cupasoop
Site Admin
Posts: 2687
Joined: Sat Mar 06, 2004 11:02 pm
Location: Ayrshire, Scotland

Post by cupasoop » Thu Oct 26, 2006 5:11 pm

Walenut wrote:I am right in saying that the spring is a compression and tension type spring and not torsion spring only torsion springs are renowned for being unreliable?
Nope, torsion spring.
Rich.

Image

User avatar
delmeekc
Posts: 744
Joined: Mon Jul 22, 2002 7:34 pm
Location: BlueWater

Post by delmeekc » Thu Oct 26, 2006 6:54 pm

Guys, i have done my race engine that I sold like this, tried the bolt, locking it solid but this works better. btw, did a storm a few years ago with my orignal mod and still running, never been adjusted.

Might aswell tell you all I aint got the time to fit any.

take a standard cct (the one you are going to use). fit it in the bike, turn the bike over a few times (by hand) and stop it at tdc comp stroke. using a screw driver back the cct all the way off til it stops, note exactly how many turns you back it off, in 1/4 turns. take the cct out, dismantle it, measure the gap inside the worm gear when it is fully compressed, add this to the travel minus (think i used 1 to 1.5mm, it's written on my garage wall, can't be butt to unlock it to have a look - measurement will be based on diameter of rod and shape of inside of components as the inside is concave) amount in brackets then cut (have some hardened stainless steel rod) a short length of this rod. Reassemble cct using a small piece of tube to hold the rod inplace inside the worm gear (to pack it out and stop it moving about). The cct will now not retract 1 to 1.5mm more than it should be set too for your current chain wear and chain guide wear but still use the spring to take up slack if needed.

Easy to check, get it on comp stroke and back it off, it will extend back if the spring is ok.

To check this worked i backed them off until they stopped (so travel limited by the rod) and revved the nuts off it and was all ok.

Del.

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Thu Oct 26, 2006 7:09 pm

cupasoop wrote:
Walenut wrote:I am right in saying that the spring is a compression and tension type spring and not torsion spring only torsion springs are renowned for being unreliable?
Nope, torsion spring.
Well we're shagged then, Del I should sell that to Honda because I've done a little research today and there having the odd problem with CBR's & vtec's.

I’m surprised that Honda use a torsion spring they always break.
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
sirch345
Site Admin
Posts: 18075
Joined: Mon Aug 25, 2003 9:35 pm
Location: Cornwall, UK

Post by sirch345 » Thu Oct 26, 2006 7:48 pm

delmeekc wrote:Guys, i have done my race engine that I sold like this, tried the bolt, locking it solid but this works better. btw, did a storm a few years ago with my orignal mod and still running, never been adjusted.

Might aswell tell you all I aint got the time to fit any.

take a standard cct (the one you are going to use). fit it in the bike, turn the bike over a few times (by hand) and stop it at tdc comp stroke. using a screw driver back the cct all the way off til it stops, note exactly how many turns you back it off, in 1/4 turns. take the cct out, dismantle it, measure the gap inside the worm gear when it is fully compressed, add this to the travel minus (think i used 1 to 1.5mm, it's written on my garage wall, can't be butt to unlock it to have a look - measurement will be based on diameter of rod and shape of inside of components as the inside is concave) amount in brackets then cut (have some hardened stainless steel rod) a short length of this rod. Reassemble cct using a small piece of tube to hold the rod inplace inside the worm gear (to pack it out and stop it moving about). The cct will now not retract 1 to 1.5mm more than it should be set too for your current chain wear and chain guide wear but still use the spring to take up slack if needed.

Easy to check, get it on comp stroke and back it off, it will extend back if the spring is ok.

To check this worked i backed them off until they stopped (so travel limited by the rod) and revved the nuts off it and was all ok.

Del.
SNAP :!: That sounds about the same as what I have come up with after doing some considerable testing on the CCTs. I found that the CCT backs of 1/4 off a turn at approximately 3,000 rev's, so IMO a fixed CCT in the long term is not the answer. The way I went about fitting the rod in the tensioner was different to you Del, when on the compression stroke at TDC I then with a home made tool (as described in the Haynes manual) turned the worm back a further 1/4 of a turn and locked it into position, then removed the CCT from the bike, I then drove out the little pin which holds the head of the plunger to the plunger itself and cut a rod short enough to fit the plunger head back into it's original position with like yourself leaving a little slack which allowed the tensioner to turn back a little further. I've only used an aluminium rod, mainly because it's light in weight, as still in the trial stages at present, also there's no pressure on that rod at all only when the spring breaks,

Chris.
A closed mouth gathers no foot. :thumbup:

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Fri Oct 27, 2006 7:37 am

What happens when the spring breaks and the tensioner is relying on the rod?

Will you hear a rattle so you'll know the spring has broke or just inspect at a set mileage and then change?

What kind of mileage have you got on this mod?

As I said previously I haven’t actually set eyes on a CCT yet but there's no chance of the rod falling out of the front tensioner when the spring breaks is there?
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
sirch345
Site Admin
Posts: 18075
Joined: Mon Aug 25, 2003 9:35 pm
Location: Cornwall, UK

Post by sirch345 » Fri Oct 27, 2006 8:18 am

Walenut wrote:What happens when the spring breaks and the tensioner is relying on the rod?

Will you hear a rattle so you'll know the spring has broke or just inspect at a set mileage and then change?

What kind of mileage have you got on this mod?

As I said previously I haven’t actually set eyes on a CCT yet but there's no chance of the rod falling out of the front tensioner when the spring breaks is there?
IMO if the spring breaks you should hear a slight rattle from the engine as at below 3,000 rev's the tensioner will then not tightened back up as it would have with the spring intact.

That's just it I've not done any long term testing (mileage wise) I think Del will have more on that score.

No chance of anything falling out if the spring breaks.

The only downside I have come up with so far on this conversion is that over time the camchain will stretch, which will mean a slightly longer rod will be needed, but that obviously that will depend on the amount of mileage you actual do, in most cases bikers don't do loads of miles in a year.

Chris.
A closed mouth gathers no foot. :thumbup:

User avatar
delmeekc
Posts: 744
Joined: Mon Jul 22, 2002 7:34 pm
Location: BlueWater

Post by delmeekc » Fri Oct 27, 2006 9:08 am

every service or when you feel the need just remove the bolt in the cct @ tdc comp stroke and see how many turns you get as the rod will stop it solid. This was you also can gauge the cam chain stretch. If i had the time and a storm i would run it without the spring installed to prove it but aint got one. if anybody is going to do it I will get the info off me wall and type it up.

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Fri Oct 27, 2006 11:50 am

delmeekc wrote:every service or when you feel the need just remove the bolt in the cct @ tdc comp stroke and see how many turns you get as the rod will stop it solid. This was you also can gauge the cam chain stretch. If i had the time and a storm i would run it without the spring installed to prove it but aint got one. if anybody is going to do it I will get the info off me wall and type it up.
I'd certainly be interested in the info mate as something has to be done because they will break at some point.
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
Walenut
Posts: 65
Joined: Mon Oct 16, 2006 4:37 pm
Location: Black Country

Post by Walenut » Fri Oct 27, 2006 11:56 am

Some more intresting info:

Torsion Springs

Torsion springs are used in a wide variety of applications - from the everyday to the specific. Their purpose is often suited to situations where torque is applied from two directions, as they are designed to offer resistance to externally applied pressures.

Torsion refers to the twisting action of the coils. Although the wire itself is subjected to bending stresses rather than torsionally applied stresses, these springs preform at a maximum when supported over a tube or rod.
Due to cutbacks the light at the end of the tunnel has been switched off!

User avatar
sirch345
Site Admin
Posts: 18075
Joined: Mon Aug 25, 2003 9:35 pm
Location: Cornwall, UK

Post by sirch345 » Fri Oct 27, 2006 1:21 pm

Walenut wrote:Some more intresting info:

Torsion Springs

Torsion springs are used in a wide variety of applications - from the everyday to the specific. Their purpose is often suited to situations where torque is applied from two directions, as they are designed to offer resistance to externally applied pressures.

Torsion refers to the twisting action of the coils. Although the wire itself is subjected to bending stresses rather than torsionally applied stresses, these springs preform at a maximum when supported over a tube or rod.
That's interesting mate.

What surprises me is when you receive a new CCT from Honda it has had the plunger fully retracted and locked in place before it's packed ready for sale, so until you actually receive it the spring is under it's up-most tension until you release it, you will probably know more about that than me, but surely that can't be doing the spring any favours :?: considering when it's fitted in the bike the spring is actually only using somewhere around half of it's full available tension :!:

Chris.

Del I'd also be interested in the info you have just to see how it compares to mine.

Chris.
A closed mouth gathers no foot. :thumbup:

Post Reply