Author Topic: Timing gear lash and lubrication.  (Read 4489 times)

Offline lucky phil

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Re: Timing gear lash
« Reply #30 on: April 20, 2022, 06:17:51 PM »
So aside from the superb craftmanship of the gears and the change of sound, are you expecting any change in performance (torque or acceleration or top end or fuel consumption or other typical KPI)?  Just curious as to why the route of changing to the gears vs. replacing with the original setup, other than it can be done, and it's cool to do so.

Thanks!

Elegance. It could be argued, and indeed succinctly that installing gears is actually going back to the original setup.

Ciao
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Re: Timing gear lash
« Reply #31 on: April 20, 2022, 06:47:33 PM »
Elegance. It could be argued, and indeed succinctly that installing gears is actually going back to the original setup.

Ciao
Also, it makes me feel good.

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Re: Timing gear lash
« Reply #32 on: April 20, 2022, 06:48:59 PM »
So aside from the superb craftmanship of the gears and the change of sound, are you expecting any change in performance (torque or acceleration or top end or fuel consumption or other typical KPI)?  Just curious as to why the route of changing to the gears vs. replacing with the original setup, other than it can be done, and it's cool to do so.

Thanks!
I do like the notion of not having a lot of load on the oil pump bearings.
That new tensioner really does apply a lot of force to them.
« Last Edit: April 28, 2022, 02:57:54 PM by Huzo »

Online John A

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Re: Timing gear lash
« Reply #33 on: April 20, 2022, 08:54:17 PM »
Whenever I put gears in a Guzzi, seems like it makes better throttle response. I’ll bet you may notice that, especially with those gears.
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Re: Timing gear lash
« Reply #33 on: April 20, 2022, 08:54:17 PM »

Online Huzo

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Re: Timing gear lash
« Reply #34 on: April 20, 2022, 09:02:56 PM »
Whenever I put gears in a Guzzi, seems like it makes better throttle response. I’ll bet you may notice that, especially with those gears.
I’ll look forward to that John.
Thanks.

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Re: Timing gear lash
« Reply #35 on: April 20, 2022, 09:08:12 PM »
I actually considered mounting them on a pair of shafts and spin them under light load submersed in oil, if my initial diagnosis comes up as too tight.
I will not start the bike again unless there is some lash present when cold.
It matters not to me how much the clearance opens up when hot, I just will not do it.

Also.

I’m open to some educating on the topic of getting the lash perfect so as to ensure completely accurate valve timing.
I figure that if there is .002” lash instead of say .004”, that’s a 2 thou error.
Now a 2 thou’ error in the rotation of the cam gear over say a 50 mm radius, will translate to a 0.0004” difference in the rotation of a cam lobe of 10 mm radius.
The numbers may not be accurate, but you can see how the error diminishes.
How much earlier/later will the valve begin to open or close with the lobe arriving half a thou’ early or late ?
I would suggest that such a tolerance would be similar to having your valve clearance one thou’ out and nobody would wet their pants over that.
« Last Edit: April 20, 2022, 09:17:07 PM by Huzo »

Offline n3303j

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Re: Timing gear lash
« Reply #36 on: April 20, 2022, 09:12:47 PM »
/2 BMW did fine with timing gears. They did have a tube that pumped oil directly at the junction between the two timing gears.
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Re: Timing gear lash
« Reply #37 on: April 20, 2022, 09:19:21 PM »
/2 BMW did fine with timing gears. They did have a tube that pumped oil directly at the junction between the two timing gears.
Yeah.
Pete Roper told me that he blanked off one of the drain holes (I think), to allow the oil to pool around the gear train.
Surely cannot be a bad thing...?

Offline jacksonracingcomau

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Re: Timing gear lash
« Reply #38 on: April 21, 2022, 10:52:52 PM »
I actually considered mounting them on a pair of shafts and spin them under light load submersed in oil, if my initial diagnosis comes up as too tight.
I will not start the bike again unless there is some lash present when cold.
It matters not to me how much the clearance opens up when hot, I just will not do it.

Also.

I’m open to some educating on the topic of getting the lash perfect so as to ensure completely accurate valve timing.
I figure that if there is .002” lash instead of say .004”, that’s a 2 thou error.
Now a 2 thou’ error in the rotation of the cam gear over say a 50 mm radius, will translate to a 0.0004” difference in the rotation of a cam lobe of 10 mm radius.
The numbers may not be accurate, but you can see how the error diminishes.
How much earlier/later will the valve begin to open or close with the lobe arriving half a thou’ early or late ?
I would suggest that such a tolerance would be similar to having your valve clearance one thou’ out and nobody would wet their pants over that.

Yes
You are barking up a very tall tree with very little fruit
The low hanging stuff, as I said, is to accurately dial in your camshaft(or if it proves to be worn or easily bettered, replaced with suitable grind)
Theoretically it will retard itself as gear faces wear (and lash increases) but never like a worn chain and academic to all intents and purposes.

For knowledge
1/ note valve timing as is with chain, correct with gears (use degree wheel, dial gauges and drill- but no money). Feel the difference
2/ Read Tuning for Speed by Phil Irving, he explains valve timing (procedure and effect) far more eloquently than I ever could, actually worth reading just for his unambiguous perfect English and to get thinking about how bad modern Australian English has become.
He was educated in Melbourne 100 odd years ago, so much has been lost

Offline lucky phil

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Re: Timing gear lash
« Reply #39 on: April 22, 2022, 01:24:15 AM »
Hmmm, the only thing I can compare it to are the gear driven cams on my Vfr750, although they are slash cut gears. Four cams and two connecting gears were in aluminium casings and went on forever.

VFR 750 gears were straight cut with spring loaded backlash gears incorporated. In RC30 WSB race engines the spring loaded backlash gears were left off to save weight and friction.

Ciao
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Offline lucky phil

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Re: Timing gear lash
« Reply #40 on: April 22, 2022, 01:46:08 AM »
I actually considered mounting them on a pair of shafts and spin them under light load submersed in oil, if my initial diagnosis comes up as too tight.
I will not start the bike again unless there is some lash present when cold.
It matters not to me how much the clearance opens up when hot, I just will not do it.

Also.

I’m open to some educating on the topic of getting the lash perfect so as to ensure completely accurate valve timing.
I figure that if there is .002” lash instead of say .004”, that’s a 2 thou error.
Now a 2 thou’ error in the rotation of the cam gear over say a 50 mm radius, will translate to a 0.0004” difference in the rotation of a cam lobe of 10 mm radius.
The numbers may not be accurate, but you can see how the error diminishes.
How much earlier/later will the valve begin to open or close with the lobe arriving half a thou’ early or late ?
I would suggest that such a tolerance would be similar to having your valve clearance one thou’ out and nobody would wet their pants over that.

Way too much overthinking here Huzo. Even with zero backlash cold thats fine it will get some as the engine warms. The crank front bearing clearance can be up to .060mm clearance and the same for the front cam journal so even tight the crank and cam journal will move to allow for the lack of clearance. If the gears fit when cold then they'll be fine, if they won't fit then you have an issue. Don't overthink it. It's like Ducati main bearing end float it set to -.1-.15mm, yes that means that when the engines cold there is compressive load on the crank main bearings from the crankcases. When you torque up the vertically split cases the cases stretch .1-.15mm and preload the crank mains. When the cases warm up with the engine running the preload reduces to near zero. Want to think about that every time you start your Ducati? Of course not. Same with the gears, if they fit cold then they are ok.

Ciao   
« Last Edit: April 22, 2022, 01:47:29 AM by lucky phil »
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Re: Timing gear lash
« Reply #41 on: April 22, 2022, 03:45:34 AM »
Way too much overthinking here Huzo. Even with zero backlash cold thats fine it will get some as the engine warms. The crank front bearing clearance can be up to .060mm clearance and the same for the front cam journal so even tight the crank and cam journal will move to allow for the lack of clearance. If the gears fit when cold then they'll be fine, if they won't fit then you have an issue. Don't overthink it. It's like Ducati main bearing end float it set to -.1-.15mm, yes that means that when the engines cold there is compressive load on the crank main bearings from the crankcases. When you torque up the vertically split cases the cases stretch .1-.15mm and preload the crank mains. When the cases warm up with the engine running the preload reduces to near zero. Want to think about that every time you start your Ducati? Of course not. Same with the gears, if they fit cold then they are ok.

Ciao
Ok Phil.
I am heavily tempted (and probably will) go with yours and others counsel. I did realise that I was probably over thinking it, but I’m a bit of a bugger for that....
Pete Roper has sourced a new pump for me and it’s en route. When I install it, I will properly check the gear train out.
I have had them in once and run the engine for a short while.
While on the topic of all this, what is the correct way to treat a loctited nut prior to removal ?
Is it an application of heat and if so how much ?
I do have a rattle gun to facilitate removal, but I’d like to know what the go is...

Offline jacksonracingcomau

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Re: Timing gear lash
« Reply #42 on: April 22, 2022, 05:54:04 AM »
I actually considered mounting them on a pair of shafts and spin them under light load submersed in oil, if my initial diagnosis comes up as too tight.
I will not start the bike again unless there is some lash present when cold.
It matters not to me how much the clearance opens up when hot, I just will not do.

Way too much overthinking here Huzo. Even with zero backlash cold thats fine it will get some as the engine warms. The crank front bearing clearance can be up to .060mm clearance and the same for the front cam journal so even tight the crank and cam journal will move to allow for the lack of clearance. If the gears fit when cold then they'll be fine, if they won't fit then you have an issue.

Ciao
A perfect description of Huzo’s dilemma, I think
Oil film areas around front crank and camshaft are non existent cold but not actually seized solid.
For taxi that shares drivers and never gets cold, maybe
Air cooled bike that stops overnight ?
Cold dry bearings might scream
Canadians use electric block heater, that would solve any cold clearance issue.
Hassle to carry around and free camping out of question Imho
« Last Edit: April 22, 2022, 06:20:56 AM by jacksonracingcomau »

Offline lucky phil

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Re: Timing gear lash
« Reply #43 on: April 22, 2022, 06:20:26 AM »
Ok Phil.
I am heavily tempted (and probably will) go with yours and others counsel. I did realise that I was probably over thinking it, but I’m a bit of a bugger for that....
Pete Roper has sourced a new pump for me and it’s en route. When I install it, I will properly check the gear train out.
I have had them in once and run the engine for a short while.
While on the topic of all this, what is the correct way to treat a loctited nut prior to removal ?
Is it an application of heat and if so how much ?
I do have a rattle gun to facilitate removal, but I’d like to know what the go is...

Red Loctite on the oil pump nut, heat. Around 220 deg C to get it to release. I have an infrared thermometer I use for this purpose. Useful on alloy parts like axle/caliper support brackets where overheating is something you want to avoid. Hit it with a propane burner for a short sharp application then rattle it off if you like but manual wrenching will work.

Ciao   
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Re: Timing gear lash
« Reply #44 on: April 22, 2022, 07:14:07 AM »
Red Loctite on the oil pump nut, heat. Around 220 deg C to get it to release. I have an infrared thermometer I use for this purpose. Useful on alloy parts like axle/caliper support brackets where overheating is something you want to avoid. Hit it with a propane burner for a short sharp application then rattle it off if you like but manual wrenching will work.

Ciao
Ok.

Offline jacksonracingcomau

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Re: Timing gear lash
« Reply #45 on: April 28, 2022, 04:21:05 AM »
Pete Roper has sourced a new pump for me and it’s en route. When I install it, I will properly check the gear train out.
I have had them in once and run the engine for a short while
Did that solve the issue?

Offline lucky phil

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Re: Timing gear lash
« Reply #46 on: April 28, 2022, 05:31:53 AM »
I think the coefficient of expansion is greater for the aluminium. Given that there is more mass, I think the crankcase will get “taller”, thus increasing the lash.
On my first assembly, I started the bike and it just sounded......”tight”.
The thought of the two shafts closing up with no clearance was a concern, so I temporarily threw the chain back in.
I considered rigging up a jig to spin them under load for a time to bed them in before refitting.

Unsure as yet... :popcorn:

A thought Huzo. Did you pre oil the timing chest before the first start? I add 3-400ml of oil through the ignition pickup hole before the first start after the cover is installed and also apply a small amount of grease by brush to each gear tooth on assembly.

Ciao
If you're not living on the edge you're taking up to much room.

Offline jacksonracingcomau

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Re: Timing gear lash
« Reply #47 on: April 28, 2022, 06:21:44 AM »
A thought Huzo. Did you pre oil the timing chest before the first start? I add 3-400ml of oil through the ignition pickup hole before the first start after the cover is installed and also apply a small amount of grease by brush to each gear tooth on assembly.

Ciao
Sussed, excellent result

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Re: Timing gear lash
« Reply #48 on: April 28, 2022, 07:28:01 AM »
I’m a bit embarrassed to admit it, but you all deserve the truth.
I did apply a little grease on the teeth, thinking it would deposit around after startup.
I should have done better.
However when I cracked open the timing chest to re install the chain, the gears were well soaked in oil.

Online Huzo

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Re: Timing gear lash
« Reply #49 on: April 28, 2022, 07:29:42 AM »
Did that solve the issue?
I have not received the pump yet.
In any case, the Norge is on the water somewhere between Singapore and England.

Offline Sye

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Re: Timing gear lash
« Reply #50 on: April 28, 2022, 10:16:14 AM »
I have not received the pump yet.
In any case, the Norge is on the water somewhere between Singapore and England.

Where is it landing Huzo?

Online Huzo

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Re: Timing gear lash
« Reply #51 on: April 28, 2022, 02:59:01 PM »


Where is it landing Huzo?
Faggs rd Feltham.
Walking distance from Heathrow.
« Last Edit: April 28, 2022, 03:05:03 PM by Huzo »

Offline Sye

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Re: Timing gear lash
« Reply #52 on: April 28, 2022, 03:03:56 PM »
Hoped it was Liverpool, you could have stayed a day or two to recuperate. Never mind, there's always another day 👍

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Re: Timing gear lash
« Reply #53 on: April 28, 2022, 03:05:49 PM »
Hoped it was Liverpool, you could have stayed a day or two to recuperate. Never mind, there's always another day 👍
So I’m not allowed to visit ?

Offline Sye

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Re: Timing gear lash
« Reply #54 on: April 28, 2022, 03:28:28 PM »
So I’m not allowed to visit ?
Of course you are, plenty of room. 👍

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Re: Timing gear lash
« Reply #55 on: April 28, 2022, 03:45:16 PM »
Of course you are, plenty of room. 👍
Heat up the bangers and mash.

Offline jacksonracingcomau

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Re: Timing gear lash
« Reply #56 on: May 01, 2022, 12:31:24 AM »
I’m a bit embarrassed to admit it, but you all deserve the truth.
I did apply a little grease on the teeth, thinking it would deposit around after startup.
I should have done better.
However when I cracked open the timing chest to re install the chain, the gears were well soaked in oil.

Don’t knock yourself out, I doubt the grease did any harm, as you say gears pick up oil pretty quick

Lash mystery may take a while ?

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Re: Timing gear lash
« Reply #57 on: May 01, 2022, 05:28:34 AM »
So aside from the superb craftmanship of the gears and the change of sound, are you expecting any change in performance (torque or acceleration or top end or fuel consumption or other typical KPI)?  Just curious as to why the route of changing to the gears vs. replacing with the original setup, other than it can be done, and it's cool to do so.

Thanks!
Nah mate, just an indulgence pretty much.
However..
I do like the notion of a perceived simpler arrangement and I love the idea that there is no load on the oil pump due to chain tension.
I acknowledge the fact that the bike has done 200,000 km with the standard setup though. I will run the gears for an appropriate time to allow them to settle in, but they’ll need to quieten down a bit….(and probably will).

Offline lucky phil

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Re: Timing gear lash
« Reply #58 on: May 24, 2022, 07:34:28 AM »
Nah mate, just an indulgence pretty much.
However..
I do like the notion of a perceived simpler arrangement and I love the idea that there is no load on the oil pump due to chain tension.
I acknowledge the fact that the bike has done 200,000 km with the standard setup though. I will run the gears for an appropriate time to allow them to settle in, but they’ll need to quieten down a bit….(and probably will).

Does your engine breathe through the cam gear Huzo? Does it have the breather hose running off the l/h side of the timing chain cover?

Ciao
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Re: Timing gear lash
« Reply #59 on: May 24, 2022, 07:46:28 AM »
Does your engine breathe through the cam gear Huzo? Does it have the breather hose running off the l/h side of the timing chain cover?

Ciao
Yes and yes Phil.

 

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