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 Roller conversion

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Evans
Grignapoco
Grignapoco
Evans


Posts : 139
Join date : 2019-12-31

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PostSubject: Roller conversion   Roller conversion Icon_minitime1Wed Apr 15, 2020 8:50 am

Unexpectedly the parts for the conversion turned up despite level 4 lockdown here.
They were already assembled and included new camshafts which made life easier than expected.

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I watched Petes video of the process and had already printed off the hardcopy of his instructions, without those things would have been much more complicated
as it was the job went easily.

What I would add is, although it's very important to do one side at a time.
Remove both spark plugs so that you can easily turn the motor to top dead centre on the compression stroke of the cylinder that you're going to work on.
The timing mark should be pointing to the crankshaft for reassembly. This is the left side thus the L mark is correct, for the other side use the R mark.

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I decided to lap in the valves and being in lockdown had to make my own spring compressor, this worked well using a 21mm socket

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Lucky I decided to lap the valves.
Two of the inlet valves on the left side were bent.
Sourcing replacements with the world on lockdown will be "interesting"

I went on to drop the sump and clean it and the filters.
In the workshop manual it says there are 14 bolts holding the sump on. I guess this is a subtle Italian joke as there are 14 on the perimeter and four surrounding the filter
which being recessed inside the filter housing are not at all easy to find especially as the manual doesn't mention them

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Anyway the sump and filters are all cleaned and the right side is all ready to go, left side dry fit until I can source new inlet valves.

One other thing to watch, Pete's instructions give torque readings in ft lbs.
It occurred to me that my torque wrenches may not be calibrated in ft lbs
which turned out to be the case, they're calibrated in Newton meters so if you have the same you'll need to convert (30 ft lbs is 40.6 Nmtr for instance)
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Pete Roper
GRiSO Capo
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Pete Roper


Posts : 10420
Join date : 2013-05-30
Age : 67

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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Wed Apr 15, 2020 9:00 am

The pics in the manual you show are for the earlier 2V motor sump. Guzzi are sometimes less than effective about updating the manuals.
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Evans
Grignapoco
Grignapoco
Evans


Posts : 139
Join date : 2019-12-31

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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Wed Apr 15, 2020 10:01 pm

This is the cover, I guess they just copied and pasted. Is there a better version ?

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    Thanks  Evans
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Pete Roper
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Pete Roper


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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Wed Apr 15, 2020 10:07 pm

Nah. Very Happy
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Lobo
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Lobo


Posts : 56
Join date : 2020-07-02

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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 12:22 pm

Today, and using the B Kit, rollerised my 5000km GRiSO. I checked the tappet clearances < the work and was pleased to have the correct settings; all borne out later with zero wear evident on the outgoing flatties.
All straight forward and by the book.... er forum. Thanks to all for the myriad of posts on it all, (and Pete Roper’s offer of phone help) - I guess the worst of it was the LH Cylinder / releasing the chain tensioner. The left cylinder took 90 minutes as I preceded cautiously.... the right took about 30 mins once I was up to speed and comfortable.
Only negative comment are the tiny hemispherical caps which reside in the tappet arms - poor engineering in my view as could easily be released during a time of absent- minded / rookie mistake type maintenance .... and slip down the oil return into the guts of the engine, WHY would you design such a flaw into an engine, particularly into an area where home mechanics are likely to delve.
Anyways - next have to remap (need a laptop first) and do the swing arm / steering head bearings - so a while away from start up.
Cheers....

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Pete Roper
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Pete Roper


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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 12:30 pm

Once the camboxes are in place and torqued down there is no way the 'Pads' can escape to go anywhere??? They have to be used to allow the rockers to move in an arc. They do it well. High mileage ones may have a small 'Step' worn in the flat surface of the pad by the tappet tower and on Michael Wynd's bike we replaced them during his engine overhaul but his bike is a testament to the design's ability to withstand abuse! Really, I never give them a moment's thought.
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Lobo
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Lobo


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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 1:53 pm

I’m not gonna ‘try it’ on the GRiSO Pete, but recently I had to change-out a couple of tappet adjusting ‘grub’ screws on the old Kombi - which is perhaps why this is at the front of my mind. If you were to completely remove these adjusting screws (for whatever reason) on the GRiSO, as I see it, those little hemispheres could well make a bid for freedom.... to somewhere nasty.
Even simply removing the rocker assembly, albeit carelessly, will allow these critters to escape to somewhere that’ll have ya crying.
Sure unlikely in the normal scheme of things.... but Sod’s law tells us this if it can happen... it will.
And as such, surely less-than-optimal engineering?
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Pete Roper
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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 5:01 pm

If you want to changeout the adjusters it's a cambox off job anyway. There are a host of things that if done wrong in an engine can result in carnage. To my mind the hemispherical pads are way down the list of problem sources. Hardly poor engineering. How would you suggest coping with the lateral movement between rocker arm and tappet? Pretty much anything else would add substantial weight to the valve train.

I'm not trying to be argumentative, simply wondering what other solution you could see?
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Lobo
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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 10:53 pm

Hi Pete; appreciate the need of the laterally sliding faces, and moreso the fact that you can screw an engine in any number of ways. At the very least I guess, I would have liked the pads somehow (loosely) captured (tiny circumferal clip whatever) in the rocker arm.
Hadn’t appreciated changing the adjusters would be a full out cam box removal. ... figured they’d just screw fully out if needed.
Given I know zip about these motors, if a pad were to escape down the oil return .... would it ‘harmlessly’ end up in the sump pan?
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Pete Roper
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PostSubject: Re: Roller conversion   Roller conversion Icon_minitime1Thu Jul 09, 2020 11:12 pm

The swivelling 'Elephant's Foot' on the valve end of the adjuster means that it has to be wound out towards the the valve, 'Down' as it were, and to do that you have to remove the rocker arm, and to do that you need to remove the cambox.

If you follow the instructions given by the factory for installation of the camboxes on a roller engine they suggest hooking rubber bands around the rocker arms to prevent them swivelling so the pads can fall out. I have to admit I've never felt the need. I just glue the pads into the rockers with grease and then hold the arms so that the pads can't fall out as I drop the cambox on to the head. Once torqued down they can't go anywhere. Any type of circlip holding the pads into the arm would be very difficult, a complete embuggerance and almost impossible to service not to mention machining the groove!

As for where they would fall if they did drop out? Well this could only occur as you're taking the cambox off and chances are it would simply drop to the deck of the head above the combustion chamber. If by some piece of bizarre bad luck it managed to drop down one of the oil return galleries it would either end up sitting on the 'Shelf' Where the head meets the barrel and could be retrieved with a magnet or, if it did wend it's way right down into the crankcase it would require pulling the sump and possibly the spacer, (On models so fitted.) to retrieve. If that occurs it should be seen as a salutary lesson to not be so bloody careless next time! Laughing
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