E: Engine Lapping head into barrel video

craig

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VOC Member
20210513_HeadLapToday1.jpg

Is there a video of some competent Vincent mechanic lapping the heads in to the barrels.
Description of the exact brand name and grade of compound used , application technique, etc.

Then a show of how you hold the barrel and head and apply pressure and twist.

Then a clean up and inspection and possibly reapplication.

I realize these bikes are quite new and maybe we haven't had the time or need for this.

Thanks
Craig

The machine work was done 7, 8 years ago , i didnt like my current measurements on fit up altho they seemed close, so this is a follow up by me .

Should i just chuck these heads up in a lathe and make sure i have couple thou clearance head to muff?
 
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timetraveller

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I can tell you how I do it. I hold the head in a vice with the open hemisphere upwards. I hold the barrel in my hands. I use fine valve grinding compound on the narrow face and coarse on the broad face. I continue uintil there is an even colour on both faces all the way round. I clean everything upwards, as often as I need during the process, to inspect the faces and re-apply fresh compound as needed.
 
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davidd

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If I used compound, I would prefer the water-soluble compounds from clover as a good wash will remove any grit.


I specify the fit with the head when I have the liner made, which is not much use to you.

David
 

vibrac

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VOC Member
A few words from time traveler beats a video but then I realise I am old school
I have recently on my forays into other makes of motorcycle come across a product called timesaver paste I made a note to try the coarse and finer pastes on those two surfaces its advantage is in what happens to any stray paste and lack of embedded particles
 

Bazlerker

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I had my heads skimmed to ensure that the liners were squeezed between the head and the muff. The setup involved several dial gauges and a very skilled machinist with an encyclopaedic knowledge of Vincent’s..
 

timetraveller

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VOC Member
I've had that done as well. Once you have it set up then it is a good idea to do the base of the muff as well to enxure that the axis of the bore is perpendicular to the line across the main bearings. That way low clearance pistons should not lock up. As you say, it needs someone with the correct equipment and knowledge to do it properly. Roy Robertson did mine.
 

timetraveller

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VOC Member
I hold the head in soft jaws with the line between the valves across the vice and clamp it onto the fins near to where the four holes which take the holding down studs go. You will need a vice with a five inch opening. From memory the gap across the wide face is supposed to be three thou when the liner flange is hard up against the head. However, Vincent is a proper engineer,I am not.
 
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