• Welcome to the website of the Vincent H.R.D. Owners Club.

    Should you have any questions relating to the Vincent H.R.D. Owners Club, or Vincent H.R.D. motorcycles in general, please contact Graham Smith, Hon. Editor and Webmaster by calling 07977 001 025 or please CLICK HERE.

    You are unrecognised, and therefore, only have VERY restricted access to the many features of this website.

    If you have previously registered to use this forum, you should log in now. CLICK HERE.

    If you have never registered to use this website before, please CLICK HERE.

ET: Engine (Twin) Fogging for Mosquitos; Valve Guide Issues and Solutions


John Appleton

Well Known and Active Website User
VOC Member
Would a really neat total solution be to make a lower guide integral with your piece ?
Chris.
Yes, that does work. it means machining both the rocker arm housing and the valve guide parent bore to ensure they are concentric, but I reclaimed a head in this fashion some 12 years ago, John.
 

timetraveller

Well Known and Active Website User
VOC Member
Hi Chris, yes I thought of that and several years ago a German member used to make valve guides like that. The problem here is if the hole for the lower guide has been damaged and enlarged, It would mean making the new gadgets with an oversized guide parts and then machining them for each application once the damage had been corrected. It would also be a problem to machine an internal recess to take an oil seal. It would be interesting, if there are enough examples, to see if there is a correlation between fitted oil seals and this problem.
Instead my gadget is intended to allow a repair with, no access to machining tools, for anyone who has had this problem. Provided that there is enough metal left to fit a new oversized lower guide with a flange then this system works. I am not trying to build up sales for this as you know that I do this for no profit but it might be a good idea for anyone rebuilding an undamaged cylinder head to install these gadgets anyway to prevent a problem in the future.
 

ClassicBiker

Well Known and Active Website User
VOC Member
In Post #88 Martyn posted a very interesting article about how Maughan does it. I decided it that is how they do it, that was how I was going to do it. First step was to clean up the damage that had been done when the valve guide failed. I set up my rotary with an angle plate so I could bolt the head down and rotate it so the axis of the valve was vertical and parallel to the mill spindle. The I centered up over the cavity and fed the 1 inch mill down first turning it by hand to make sure all was good and I found a couple of spots where the casting was a little rich. So I was ready for that so I turned the mill and gently fed the cutter in checking frequently as I cleared away the damaged thread area and just kissed the bottom of the cavity.

100_3056.JPG
100_3053.JPG
 

ClassicBiker

Well Known and Active Website User
VOC Member
Now to make the tool Maughan used. First I decided I would make a hand chuck to turn the reamers.
100_3055.JPG
This allowed me to turn the reamers by hand with ease.
Next came the first guide to clean up the valve guide hole.
100_3060.JPG100_3062.JPG100_3063.JPG
Here it is being used.
100_3052.JPG
So that cleaned up where the new valve guide was going.
 

ClassicBiker

Well Known and Active Website User
VOC Member
I had decided at the outset that I would install the sealed type valve guides. I measured up everything and added 0.001" or 0.002" so the valve guides would be nice and tight when fitted, I then placed my order with VOC Spares. My mistake was one of the sizes I ordered was right on size so it was an easy push fit. That was on me, so what to do now? Order the correct size and wait or order AMCO 45(C6300) or 954? After all I had a good seal type valve guide to use as a pattern. I did the latter and as luck would have it was the correct choice.

So valve guides installed and time to ream them. I wanted the the lower valve guide axis to be co-axial to the upper guide and perpendicular to the upper guide seating face to I made another reamer guide. Using an old Triumph inner valve spring to hold the guide in place under an old an damaged valve cap I reamed the lower guides.

100_3057.JPG100_3058.JPG
I made the guide tall enough that if someone wanted to use it for a standard guide the reamer will slide up into a clearance area.
 

ClassicBiker

Well Known and Active Website User
VOC Member
Now it was time to install the lock rings. As I said I ordered everything for the seal type valve guides. The VOC Spares Co. sent me exactly what I ordered. Unfortunately someone in the past decided that three 20 tpi lock rings needed to be 14 tpi. Oh and the inlet instead of being 3/4" was 7/8" on the front head.
100_3067.JPG
this meant I had one lock ring from the Spares Co that would work and three that wouldn't. No problem. I had a foot long length of 954 and C6300. This is my first attempt, I was working out the pin spacing for the tool the Spare Co. provided. I got it right in the end.
100_3064.JPG100_3065.JPG
 
Last edited:

ClassicBiker

Well Known and Active Website User
VOC Member
In Post #41 Time Traveler refers to a thread about a clamp device. Well that was the route I went with. I took the design that was posted in that thread and ran with it. I wanted to have the seal type valve guides on all the valves. I bought a length of 1.25" diameter 7075 to make it from. On the bottom I spot faced to take the "X" ring seal supplied by the Spare Co. Unfortunately I made it 0.010" short so I made a shim that I super glued to the bottom of the Upper Guide. I ordered 8 valve circlips, it was lucky I did, not because they shot off into another dimension but because in fitting this it was in and out a couple of times. I had decided to use the modified locking rocker bush. This pulls the rocker bush to the top of the rocker tunnel. Which is all well and good but as I did up the modified feed bolt the bush pulled up and clearance between the rocker arm and clamp disappeared. So it had to come out. I felt it would be foolish to re-use the circlips when I had extra. After a couple of goes I finally managed to get an amount to clearance that satisfied me.
100_3068.JPG100_3069.JPG100_3070.JPG

But I began to worry that oil would build up under the clamp and seep between the clamp and lower valve guide negating "X" ring seal in the clamp. So knowing that the shoulder of the valve guide is 0.057" thick and 0.625" in diameter I went looking for Viton O rings which are good to 425 degrees F and placed that down the well.

100_3071.JPG100_3073.JPG
 

ClassicBiker

Well Known and Active Website User
VOC Member
I should say that before fitting all the valves I ordered a 30 degree valve seat cutter set from Neway. These come with carbide inserts allowing for a range of seat sizes to be cut. These are intended for automotive use so the guide is rather long and as such the taper it has doesn't allow the cutter near the seat on a Vincent head. But a 3/8" transfer punch, which measures 0.374" incidentally, works nicely once you roll it on a surface plate to make sure it hasn't been bent by its intended use. Using the cutter cleaned up the faces quickly and easily. I was curious how many actual turns it would take to get the faces clean 3 out of 4 were cleaned up ten light turns. The fourth to 20 due to some deep pits. Grinding in the new valve bought from the Spares Co. then only took ten minutes each. I very pleased with that.
I've temporarily fitted the heads back to the bike and lightly snugged them down without push rod tubes. I've fitted each push rod individually and turned the motor over a few times to make sure that nothing jams up or binds, then removed it before fitting the next one. So far so good.
That's where I am at to date.
I should also mention that I have drawn all this up in Teamcenter NX so I have 3D models and dimensioned drawings of everything and the drawings are also available in PDF format.
Steven
 
Last edited:

timetraveller

Well Known and Active Website User
VOC Member
Just to keep you all updated,twenty of the devices I designed, and which are mentioned above are currently being CNCd for the Spares Company. I offered to get a batch made for the general membership so that some could be held by various sections for ready access. There was no interest but Bob, from the Spares Company, phoned me and said that they would hold twenty for future requirements. They are being made from 7075 Ali which is as strong as mild steel. I will eventually write something for MPH when they are ready.
 

genedn

Well Known and Active Website User
VOC Member
The hole in the cap is really the "Secondary" breather, the chain oiler is the main breather which most seam to blank off all together. You only need to wind the adjuster screw fully in to blank off the oil flow and leave the main outlet pipe open to vent the tank as it was designed. I feel the pin hole in the breather cap is barely able to vent the tank correctly especially at elevated speeds.
What if this was a B UFM?
 

greg brillus

Well Known and Active Website User
VOC Member
Same, same.......but it does not have the adjuster screw to stop any oil flow. The one on my Rapide is a "B" oil tank, at one point I set it up as per the factory, but it dribbled too much oil onto the rear chain. I have since hooked it up via a "T" piece coupled together with a "D" type breather cap over the front exhaust valve, and these vent just past the rear axle with a length of 3/8" bore oil/fuel hose. It will dribble a little oil after a descent run, but not too much.
 

Can't Find What You Need?

Buyer Beware: Fake or Real?

Top