Mushroom Head Tappet/Rocker Adjusters (2005)

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Mushroom Head Tappet/Rocker Adjusters (2005)
 
Will Leo know how much to shorten the valve stems for the correct geometry without the whole engine there?

Dave
69S
 
I'd suspect assembled engine needed unless good measures taken prior.
Getting everything you want right can take years ya know.

hobot
 
I see I can get them from RGM for 7.7 pounds which including shipping would be a whole lot better than $50, but they do not include the lock nuts and as Leo says there are a bunch of them out there with the wrong thread.
Click to expand...
A few years ago I bought a set from RGM and none would fit my arms. Since it's an odd thread I couldn't tap or die the parts for fit. Basically they were too large diameter. They took back the 3 I didn't ruin!
 
I put in a set of mushroom headed adjusters (BBC) over the winter and I'll see how they do. The standard adjusters wear into the end of the valve stem in less than 5000 miles. Once they wear, I have to adjust the valves with a dial indicator (a pain) or by backing the adjuster off by 1/4 turn (hopeful at best).

Greg
 
Years ago I ran a Trident. I replaced the floating ball end for caps and hardened
adjuster. Best part was the adjuster was an allen. Made life easier at adjustment
time. I remember that the caps didnt wear as fast as the stems used to so that
was good.
The rocker geometry on brit bikes usually seems poorly thought out.
 
Got the head back from Leo, nice job. Had to order the mushroom adjusters from Walridge, one of them was bad, plus it would not go into one of the exhaust rockers. Got a new one, better threads, but it still won't go all the way through that one adjuster. All my old ones thread in just fine. All the mushroom ones will not go through the one exhaust rocker. Measuring the diameter of the mushroom adjusters vs. the original ones, they are slightly larger diameter, maybe 1-2 thou. just enough just to not fit in that one rocker. I have been putting grinding compound on that one adjuster, trying to bit by bit get the adjuster to go through. Very slow going. Leo suggested a new rocker, but there is no guarantee that one will work either plus a used one is another $60. He also said the rockers are hardened and will probably not take a tap, same with the adjusters, and what would a BSF tap or die cost and that might not work either?

Anyone else have any ideas, use my old one?

Dave
69S
 
So I'm attempting to install my Walridge set . #039DRL. It looks like one of the adjusters has a thread-cut issue as it will not fit into- with any of the 4 rockers. The other 3 fit all rocker threads fine but not the 4th one , it goes in too tightly about halfway , shedding a few tiny metal bits enroute so I stopped and backed it out. Wiped clean , refitted the stock ones no problem. That now leaves me thinking to use 2 of the known good mushroom ones for the 2 intake rockers. I could fit stock to the 2 exhaust as suggested previously in this thread. Also it looks like I will have to pull the intake spindles and rockers to achieve clearance to enter from below for the intakes. The valve spring compressor does not like the adjuster length unless I'm missing something here. It's an RH10 head on the workbench.
 
There used to be some adjusters (Triumph, I think) that were a ball-and-socket affair with one side of the ball flattened for contact with the valve stem tip. Any scrubbing action translated to sliding and the contact area was more or less constant and not concentrated, which is what caused the stems to wear in a small concave pattern, making it difficult, if not impossible to set the valve clearances to spec.
 
I have had some failures with some of the adjusters. [3 to be exact in two different motors] They were hard and brittle as glass.
One of them would not come out without destroying the rocker arm after a small piece of thread chipped off the adjuster halfway through the hole and jammed up the works.

I have bought a couple sets from British Cycle Supply recently and found them to be very good quality and fit. They are only hardened on the face of the adjuster.

For those wanting to experiment, you can install a 6mm helicoil insert into the stock threads in a Norton rocker arm and use one of the many available 6mm pivoting adjusters that are available. [think KTM or Husky]
Unfortunately they didn't seem to handle high rpm very well in a Norton race motor.
 
Decided to just fit the mushroom adjusters to intakes only , exhausts to stay stock... Heated the head in the oven , pulled the rockers , installed with compressor the 2 valve assemblies , then tapped the rockers back into place hot. I used Kibblewhite seals this time , they pressed straight down ( oiled ) over the guide tops and into the slots easily with firm finger pressure. The Norton seals were hard as a rock and sliding up and down with the vale stems ! :shock: Really hope these adjusters do not break up down the road , I'm not a higher R.P.M. driver. The packet says European Spares Ltd.
 
I had a similar problem, that none of the Walridge mushroom adjusters would fit in one of my rocker arms. I bought a new (used) arm and it worked.
 
comnoz said:
I have had some failures with some of the adjusters. [3 to be exact in two different motors] They were hard and brittle as glass.
One of them would not come out without destroying the rocker arm after a small piece of thread chipped off the adjuster halfway through the hole and jammed up the works.

I have bought a couple sets from British Cycle Supply recently and found them to be very good quality and fit. They are only hardened on the face of the adjuster.
/quote]
Hi Jim,
I am using a 560-NR MegaCycle in my 850 Interstate now with the type of Mushroom adjusters that you have had failures on. My stock cam was worn some so I replaced it during the rebuild. So far so good with no issues with over 20,000 miles on the rebuild. This is a slight improvement from a stock cam so it is mild IMHO
Your failures on the two different engines has got me curious. What cam were you using? My thinking (maybe I shouldn't) :roll: is that if it is a high lift cam Like a 2s of 4s or the 12a webcam on your rig, might be putting a lot of load on the outside of the mushroom like the one you showed us before you went to LOP and Barber on another thread. These are thinner at the outboard circumference as compared to the ones from BCS. What are your thoughts? I might be overthinking this as it might just be a hardness issue for the batch of adjusters.
Cheers,
Thomas
CNN
Click to expand...
 
CanukNortonNut said:
Hi Jim,
I am using a 560-NR MegaCycle in my 850 Interstate now with the type of Mushroom adjusters that you have had failures on. My stock cam was worn some so I replaced it during the rebuild. So far so good with no issues with over 20,000 miles on the rebuild. This is a slight improvement from a stock cam so it is mild IMHO
Your failures on the two different engines has got me curious. What cam were you using? My thinking (maybe I shouldn't) :roll: is that if it is a high lift cam Like a 2s of 4s or the 12a webcam on your rig, might be putting a lot of load on the outside of the mushroom like the one you showed us before you went to LOP and Barber on another thread. These are thinner at the outboard circumference as compared to the ones from BCS. What are your thoughts? I might be overthinking this as it might just be a hardness issue for the batch of adjusters.
Cheers,
Thomas
CNN
Click to expand...

I bought 2 sets last fall and installed 1 set in my 312a cammed bike and the other set in my stock MK3.
One broke in my EFI bike.
Two were broken in the stock bike with no more than 1000 miles on them.
It may have been a bad batch but I think I will stick with the type that is hardened only on the end instead of through hardened.
The copper flashing on the threads means they are only hardened on the end.
 
comnoz said:
CanukNortonNut said:
Hi Jim,
I am using a 560-NR MegaCycle in my 850 Interstate now with the type of Mushroom adjusters that you have had failures on. My stock cam was worn some so I replaced it during the rebuild. So far so good with no issues with over 20,000 miles on the rebuild. This is a slight improvement from a stock cam so it is mild IMHO
Your failures on the two different engines has got me curious. What cam were you using? My thinking (maybe I shouldn't) :roll: is that if it is a high lift cam Like a 2s of 4s or the 12a webcam on your rig, might be putting a lot of load on the outside of the mushroom like the one you showed us before you went to LOP and Barber on another thread. These are thinner at the outboard circumference as compared to the ones from BCS. What are your thoughts? I might be overthinking this as it might just be a hardness issue for the batch of adjusters.
Cheers,
Thomas
CNN
Click to expand...

I bought 2 sets last fall and installed 1 set in my 312a cammed bike and the other set in my stock MK3.
One broke in my EFI bike.
Two were broken in the stock bike with no more than 1000 miles on them.
It may have been a bad batch but I think I will stick with the type that is hardened only on the end instead of through hardened.
The copper flashing on the threads means they are only hardened on the end.
Click to expand...


Ok Jim,
That throws out the high lift cam theory. I have not fired up my p11 build yet with these Copper washed Mushroom heads yet.
I like them too.
Cheers,
Thomas
CNN
 
comnoz said:
snipped
I have bought a couple sets from British Cycle Supply recently and found them to be very good quality and fit. They are only hardened on the face of the adjuster.

For those wanting to experiment, you can install a 6mm Helicoil insert into the stock threads in a Norton rocker arm and use one of the many available 6mm pivoting adjusters that are available. [think KTM or Husky]
Unfortunately they didn't seem to handle high rpm very well in a Norton race motor.
Click to expand...
Reviving this old thread, after researching threads on the subject of mushroom adjusters. I'm hoping to get updated reports on the quality of the USA made mushroom adjusters sold by British Cycle Supply. These adjusters are on sale there this month. Click on the "Current Parts Flyer" at the link below.

https://www.britishbikeconnection.com/

Also, has anyone tried the 6mm Pivoting Adjusters suggested by Jim above, or the Porsche adjusters suggested by Hobot?

Charlie
 
I had a bit of a disappointment with mushroom adjusters in my Commando recently. On both exhaust tappets the mushroom edge chipped off. That means that unless the little hardened pieces got caught on my magnetic drain plug or lodged nicely in the crank case somewhere then they went through my scavenging pump. I'm going back with stock type adjusters.

Dan.
 
motorson said:
I had a bit of a disappointment with mushroom adjusters in my Commando recently. On both exhaust tappets the mushroom edge chipped off. That means that unless the little hardened pieces got caught on my magnetic drain plug or lodged nicely in the crank case somewhere then they went through my scavenging pump. I'm going back with stock type adjusters.

Dan.
Click to expand...
What brand were they?
 
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