Mushroom tappet adjusters

Is there any advantage to fitting these on a Commando ? I've had them on my triples for years, but only to negate the risk of the "floating balls" parting company with the rocker arms.
sam

they are hard er to install than non mushroom, but I have them fitted because I was worried about valve surface scuffing. However there was some concern the radius of the mushroom might not be right. I think lash caps with standard adjusters might be a good compromise?

Just my humble thoughts

Cheers Richard

With Genuine Factory valves you don't need the mushroom adjusters, because they have stellite tips- many of the pattern valves don't. Their wear on the valve tip is considerable and as the tappet adjuster "digs" in, it tilts the valve resulting in wear in the valve guides.
The "floating balls" need plenty of lubrication and tend to seize if they don't- as I would suspect in a Norton engine. And they got a reputation for doing that in Trident engines, I hear.

With Genuine Factory valves you don't need the mushroom adjusters, because they have stellite tips- many of the pattern valves don't.

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They sure dont as witnessed by my horrible exhaust valves from a well known Cyl head operation in the UK. They last about 3000 miles before the valve starts to look really bad. Did try some mushrooms from RGM but they would not all thread into my rockers. They promised to find a set that did but didn't fancy pulling my rockers to mail off to them.

trident sam said:

Is there any advantage to fitting these on a Commando ? I've had them on my triples for years, but only to negate the risk of the "floating balls" parting company with the rocker arms.
sam

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Hi Sam, I had a Trident T150V with the floating ball type tappet and as you say, mine had also chipped and cracked the thin casing around the half ball. I don't think those are called mushroom tappets, as I had mine replaced with large headed mushroom tappets from Normal Hyde that were just mushroom shaped with no moving parts. They seemed good on the Trident as their was more area of tappet on the valve top. I have put new valves in my Commando (genuine ones from Andover Norton)and already there is an indented line on the top of the valve from the tappet. I didn't know there was such a thing for the Commando, but I would say it was worth trying and I might get some for my bike

The 'shroom RGM adjusters in Ms Peel required cutting down the valve stems shorter with hard caps on top and still got scored worn caps and flattened mushrooms in under 10,000 miles. I was able to fit 'shrooms with head off w/o pushrods stopping the rocker lift. Thought for sure factory Trixie would of scored her Norton kit after 8000 miles but nope just burnished better finish than on install. I did use discipline to hardly ever shut Trixie off till full heated to lay down the ZAPP layer everyone is so concerned about and gets wiped off on each start up. I also swore never to rev stock Trixie Combat into valve float range as discovered on 1st pre-Peel factory Combat valve train. Next Peel gets lash caps and plain rocker adjusters and just change out caps now and then. If seeking a bit less inertia might drill cores out of the adjusters short short of poking through sliding hard end.

Horror said:

trident sam said:

Is there any advantage to fitting these on a Commando ? I've had them on my triples for years, but only to negate the risk of the "floating balls" parting company with the rocker arms.
sam

Click to expand...

Hi Sam, I had a Trident T150V with the floating ball type tappet and as you say, mine had also chipped and cracked the thin casing around the half ball. I don't think those are called mushroom tappets, as I had mine replaced with large headed mushroom tappets from Normal Hyde that were just mushroom shaped with no moving parts. They seemed good on the Trident as their was more area of tappet on the valve top. I have put new valves in my Commando (genuine ones from Andover Norton)and already there is an indented line on the top of the valve from the tappet. I didn't know there was such a thing for the Commando, but I would say it was worth trying and I might get some for my bike

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Perhaps I wasn't clear,
I meant that I've had the mushroom adjusters in my triples for years which replaced the standard "floating ball" type fitted at the factory

Leo Geoff recommended the mushrooms and I got a set from Walridge. One of the rocker arms, only the old tappet would go into, so I had to get a used rocker arm. Can't speak to how it will work out, but here are my original valves after 13K miles.



Dave
69S

I tried the mushrooms when I installed new valves but the angle of the rocker-to-valve angle was terrible - ended up with considerable side pressure on the valve so I removed them and installed a new set of stockers with the new valves.

trident sam said:

Perhaps I wasn't clear,
I meant that I've had the mushroom adjusters in my triples for years which replaced the standard "floating ball" type fitted at the factory

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Ah sorry, I didn't realise the floating ball type tappet was standard in the Trident. I had 2 at the time and the other engine had ordinary tappets so I thought the ball type was an after market tappet.

I also put new tappets in my Commando, with the Allen head, from Andover Norton. They were so tight I couldn't fit them without spinning in a lathe and using a thread file on them. Hearing the problems with the mushroom tappets in Commando's, I think I'll leave mine as is.

I put mushroom tappets on the Combat perhaps 150,000 miles ago. Checking valve clearances is largely a formality--the exhaust valves may waver a thou every 20,000 miles or so



Tim Kraakevik
kraakevik@voyager.net
'72 Combat, '74 RH10 850