RH 4 dont panic Apparently

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3 of them

3 of them

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Jan 22, 2018
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went to see Norman White today . While i was there i asked about the perceived problems with the 850 RH4 cylinder head cracking in the roof of the inlet port .He told me that the only times he has come across this problem is when it has had a bad porting job or valve guides have been ham fistedly fitted. although he told me that they do suffer a problem of cracking in the tunnel where the 5/16 studs come up through from the barrel this by the way is both RH 10 and RH4 heads , but deep joy this can be repaired by a laser welding process (dont ask me only repeating and passing on info )
 
Good to know, maybe I'll sell that RH10 or stick it on another motor.
As an elderly accountant told me once, when I was full of worries about our business( which did ok , as it turned out)

"99% of a man's worries in life never materialize into anything"

Glen
 
worntorn said:
Good to know, maybe I'll sell that RH10 or stick it on another motor.
As an elderly accountant told me once, when I was full of worries about our business( which did ok , as it turned out)

"99% of a man's worries in life never materialize into anything"

Glen
Click to expand...

How much dya want for it...?
 
Nigel, I might be using it on another engine here . If not then I will sell it at cost + shipping. I believe that cost was $440 us three or four years ago. I bought it from a US member here.

Glen
 
If I were you, I wouldn’t sell it!

But if you end up not wanting it Glen, I will gladly have it.
 
I'll definitely give you first shot at it.




Glen
 
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The problem with people who stress out is they worry about things in life, myself never worry about anything, I take life as it comes, if you worry about things then things will happen, just be happy and get on with life and don't think about it.

Ashley
 
I have a RH4 head with no cracks. I think as stated above, ham fist guide installs created the issue. The RH4 had 32mm ports and the larger 850 style guides which compounded the weakness in the intake area. RH10's went to smaller port size and beefed up the tunnels.
cheers,
Thomas
 
ashman said:
The problem with people who stress out is they worry about things in life, myself never worry about anything, I take life as it comes, if you worry about things then things will happen, just be happy and get on with life and don't think about it.

Ashley
Click to expand...
If there is a solution, why worry? If there is no solution, why worry? – (The) Dalai Lama
 
I have two RH 4s, one on each bike, one of which I installed the guides in years ago. If you can't follow directions, it's best to leave stuff like valve guide installation to someone who can.
 
This process has been tested and used for well over a thousand miles and is still leak free. If they can focus the laser they can weld it, this includes putting new valve seats in one piece block and heads, The oil in the crack is not an issue as it is vapourised when the weld is being applied. Another benefit is that the they apply the weld, switch off beam and you can instantly touch the weld, so no distortion, and with weld that can be applied 0.2mm wide, minimum clean up.
 
Well, it's an interesting theory that the crack can be blamed on ham fisted installations of guides, but if so, some of those ham fisted installers must have been working at the factory. I've so far found two heads with cracks at the guides that still had the original, factory installed, standard size, iron guides.

The laser welding sounds good. I used to work with missile body sections that had been laser welded in a large CNC welding chamber at a Raytheon plant, but haven't encountered anyone with such a facility offering the service to motorcycle folks. Do any of you know of a shop that will do the repair here in the US?

Ken
 
lcrken said:
Well, it's an interesting theory that the crack can be blamed on ham fisted installations of guides, but if so, some of those ham fisted installers must have been working at the factory. I've so far found two heads with cracks at the guides that still had the original, factory installed, standard size, iron guides.

The laser welding sounds good. I used to work with missile body sections that had been laser welded in a large CNC welding chamber at a Raytheon plant, but haven't encountered anyone with such a facility offering the service to motorcycle folks. Do any of you know of a shop that will do the repair here in the US?

Ken
Click to expand...

Yes, I have also worked on many heads that were cracked in the intake and still had the factory installed guides.

The good news is if the head is not cracked -it is not likely to crack in use. As long as someone does not exceed the .001 interference fit of the guide when rebuilding, they are not likely to ever give a problem. Jim
 
more good news from those who know .Quality control at the factory must have been dire
 
What are K-liners? Inquiring minds want to know.

Never mind. I googled it. I've never seen them before.
 
They look like a brilliant idea to me.

I’ve never used them though.

Anyone got any feedback?
 
I recently had K-liners installed, works ok so far, although I have not done a lot of mileage yet since the installation.
 
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