Replacing exhaust valve guides R100GS

[Windmill John]

Hi,

Can anyone point me at a thread, or how to, or tips for doing this

What would be suitable for driving out the old guide.

Any help appreciated.

John

 

[Shep]

The only advice from me would be to let someone else do it unless you have all the seat cutters and reamers, drifts etc you need to do the job properly.

I can't recomend anybody but i'm sure there will be very able engineering companies offering the service

Shep

 

[cookie]

The only advice from me would be to let someone else do it unless you have all the seat cutters and reamers, drifts etc you need to do the job properly.

I can't recomend anybody but i'm sure there will be very able engineering companies offering the service

Shep

...and then probably best not watch how most actually do the job

proper way: core drill 95% of the guide out. the remainder will then come out with a very light drift, which needs to be exactly made for the job.

anyway, after you get the guide out, you will need to recut the seat. definitely not a job for the amateur at home.

i get this guy to do nearly all my head work. very good, but you'd best not be in too much of a hurry.

 

[Rob Farmer]

The valve guides tend to mushroom over making it difficlt to remove them. I believe the usual thing is to mill the top of the guide off level wit the head and drive it down into the combustion chamber.

Fit new valves at the same time and get the seats recut and you can forget about them for another 50k

These guys are good http://www.cylinderheadshop.co.uk/

Or

http://www.scriminger.co.uk/

Plenty of other out there as well.

 

[Windmill John]

valve guides

Thanks for that guys,

Even though probably the right answer, a pain of an answer.

Without a garage, that means leaving the heads off for a while outside.
Might try and find someone who can take the bike as well, whilst the work's done

Cheers

John

 

[cookie]

did motobins operate an exchange scheme for bmw heads or am i imagining things?

 

[Steptoe]

i use [URL="http://www.blrengineering.co.uk/guides.html"]BLR[/URL] engineering. they make the guides to fit the valves, rather than off the shelf jobs.

 

[(RIP) pastyman]

I had mine done using a K-line system where instead of rmoving the old guide and risking damaging the head, they simply drill throught the guide and insert a phospher bronze bush which is then reamed out by blowing a calibrated steel ball through it. Better oil retention but allows for better fit of the stem in the guide. They recon it is quicker too, a few mins to do a four cylinder head. Ive done about 4000 miles since mine were done and the oil in the engine stays clean rather than going black straight away. I had it done by a mate so cant say much more but I believe a lot of engineering works can do it. Its quite common in racing circles and HGV garages. I am a bit surprised that its not more well known on this site

 

[cookie]

I had mine done using a K-line system where instead of rmoving the old guide and risking damaging the head, they simply drill throught the guide and insert a phospher bronze bush which is then reamed out by blowing a calibrated steel ball through it. Better oil retention but allows for better fit of the stem in the guide. They recon it is quicker too, a few mins to do a four cylinder head. Ive done about 4000 miles since mine were done and the oil in the engine stays clean rather than going black straight away. I had it done by a mate so cant say much more but I believe a lot of engineering works can do it. Its quite common in racing circles and HGV garages. I am a bit surprised that its not more well known on this site

i've had several sets of heads done like this by the cylinder head shop i (and rob) linked to. it's standard practice for them.