R100 head rebuild

[beemerchuck]

I am working on a newly purchased 81 R100RT for a friend. Both exhaust valves have severe recession, 1 mm and 3mm.
Surprised to see that on an 81, but the air injection was damaged, without the feed lines being plugged, so that may have caused the recession.
Thinking it may need seat replacement as well as new valves.
Last time I did an airhead valve job was in the mid 80’s.

Any recommendations on shops that you have used recently?
Several shops from previous threads have closed or no longer do head work.

Thanks, Chuck Swenson MOA#9162

 

[20774]

1981-1984 models had poor metallurgy for the seats which did not transfer heat from the valve into the head, thus the valve face took all the heat. Per Oak, this was not valve recession but he used the term valve face plastic deformation. This was corrected with new materials in 1985. You should change the valve seats as well as the valves. Ted Porter used to do Airhead head work but I believe is no longer doing it. You could check with him and see what he recommends or check with Tom cutter at Rubber Chicken Racing Garage.

 

[stevenrankin]

Shop

Yeah, you got bit by the BMW valve problem of the early 80's. Max BMW I believe does head work. St.

 

[kbasa]

Ted used to do this, but you could probably rely on Max or Bob to set you up properly.

FWIW, I just had my '84 done last year and I got them ported, which makes a big difference in mid range roll on, if you're up for that kinda thing.

 

[barryg]

I’ve enjoyed seeing a thread on heads, thought I’d post a pic of a head I done years ago.

Good memories from working in a head shop.

 

[20774]

Yeah, you got bit by the BMW valve problem of the early 80's. Max BMW I believe does head work. St.

From their website:

https://www.maxbmw.com/classic-service-center

 

[beemerchuck]

Thanks everyone. Found a local shop that can handle the job.

 

[52184]

https://www.youtube.com/watch?v=R1rI3pog1DU

Best,
DeVern

 

[James.A]

Be aware that Black Diamond valves are not compatible with OEM valve guides. I let a parts guy from Bob's BMW talk me into using them to save some $ and ended up with a bent exhaust valve after about 500 miles.