Theres an interesting video of a guy fitting seats to a BMC A series head using a pillar drill
That could serve nicely as a how not to video. Unlike those in a mill, the bearings and the way they're installed in a pillar drill do not resist side thrust, which means the runout of any of them is greater than 0.001". Also, you don't want lubrication between the seat and head since it will decrease the thermal conductivity, and a proper how-to video would feature micrometers.
Originally Posted by gunner
It will be interesting to see how you machine the head and fit the seats
After being temporarily stopped by my valve spring remover yesterday, it only took a few minutes today to machine an adapter from a piece of thick-wall Al. However, even hammer blows wouldn't make the exhaust valve move more than ~1/4" so it was back to the hydraulic press to overcome its resistance.
Since I'm going to work on the rockers first there's no urgency to get the BSA head mounted in the mill so I dropped it in a 5-gal. bucket of derusting solution to marinate for a few days. I don't need the rust off to machine the pocket for the seat, but it will make handling the head less messy. Also, I'll never use the valve springs and valves again, and I should just throw them away, but they along with the rocker parts went in the derusing solution as well.
Hey MM! What's your de-rusting solution of choice?
I have a 5-gal. bucket filled with Rusteco that I bought ~25 years ago and have used many times since then. The company is still in business and I suspect it's just a molasses/treacle solution.
I went back through the early part of this thread because I remembered having used it before and I found the post that shows the results on a rusty mudguard after two days plus a light brushing with a Scotchbrite pad (nb. this journey back through time reminded me just how much work I did to rebuild this this bike), I wouldn't have needed the pad if I had taken the mudguard outside to hose it off instead, which I didn't do because it would have left a trail of dripping molasses across the garage floor.
Not because the solution didn't seem to be working well after 25 years and many de-rustings, because it did, but for no good reason at the time I added a bottle of blackstrap molasses. I also had no good reason to use blackstrap rather than normal molasses, other than it just looks more "heavy duty." I don't know if this made the Rusteco work better or worse, but it still works fine.
The 5-gal. plastic pail of Rusteco/molasses with screw-on cover sits next to the one of Gunk/diesel. De-rusting and de-greasing are the two dirtiest and time-consuming jobs in rebuilding a motorcycle, and being able to just drop parts into a bucket and retrieve them a few days later saves me much time and effort. The buckets are big enough for most parts on a motorcycle, and the mudguard post shows how I deal with bigger items.
Last edited by Magnetoman; 3 hours ago. Reason: added photo of head pulled part way out of Rusteco bucket