That is, cheap valve seat cutters from India, not cheap cutters for valve seats on Indians, though they may well work for Indians, of course.
Anyway, having established that an HSS cutter would function on the BSA valve seats, I decided to take a punt on a cheap set from India.
Perhaps it would be wise, at this point, to define “cheap”.
Assuming that we’re talking about doing the job by hand and not with a massive piece of custom built machinery, then the de-facto standard appears to be Neway. You can pick up a set of four cutters, with pilots and a handle for around £700 at the time of writing.
Moving down a notch you can get a similar set of three Sealey ones for £500. Aim for a wider selection and you pass the £1000 mark in very short order.
On the other hand you can get a set of 12 cutters, plus pilots and handles from India for £60. That will double if you want to cut modern hardened seats, but it’s still less than a single cutter from a reputable make.
To be honest, there’s no way I’ll ever get payback on a pukka set, I just don’t do enough valve seats to justify it, so it’s worth a punt on the cheap and nasty ones… or is it?
Well, they arrived in about a week and at first sight, the cutters themselves looked fine.
The handles and pilots, perhaps less so. The threads on the pilots were poorly cut, which meant that they rely on the taper for good alignment with the handle. And concentricity between the pilot and the cutter is truly critical here. Alas, the way the handle was threaded meant that that didn’t work terribly well.
Added to that, the arrangement at the end of the pilot, meant that it wouldn’t go far enough up the valve guide to cut anyway.
So far, not so good.
Not being one to give up lightly (especially having parted with money) I stuck the handle in the lathe and, firstly stuck a dial gauge on it to establish that the cutters do actually run true to the handle, which they do.
So then it was a pretty easy job to stick a little boring bar up it and make sure that it had a clean taper for the pilot to sit in.
Then to turn down the big lump on the end of the pilot, so that it actually fits up the guide.
The next step was of course, to find out if it now worked. I have a bit to play with on my inlet valve (as I’m putting a bigger valve in) so I was able to give it a little go.
First, a light coat of engineers blue (am I the only one who always ends up looking like a fashion advert for woad as soon as I open the tin?) round the seat and then scrape it off with the cutter.
Which did quite a nice even job of it.
The the next step was to cut it just a little bit more (to make sure I was seeing the true cut) clag some more blue on it, shove the valve in and give it a tiny lapping motion.
Which transferred a pretty even coating onto the valve. For those who actually look at the pictures, that attempt had far too much blue on it, so I wiped it off and re-checked it, but forgot to photograph the result.
So, the conclusion?
The cutters work just fine, but not straight out of the box. If you have a lathe and can be bothered to fart around a bit, I’d say that this set are worth the effort. To be fair, even if I produce a whole new handle and pilot arrangement it’s still good value for twelve cutters at half the price of one posh one.
What I don’t know, is whether I got the Friday model or the Tuesday model. Looking at the workmanship on the pilots I’m willing to bet that they’re not fantastically consistent, but for me, worth a punt.