Can anyone machine a wee cylinder of metal for me? (NLC)

[robin]

Good, now you need to try planishing one and seeing whether you can maintain that 0.01mm repeatability

[graeme]

Your lack of faith is disturbing.

It's almost as if you've somehow, 14 months into the 2 week project, arrived at the insultingly unjust opinion that I have absolutely no idea what I'm doing...

[robin]

More like I know that obtaining .01mm accuracy with a machine is not trivial, so doing it with a bit of sand paper is impossible

[woody]

Yeah, tend to side with Robin here... once I converted to inches. Accuracy 4 tenths is going to be a push. What are you measuring with?

ETA, I'd see if someone with a grinder (as in machine, not angle) could do it.

[graeme]

Measuring with a combination of cheapo 0.01mm digital calipers and a set of cheap 0.01mm micrometers. I can double check the gaps after build with feeler gauges too. As long as I err on the side of caution (take off too little, not too much) I should be ok. Maybe.

At the end of the day, if I balls it up and have to order a complete new set from Subaru, I'm no worse off than I am now.

[Dominic]

Yeah, tend to side with Robin here....

Me too! No idea what anyone is talking about though

[Shug]

Measuring with a combination of cheapo 0.01mm digital calipers and a set of cheap 0.01mm micrometers. I can double check the gaps after build with feeler gauges too. As long as I err on the side of caution (take off too little, not too much) I should be ok. Maybe.

At the end of the day, if I balls it up and have to order a complete new set from Subaru, I'm no worse off than I am now.

What's your actual tolerances for valve clearance? Is it really +/-0.01mm? Or do you just want that accuracy, so you can get it in the middle of the tolerance before bolting back together?

I'm sure you'll have enough wiggle room to be close enough - if you have the patience to stick with it (I wouldn't!)

[graeme]

Inlet - 0.20 +/- 0.02mm
Exhaust - 0.35 +/- 0.02mm

Ticht as a nun's proverbial. So yes, I do need thousandth of a mil accuracy.

I can swap a few around to get about 4 spot on, but that's using up all the smaller follower sizes so I quickly end up with a pile of thick ones that are no use. About 12 of the 16 will need planished by some amount.

It'll be scary putting shiny thing to abrasive surface, but it's ok because I'll be drunk.

[Shug]

Aye, good luck with that then...

Still, as you say, you can't put yourself in a worse position than you are and you might actually save a few bob if you get some right

[campbell]

It's the automotive equivalent of deciding which wire to cut. All rootin' for you here, G.

[smee]

Shed. That's my valuable contribution.