Grinding shims

[Sam_Q]

I have no idea, its just a random picture I got off the internet. I would get the guy in our tool room here at my work to do mine.

The reason I asked about this subject is that someone I know who is usually always right said that you cant grind shims no matter what and it confused me as I didnt see the problem.

[love ke70]

they are case hardened.
not hardened all the way through.
yes u can do it, but viper, could you please dig up those details? i would like new ones with my build.

and sam q. what motor is this for? the one you are currently building?
because, when you get a head machinedand the valves done etc, they can set your valve clearances using your current shims, by taking the tip off your valve stem...
cheers, andrew

[oldcorollas]

they are case hardened.
not hardened all the way through.
yes u can do it, but viper, could you please dig up those details? i would like new ones with my build.

and sam q. what motor is this for? the one you are currently building?
because, when you get a head machinedand the valves done etc, they can set your valve clearances using your current shims, by taking the tip off your valve stem...
cheers, andrew

are you sure they are not through hardened?
if th eshims are only a mm or so, they might be surface hadened only if they were carburised or nitrided.. but if they were induction of furnace heated followed by quenching, then it is more likely to go through thickness..

if anyone has a spare they wanna send to japan, i have a microhardness tester, and probably a nano indenter i can use

you can only grind the tip by the amount the valve seat is machined.. you don7t want to do that too many times .. but yeah, it can be done..

[love ke70]

are you sure they are not through hardened?
if th eshims are only a mm or so, they might be surface hadened only if they were carburised or nitrided.. but if they were induction of furnace heated followed by quenching, then it is more likely to go through thickness..

2.5mm thick shim. engineering shop i took mine too said only case hardened, but hey, could be wrong....

if anyone has a spare they wanna send to japan, i have a microhardness tester, and probably a nano indenter i can use

how much is postage gonna be? and do you want a ground or unground shimmy bimmy?

you can only grind the tip by the amount the valve seat is machined.. you don7t want to do that too many times .. but yeah, it can be done..

why cant u take a little extra?
and on a standard head job ahem thats all you need....

[oldcorollas]

ahh.. 2.5 is a bit bigger than i thougth they were .. maybe they are case hardened then... i was thinking more like 1mm thick.

nfi on postage.. although there aren't any 4AGs at the wreckers, if there are more common toyota engines (2J? 1UZ? 1G?) that have the same shims, i cna prolly snag one for free... once the 2 or 3m of snow melts

hmm, taking extra puts the valve further in = slightly lower compression, thinner seats etc etc.... is not that bad, but.. meh, shims are easier

[love ke70]

the valve doesnt come any further up if you only take extra off the tip to make it work with the shim you have dutifully chosen.....
it still comes up against the seat, the only thing thats changed is the very end, which just determines the clearance from bucket to shim, nothing else...right?

the thinnest of mine are 2.4 mm from memory, 2.8, 2.9 is pretty common factory for the 1g, and 3s which i grabbed some from.

theres a heap of motors with the same shims, 4a, 3s, 1g, and almost all varients of these motors, even the single cams, have the same shim.

[oldcorollas]

i thought you were talking about when you have the seats ground or recut...
because then the valve sits further up in the head, and then you can grind the tip of the valve to get back the clearance without changing shims...

[Sam_Q]

it is for my engine I am building using the 7AFE head. I would have to make up some sort of jig if I were to grind the stems, but grinding the shims is easy on the surface grinder. So how thicks a case hardened layer anyway?

also why would it matter how hard/soft it really is? I mean its the low side with a almost total suface area coverage so whats it matter?

[love ke70]

i thought you were talking about when you have the seats ground or recut...
because then the valve sits further up in the head, and then you can grind the tip of the valve to get back the clearance without changing shims...

well yes, they can do it then, and unless you ahve a head with no shims and you just grab a handful of spares, why would u not have the right shims anyway?

i dont see an issue doing it either way, was just pointing how you can do it, seeings as you can grind them yourself, i see nothing wrong with that method.