Grinding intake and exhaust valve tips?

[amichie]

If your valves are too long is there any reason why you cant have about 1mm ground off the tips. Obviously I will check that the bucket is still pushing on the tip and not the retainer etc. I guess the question is there any special treatment on the surface that gets ground off if you go too far?

[fixeruperer]

no problem at all, ive only used a valve griding machine to grind valves.
as you said, just make shaw the shim is in contact with the valve stem.

dont go to far , just keep measuring.

[love ke70]

thats how most shops set valve clearances when they reseat the valves...

[amichie]

thats how most shops set valve clearances when they reseat the valves...

Yeah. I know.

I was just asking if its possible to take too much off.

The motivation for my question is I want to try and fit 2jz valves into my 7Mge head.

2JZ valves are about 0.5mm longer and I would prefer to just grind the tips back rather than buy 24 new shims.

Anyway thanks for the input.

[30psi 4agte]

If you go too far you will take the hardness of the tip.
So yes it is possible to go too far.
.5mm should be ok. 1mm mabe too far.

[andrew_mx83]

foget the valves

grind the cams

more lift

win.

[amichie]

foget the valves

grind the cams

more lift

win.

Hi Andrew

I am planning on using my BC 264 cams that have a 8.5mm lift already.

[andrew_mx83]

more lift

win.

[JKLMATE]

Grave dig. Anyone have experience with this?
I'm looking to more the of 1-1.2mm range.

Valves with heat treated tips seem like a no-no.
$$ valves with pressed in 'hardened tips' should be fine assuming care in machining?

[aus jd 2703]

I believed your quality valves did have a heat treatment on the tip to extend life.

are you sure you machinist didn't cut the seats to far into the head? that has happened to some 3sgte guys, they then couldn't find thin enough shims and yeah. machinist error.

http://www.ferrea.com/tech_tips.php?tech_tips_key=19
"They feature a one-piece forging made from stainless steel, a special heat treatment process, hard chrome stems, and hard tip."

[oldeskewltoy]

1mm... really, that much? Seems like quite a bit. as aus jd 2703 points out, maybe your machinist cut too much from the seats???

[JKLMATE]

Hey guys, I contacted Ferrea and they say that at most 0.5mm from their heat-treated tip'd valves can be removed without issues.
I would assume this would be different for vavles with pressed-in hard tips; where the engine design has direct interference on the valve tip...

My reasons are the same as amichie, I want to use 'off the shelf' valves from one engine in another different engine (that has no aftermarket support).
Sadly even machining off 0.5mm I think I will be unable to re-shim my valves properly once valve seats are re-cut.