stock valves can be machined or laped?

[mikyrc]

I have a quick question.
I've been told that our valves have layer of special hard matarial on them. That means that they can't be re-machined or laped to make them seal again. Because you can risk burning them if you take that material out.


Is that true or can they be machined without problems?

I'm rebuilding a 2G head and i would like to know if i have to buy new valves or just have the stock ones re-machined to 45º and laped.

In case i have to replace valves, do you guys know if evo valves (i think the're sodium filled) work on our cars without modifying anything?

Any help?

 

[iwannagofast89]

i did it in my laser with the 2g vavle in the 2g head and hasnt has problems yet its been running for about 2 weeks

 

[NATAS]

Are you on a major budget or do you just not want to wait? If you're taking the trouble you may as well get new valves as they're pretty damn inexpensive for how important a component they are. I huffed just 1 pair of valves about 6 years ago with my 1st 1G and since time and money were a major issues I did re-use a pair out of another parts head I had and it worked even lapping them by hand, but the motor did fail about 3 months later and I mean it grenaded.

IDK for sure if it was a direct result of the shoddy valve replacement, but it wouldn't surprise me. I'm now a strong believer in the, "do it once, do it right" mantra. I strongly recommend you nut up and buy new valves for your motor especially if you want it to last a long time.

 

[mikyrc]

Thanks guys, I've talked to other people and they told me the valves can be laped or "make it seal" without problems. There's nothing about any special layer or something.

 

[Defiant]

I think these days all valves are induction hardened, which does only treat the outer .125" or so. You'd drop the valve through the seat before you dressed it down below the hardening. But a set of stainless valves is just too cheap to bother.
I'm in favor of hand-lapping any valve job.

 

[mikyrc]

Thanks Defiant. That makes a lot of sense.