F&*k! this guy has the same problem with the comp valves I am running.
From here - http://www.mr2oc.com/showthread.php?t=404589&highlight=ferrera+valves&page=5
I never rev above 7000rpm and generally change at 6500rpm. No need to over rev my engine - it's got lots of bottom end torque.
 

Dude on another forum
Great.
Having the same problem to.. 2 intake valves have closed up to 0, and i have even lost some comp on that cyl.

And i even have the comp valves, where this was not going to be a issue.

2 gen gte, bc springs, bc retainers, gsc 274-9.9mm, 8200rpm, 2000 miles, and bought feb 2011."
 

Someone totally needs to start a thread on parts not to buy for an MR2.....

Mrskylighter
I think Surok had an issue my my old cars engine that had something to do with the 1mm OS ferrera valves. Think he got the new ones for free as suggested in the Mr2oc thread above.

Im pretty sure that they were not the comp + valves and they upgraded him to them.
Think I will keep a eye on my clearances now

Its not a engine build, its maintenance !

What oversized valves are you using? The entry level 6000 Ferrea valves have a known problem (unless very recently purchased/manufactured). There's a material incompatibility problem with the Yamaha head. Basically the 3S valve seats are too hard & lead to deformation of the valves. Given your intake valves are the ones affected, sounds to be the issue to me.
 
If you do have Ferrea valves, I believe they'll replace them free of charge.
 
Edit....Oops, didn't read the last page. Head's coming off buddy.

Thoughts?

What brand of 1mm oversize valves do you guys suggest I buy instead of Ferrea? I ideally want to hear from those of you that have raced with them rather that just what you have used in street engines. Race engines get much more punishment.

This is what it should look like

 

Just throwing this out there, is there an actual need for aftermarket/oversized valves?
Is there substancial proof that they provide a lot of improvement or is it a case of "Bigger should be better".
 
You might be able to just stick with good ole reliable factory toyota valves?

I haven't tested it though I made 3 major changes in this build -

• 3SGE NA cams
• 1mm oversized valves
• 200cc additional capacity

I now make the same power as before though with 5psi less boost