Admin
I'm thinking of buying Supertech TIVN-1012 stainless steel with black nitride coating as per this page -
http://www.supertechperformance.com/cat-ivalves?mk=10&ca=398&en=60
Does anyone object?

I have a feeling these guys are using the same one's (autocraft-uk) but might be worth dropping them an email or giving them a call as they seem to turn out a lot of top end engines and they say the valves they run are up to the task, not mentioning the brand though.
 
http://www.autocraft-uk.com/page24.html
 
They list out there builds and they use a 1mm oversize on the intake.
 
http://www.autocraft-uk.com/page28.html

I had a dodgy batch of valves and ferrea replaced them no problem. Im surprised that these valves were sold to you as late as 2013, Im thinking the vendor sold you those having known about the dodgy batch and should have checked. Do you have the part numbers so I can compare to mine?

The only thing I can mention is make sure the valve guide clearance is correct, and ive only ever heard of issues with the nitrate on the exhaust side when exposed to continuous temps over 800c for extended periods. I have run supertech valves for a few years in my car without issue.

track_mr2

Admin
I'm thinking of buying Supertech TIVN-1012 stainless steel with black nitride coating as per this page -
http://www.supertechperformance.com/cat-ivalves?mk=10&ca=398&en=60
Does anyone object?

I have a feeling these guys are using the same one's (autocraft-uk) but might be worth dropping them an email or giving them a call as they seem to turn out a lot of top end engines and they say the valves they run are up to the task, not mentioning the brand though.
 
http://www.autocraft-uk.com/page24.html
 
They list out there builds and they use a 1mm oversize on the intake.
 
http://www.autocraft-uk.com/page28.html

Thanks though the photos on their site shows Ferrea valves. I'm not going to use them again.
FYI I bought Ferrea because I had used them in my Escort race car without issues. I don't follow what others do (as in on the MR2OC forum). I like to come up with my own ideas. That's probably why my engine fails so often!

Valves are out. Here are some better photos showing the deformation.


 

'Ferrea', sounds Italian - that alone would make me stay away from them.

Italian machines? No! (except coffee machines), Italian food? Yes!

Those are better photos. I can see the problem now. Get your cylinder head bloke to check his seating width on the inserts too. If they are cut too narrow it can cause this as it doesn't allow sufficient surface area contact to dissipate the heat from the valve head. ? ?  Might be an idea to open the valve clearance a little wider too.  Allow the valve a bit longer on its seat. 

Standard valve talk doesn't really help Bud unfortunately, but to summarize what's pretty crystal clear for others, the rather small power gain that 1mm oversize valves would bring, wasn't justified by myself given reliability concerns of aftermarket valves, hence why myself & Rob stuck with trusted OEM valves.

Hope you sort things out once & for all Bud.

Me too!
Supertech 1mm oversize valves have been ordered

Good move Admin,
Its the only way to fly