Crouch Posted March 26, 2016 Share Posted March 26, 2016 Just thought I'd pose a quick question regarding valves for the 2JZ. I bought a valve train for my big build a little while back and at the time I opted for the Supertech +1mm valves with dual springs option. I have now got to the stage where I need the head machined in terms of flowing, over sizing the seats and measuring for shim less buckets. I contacted a trusted performance shop about my requirements and was surprised that from the way it reads it seems that the Supertech valve train was completely dismissed and Ferrea was given in spec. Here's the question then... is there a problem with Supertech valve trains? I checked and Supertech have been used on some serious builds so what's going on? Thanks Gary Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 26, 2016 Share Posted March 26, 2016 No idea, what is the material spec of the valves and will they put in writing the exhaust valve material is suitable for a performance turbo engine? I myself would never buy US valves, I have too many times checked material specs and found them unsuited for the claimed applications. But the US will have a big marketplace for 2JZ valves and advertise heavily. Very few valve manufacturers outside Germany, Japan and the UK make truly suitable material exhaust valves for serious turbo applications. Quote Link to comment Share on other sites More sharing options...
Crouch Posted March 26, 2016 Author Share Posted March 26, 2016 Mr Wilson if you had a choice of valve train who would you use in a big spec build? Is it more about personal preference when you use top end products or is there a true difference? The research that I have done there was stories that Ferrea valves will bend but never snap. Owners gave stories of having had massive engine failures never having to do more than change bent valves and press new guides in. The same owners would often claim that they have been using other brands they'd be digging valve heads out of the under side of a unsalvageable head. Sounds like the usual Internet waffle to me mostly but I'd rather ask and get it correct the first time. I just hope I don't need to buy another valve set as it's all money side stepping not achieving the end goal. Thanks Gary Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 26, 2016 Share Posted March 26, 2016 I would want to know they were one piece valves and I would to know the material spec too, especially for the exhaust valves. I tend to buy my race valves from these people, they are one of the finest valve makers in the world and are right here in the UK. http://www.gsvalves.co.uk/ The have some great info you can download. I would go to extreme lengths NOT to replace guides as the OE ones will NOT be drilled concentric with their OD, but the new ones will. Result, badly pocketed valves by the time the seats are cut! I would not want to even consider Titanium retainers, unnecessary and they tend to gall and work harden, the 2JZ won't rev anything like enough to make them necessary. I would not use American cams, their profiles always seem years behind Japan and Europe, probably because they are still entrenched in the pushrod era. Right now the only thing I rate about the USA are some of their machine tools and Donald Trump. Quote Link to comment Share on other sites More sharing options...
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