Sunday, February 09, 2014 - 02:14 pm, by: Matthew Sharpe(Madmatt)
Kalin August wrote on Sunday, February 09, 2014 - 11:37 am:
Can't say on the 1JZ as I don't own one - but in my experience, valve springs can suffer metal fatigue after enough duty - this has certainly caused valve bounce in a high performance engine I had. I ended up having the cylinder head totally reworked and installed uprated valve springs (and oversized valves as I had it ported), problem solved.
Anyhoo anecdotes aside, I think that rev limiter or not, it's possible that a tired set of valve springs could cause bounce.
Sunday, February 09, 2014 - 03:50 pm, by: Robert Day(Lexsmaz)
Kalin August wrote on Sunday, February 09, 2014 - 11:37 am:
Nothing sounds better than when they Valve Bounce
Are you sure its valve bounce you have heard as personally I reckon it makes a car sound when it happens, do you maybe mean Rev limiter ?? Two totally different things though ..
In answer to your question I'm sure it could happen to the 1JZ but they seem to run some pretty good valve springs from the factory so it doesn't seem to be a problem & not sure why you mention an Auto as it doesn't make any difference if Auto or manual ..
Sunday, February 09, 2014 - 05:59 pm, by: Blake Gloyn(Blakenz)
in my opinion, you can't hear it, it just means you don't make as much power as you would expect in the upper revs. More common on a high km 1jz or perhaps one that has been cooked.
Sunday, February 09, 2014 - 06:31 pm, by: Robert Day(Lexsmaz)
I must admit I have never heard it on a turbo car, so not sure if the turbo's stop some of the reverberation noise, but what I have found on a NA car its not a case of making as much power as you expect, it just goes flat & drops off power too & will not rev past that point either, similar in that way to a rev limiter ..