Mgrene Posted March 26, 2021 Share Posted March 26, 2021 So I’m in the process of installing my camshafts and I have reached the point where the manual says I have to rotate both cams leaving the forward pin up. Since cylinder 1 & 6 are top dead center, the valves will of course not allow me to rotate the camshafts far enough to get the pin facing up because the valves are hitting the pistons. why is the manual asking me to do it when it is not possible? What am I missing here? sure I could rotate the crank but the manual does not say anything about that and I really don’t want to because then my cambelt will most likely move out of its position on the cranksprocket. does it really matter to untighten and then tighten the camcaps again afterwards? bonus question: I’ve heard many talking about a 2JZ being a non interference engine. Then how come my valves are hitting the pistons? Or maybe I have misunderstood the actual meaning of non interference? Quote Link to comment Share on other sites More sharing options...
Mike2JZ Posted March 27, 2021 Share Posted March 27, 2021 What camshafts are you running? If you have high lift 10mm+ then its possible for valves to touch. In which case you need to dismiss the factory repair guide as thats intended for stock cams, different ball game with high lift aftermarket valves as the motor will no longer be non interference as it is from factory. For high lift cams the install procedure should follow like: a) Without cams installed, set crank to TDC, then retard by 30 degrees. this will allow all pistons to be below the top of the the deck so no chance of valves hitting on install. b) install exhaust cam as normal. c) when installing intake cam make sure the lobes pushing down on valves, arent the same as the lobes that are being pushed down as the exhaust cam. that way no valve to valve contact possible. once isntalled. rotate both exhaust and intake to tdc. d) move crank back to TDC, install belt and away you go Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 27, 2021 Author Share Posted March 27, 2021 4 hours ago, Mike2JZ said: What camshafts are you running? If you have high lift 10mm+ then its possible for valves to touch. In which case you need to dismiss the factory repair guide as thats intended for stock cams, different ball game with high lift aftermarket valves as the motor will no longer be non interference as it is from factory. For high lift cams the install procedure should follow like: a) Without cams installed, set crank to TDC, then retard by 30 degrees. this will allow all pistons to be below the top of the the deck so no chance of valves hitting on install. b) install exhaust cam as normal. c) when installing intake cam make sure the lobes pushing down on valves, arent the same as the lobes that are being pushed down as the exhaust cam. that way no valve to valve contact possible. once isntalled. rotate both exhaust and intake to tdc. d) move crank back to TDC, install belt and away you go Thanks Mike. I’m running HKS 264 cams and Brian Crower valves, springs and retainers. Quote Link to comment Share on other sites More sharing options...
Mgrene Posted March 27, 2021 Author Share Posted March 27, 2021 Final stupid question. when retarding the crank is it clockwise or counterclockwise? or maybe that doesn’t matter Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted March 27, 2021 Share Posted March 27, 2021 Anti clockwise Quote Link to comment Share on other sites More sharing options...
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