Non-interference Engine - Toyota Nation Forum : Toyota Car and Truck Forums

supra saiyan · 05-24-2008, 09:57 PM

I have a question for the pros. I know that my 2JZ is a non-interference engine, the valves will never hit the pistons if the timing is ever off. But someone told me that the valves can still hit each other, meaning the intake and exhaust valves can run into each other if the timing was off.

I have the timing belt off and want to check cam clearance, just wondering if it's safe to turn the cams without worrying about the valves hitting each other.

Jeeves · 05-27-2008, 12:29 AM

I'm 90% sure that the valves and pistons will never touch. However, you'd have to be amazingly out of whack to have them both full open.

willtotheumm · 06-02-2008, 04:34 PM

yeah good point Jeeves... both valves open at the same time, something is wrong lol

supra saiyan · 06-03-2008, 03:07 AM

I guess I should have been more specific. The engine is out of the car and I'm doing cams and shimless buckets. I have the timing belt off, so there is no timing at all. I was wondering if I could turn the intake cam by hand when I start checking for clearance, and not have to worry about the intake valves hitting the exhaust valves on the other side. I will be doing one cam at a time so one would be stationary all the time and the other one will get at least one full turn, meaning that at one point the valves on both sides will be fully open.

Jeeves · 06-03-2008, 03:27 PM

Quote:

Originally Posted by supra saiyan

I guess I should have been more specific. The engine is out of the car and I'm doing cams and shimless buckets. I have the timing belt off, so there is no timing at all. I was wondering if I could turn the intake cam by hand when I start checking for clearance, and not have to worry about the intake valves hitting the exhaust valves on the other side. I will be doing one cam at a time so one would be stationary all the time and the other one will get at least one full turn, meaning that at one point the valves on both sides will be fully open.

Should not have a problem doing that at all. Though even if you collided, you'd know it fast, and it'd take work to actually do you some damage. 1 rpm is far safer than 1000 rpm.