Forum » Off Topic Discussion » Advice on finding data on cam phasing limits for an engine without dismantling the engine to physically looking

Advice on finding data on cam phasing limits for an engine without dismantling the engine to physically looking

Off Topic Discussion

If it's not really about tuning or wiring. Then it belongs in here.

Page 1

Hi, I am looking for information on a Nissan engine as to the limits of the intake cam phasing advance and retard settigns.

I have pretty much given up on finding the answer using a google search. How else might I obtain this data? I don't want to experiment on a off chance that it could allow valve to piston contact, which I think is unlikely but have not proof that it is impossible.

If it is an OEM application then I would say you should not be worried but if it is a custom (High Compression, or High Lift High Duration Cams) then you must check it physically. There is no way to really check. One easy way is to use what is called, check springs (very soft springs that replace the actual valve springs). Using a degree wheel on the crank, you can rotate the motor and push down on the valve spring and using a dial indicator you can check the p2v clearance. Its bit more complicated for valve to valve clearance and that should be checked with cylinder head off.

OP can you provide more background information on your question?

Thanks Tommy, in the end I googled lots of images till I found pics of the internal workings of the unit and then decided that the engineers who designed the system would have taken that into account and so pushed it to the physical limits (35 degrees advance in this case)

Raymond, I was looking for the info on how far I could safely advance the intake cam.

G'day Rob. If this is a variable cam timing system, and you're adjusting the cam timing via the ECU, the OEM system will almost certainly be designed to that at either extreme of travel, there wont be any interference. I've not seen an OEM setup that can be put into a situation where it will have an issue.

As Tommy said though, once you change up the cams, or pistons, you absolutely need to check things manually.

And more than that, if you do have interference, you need to physically modify the phaser to prevent the interference. While the ECU controls the cam position, it can go outside the commanded range under normal operation -- so there must be physical stop to prevent damage.