Clearance check for Cams in a interference head

[T2 MSW]

Ive just bolted up the head on my 2JZ and realised I need to check the aftermarket higher lift Cams are non interferance, annoyingly they are interferance hence my question.

 

How to you check valve clearance and correctly shim the buckets as the valve will now meet the piston? Do you have to shim it all up with the head off the block and then install with everything aligned?

 

Cheers

[rider]

Fit the timing belt so the valves hit fully open midway between TDC and BDC? There are videos on shimming with 2 thou increment shims with the head on after the cams are removed then reinstalled and rechecked.

 

I was going to use as reference when I remove my cams later this month, obviously its using standard cams because no interference issues there with cam rotation Edited April 17, 2018 by rider (see edit history)

[T2 MSW]

Thanks for the input Rider, however thats no good to me as these are non standard cams and will 100% interfere, you cant check cam clearance with just the cam bolted in it needs to be rotated and with the likelihood they are going to have to be removed multiple times to get the shims right I dont want to build the front of the engine up each time.

 

I think in my case it needs to be done with the head off the engine, just looking for confirmation from someone with the experience of interference cams

 

For a stock engine you dont need to worry can rotate each cam and the crank independently without fear of cocking it up. just make sure all the marks line up when you put the belt back on.

[Suprakeith]

I had my aftermarket cams set while the head was off, I was told this is best way to shim aftermarket cams.

Hope that helps

[Tricky-Ricky]

If the cams are installed and timed correctly despite being interference there should be no issues with measuring and sorting the correct clearance shims of the non-loaded valves, just like you would with a non-interference cam.

[T2 MSW]

I had my aftermarket cams set while the head was off, I was told this is best way to shim aftermarket cams.

Hope that helps

 

Thanks for confirming, ill take the head back off

[T2 MSW]

If the cams are installed and timed correctly despite being interference there should be no issues with measuring and sorting the correct clearance shims of the non-loaded valves, just like you would with a non-interference cam.

 

Engine is being built back up, wasn't going to put all the front of the engine back on before doing cams so wont be timed as no belt on it.

[Chris Wilson]

Tappet clearance shimming and piston to valve contact are mutually exclusive. First check piston to valve clearance with very weak springs after shimming correctly on the bench, so you can push a valve down at various points before and after TDC and max valve opening with the head nipped down on an old gasket, and measure clearance with a DTI. Once you ascertain no piston pocketing is needed do a final head build with normal valve springs on the bench and bolt it on.