Significant Variation in Piston to Valve Clearance #1-I to #4-I
 

I measured my piston to valve clearance (assembled - post cam timing) this evening and came up with some odd #'s :confused:

Piston #1 Intake came in at ~ 1mm (1 full turn of the screw at closest P to V point, approx. 80 deg ATDC)
Piston #4 Intake came in at ~ 2.75mm (2.75 turns " " " ... , approx 88deg ATDC)

I was surprised to find a 1.75mm variation and now feel like I've done something wrong...

Background on the engine and what I've checked:

Followed the piston to valve clearance check process from Wayne's Engine Rebuild book to the T.

I'm rebuilding the engine, so I know that I have the same cylendar base gaskets on all 6. I also measured deck height for each cylinder - all came in pretty close / nothing out of the ordinary.

I rechecked my camshaft timing and things still look pretty tight side to side (4mm spec for GT2-102 timing):

-4.0mm left cam
-4.10mm right cam


Bottom line - I'm stumped - but should I be concerned?

As always, any and all input is appreciated.

Thanks, Gordo

The pistons should be half way down their stroke at 80 degrees after TDC. I don't see how you could have the pistons within 40mm of the valves at that point. The closest approach should be within 10 degrees of TDC.

-Andy

Thanks
 

Andy,

Thanks for the blinding flash of the obvious - sometimes I need that (no sarcasm intended, no kidding - thanks...).

No clue what I was doing/thinking last night. I rechecked tonight - all is good.