Instructions say 2-7mm piston extension from tensioner housing to contact point on lever arm (new belt) and not more than 9mm with used belt. A bit of a struggle to get an accurate reading, but I have ~ 7.5mm with a new Gates belt (a stack of feeler gauges and a vernier caliper). Have already drilled out the taper in the three mounting ears per Instructions (didn't bevel, but could yet) and offset the tensioner ***'y to get a lower extension measurement per Instructions. I am a heck of long way from the middle of 2-7mm. Engine is unmodified AFAIK.

Should I be sweaty about this and drill up some larger diameter and make some offset bushings?

I would appreciate any insights the Porken cohort has to offer about this.
Thanks for your time and effort. T

 

where are you measuring from?

IIRC it has to be the top of the body.

 

Hi Malcolm; yes, measuring from the top of the body, (not from inside the ***'y where the circlip is recessed internally into the casting) Thx/T

 

ok good.......how many times has the engine turned since belt install?

remember it has to go around twice to get back to TDC so 6 spins is 3 full rotations....then remeasure

 

(From hotel at SF11.)

Turning the engine by hand a couple of times is key as Malcolm indicated. When the belt is first put on, the extension will vary.

Sounds like you did it right, but to be sure, the measurement should be taken along the centerline of the T/D piston.

 

Kudos to Malcolm and P-Ken; I am still a bit sideways on this measurement.
As found, with stock tensioner, belt tension value between Left Cam and underside of water pump sheave was 107-108 Hz (Clavis tool)
Put new belt and WP on, set up tensioner - only applied ~ 13 N-m preload, (~10 lb-ft). Walked the engine through 2 revs, and checked tensioner piston lift clearance - this is about 7.5mm. Left car sit at TDC for 48 hours, checked belt tension value between Left Cam and underside of water pump sheave, got 102 Hz (good, I think, after settling for 48 hours). Measured tensioner piston lift clearance - this is about 7.6mm. Walked the engine through 2 revs, and checked belt tension value between Left Cam and underside of water pump sheave was 110-111 Hz (Clavis tool). Measured tensioner piston lift clearance - this is still about 7.6mm...Hmmm next steps? see pics; All Advice is appreciated. Best, Tim

 

The tension is good as long as there is no slack anywhere around the gears. The 2 through 7 mm measurement, with a new belt, assures that there will be sufficient piston length to accommodate a cold and hot engine, and a new and seasoned belt.

It appears to be sorted well enough to spin the engine with the starter. (Unplug the EZF or relay.) This will equalize the belt length around all the gears properly. Then measure with the caliper as directed in the PKT manual (make sure you have the most current version - http://porken.com).

 

Thanks P-Ken, and also to Malcolm for dialing me in.
Much appreciated.
Tim in Calgary