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914World.com _ The Paddock _ cam timing

Posted by: Charles Freeborn Apr 21 2021, 01:01 PM

Assembling my 2.0L / T4. with a fresh WebCam 86b with 106º lobe centers. Cam drive is straight cut gears with slotted holes for timing. Question for those of you who have done a set up with these parameters. Did you do the positive stop TDC with heads on or off, with a stop bolt or dial indicator? Through the plug hole with heads on? Because of the Lobe Center specs considering retarding 1º from cam card spec.
Thoughts?
Thx.

Posted by: Driver174 Apr 22 2021, 11:04 PM

The positive stop method works great, and there is no need for a dial indicator when determining TDC.

Once your degree wheel/pointer is set to indicate top dead center, you will need a dial indicator to measure valve lift. The heads have to be installed, and valve lash adjusted to measure valve lift.

Posted by: Krieger Apr 25 2021, 08:56 AM

I've done it both ways. I think the best way was heads off with a dial indicator. Once I found tdc with dial indicator I used a short, skinny metal ruler to scratch a tdc mark on the flywheel relative to the location of the engine stand next to flywheel. I would recheck tdc with the ruler when needed.

Posted by: Charles Freeborn Apr 25 2021, 10:17 AM

Tried both methods and built some tooling for TDC, etc. Postive stop as well as dial - both work fine. I got a degree wheel from Webcam so that's spot on.
However... there are some tricky bits. Webcam gives it's spec at .050" of lift at the valve not the lifter, so one really has to take the measurements with heads on, dial set up to read from top of valve retainer and everything parallel and square to the travel of the valve. Fiddly but do-able. I spent the better part of an entire day doing rocker geometry, cutting pushrods and setting timing.
Hopefully everything is correct and the rest of the assembly goes smoothly. This engine has been a task to say the least. Took some bad advice early on and am still paying for it now..

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