Pelican Parts Forums

Pelican Parts Forums (http://forums.pelicanparts.com/)
-   Porsche 911 Technical Forum (http://forums.pelicanparts.com/porsche-911-technical-forum/)
-   -   Checking Cam Timing with Engine In (http://forums.pelicanparts.com/porsche-911-technical-forum/1071779-checking-cam-timing-engine.html)

boyt911sc 09-01-2020 10:40 AM

Follow these instructions (yelcab’s).......
 
Quote:

Originally Posted by yelcab1 (Post 11009820)
Oh man, that thing looks totally non-stock. Turbo and all. Since you are going through the trouble, check both sides.

Bring it to top dead center number 1. See if there is any valve slop on the rocker arm.
Install your dial indicator, and zero it.
Turn it 360 degrees, read the over lap.

Then, bring it to number 4 TDC (technically, you are already there from the last step), check for rocker slop.
Move the dial indicator over to bank 2, zero it
Turn the engine 360 degrees, read the overlap.



To OP,

A version of the above instruction:

If you have two (2) sets of dial indicators, it would be much easier. Set it @TDC @Z1, for cylinder #1 and turn the crankshaft 360°. Read the dial indicator. You are done now for cylinder #1.

Move the dial indicator to cylinder #4: Reset to zero and turn the crankshaft another 360° (back again to TDC @Z1). Read the dial indicator.

Repeat again and get an average.

You are not alone. Even the experienced individual commits same mistake/s.

Tony

RogueEngineer 09-01-2020 12:42 PM

Update:

Took timing cover off the right side along with upper valve covers.

Both banks were definitely timed the exact same.

I moved the crank to TDC on cylinder 1, with the intention of then loosening the right bank's cam bolt and rotating the crank 360 degrees. While the #4 intake valve was closed, I set up my indicator to measure lift.

I loosened all the valve adjuster nuts to max - rotated 360 degrees, pinned the cam adjuster/quarter tightened the cam bolt, and remeasured the timing. It was still in spec at ~1.6mm.

Adjusted valves and buttoned everything up.

Car started immediately! It also cranks much, much faster now that starter isn't trying to push through 2 cylinders in their compression cycle.

Thank you for everyone's help!

- Ian

yelcab1 09-01-2020 01:12 PM

Imagine no bent valves !!!

yelcab1 09-01-2020 01:13 PM

Quote:

Originally Posted by boyt911sc (Post 11009873)
To OP,

A version of the above instruction:

If you have two (2) sets of dial indicators, ,,,,

Only the most die-hard of enthusiastic DIYers would have ... two sets of indicators and 2 z-blocks.

911obgyn 09-01-2020 02:02 PM

Whew, nice conclusion!

Eagledriver 09-01-2020 05:51 PM

Quote:

Originally Posted by JSV798 (Post 11008491)
Wouldn't valves hit pistons if it's that far out? But the ignition timing could be 180 degrees out.

No. Cam 180 out is crank 360 out. Perfect timing except both sides are trying to fire at the same time.

boyt911sc 09-01-2020 07:29 PM

Stomski tools.........
 
Quote:

Originally Posted by yelcab1 (Post 11010175)
Only the most die-hard of enthusiastic DIYers would have ... two sets of indicators and 2 z-blocks.



Yel,

There are no z-blocks in my tool box anymore. A switch has been made some years ago to these:

http://forums.pelicanparts.com/uploa...1599010860.jpg

http://forums.pelicanparts.com/uploa...1599010860.jpg

http://forums.pelicanparts.com/uploa...1599010860.jpg

You don’t need these fancy tools to do a good job for your engine rebuild projects. I’ve been using home-made tools from Home Depot, Lowe’s, and Harbor Freight rebuilding more than a dozen engines before owning my first Stomski tool.

You would think that these tools are expensive and extravagant to possess but wait till you use them. Your perception would change. I am cheap and frugal and only bought the wrenches I needed to do the job from HF.

Then one day, I decided to replace my home-made PVC cylinder hold down gadget with Stomski SR-007 and continued adding more. There is no substitute for good quality tools.

Tony

yelcab1 09-02-2020 06:31 AM

Like I said, only the die-hards have those tools. I do cam timing on Ferraris and Porsches all the time and I don't have those high end tools. I finally bought some digital calipers and dial indicators because of the "zero" features. The math was too hard on analog scales. I also bought a fully articulating mounting arm with a single tightener and it really was a game changer.

Still, I can't see myself with that Stormsky set up. Maybe if I do a 911 once a week...

I do have 12 torque wrenches....

47silver 09-02-2020 05:58 PM

great that you found the problem
those stomski's are nice i have the exhaust stud tool but have not splurged on the others

yet.


All times are GMT -8. The time now is 04:43 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website


DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.