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sand_man sand_man is offline
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Join Date: Oct 2005
Location: Cooterville, Cackalacky
Posts: 6,778
backside valve adjustment - my thoughts

So I thought I'd give the "backside" method a shot.

For the record, I've adjusted more valves than someone who doesn't own a shop, ever should!!!! I have always used the traditional method of the feeler gauge (with the special holder) in between the rocker adjustment foot and the valve stem. Over the years, I have developed the infamous "feel" that many say is hard to get. I have to confess, one thing I've always hated about this method, is often times, I can't get the feeler inserted to check or double check. Even with the special feeler gauge holder, it can be awkward. Many times, I'll just break the adjustment loose, insert the feeler and tighten it back up until I can get that "magnetic drag" like feel. In other words, I'm sure I adjusted some valves that probably didn't need it, only because I struggled to get the feeler gauge in place. Once the adjustment was made and I pulled the feeler out, I never double checked it other than to wiggle the rocker and see if the "clicking" sounded right (checking by "feel")....still some possible guess work.

Fast forward to the "backside". What I like is that by using a .0025" gauge as your "go" and a .003" gauge as your "no go", you can easily check your existing adjustment and double check your work if a valve was in need of attention. Slipping the traditional sized feelers in between the cam lobe and rocker arm is pretty straight forward from above and below the engine. The gauge either goes in or it doesn't...none of this climbing around the engine compartment like a ******* Hindu circus contortionist with arthritic hands and fingers to get that special feeler gauge holder inserted!

I'm not really sure how much time this method saves, other than in my case, keeping me from adjusting valves that might not have needed it. Valve adjustments in a nut shell aren't much fun...especially on the driver's side!! It is what it is.

A few tips:
  • Keep the spark plugs in until the adjustment is complete (if you plan to replace them). The engine is actually very easy to turn over by squeezing the belt around the alternator pulley while turning the pulley nut. Removing the plugs BEFORE a valve adjustment can dislodge carbon that might affect your results.
  • I usually jack up one side of the car so that any oil in the lower valve cover of that side will run back into the engine case.
  • I adjust all the valves on that side and button it up BEFORE lowering the car, and moving on to the other side. This is done by rotating the engine 240 degrees each time you are ready to move on to a different cylinder's valves. Normally you would rotate the engine 120 degrees if you are working from side to side.
  • I use the silicone re-usable valve cover gaskets (reddish/orange in color). I can't tell you how many times I've had my covers off and still no leaks...they have more than paid for themselves!
  • I also [[[GULP]]] re-use my hardware at least three or four times before splurging on new stuff! I clean it up with some brake clean, blow it off with compressed air, and it's good to go. YMMV!
  • When working on the driver's side valves, I remove the lower tin that runs along side the engine compartment. To make this piece of tin easy to remove and install, I have just enough hardware securing it so that it doesn't rattle or fall off. If I need a bit more clearance for my forearms, I'll sometimes remove the engine compartment fuse panel cover...be sure to disconnect the battery, in case a wrench or some other tool hits one of the exposed fuses you won't roast anything. Keep in mind, my car has no smog equipment installed so it's a bit easier to reach things. I have found that removing the intercooler provides no additional clearance. YMMV.
  • When installing the valve covers, I think the biggest mistake people make is in over tightening the the nylocs!! It doesn't take much torque. SEND THE GORILLA BACK TO THE ZOO! The upper valve covers almost never leak, so I just snug the nuts and call it done. For the lowers, same thing...I get all the nuts just until they bottom out. Then I go around and snug them up with a short handled ratchet. The silicone gasket should just be barley squeezing out if at all. If one of the covers and/or nuts leaks, just a little bit more all the way around usually fixes it.
  • I've never tried it, but I've heard that valve covers that are slightly warped can be put right by running them over some sandpaper that has been affixed to a flat surface like a piece of glass.
I hope this helps...give it a shot for your next adjustment.

Traditional valve adjust:
http://www.pelicanparts.com/techarticles/911_valve_adjust/911_valve_adjust.htm
Backside method:
http://www.pelicanparts.com/techarticles/911_backside_valveadjust/911_backside_valveadjust.htm
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back in the saddle: '95 993 - just another black C2
*SOLD*: '87 930 GP White - heroin would have been a cheaper addiction...
"Ladies and Gentlemen, from Boston Massachusetts, we are Morphine, at your service..." - Mark Sandman (RIP)

Last edited by sand_man; 02-01-2008 at 12:07 PM..
Old 02-01-2008, 08:37 AM
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