Backside Method Valve Adjustment
 

Hi, i studied the backside method of doing valves on my 1980 911sc. Not sure if reading the feeler gage right. Says i need a ordinary 2.5 and 3 thousandths feelers as a GO and NO-GO.Went to my local auto store to pick up a gauge and they never heard of such sizes or in other words it be as thick as cardboard. And the .0025 feeler would be thinner than paper.Is the decimal in rong spot? I have a nice 30$ GO-NO-GO gauge that starts from .004 to .027 with a .002 step ground on each blade. Well this work for backside. thx.

"2.5 and 3 thousandths" is .0025 and .003. Decimal point, tenths, hundredths, thousandths, ten-thousandths, etc. Sounds like thinner than paper is about right...after all, you're talking about a cam slapping a follower 6,000 times a minute.

Can i buy such a gauge that goes that low from a large outfit auto store?

Yes, I think I got mine from O'Reilly. If not there then Autozone or Advance Auto.

Having JUST gone through with Wayne (Oh Haha) on my 930, I think this is the way to go. One thing all those posts and articles don't tell you is that you HAVE to have the time EXACTLY on for your .0025 gauge to fit in there. If it isn't RIGHT ON, that .0025 WILL NOT FIT either. Just so you know.

We had to adjust the timing a bit to get the .0025 to fit. Once we did it was like everyone said. But if the marks lined up the .0025 wouldn't go either.

Also, cause it WAS our first time doing the backside valve adj, we double checked our work with the normal elephant method.

I picked up a feeler gauge from my local CarQuest.

Just use a .004 gauge and do it the way it was intended....If you grew up doing the old Chevy 235 straight sixes, owned a bunch and British cars and 50+ motorycles, it will be a walk in the park.......Did it the 1st time in 2 hrs...

hi ,again thx for the info. u guys gave me on this forum. I thank u much for your help. I did my first #1 piston rockers tonight after work using the backside method. At least i think i did it right. Just wanted to clear up one more thing. The normal .004 procedure of doing the values is same for backside starting at Z1 and then going threw the firing order,but just using the cam rocket end to adjust?.My adjustment for #1 piston is, i made the .0025 feeler just barely slide threw up and down against the cam and rocker arm and the .003 seems to not really go threw unless i really force on pushing it in but i'll probly bend the gauge. Does this sound about right on what iam doing? Taking my sweet time to do this or atleast by April 10/2007. thx.

are you happy enough with a plus or minus adjustment, rather than a right on adjustment? just do it the normal way and get good at it.

I agree. I am just a newbie with only two adjustments under my belt, but I found the traditional method more to my liking.

I also found it pretty easy to do the regular way. But I have alot of experience doing motorcycles.

I found the backside method easy & exact. It's no or no-go. The 'normal' method was just too fiddly. I mean, just how tight is "until you almost wreck the feeler when you pull it out" & similar instructions? After 3 attempts, I tried the backside way nailed it.

Ian

In my case I found the backside method to be innaccurate to which I have posted before. Still looking for someone with an engine open and a dial indicator handy to confirm this works. I got a .003 lash every time on the dial indicator.