backside valve adjust method - am i doing this wrong

[monkeyodeath]

I'm doing my first 911 valve adjustment and I figured I'd try the 'backside method' as it seemed more foolproof.

I'm having a lot of trouble, though, feeding the feeler gauges into the cam/rocker arm gap.

Some of the valves are easier, but others are a giant pain in the butt to locate the gap.

Am I missing some kind of trick? Getting sick of constantly having to go from the bottom of the engine to the top...

[Bill Jennings]

If you remove the engine tin from both sides it makes the access really easy!

Cheers
Bill

[gtc]

Originally Posted by monkeyodeath

Getting sick of constantly having to go from the bottom of the engine to the top...

Ha, yep, that's why i quickly gave up on the backside method.

[john walker's workshop]

Yup.

[cabmandone]

When I do mine, I lightly loosen the locking nut and then slide the .0025 feeler in then tighten the valve while it also turns the nut to tighten it. Once I've got very slight drag on the feeler, I remove and reinstall it if it still goes, I finish tightening the lock nut and once more slide the go feeler in. Then try to slide the no go. It doesn't take me that long to do my valves using the backside method.

[Canada Kev]

I think the point of the backside method is that it's easier to get the feeler in without having to loosen the nut. If you do loosen the nut, you might as well just use the regular old .004 gauge. I suppose if you can't get the .0025 in, you need to adjust anyway, as its too tight.

I just use the BS method just as an easy check of my adjustment or to see if that valve even needs to be adjusted, or on cylinders that are difficult to get to using the normal way. I often have difficulty getting the .004 gauge in under the foot without loosening the nut, so I check the BS first to see if I need to adjust.

I've found that the biggest time soak with adjusting valves and the BS method is the crawl under the car to adjust the valve and then crawl out to check with the gauge up top and then crawl back down to adjust again, etc... If you had two people, it'd be a snap.

[monkeyodeath]

Finally finished this.

Taking the tins off either side helped immensely. I had the cat off for other reasons, which helped a lot as well, but that's lots of extra work.

I think this method is a great way of checking the valves initially to see which ones need adjustment, but not so sure I'd use it again to adjust each valve. In some cases, it was pretty easy to adjust the screw and insert the feeler gauge at the same time. Others required lots of laying down, then standing, then laying down.

Being more familiar with shim-over-bucket valve systems, this definitely was a bit of a learning curve for me. Hoping I did ok.

[T77911S]

i have my engine out and did the valves. did them both ways. even with the engine out the backside is a pain in the A$$.

[david.avrahami@]

How do you remove the tin plates? how many bolts on each side? and where are they located?

[88911coupe]

same question here as David asked...IIRC removing the tin plates would require a LOT of other things to be removed. Maybe I'm wrong. I can see how it would make the backside method a lot easier. I like the method but the constant back and forth (top/bottom) was getting to me.

[OsoMoore]

Originally Posted by 88911coupe

same question here as David asked...IIRC removing the tin plates would require a LOT of other things to be removed. Maybe I'm wrong. I can see how it would make the backside method a lot easier. I like the method but the constant back and forth (top/bottom) was getting to me.

Backside worked great for me when the engine was out of the car. In the car, I think I'll stick with the normal method. I already have to take off the CAT, and the more things that have to come off the more time it sucks up.

[monkeyodeath]

The engine tins aren't actually terribly hard to remove. There are 3 small 10mm bolts in a row that hold the tin to the cam carrier itself, between the valve covers. You can access those from the bottom.

Then there are 2 bolts at each end of the tin. The 2 on the forward end of the tin are accessible from the bottom and screw into the big piece of tin that sits in between the engine and the rest of the car.

The 2 in the back are accessible from the top, and they screw into the rear engine tin, in the corner of the engine compartment. It's a pretty tight squeeze from the top -- you'll probably want some extensions/wobble joints.

The driver's side tin has the O2 sensor wire passthrough -- easy to just disconnect the sensor and pop the rubber bung out of the tin.

Before you take them off, note how the tins are installed. The end of the tin that faces towards the back of the car sits on top of the rear engine tin and bolts into it. Also, make sure that the rubber skirt sits on top of the tin when you reinstall it.

So, you really don't have to remove anything, other than disconnecting the O2 sensor. It's definitely a bit more work, but it did give me the chance to clean off all of the grime and old oil that had collected on the tin below the oil filter. Also gives you much better access to the whole area.