Lessons learned from my first valve adjustment
 

Just thought I would share some pointers...I did my first valve adjustment on my 83SC (with 77 CIS 3.0 engine) while I had the engine partially dropped for an internal thermostat replacement. I thought this would make the job much easier (and yes it does). Luckily I had read the 'backside adjustment method' technical article on this site which saved my life.

1. I can't image doing it the conventional way (as described in Bentley and Waynes 101 book) where you measure the gap between the valve stem and the rocker arm foot. Even having the luxury of looking straight at the piston as I did, I could not get the feeler guage in the gap without significant trial and error and effort. I would say it would be impossible if you couldn't look at it straight on. The only way would be to back way off on the adjustment screw, put the gauge in, then tighten down. Which means that if the gap was correct to begin with, you just did a lot of work for nothing. Once you take the guage out, you can't really double check the gap easily the second go-round.

2. Getting the right feel of how tight the gauge is in is also very tough the conventional way. Again, it would be an order of magnitude harder if you couldn't see what you were doing, without dropping the engine.

3. The net is, if you do it the conventional way with the engine in the car, I think there is a high probability you will end up with a worse adjustment than you started with after a lot of effort.

4. That's why I'm surprised I haven't seen more people talk about the backside method. This was in my opinion at least an order of magnitude easier and also the go/no go guage insertion method takes away the guessing game of whether you have the right adjustment. I would highly recommend doing a partial drop (easy to do) and using the backside method.

I just checked out this back-side article and this seems like such an easier way of doing it. I have probably adjusted the valves on my 72 at least 10 times and what a pain in the ass it is doing it the conventional way.
Thanks

I tried the backside method the other day on my 2.7. I was meaning to update the site here but forgot about it until now. I'm still out on this one, being that with the engine in and all tin around one has to go from top to bottom (and vise-versa) repeatedly when a valve is found needing adjusting.

I'm thinking use this as a good check, but if a valve is found to need adjustment, use the old standard on that one. . . then go back and do the go/nogo for a final.

Partial engine drop and go no go are the only way to go. That's the only way to do it and how all my valve adjustments are done.

Never dropped engine down after 35 years of adjusting valves you get used to it. C2 and turbo models are the worst. Standard 911 models with a/c air pumps etc.. Is a 3 and a half hour labor operation and engine must be at room temperature it is a feel thing the more you do the easier it is. Practice practice practice regards tom

If I was running a shop, I'd do it the conventional way. I'm sure it's faster *if* you've done a bunch.

Being my own mechanic, I use the back side method. I willingly trade my time to assure I'm being accurate. I only adjust the valves once every decade or so.

Get one of these things and make your life easer.
http://forums.pelicanparts.com/uploa...1276206533.jpg
Quick, easy, cheap.

Ok, what the hell is that?
So, in order to this back side method on say a 72 without ac, one has to drop the motor some?

no motor drop on ANY 911 valve adjustment!!! Might have to take things out of your way but don't have to drop the engine, who told you that?

Gap Adjustment Screw Tug
 

No matter what method, tool, etc. you use, the final check is always a "tug" on the adjustment screw to feel the gap. If it don't feel right you'll do it again even if the gauge went in tight.

A good way to learn the feel is before you start your adjustments, rotate the engine to each valve and "tug" each one, some are looser, some are tighter. They all might be wrong depending on how they were last adjusted.

Then using your gauge adjust a single valve to where you think it should be, compare it by using the "tug" to the other valves. You will probably be amazed at how a good sensitive tug can help get you a better gap.

Since I have learned to do the tug its all I do, so put the gauge away and get in the garage and tug one out today!

I guess if you aren't good at tugging a gap you could use the backside!:rolleyes:


Shane

I need one of those dealie-bobber gizmos that James pictured. Where do I get it, and then...of course.. what do I do with it?

I would guess that homemade tool is to visually aid you when you turn the screw i.e. a quarter turn, and help you keep the screw in the same position when you counter turn/tighten the corresponding bolt. But not necessary IMO.

The one thing that caused me problems over the years is when the oil is at room temperature it is difficult to properly feel the gap. A thick film of oil on the feeler gage, in the elephant foot, and in the rocker shaft all added up to noisy lifters when the motor was warmed up. I even tried using a dial indicator.

The last time I adjusted my valves I did so when the motor was still somewhat warm. I waited until I could touch the motor without discomfort. When I used the feeler gauge I could easily feel when the gap was correct. An guess what, quiet valves!

I know the book says adjust when cold. But when using 20-50w oil I could never get it right when adjusting cold.

I'd like to hear more about just what a "tug" is. I don't think that is in my Bentley or 101 Projects. ;)

Our host has these. I use it as a check for the conventional method.

http://forums.pelicanparts.com/uploa...1276217963.jpg

That screwdriver looks cool...I found a demo on how to use it on youtube.

YouTube - VAS Video

The screwdriver pictured takes into account thread spacing, so if you close the screw all the way in, you then back it out using the arms as a measure (I think it is 30 degs) it will back the screw out exactly .004".

You could easily make your own with a small bit, some nails and a donor stubby flat tip.

You still have to tug the screw to check it. SmileWavy

Milt, It is good to have you back. :)

Shane

I have some thing for you to tug!!!(badda-bing). I got this thing off rennlist, not sure but do a search for it. Around $15.00

Read above where a few state that a partial drop is required for the back side method?

Congratulations !
I think perfroming the valve adjustment helps bond a relationship with the car.

I just performed my first valve adjustment with my brother the other week using the traditional method.

Took us about an hour after the covers were off. It was probably his 200th time he did a valve adjustment so he had no problem with the "feel" getting the feeler gauge in to verify the gap.

Much easier then the job he did on a co-workers 964 the day before.

One exhaust was a hair loose and #4 & 6 intake were just a little tight, could have been a false reading but we readjusted just to be sure.

Back-dated heat, no AC and SSI's help create lots of working room.

Having recently done this trial by fire myself (on my 85), I want to be much more confident of it's outcome the next time. James, on a factory setup can you get this gizmo in and can you see the pointers on most (or all) of the valves? And do you check with a feeler guage after? My experience was, that I had to back off the valve, insert the feeler, tighten the screw, move the feeler around (while hoping to feel that vague tugging feeling) ....then while holding the feeler in place and holding the screw, tighten the locknut. Of course the feeler would drop out or the screw would turn slightly setting up the next attempt. I can't imagine, given the space and the visibility, trying to push the feeler in without backing off the adjuster.... you (I) can only actually SEE a couple of places where the feeler needs to go. To use this gizmo, do have to drop the exhaust or anything else? I'm definitely looking for a better solution compared to my last experience, Thanks.

No need to do a partial drop. Removing the side tins does help though. Keeps you from crawling out from under the car constantly.

i did mine in the dirt, no jack and raining. not fun but only had to removed the valve covers. Totally doable. but jacked up would be the way to go. Depends on your ability and your experience.

Just a warning to the guy who adjusts his valves with a warm engine. Your valves will be too tight. That's why your valve train is so quiet now. You risk burning an exhaust valve if your clearance is too tight.

-Andy

I'd have to agree here. You'd be surprised at how much difference you'll see in metal expansion between even 75F and 105F (not too uncomfortable to the touch).

But then. . . .what about guys in Pheonix where the ambient temp is like 120 anyway LOL

I've a question. . . being that we can't really get a conventional torque wrench on the lockers, how tight should we get these? . . . one grunt, . . two. . . or just a 'hmm'.

I've often wondered about getting these too tight.

Something else I'm wondering about: If you adjust the valves cold to .004 so when they heat up to around normal operating temp (160-220) valve lash is around 0.0, why not just adjust when all warmed up to 0.0? In other words, screw down the foot to the cam and lock it in, move to the next set and so on. Should be done before the car cools off. And when it does cool off, it should be .004

One thing always seems to happen when I read these threads on Pelican. There are always guys who seem to think that they know more than both the engineers who designed the car, and the factory techs who wrote the manuals.

Two things to keep in mind.

A) The engine must be at normal temp for adjustment because of METALLURGY. Adjusting at temp, you are chasing your tale, so to speak. Engines are designed to be assembled and set up at room temp. Therefore, ADJUST them at room temp.

B) No freaking competent auto manufacturer EVER designed an car for which the valves couldn't best be adjusted while the engine wasn't fully in the freaking car!

Reading threads like this, I need a month away from public web boards again.

Are you saying that the valve clearance is less as the motor warms up?
If so, when adjusted warm, they would be too loose when hot. Because they already had smaller clearances when hot and I would be opening them up to .004".
Right? Or is it the other way around?

If there tight when cold, they will be tighter when hot. (cold means room temp. 15C,59F hot means engine operating temp.) if that helps.

Screenwriter-x, what was your name on here prior to being banned?

Holy crow James.....how big are you? I had my car on jack stands at a reasonable height, and still it wasn't wonderful. I have to see some of you guys in action doing this task. All BS aside, I guess you would recommend the "gizmo". I guess I should get one. Thanks

I work on aircraft, these things are roomy and spacey!!

I believe we may all stand corrected here.

If Track is adjusting them to .004 when warm (when they technically should be tighter), then when cold the worst case would be a wider gap.

Laws of physics applied would dictate that they would be looser at hot then, not tighter. Unfortunately, I never studied law. :rolleyes:

Radials much?

I have adjusted the valves in my 72 in the dirt numerous times and it's really pretty easy once you get the hang of it. But adjusting the valve with the engine warm, huh?

Oh I see, so you've been genetically selected for your "universal type" elbows, wrists,and knuckles..... and your eyeballs that see around corners.....cool! LOL

lean on rocker before 1st trying to insert feeler so it's as open as can be

Perfected my "remote hands" working on F-4 phantoms, not much room in there to see let enough put on 1/4" lock nuts and then safety wire everything!! Radials are a piece of cake!

Yeah, yeah. . . but they're SO much cooler. . . we have the remains of an old Liberator up on on of our mtns. Most of one of the 1830's is still intact. I'd love to bring that home!

Better yet, find me a 3350. BTW. . tale is Lufthansa will have the only airworthy L-1649 in a few more months. How cool is that!

done mine both standard and backside method, if you want to make the backside even easier take out your engine tin (did it while i was touching up then tin) and was great, and like James said lots of room .............

and speedy go back to the PRIVATE board if the public offends you