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914World.com _ 914World Garage _ Doing valve clearance adjustment...

Posted by: 914zim Feb 3 2006, 11:26 PM

Hey guys:

I wanted to check the clearances before I even started loosening things up and I'm finding they are way too tight (assuming I'm doing it right).

My 1976 914 only has about 76K miles on it and I'm not sure when the last valve clearance adjustment was done (if ever) and I've never done this procedure before.
I'm using the Cap'n's adjustment procedure and I'm looking at the chart that's provided.

Here's the issue... I can't measure any more than .006" on ANY valve! Most of them are between .002" and .005". I can't even get ANY size gauge on 2 of the valves!
What am I missing here? It was a little difficult to get the "rocking" part figured out, but I think you're supposed to measure when the opposing valve is at it's very lowest point. I this correct?

Is it possible that my valves clearances could really be this tight, or am I missing something major here? I was expecting them to be way loose if anything.

Thanks in advance for any help or suggestions from the experts on this.

Andy...

Posted by: alpha434 Feb 3 2006, 11:57 PM

You need to adjust the valves every 3000 miles. I do mine every 1500. .006 on the intake .008 on exhaust. Otherwise they sink in from the constant hammering. My car was worse than yours when I bought it.

Posted by: Twystd1 Feb 4 2006, 01:40 AM

On a stock engine.

I use 6 thou intake and 6 thou exhaust.

The old 6 & 8 setup was wrong in many manuals in my opinion.

I think the Crusty one will come along and set us all straight.

Thats my .02 worth

Twystd1

Posted by: alpha434 Feb 4 2006, 01:45 AM

Porsche maintenence manual said 6 and 8. But the local porsche master said 6 and 6 would be fine as long as you actually keep up with adjustments. I just did mine the day before yesterday... 6 and 6. But I also do an adjustment every 1500miles

Posted by: GBallantine Feb 4 2006, 07:30 AM

Anyone know what the recommended valve lash is on a race motor with chromoly valves?

Posted by: DNHunt Feb 4 2006, 08:31 AM

Andy

If you are not sure use the top dead center method to check your settings. Better yet offer some beer to someone who's done it before to look over your shoulder. I suppose because I get kind of anal I would double check. Remember you want the lifter on the base circle of the cam when you check valve lash. Crusty's method relies on a couple of things. 1) 2 lifters on opposite sides of the enginge share the same cam lobe and 2) when one of those lifters is on the nose the other is on the base circle. So, if one valve is fully open the other is fully closed and can be adjusted. Once you get this method down it's easy and fast cause you never have to get out from under the car. My problem is I always get confused this way so I usually use http://www.pelicanparts.com/techarticles/914_valve_adjust/914_valve_adjust.htm. Somehow it just seems easier to remember. On a best case senerio you just got things screwed up with the position of the cam when you checked them and you just need to readjust (I suspect). Worst case, valve seats are dropping (I doubt). Anyway, get it checked out.

GBallantine

Do you really mean chromoly valves? I suspect you mean chromoly pushrods, in which case, the lash is 0.0. I like the rocker to just be able to move laterally on the rocker shaft with no feeling of lash. Much easier than messing with a feeler gauge.

Dave

Posted by: redshift Feb 4 2006, 08:44 AM

When a rocker is all the way in, adjust other side.

When it's pushed all the way in... when it's more inside than out... when it looks least like the position of the other rockers..

You need a sketch?

M

Posted by: bd1308 Feb 4 2006, 08:47 AM

guys, dont F him up.

if you have a 2.0, i dont care where you're from or HOW often you check the valves, its .008 for exhaust and .006 for intake...

for a 1.7/1.8, its all .006.

the Milesean method is muy besser, sehr gut.

b

Posted by: Jake Raby Feb 4 2006, 09:40 AM

VALVES DO NOT HAVE TO BE ADJUSTED EVERY 3,000 MILES!!!!!

I recommend every 6,000 that the valves should be checked... If the valves are tight its ONLY because of one reason and thats the fact theat the engine is running "over temp" and things are expanding and contracting too much.

It has been 3 years since a single valve needed adjusting in my 912E engine... I have checked them when I think about it, but have not needed to adjust a single one after 94,000 miles! The key is monitoring head temps and if the gauge goes over 400, then check the valves because they will be *tight*.

If your valves are tight, save the time of constantly adjusting them and spend it on finding and solving the problem thats the root of the tight valves- else you WILL be VERY sorry when something goes "BOOM" out of the blue one day while the car is running perfectly fine.

Buy a CHT gauge and live by it.

Posted by: Cap'n Krusty Feb 4 2006, 10:23 AM

QUOTE (Twystd1 @ Feb 3 2006, 11:40 PM)
On a stock engine.

I use 6 thou intake and 6 thou exhaust.

The old 6 & 8 setup was wrong in many manuals in my opinion.

I think the Crusty one will come along and set us all straight.

Thats my .02 worth

Twystd1

.006"/.006" on engines with conventional steel valves, .006"/.008" on engines with sodium filled exhaust valves, which stock 2 liter engines have. The Cap'n

Posted by: 914zim Feb 4 2006, 03:26 PM

Guys:

I appreciate the help.

From what I'm reading, it is NOT unusual for the clearances to be this tight due to 2 things. 1) wearing over time "sinking in".
2) running over temp.

The temp gauge on my car is not working. This is on my list of things to address. Since it is the winter season here in Wisconsin, I'm not driving the car now and adjusting the valves seemed like the thing to do while it was put away for the winter, especially since I don't know when/if it was ever done. I haven't driven the 914 since October last year, so it's stone cold.

I'm just worried that I'll f*** things up worse than they may already be if I don't do it right and drop a valve because I did it wrong. At this point, I have not lossened anything up. I'm trying to take measurements before I even start, to see where I'm at.

I'll take another look at the PP tech article and maybe get my a** out in the garage again, even though it's freezing out there!

Thanks again. Any additonal comments would be great.
Andy...

Posted by: Jake Raby Feb 4 2006, 03:34 PM

The stock temp gauge in your car is oil temp and its pretty worthless...

Install a CYLINDER HEAD TEMP GAUGE and live by it. It is entirely possible to fry your heads and still have cool oil.

Hot heads KILL, hot oil is very forgiving as long as you have pressure..

Posted by: 914zim Feb 4 2006, 05:56 PM

Thanks Jake.
I'll do a search, but can you make any recommendations on a CHT?

Andy...

Posted by: Joe Ricard Feb 4 2006, 07:07 PM

I just bought a dual Westach CHT gauge. rocking nana.gif
the unit CB performance is a decent one and works well enough.

Posted by: Dave_Darling Feb 4 2006, 08:37 PM

Just a quick question--

You realize that by "opposite valve", it means the same valve on the other side of the engine? I.e., when the exhaust valve on the left-front cylinder is open, you adjust the exhaust valve on the right-front cylinder?

...Just makin' sure.

If your valves are too loose, you'll hear one hell of a racket when you start the engine up. You may wind up "pounding" the parts, too, and doing some damage if you run it that way much. If the valves are too tight, they won't cool properly and you risk burning them, particularly the exhaust valves. Plus you'll leak out some compression and lose a little bit of power.

Maintenance schedule for valve adjustments is every 6,000 miles--every other oil change.

--DD

Posted by: Twystd1 Feb 4 2006, 08:47 PM

As always... The Crusty one sets me straight...

Thanks...

Twystd1

Posted by: Travis Neff Feb 4 2006, 09:14 PM

Hydraulic cam and lifters??

Posted by: 914zim Feb 6 2006, 12:43 PM

Thanks again guys... DD, yes I understand... I am using the PP tech article and also have a Haynes as references.

I'm concerned enough that I'll f*ck something up and make things worse, that I'm considering skipping the adjustment altogether and putting the covers back on.
I don't have any "lifter noise" and it seems to be runnng fine.
I just thought I'd do an adjustment since it's stored for the winter and it probably hasn't been done in quite some time (if at all).

Or, maybe I'll take the plugs out and give it another look. If I can turn the wheel easier, maybe I'll feel better about adjusting when doing the whole "rocking" thing.

The oil temperature gauge is not working and it does seem to run a bit hot, but I have nothing to compare it too. I probably should spend the time putting in the CHT like Jake recommended and see where I'm at with temperature first.

If I understand it correctly, if the valves are tight, this will cause it to run too hot. Is this correct?

Sorry guys, I guess I'm just trying to convince myself to JUST DO IT!!

Thanks agian for all the comments, suggestions and help.

Andy

Posted by: ChrisNPDrider Feb 6 2006, 01:07 PM

Put on long underwear, your wool hat, and JUST DO IT!

Nothin is more satisfying in my book than getting the maintenance tasks wired - a little preventative checking can go a long way!

Posted by: dmenche914 Feb 6 2006, 03:37 PM

If your valves are that tight, and they ain't hydrolic lifters, you NEED to make them right at .006" Do not leave them as is. keep in mind if you are having trouble with adjustment, that you must be at or close to TDC when the valve measurement is taken. when making adjustment, the cam is set to give the biggest gap of the valve to rocker (at TDC) to check that you are not missing the correct TDC, turn the engine a bit, and assure the valves tighten up as you turn away from TDC, if the valves start to have MORE gap , then you were not at TDC the first time.

Valve adjustment is set at maximum valve gap (lash) if you can create a bigger gap by rotating the cam, then your initial timing marks was not correct.

Vavles too tight will result in a short engine life, no doubt about it.