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Discussion Starter · #1 ·
Ok, yes, i'm stupid and i have never seen valves like this. To adjust the clearance between the rocker and valve stem on normal cars, i would undo a nut and then adjust the clearance with a screwdiver inside that nut, then tighten nut. all good.

But on the Opel theres just one nut, and if its not tight, it gets undone and the rockers start flapping like crazy.

I have read some info about this before, but didn't quite understand it, says they should be adjusted with the car on? thanks to that info i now have a really greasy black engine bay, so that can't be right. Thanks for your help.
 

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Rocker arm nuts . . . self-locking

Sven said:
Ok, yes, i'm stupid and i have never seen valves like this. To adjust the clearance between the rocker and valve stem on normal cars, i would undo a nut and then adjust the clearance with a screwdiver inside that nut, then tighten nut. all good.

But on the Opel theres just one nut, and if its not tight, it gets undone and the rockers start flapping like crazy.

I have read some info about this before, but didn't quite understand it, says they should be adjusted with the car on? thanks to that info i now have a really greasy black engine bay, so that can't be right. Thanks for your help.
Stock rocker arm nuts are supposed to be "locking" type (they're pinched at the top, if you look closely). They DO lose that "locking" ability the more they're turned over time though. A new set of rocker arm nuts would fix your problem. :(
 

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Discussion Starter · #3 ·
tekenaar said:
Stock rocker arm nuts are supposed to be "locking" type (they're pinched at the top, if you look closely). They DO lose that "locking" ability the more they're turned over time though. A new set of rocker arm nuts would fix your problem. :(
Ah, great. this is the first thing i don't like on the Opels, everything is simple, everything that breaks on other cars, i can laugh at coz Opels have it nice and simple, it never breaks. When people see how junky my car looks like they think that everything is broken, when if fact its 30 years old and allways worked. "Sven, my exhaust is broken, where do you get yours fixed? say what? exhaust? thats for crappy cars only, Opels don't have exhausts (not mine anyway)

These self locking nuts are real stupid then, why are they self-locking when they can be normal and still work many years like the rest of the parts on Opels?

Thanks for letting me know, i guess i have to go get some nuts then.
 

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Sven,

I'm not sure what cars are normal in Croatia, but this style of adjustment is quite common in the US. Look at most any push rod engine(the infamous small block Chevy for example) and you'll find this arrangement.

BTW, a normal nut will NOT work for you as it will loosen. You must use some sort of locking arrangement, either the stock nuts, a set of poly locks or in a pinch you could likely 'double nut' it. You'd have to check for any clearance issues however...

-Travis
 

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Discussion Starter · #5 ·
double nut? ummm.. good idea, thanks.

I don't know whats common, i only worked on ladas, but in my book, normal is usually the simpler, better thing. (Opel style) And abnormal is something that is made different for no reason but to break sooner (Italian way)
 

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It is possible to just remove the original nut and put the ends of the nut flats into a vice and squeeze them a wee bit to "tighten" up the self-locking ability.
If you look carefully at the nuts you will see how this was done by the manufactuers in the first place. Only a wee squeeze is needed so be careful not to go too far!
 

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Discussion Starter · #8 ·
I guess the nuts never really lost their locking ability, and i found that out just now when i went through all the trouble of finding replacement nuts for them to tell me they are inch nuts.. :confused: why does a german car have imperial nuts???

bah.. whatver, doesen't matter because i don't need new ones anyway, this is the reason the rockers started flapping when i undid the nut... it wasn't the nut i was undoing, it was the whole thread its attached to.

what does one do in such a situation? i tryed double nutting the other side to hold it in place while i try to undo the nut.. but the double nuts just rotate together like they were one nut.. :confused:
 

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Old Opeler
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Sven, See the tapered ring above the coarse thread that goes into the head?
That locks the rocker stud in place. Clean the surface in the head and on the stud and wash them with petrol so they will be dry when you reassemble the stud into the head. Before doing that check that the small oil hole drilled through the stud is not blocked (oil for lubricating the rocker ball comes out through there).

Screw the stud back in without the rocker on it - just the stud, ball and nut.
Use anothe rrocker nut to double nut above the one that is already stuck on there. tighten the stud into place then unscrew the lower of the two nuts - this is the one that is stuck so screwing it down should loosen it and will be easier since it will just tighten the stud. When that nut moves a turn or so remove the top nut and see if the original nut will now undo.

With luck you will have locked the stud in place on the taper and unstuck the original nut. Now refit the rocker.

BTW the nuts are NOT inch nuts - they are metric (10mm X1.0mm pitch).
Also you do not need to run the motor to set the rocker clearances. They can be set hot or cold and while the motor is not running. Check "Setting Valve Clearances" or "adjusting valve lash" for the thread dealing with this very thing, using the Search feature.
 

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1. Engines fitted with conventional tappet barrels (all European cars {sic}) should have a rocker to valve stem gap of 0.012 inches. Engines fitted with hydraulic valve lifters (all cars sold in the USA {sic}) have zero 'gap' between the rocker and valve stem.

2. If the engine is in the course of re-assembly, and the cylinder head has just be {sic} refitted, tighten the nuts on the rocker pivot studs so that as the engine is turned, the rocker transmits progressively more movement to the valve. Do not tighten to the point where the rocker ceases to become slack at some point during the rotation of the engine.

3. With a cold engine, and with the conventional tappets {i.e. solid lifters} tighten the pivot nut down until a 0.012 feeler gauge can just move between the rocker and the top of the valve stem. (photo)

4. It is important that the gap is set when the tappet of the valve being adjusted is on the heel of the cam - that is on the opposite side to the peak on the lobe. This is achieved by carrying out the adjustments in the following order:

Valves numbering front to rear
Valves Fully Open - - - - Check and adjust
No. 8 - - - - - - - - - - - - - - - - - No. 1
No. 6 - - - - - - - - - - - - - - - - - No. 3
No. 4 - - - - - - - - - - - - - - - - - No. 5
No. 7 - - - - - - - - - - - - - - - - - No. 2
No. 1 - - - - - - - - - - - - - - - - - No. 8
No. 3 - - - - - - - - - - - - - - - - - No. 6
No. 5 - - - - - - - - - - - - - - - - - No. 4
No. 2 - - - - - - - - - - - - - - - - - No. 7

5. The importance of correct rocker/valve adjustment cannot be overstressed. If the gap is too large, the valves will not open fully and the engine 'breathing' will be constricted. If the gap is too small, the valves and pistons may damage each other, and the engine 'breathing' will deteriorate because during the engine cycle both inlet and exhaust valves will open for longer periods that {sic} intended. Both effects will reduce engine economy and power.

6. On engines fitted in cars sold in the USA, and which use hydraulic valve lifters instead of the conventional tappets, proceed as follows:

7. In the same adjustment order as listed in paragraph 4, screw the pivot nuts down until the rocker-valve stem gap diminishes to zero.

8. Undo the nut until a clearance exists and is detectable and then screw back down one full turn. The adjustment is now complete.

9. On the USA engines it makes no difference whether the engine is hot or cold during adjustment.
 

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Discussion Starter · #11 ·
unscrew the lower of the two nuts - this is the one that is stuck so screwing it down should loosen it and will be easier since it will just tighten the stud.
But i think the whole reason its stuck is because its screwed all the way down, so there is no way of screwing it even more, i tryed, if i did any harder, it would break the stud.. 3 out of 8 valves did this, and none of the 3 will undo, i cleaned and dryed head and studs, no luck.


@calvin: I know there should be a 0.012in /0.3mm gap between the rocker and valve stem, but there is no way of adjusting it when the nut is stuck in its lowest position, causing the valve to allways be open.. loosing power and burning my valves...
maybe its time to buy another engine, though i think this one is in pretty good condition.. if only it didn't have those self-locking parts which obviously don't work too well :(
 

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Discussion Starter · #13 ·
jerseyopel said:
I had the same problem but it was an easy fix.When I realized two nuts would not work, I used three. Also make sure your wrench only catches one nut at the top. Mine came right off this way.
tryed three nuts... they still all rotate together... i guess i'm left with heating it... Why does everything have to hapen to me?? :mad: :mad:
 

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Plenty of Nuts!

Sven,

If you have spare nuts and really need to save the stud get a sharp cold chisel ( or an Engineer friend with one!) and cut the nut parallel to the thread to split it and remove it. Even some delicate "bashing" on the flats and flange of the nut may expand it enough to loosen it so that it can be removed.

Failing that I guess you are going to have to find another old head with spare studs in it you can salvage.

BTW: unless the nut went down that far due to the stud unscrewing out of the head you need to put a washer between the nut and the rocker ball so it does not screw down too far again. But in that case something must be very worn to let the nut go down that far - so I think it must be because it was loose in the head.

If you cannot get another stud ( or three ) one of us will have to send you some by post - though heaven alone knows how long even such a small parcel would take to get from New Zealand to Croatia
 

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Ship time to Croatia . . .

GTJIM said:
Sven,

If you have . . . .

Failing that . . . .

BTW: unless the nut went down . . . .

If you cannot get another stud ( or three ) one of us will have to send you some by post - though heaven alone knows how long even such a small parcel would take to get from New Zealand to Croatia
Actually, other than being held up for a few days at the receiving end by the local "post lady", the electric fuel pump and filter (small package) I sent him from the States only took ~4 days to get to Zagreb, as I recall. :)
 

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Address

In that case PM me an address and I will send some rocker studs - I have just removed some to replace them with ARP Chevy V6 screw in studs .......
 

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GTJIM said:
In that case PM me an address and I will send some rocker studs - I have just removed some to replace them with ARP Chevy V6 screw in studs .......
Hopefully you found someone to drill them for oiling then? Opel rockers rely on the drilled passages in the stud for rocker arm and pivot ball oiling. Failure to do so will result in failure Jim!

Bob
 

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sven, try this if you haven't got the nut off yet:
1) put 2 nuts on the stem and lock it into a vice REALLY hard.
2) use a propane torch to heat the Opel-nut (not you! :D ).
3) every 10 secs try to turn it (little jerks).
4) if after 2 mins, turn off the torch and buy a nut splitter (handy item to have around).
Just one of my old tricks.
 

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Sven's address in Croatia . . . still good?

GTJIM said:
In that case PM me an address and I will send some rocker studs - I have just removed some to replace them with ARP Chevy V6 screw in studs .......
OK, here's what it was last September when I sent him the EFP:

Sven Franic
2. Cvjetno naselje 25
10000 Zagreb
Croatia

Probably need to send him rocker balls and nuts with the studs, as well.

Suggest you let him verify his address here before you send anything blindly. Sven . . . address still OK? :confused:
 

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Discussion Starter · #20 ·
Hi.. yea, i sent GTJIM a pm, same old adress. :)

but its only now that otto mentioned it, i remembered the balls were stuck in between the stud and nut :rolleyes: ehh..

@Old Hippie: i was going to take it to a mechanic to heat it for me, as i don't have a torch, but they won't like to do it.. though i just thought of something.. maybe using one of those flex electic metal saws i could carefully cut the nut without too much damage to the stud, and then.. since i now know for sure the nuts aren't in inches, get double nuts. (they probably thougt they were inch nuts because they are squeesed so when he put his ruller in, it didn't quite match 10mm.)
 
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