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Discussion Starter · #1 ·
I have an engine thats been rebuilt in 95' driven seldomly for two years, and then deserted up until now.. it has apsolutely no leaks, runs great, i've changed the oil, and was hoping for a nice new engine, but now i find the exhaust fumes are a little excessive, and blueish... after sitting for 5 years, i am expecting the water pump to go pretty soon, but would it be expected, the valve seals have gone hard from sitting too long?

Those shouldn't be expensive, (i think), but is it necesary to take the cyl head off to change them? i'd like to do this myself.

Thanks! :)
 

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Old Opeler
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Possible!

The seals CAN be changed without removing the head. First the cylinder you are working on is brought to Top Dead Centre on the compression stroke so the piston is right up at the top of the bore and both valves are closed.
Now connect an air compressor up to the spark plug hole ( by making an adaptor from the body of an old spark plug and an air line connection )

OR you can use a hand operated tyre pump with a similar adaptor made from the body of a spark plug and a tyre air inlet fitting.

OR you can use the age old "English" method of filling the combustion chamber with string by stuffing it in through the spark plug hole - yes the string you tie up packages with, preferably the white stuff without too many "hairs" on it so it is easy to pull back out again ( leave one end hanging out of the spark plug hole!!).

This is all to stop the valves "falling" down into the cylinder when you remove the valve retainers and springs. The removal is done with a specially made lever that is hooked to the head on one side and has a small hole that is positioned over the valve cap retainer area so when you push down on the outer end of the lever the valve spring is compressed so that the valve stem comes up through the hole and the retainers can be removed.

Have a look at some older "Do it Yourself" car manuals - especially those printed in England fifty years ago as they usually explain this method.

HTH!
 

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Discussion Starter · #3 ·
great... now i only have to overcome the fear of taking the roker studs off, you know my bad experience, you sent me your set because i couldn't get the self locking nuts off.. wouldn't want to go through that again. :eek:

anyway, this is the tool i found in an old 70's english book... but i am guessing thats not it, since the head has to be off for this...

thanks for the info! ;)
 

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Old Opeler
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Not the Tool!

That is a Sykes-Pickuvant valve spring compressor - you need an older book!

The talk of rocker studs joggs my memory - the tool I am speaking of is simply a flat bar of steel with a hole in one end that goes over the rocker stud and the nut is put back on to anchor it. The bar sticks out over the valve side of the head with another hole above the valve. Simply pulling down on the long end then compresses the spring - I'll do a drawing ....
 

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Opeler
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compressed air is grate if you have good valve setting if you brake the seal your screwed,, I would use rope instead of string.. and a socket on the crank to hold the pressure.. I have used this method many time for checking valve guide clearances, and seals.
 

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Make Sure ..

Sven, Make sure that the hole that goes on to the rocker stud is big enough to allow the bar to swivel - make it too tight and the stud could get bent ......OK?
 

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Hello..
I was planning to change the seals.
I changed a sparkplug into an adapter so i can put some compressed air on the cilinder.
I set the enigine on firing at cilinder #1 (the one nearest to the radiator), ball on flywheel marks pointer, valves are closed (rockers can be moved slightly), and rotor is pointing indeed to the #1 sparkplugcable.
So everything is set up well...i guess.
Now i tried to put some pressure on the cilinder ( a Bar or 2, 30 PSI).
But when i put the compressor off, i hear hiss and the pressure slowly drops down.
I don't have the idea that the compressed air leaks trough the valves.
A few questions ofcourse.
Is it correct that the pressure drops?
How many pressure is advisable to put on?
Any tips on doing this are always welcome.
Thanks for your help.
Rini.
 

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Did you run a compression check by chance on the engine prior to this? It is either losing air thru the rings or thru the valves. A tablespoon of oil in the spark plug hole will slow the leaking thru the rings. If it is thru the valves, you might as well pull the head and have them re-done while you are at it, but check with others here before starting that. Just wait for someone with more valve experiance than me to comment.

The other possibility is that you are losing pressure thru the adaptor you made, but I am guessing you would have found that already.

I hope this helps,
 

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No it isn't the adaptor.
I did a compressioncheck a few months ago,
But i did it at the wrong way (didnt remove all the plugs, and didn't give a full throttle). At that test i get about 90 PSI on every cilinder.
I'm planning to do a compression recheck though....
Rini
 

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Yes, 90 is very low. But I think with all the plugs removed and the carb open, it will be much better. Also if the number comes in low it is a sign of wear. If there is wear, measure them all just as is, then put a tablespoon of motor oil in each cylinder and try it again. Record both numbers for each cylinder. If there is a big difference between wet and dry, the rings are worn. If there is no improvement with the oil, then the valves are worn.
 

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Well...i didn't do a comressioncheck, hope to do that very soon.
But i did the "tablespoon of oil" check.
After i did the oil in the cilinder i put again compressed air on it.
I still hear the air leaking, but this time it was more "sputtering".
So i'm afraid it are the rings who are worn.
I don't remember it very well, but i think is saw a bit of blue smoke when i removed the dipstick (the engine was running, and looked into the dipstich hole) a few months ago.
This maybe also caused by worn rings, i guess?
Rini.
 

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adapter

"Now connect an air compressor up to the spark plug hole ( by making an adaptor from the body of an old spark plug and an air line connection )"

I've never made an adapter to do this. I've always pulled the vale core out of the compression tester whip. Remore the core out of it, like removing the core out of a tire valve stem. Your compression tester leads (whips) have the quick connect fittings that will connect to compresser hose quick connects. I've done numerous valve stem seals this way and have never dropped a valve.:yup:
 

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asdasc said:
It is either losing air thru the rings or thru the valves.
Well...today i thought that there might be a third cause of losing the compressed air.
The cylinder headgasket maybe damaged also...
If i listen carefully ( i will say this only once...LOL) i have the idea that the air leaks in the area around the distributionchain.
I'm gonna keep an eye on my water level, sludge at the oilcap and white smoke.
 
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