F 134 intake valve O ring replacement ?

Maybe not so smart question. Can you replace the intake valve O ring
without pulling the head ?

 

Valve keeper work, generally, can sometimes be accomplished by using constant air pressure in the spark plug hole to keep the valve up (closed).

 

Disclaimer: I am just a shadetree mechanic (if that), so anything I say could well be completely wrong and a terrible idea.

I've also held the valves up in motorcycle engines before by threading a rope down the spark plug hole with the piston on it's way up on the compression stroke, then turning the engine to squish the mass of rope up against the valves. Have to turn the engine backwards to get it loose, which is a big no-no, I guess, but it doesn't seem to have hurt anything.

I don't know how well this would work on an F-head, though. No idea!

 

Are you by chance referring to the valve guides? I don't believe there are any O-rings on the valves of an F-Head engine.

 

I believe it has o rings, [oil seal] on the intake valves, that keeps the oil from leaking down the valve stems into to
the cylinders...

 

Disclaimer: (As above)

They may be o-rings++, or maybe just regular o-rings, I dunno. I haven't had my F-134 open yet, but on the other motors I've done them on they've been much thicker than o-rings, squared off, and made of viton rather than regular ol' rubber. The more correct term is probably "valve seals". I don't have any idea about the exhaust valves, but all the OHV engines I've done it on could be done without pulling the head, if you can keep the valves from falling down and making you sad. So I would go out on a limb and guess that the intake valves could be done with the rope-trick or compressed air, but no idea on the exhaust. But if you do lose those valves down into the motor, you'll probably be very sad and say things that would get you kicked out of church.

This is all assuming that the F-134 does indeed have them, which I have no idea about.

 

F-134 does indeed use "O" rings to seal the intake valves only.
The valve locks and valve spring retainers must be removed in order to install the "O" rings onto the valve stems.
I don't expect that one could remove all those valve parts without removing the head assembly from the block.
Might as well figure on doing a complete rebuild of the intake valve system.

 

Guess it could be done without pulling the head, but the last one would slip and drop sure as i'm
sitting here.. So, looks like I may as well bite the bullet and pull the head...
Was hoping someone had a "secret trick" I could use..
Thanks..

 

My opinion, which ain't worth much.... If you don't mind turning your engine backwards a hair to free the rope, I've used the rope trick on 3 different motorcycle engines and never lost one. But YMMV. I don't know if the sidevalves for the exhaust would make a place for the rope to get lost and not work or what. Personally, I'd probably try it and then pull the head if I lost one. Or just keep adding oil and letting it smoke until I had to pull the head to fix something else.

But like I said, I usually don't know what I am talking about, and that may well be the case here too.

 

The main problem with stuffing a rope into the cylinder bore is the location of the intake valve.
The intake valve is offset away from the cylinder bore.
And then how do you plan to compress the valve springs in order to remove the locks ?

 

Would it work with a lever tool, using a rocker shaft stud as a fulcrum? (Against air pressure in the cylinder.)

On the other hand, removing the whole head only adds a few hours.

 

Seems like a lot of constant supplied air pressure would be required to allow for pressure leakage.
Many PSI of upward force will be required to sufficiently depress the valve springs.
The valve springs are the source of the highest pressure within an internal combustion engine.
Force require to sufficiently depress the springs in order to remove locks could be calibrated but I don't have any books handy in order to determine exact force required.

 

I have done all of them on big block Chryslers with air pressure and an external spring tool, the only real trick is locking the engine so it doesn't try to turn when you apply pressure, and smaller engines with the rope, can't say for sure if the rope will work on the F-head.

 

"Many PSI of upward force will be required to sufficiently depress the valve springs."

That may be true to break the keepers free, in some cases. But the springs themselves bear down against the head, not the valve.

 

That one will work on the exhaust valves, this one will work on the intake:
http://www.amazon.com/Lisle-16750-Valve-Spring-Compressor/dp/B0009OR96K#productDetails
Use an air fitting (or convert an old plug) to put air pressure in the cyl to keep the valves closed.

 

Yep I still have one of them in my tool box, I haven't used it for 40 years but it's still around.
One of my compression guages is set up with quick connect fittings that match my air system.
Something like this should work well for you.

 

Granted, I haven't dinked with my F-head yet, it's been in my garage on a dolly for years. But is pulling the head off one that big a deal? Little bitty thing.....

 

Ok, you can change the valves seals without pulling the head.. A screwdriver will easley reach the bottom of the valve through the
spark plug hole. Did it on an old head..Checked the location of the oil seal on the "practice head" and it was on top of the valve guide
and the spring retainer stem went over it.?
The FSM states it is supposed to go on the stem between the spring retainer and the retainer locks.. Hoping some one with knowledge
will chime in. This is on the F134 engine..