Foggy brain today. A member here recently had a better idea for stuffing "something" (rope alternative) in through the spark plug holes to keep the valves from dropping into the cylinder during a valve seal replacement. I can't remember who or what it was, but it was brilliant.

 

A spark plug wire would work without boot of course.
ive always used a compressed air adapter works well.

 

I think that was it - spark plug wire. Thanks.
I use the air adapter myself. But if it gets disconnected or you run out of air...................

 

.

 

I've always just put the piston close as I could to TDC while feeling with a screwdriver as I carefully turn the engine over with a ratchet

 

Probably me, advocating rope. Not sure about any alternatives... can't think of anything that would work anywhere near as well.

EVERY SINGLE TIME - and I do mean EVERY with a capital V - I have ever tried to use compressed air, it has been a FAIL. It invariably pushes the piston to TDC, and/or doesn't hold the valve in place securely enough to dislodge the keepers, and/or allows the valve to drop into the cyl when the keepers finally do dislodge. Not all motors will keep the valves up high enough to retrieve when they fall in.

So now, I put the piston near TDC, stuff abuncha rope in, put it the rest of the way to TDC, and whap the retainers with a BFH and a socket to break the keepers loose. Since about 99.9% of the time I'm putting new keepers back in ANYWAY, because, of course, used parts, I don't care where they fly off to, as long as it's not into the motor or my eyeballs.

The rope thing is so simple, so eeeeezy, so cheeeeep, so quick, and so effective, apparently some people refuse to believe it's even possible. Humans can be so closed-minded, so Dunning-Kruger, so confirmation bias, so ... human ... sometimes.

Not sure why an "alternative" would be needed, or even wanted; unless you lost your trusty experienced rope, and were doing a valve guide seal job somewhere that there's no 24-hr Wal-Mart close by. (is there such a place??)

Sometimes simple is best.

 

nah, noemissions is right, someone did post something else and it did seem like a great idea. I remember reading it here on TGo and thinking it sounded like a smart idea too. . I can try to search backwards for it.

 

I’ve done the rope method. Works great!

 

It's just that I tried getting the rope in through the spark plug hole (sounds so simple, right?) and it fought me terribly.
And if it should get twisted, then it could form one of those kinks or knots, and you're not pulling it out.
There is a post on here about that. A used spark plug wire will slide right in and never knot up. I love the idea.
An even a guy like me, that somehow can't get a piece of rope in that hole, could do it easily.

 

3/8" braided nylon rope is pretty simple and effective. It is limp enough to coil around and compress safely against the valves, It is strong enough to be pulled out without breaking off. It is fairly oil and fuel resistant. Rotate the crank to get the piston down a bit in the cylinder, stuff in the first foot or so of rope (with some hanging out the plug hole, of course), then crank the piston back up until the rope is compressed into the chamber. You'd almost have to try (with additional help from friends) to screw it up.

 

yea, maybe it was a spark plug wire that was mentioned. I searched through 8 months of my replies and could not find my reply to whomever did write the suggestion. But, spark plug wire does make sense, so maybe that was it! I wish i could remember for sure though

 

No offense to the experts in this thread. I've done stem seals so many times. Always use the air method, which works fine as long as you don't go too high with pressure that you force the piston down to BDC, then you could drop a valve. It's about the same as doing a leakage test, 40-50psi is usually safe. Keeping the piston at TDC is insurance against a dropped valve. I don't know of any domestic OHV engine that will allow a valve to drop past the guide with the piston at TDC. I've done every brand of OE I can think of, never seen it. If a valve drops past your fingertips into the guide, a small diameter magnetic retrieval tool will lift it right back up.

One helpful trick is don't pull all the plugs, makes it too easy for air pressure to rotate the engine. The air pressure, or I suppose a piece of rope stuffed into the chamber, holds the valve up as needed to install the locks. Just seems like the rope trick would take more time. I have done a few with no air at all. The valve falls down maybe 1/2" with the locks out, piston at TDC. Just have to use that retrieval tool to pull the valve back up when you go the install locks. I've done this on some older low compression motors that are too easy to rotate with air, even with plugs in.

 

Can't say I've had any issues either.

 

https://www.thirdgen.org/forums/tech...p-rockers.html

 

thats what i found depending on the piston dish, but usually valve drop from
chamber to piston isnt that far at tdc. I never did a spring install on a sbc head on the car, i’ve always had them off the car, but have done them with my bbc and i got plenty of room with a flat top piston to change them out by using the piston to stop the valve motion.

all my buddies use air. Mostly lsx builds but it works well for them.

 

I only used rope because at the time I didn’t have an air compressor. Just being resourceful and it worked fine.

If I had a compressor back then, I probably would have done the air pressure method. Been done this way many times and it also works.

 

Thanks John. That was the thread.

 

No Problem ! I normally direct the wire down first and twist it as I push it thru the hole to help fully fill the hole. Never had much luck with air and was never able to control the rope well enough when stuffing the hole. I found the plug wire was easier to manage than the rope that I was using at the time and never tried using rope again.

 

I have done this a number of times using a length of windshield washer hose rather than rope. It is relatively soft and small diameter. What bothered me about rope is that it tends to pick up grit. You can clean around the spark plug holes, but on an older engine it's hard to get it clean enough. The hose is easy to wipe down between cylinders. Never lost a valve.