Rope length for replacing valve springs.

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This Bad Demon

This Bad Demon

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Good day everyone. I made a post a few weeks ago about valve sizes and valve springs. Welp the time has come that I'm ready to tackle the job. I'm planning to do the nylon rope trick and was wondering what's the consensus on length of rope to use? I don't have access to an air compressor.... . Thanks in advance for the help. Oh and the engine is a 360 with X heads on it.
 
Bring the piston as near to the top as possible, then I usually pack the rope in the cylinder until it won't take any more.
 
Remove all plugs so it turns over easier. Put some rope in first then gently move piston up with a breaker bar on crank bolt. much easier.

Don't use the starter!
 
If your gentle and the piston is at TDC, you can skip the rope. And to anwser, 18 inches is enough, with about 8-10 in the hole
 
This Bad Demon said:
Good day everyone. I made a post a few weeks ago about valve sizes and valve springs. Welp the time has come that I'm ready to tackle the job. I'm planning to do the nylon rope trick and was wondering what's the consensus on length of rope to use? I don't have access to an air compressor.... . Thanks in advance for the help. Oh and the engine is a 360 with X heads on it.
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It depends on the rope size obviously.
I use 1/4 nylon and with the piston still down a ways I feed about 3 feet in, and then bring the piston up on the compression stroke until it stops.
This ensures there is enough rope in the cylinder to hold both valves securely closed and up so there will be zero drop when you take the springs off.

I hate fighting a valve that won’t stay all the way up.
Just getting the piston at tdc without the rope works, but the valves WILL drop a little making it a pain in *** to get the locks back in.
 
I always try to give the retainer a little rap with a Harbor freight plastic (orange) hammer to help unseat the keepers. Cut some nice clean rags so you can stuff them in the head drain holes just in case you drop a keeper. Have a telescoping magnet to help pluck them out. Put some vasoline on the keepers to help hold them in place when you put it back together. I use a pick to push the vasoline covered keeper so it sticks in the valve groove.
 
This Bad Demon said:
I'm planning to do the nylon rope trick
Click to expand...
I would use cotton cord. If any gets inside it will burn away vs turn to plastic

As for length, a couple feet 1/4" is smaller should be plenty. Like cloths line.


You really only need enough to fill the head chamber volume
 
I knew a gal that did a rope trick once. Well, maybe that's for the blue room. lol
 
The last one I did valve seals on, I used compressed air and it worked well. I've used rope in the past and it's fine, but if you have access to air it works well too. Heavy shop air will tend to want to kick the engine over though, but only until said piston is at BDC. ....admittedly, not the best place to be when removing the valve springs, but if you're careful it'll be fine.
 
Dude. Go get a pancake air compressor for a $100 bucks at home Depot. Or look one up on Facebook marketplace for $50. It's so easy that way.
 
piston at bdc, feed in as much rope as will fit and turn the crank' until the rope jams the piston. the valves are now held. also as above tap the edge of each retainer to break the seal between it and the locks. with the air method there is that possibility of dropping a valve onto the piston, with rope it just can't happen as they're physically held. oh, and a length of rope is cheaper than even a cheap compressor.
 
I did a 360 van engine recently. On the first cylinder I didn't have enough rope in the hole and the engine just rolled right on around past TDC.

So then I started jamming the rope in with a screwdriver, because otherwise it's like pushing a rope uphill. That worked. I ended up with feet of rope in, not inches.

But in one cylinder I got a little too enthusiastic and had the rope caught in the hole after I replaced the springs/keepers. For a minute I thought I had managed to tie a knot in the rope that wouldn't fit back out the plug hole. If it was, it was a slipknot because with luck I eventually got it out of there.

I guess what I'm saying is, use your head and don't get carried away like I did.
 
Uncle Bob said:
For a minute I thought I had managed to tie a knot in the rope that wouldn't fit back out the plug hole. If it was, it was a slipknot because with luck I eventually got it out of there
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That's why to use cotton rope. (edit) or hemp rope. A little fuel and it will burn to ash
 
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Beats me why anybody uses rope........
Totally unnecessary....
Too late once the rope gets caught or knotted.....
And you don't need a compressed air either....


Get the piston to TDC. Get an screwdriver & put a 45* bend in it about 1.5" from the end. Put in the spark plug hole & let the tip rest against the valve that is going to have the spring replaced. S'driver handle acts as a counterweight & keeps the valve closed while removing/replacing springs. Often, just the friction of the stem seal keeps the valve in position. If valve drops, seals might need replacing.
 
Revising the bend in the shaft. 45* might be too much, try 20-30*. Whatever works. I have replaced many spring sets using the above method.
 
It kinda honestly surprises me that in this day and age guys don’t have a compressor. I have a quiet two gallon compressor that I take to the track that cost around 140.00 that can do about any mechanical job on a car. Very nice to have around the shop.
 
I have an air compressor. But I do not need to use it to change valve springs, as per post #19.
 
Screwdriver could fall at an inopportune time. Sometimes the locks need a light rap on the retainers with a mallet to break loose. That could dislodge the screwdriver. I'll stick with air.
 
Mean416 said:
Screwdriver could fall at an inopportune time. Sometimes the locks need a light rap on the retainers with a mallet to break loose. That could dislodge the screwdriver. I'll stick with air.
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Not unless the handle is smaller than the spark plug threads. It might fall out but it won't fall in. :BangHead: :lol:
 
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