Valve spring swap question
Thread Starter
Joined: Jul 2013
Posts: 303
Likes: 1
From: Indianapolis, IN
Valve spring swap question I will soon be replacing my valve springs in my '02 C5 Z06 out of paranoia. I do not have an air compressor so I have been researching alternate methods of keeping the valves up. One method that I found was to stick some rope in the plug hole and bring that cylinder to TDC. I am confused as to how this would hold the valves up. Do they stick a lot of rope into the cylinder so that it kind of coils up? What length and diameter rope would I need? Also, how will I be able to tell when a cylinder is at TDC? This seems like a straight forward job, and I have dealt with much smaller scale small engine valve spring swaps so i understand the basics. I'm just a bit unclear on the details.
Last edited by 1995_maro_z; Aug 1, 2016 at 11:17 AM.
Restricted User
Joined: Mar 2014
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From: Ohio
I don't like using any method other than the air compressor method. The problem with jamming something in there is that if the valve isn't completely closed, it can be hard to get the keepers back in even with the spring fully compressed.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
Thread Starter
Joined: Jul 2013
Posts: 303
Likes: 1
From: Indianapolis, IN
I don't like using any method other than the air compressor method. The problem with jamming something in there is that if the valve isn't completely closed, it can be hard to get the keepers back in even with the spring fully compressed.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
TECH Apprentice
Joined: Jan 2013
Posts: 328
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I don't like using any method other than the air compressor method. The problem with jamming something in there is that if the valve isn't completely closed, it can be hard to get the keepers back in even with the spring fully compressed.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
If you're going to stick rope in there, use Nylon rope that is as large of a diameter as you can get that still fits in the hole. Nylon will be less likely tear and leave bits in the cylinder.
Do you have a buddy who will loan you a compressor or a place to rent one? I wouldn't try to do springs without one. The valves need to be COMPLETELY closed to get the locks on and I don't know that a rope would do that.
TECH Resident
Joined: Apr 2014
Posts: 985
Likes: 12
You take the rockers off first, valves won't be open. Just get some rope that fits the spark
plug hole put it in till you can't fit anymore in
leave some out, rotate crank around easily till it
won't rotate anymore. Don't overthink it.
soft cotton rope works great, I have used that
method lots of times swapping out valve seals.
plug hole put it in till you can't fit anymore in
leave some out, rotate crank around easily till it
won't rotate anymore. Don't overthink it.
soft cotton rope works great, I have used that
method lots of times swapping out valve seals.
Thread Starter
Joined: Jul 2013
Posts: 303
Likes: 1
From: Indianapolis, IN
You take the rockers off first, valves won't be open. Just get some rope that fits the spark
plug hole put it in till you can't fit anymore in
leave some out, rotate crank around easily till it
won't rotate anymore. Don't overthink it.
soft cotton rope works great, I have used that
method lots of times swapping out valve seals.
plug hole put it in till you can't fit anymore in
leave some out, rotate crank around easily till it
won't rotate anymore. Don't overthink it.
soft cotton rope works great, I have used that
method lots of times swapping out valve seals.
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TECH Resident
Joined: Apr 2014
Posts: 985
Likes: 12
Very simple, remove all plugs, remove all rocker arms, pick a cylinder start feeding
rope into spark plug hole, if you only get a little rope in, rotate crank till piston moves down some, you want a good amount of rope to get under both valves, doesn't have to be exactly BDC.
You might can look down plug hole with light and mirror, or simply stick something down spark plug hole and see how deep it is, use something stiff but nothing that will scratch,
like the straw on a WD-40 can? When hole is full of rope, GENTLY turn crank till you feel
piston pushing rope against valves, I like the cotton rope because it compresses nice
against valves, of course use clean rope, its cheap at hardware store $5 or 6 in a package.
If you are tearing rope in there you are being a little rough, don't do that.
I like it better than air because you can step away from job if you need to, air will bleed out if you loose air supply, rope is solid. When you are finished swapping whatever,
rotate crank off of rope and pull it out, go to next cylinder. Do 1 cylinder at at time.
When all 8 holes are swapped then start putting rockers back on and finish up.
Hope that was a little more clear than mud.
rope into spark plug hole, if you only get a little rope in, rotate crank till piston moves down some, you want a good amount of rope to get under both valves, doesn't have to be exactly BDC.
You might can look down plug hole with light and mirror, or simply stick something down spark plug hole and see how deep it is, use something stiff but nothing that will scratch,
like the straw on a WD-40 can? When hole is full of rope, GENTLY turn crank till you feel
piston pushing rope against valves, I like the cotton rope because it compresses nice
against valves, of course use clean rope, its cheap at hardware store $5 or 6 in a package.
If you are tearing rope in there you are being a little rough, don't do that.
I like it better than air because you can step away from job if you need to, air will bleed out if you loose air supply, rope is solid. When you are finished swapping whatever,
rotate crank off of rope and pull it out, go to next cylinder. Do 1 cylinder at at time.
When all 8 holes are swapped then start putting rockers back on and finish up.
Hope that was a little more clear than mud.
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TECH Fanatic
Joined: May 2016
Posts: 1,292
Likes: 436
From: St. Louis
I have always used the Top dead center method I learned on LS1howto.com back in the day. I've never had any problems doing it this way and it doesn't require any extra tools besides the valve spring compressor and a pen magnet to catch the locks should they pop off.
Thread Starter
Joined: Jul 2013
Posts: 303
Likes: 1
From: Indianapolis, IN
Very simple, remove all plugs, remove all rocker arms, pick a cylinder start feeding
rope into spark plug hole, if you only get a little rope in, rotate crank till piston moves down some, you want a good amount of rope to get under both valves, doesn't have to be exactly BDC.
You might can look down plug hole with light and mirror, or simply stick something down spark plug hole and see how deep it is, use something stiff but nothing that will scratch,
like the straw on a WD-40 can? When hole is full of rope, GENTLY turn crank till you feel
piston pushing rope against valves, I like the cotton rope because it compresses nice
against valves, of course use clean rope, its cheap at hardware store $5 or 6 in a package.
If you are tearing rope in there you are being a little rough, don't do that.
I like it better than air because you can step away from job if you need to, air will bleed out if you loose air supply, rope is solid. When you are finished swapping whatever,
rotate crank off of rope and pull it out, go to next cylinder. Do 1 cylinder at at time.
When all 8 holes are swapped then start putting rockers back on and finish up.
Hope that was a little more clear than mud.
rope into spark plug hole, if you only get a little rope in, rotate crank till piston moves down some, you want a good amount of rope to get under both valves, doesn't have to be exactly BDC.
You might can look down plug hole with light and mirror, or simply stick something down spark plug hole and see how deep it is, use something stiff but nothing that will scratch,
like the straw on a WD-40 can? When hole is full of rope, GENTLY turn crank till you feel
piston pushing rope against valves, I like the cotton rope because it compresses nice
against valves, of course use clean rope, its cheap at hardware store $5 or 6 in a package.
If you are tearing rope in there you are being a little rough, don't do that.
I like it better than air because you can step away from job if you need to, air will bleed out if you loose air supply, rope is solid. When you are finished swapping whatever,
rotate crank off of rope and pull it out, go to next cylinder. Do 1 cylinder at at time.
When all 8 holes are swapped then start putting rockers back on and finish up.
Hope that was a little more clear than mud.
I also used the TDC method, worked fine no rope or air needed. Once the spring is compressed you need to pull the valve up all the way using a screwdriver on the slot at the top of the valve to give you enough extra space to glue on the keepers with grease. You just need to keep track of which cylinder is at TDC if you rotate 1/4 turn of the crank to go to the next one.
On The Tree
Joined: May 2016
Posts: 104
Likes: 1
TDC method or air. Don't use rope. I know a lot of people get away with it and it's been done for a LONG time... But all it takes is for one strand to fray and get stuck in the piston ring lands or worse and you have a nightmare of a problem. If I didn't own a compressor I would just use the TDC method. Good luck!
TDC method here as well, worked without issue. I just picked up one the cheap USB boroscope cameras on amazon for like 20 bucks, put in the sparkplug hole and found TDC. Also great for checking the condition of the cylinder/piston.
On The Tree
Joined: May 2016
Posts: 104
Likes: 1
Someone who hasn't worked on engines before is not getting that cylinder to TDC. They then decide to stuff in 5' of rope or more and realize its not enough and instead of pulling it all out and rotating the crank to get the cylinder in the correct position they decide to just rotate the crank with all that rope in the cylinder. Some of the rope frays on the sidewalls, gets caught in the rings of the piston and now they have a big issue.
Again I am guessing here, but that's about the only way I can see it happening. If they have already removed all the rockers, then all the valves are closed, so I don't see them getting the rope stuck in a valve.
Common sense goes a LONG ways.
Teching In
Joined: Oct 2014
Posts: 48
Likes: 0
I will soon be replacing my valve springs in my '02 C5 Z06 out of paranoia. I do not have an air compressor so I have been researching alternate methods of keeping the valves up. One method that I found was to stick some rope in the plug hole and bring that cylinder to TDC. I am confused as to how this would hold the valves up. Do they stick a lot of rope into the cylinder so that it kind of coils up? What length and diameter rope would I need? Also, how will I be able to tell when a cylinder is at TDC? This seems like a straight forward job, and I have dealt with much smaller scale small engine valve spring swaps so i understand the basics. I'm just a bit unclear on the details.
Thread Starter
Joined: Jul 2013
Posts: 303
Likes: 1
From: Indianapolis, IN
I know this is old, but I never updated, and would like to make sure this helps any future searchers. The rope method works very nicely. I used nylon rope, burned the ends to prevent fraying, and turned the engine over by spinning the rear wheels by hand with the rear jacked up and the car in 4th gear (manual). With all the plugs out, the engine turned over very easily using this method. It was a very easy process, and the car was raced often after the swap with no ill side effects.
I know this is old, but I never updated, and would like to make sure this helps any future searchers. The rope method works very nicely. I used nylon rope, burned the ends to prevent fraying, and turned the engine over by spinning the rear wheels by hand with the rear jacked up and the car in 4th gear (manual). With all the plugs out, the engine turned over very easily using this method. It was a very easy process, and the car was raced often after the swap with no ill side effects.