Anyone ever replace a valve spring in car? |
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Anyone ever replace a valve spring in car? |
-JR- |
Jul 23 2011, 12:10 AM
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#1
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Life goes faster at 150MPH Group: Members Posts: 276 Joined: 12-May 04 From: Victoria BC Canada Member No.: 2,055 |
Broke an exhaust valve spring on my newish (2000 miles on it, but 4 years old) motor Wed. Just did a compression check and pulled off the exhaust for #4 cylinder tonight.
Good news is I shut down quick but not before the valve spring washer had been pummeled, but I have spares. Piston, bore and valve look good fortunetly. The trick will be getting the valve spring compressed enough to get the keepers back in while it's still in the car. Anyone ever done this, have some suggestions? (IMG:style_emoticons/default/confused24.gif) It's sort of weird, the spring seems to have broken into three pieces. Thinking I shouldn't have used new stock springs now. (IMG:style_emoticons/default/headbang.gif) The 2.2L engine has a light weight flywheel, the top end has been flow benched and the compression raised. So it rev's like mad and it's a ton of fun between 3000K and 6500K. If I keep the motor I'll probably invest in a set of performance springs. |
vwsamba |
Jul 23 2011, 01:28 AM
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#2
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Newbie Group: Members Posts: 46 Joined: 20-November 10 From: Malibu, CA Member No.: 12,407 Region Association: None |
I've done this a few times , its easy, getting the broken spring out is straightforward. Put the new spring in a vise and compress it, then tie multiple sections of it together with safety wire. put in the head replace keepers and then snip out safety wire (IMG:style_emoticons/default/beerchug.gif)
Broke an exhaust valve spring on my newish (2000 miles on it, but 4 years old) motor Wed. Just did a compression check and pulled off the exhaust for #4 cylinder tonight. Good news is I shut down quick but not before the valve spring washer had been pummeled, but I have spares. Piston, bore and valve look good fortunetly. The trick will be getting the valve spring compressed enough to get the keepers back in while it's still in the car. Anyone ever done this, have some suggestions? (IMG:style_emoticons/default/confused24.gif) It's sort of weird, the spring seems to have broken into three pieces. Thinking I shouldn't have used new stock springs now. (IMG:style_emoticons/default/headbang.gif) The 2.2L engine has a light weight flywheel, the top end has been flow benched and the compression raised. So it rev's like mad and it's a ton of fun between 3000K and 6500K. If I keep the motor I'll probably invest in a set of performance springs. |
-JR- |
Jul 23 2011, 01:47 AM
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#3
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Life goes faster at 150MPH Group: Members Posts: 276 Joined: 12-May 04 From: Victoria BC Canada Member No.: 2,055 |
Niiiiice, I like it.
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HAM Inc |
Jul 23 2011, 07:43 AM
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#4
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Senior Member Group: Members Posts: 846 Joined: 24-July 06 From: Watkinsville,GA Member No.: 6,499 Region Association: None |
Better replace them all. Assuming that all of the springs are the same age if one broke the others are capable of the same failure.
And if my suspicion is correct that the re-builder re-used the old springs, then not only are you at risk of more broken springs, but you are also at risk of losing a valve seat as weak, tired springs are not capable of controlling the valves at higher revs. This allows the valves to land hard against the seats which rattles them loose. (Seen countless examples of this over the years!) And when I say higher revs, I don't mean race speeds. Just the rpm's you hit when winding out a gear just before an up-shift can be enough for a weak spring to loose control. The intakes take the brunt of it as they are heavier than the exhaust valves. If the re-builder did replace the springs then rust from sitting would be the next likely reason a spring broke. If that is the case then look the others over very carefully. It doesn't take much rust to cause a stress riser that will lead to a failure. |
Krieger |
Jul 23 2011, 08:06 AM
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#5
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Advanced Member Group: Members Posts: 4,711 Joined: 24-May 04 From: Santa Rosa CA Member No.: 2,104 Region Association: None |
Something I have heard of people doing (no I have not done) is screwing in a compression tester into the spark plug hole and then hooking your compressor to the other end pressurizing the combustion chamber. I have no other details, but it seems low risk. Just gotta figure out how to compress that new spring to install. I agree with Len though. This would just be temporary until you could change them all.
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TargaToy |
Jul 23 2011, 11:17 AM
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#6
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-NONSOLIS RADIOS SEDIOUIS FULMINA MITTO- Group: Members Posts: 692 Joined: 26-March 10 From: DelMarVa Peninsula Member No.: 11,509 Region Association: MidAtlantic Region |
Or feeding a CLEAN, NEW length of nylon rope into the spark plug hole and bringing the piston to TDC...will supposedly keep the valve closed.
I've never tried this personally. |
underthetire |
Jul 23 2011, 12:09 PM
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#7
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914 Guru Group: Members Posts: 5,062 Joined: 7-October 08 From: Brentwood Member No.: 9,623 Region Association: Northern California |
Close both valves (remove rockers obviously) and use a sparkplug air adapter to the compressor. Did it myself back in the old automotive machinist days on a caddy. Had a new spring break on start up on a customers head. A type 4 may be a bit more of a challenge, since the caddy had individual rocker studs for each valve. That allowed the use of the valve removal bar.
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DBCooper |
Jul 23 2011, 03:09 PM
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#8
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14's in the 13's with ATTITUDE Group: Members Posts: 3,079 Joined: 25-August 04 From: Dazed and Confused Member No.: 2,618 Region Association: Northern California |
Stick a chopstick in there, works almost every time.
Seriously, Len's absolutely right. One's a sign. We'd do it back in the day, but those engines aren't like these. |
Jake Raby |
Jul 23 2011, 07:07 PM
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#9
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Were the springs rust pitted? If not, something made it break. I'd look for that.
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-JR- |
Jul 23 2011, 08:04 PM
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#10
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Life goes faster at 150MPH Group: Members Posts: 276 Joined: 12-May 04 From: Victoria BC Canada Member No.: 2,055 |
No rust on any of the valve train on the right bank currently. The car has been stored in doors in a dehumidified garage. They were new 4 years ago as I supplied the parts and the rebuilder is a trusted local VW guy who's been doing VW's and Porsches locally for decades. Always had top notch work from him in the past.
Problem seems to be more this case is cursed. It's been rebuilt three times in the last 3000 miles. First time, valve step came loose from the end and crashed into the head. Second rebuild the cam lobes melted down. Third time I thought I would have a professional shop do the work. Each rebuild new parts were used. Compressing the spring has turned into a moot point. Now that I can spin the valve around 180 from where I could see it through the exhaust port, it's obviously bent. (IMG:style_emoticons/default/sad.gif) Already pulling the car apart. The sad part is that I just wanted to run this motor until the end of September when I start my 3.6 project. |
Jake Raby |
Jul 23 2011, 08:13 PM
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#11
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Valve springs hate to sit static.. If an engine sits without running at least two valves are compressed and those springs die from compression over time.
If an engine is ever stored, pop the rockers off to remove load from the springs. That valve should be bent.. I'd expect that. Pull the head, do it right. |
-JR- |
Jul 23 2011, 09:20 PM
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#12
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Life goes faster at 150MPH Group: Members Posts: 276 Joined: 12-May 04 From: Victoria BC Canada Member No.: 2,055 |
The engine did get run fairly frequently as it was moved around the shop from time to time. Longest it ever sat was about 4 months.
I'll take a picture of what's left of the spring and post it tomorrow. Three pieces! |
Jake Raby |
Jul 23 2011, 09:39 PM
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#13
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Three pieces is normal for a broken spring.. every one I can remember breaking has had three pieces.
Either the springs were junk, tired or you have another problem... Coil bind? Valve float? |
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