#1
IP: 71.134.240.155
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Valve Spring Job Done!
The war is over.
Springs are replaced, and the engine runs! It is possible to replace the valve springs without removing the head, and with the engine still in the boat. The Lisle Small Engine Valve Spring Compressor tool will in fact fit over the head and still be able to slip under the springs. Cautionary note: the metal used in the tool "fork" is brittle, and breaks fairly easily if you use it to "pry" between spring and retainer. Better to use a fine screwdriver to do the prying, then slip the tool into that space. It took a while to learn the pattern: 1. Lift the spring and retainer disc together. 2. Tap the valve stem down to free the two keepers. 3) Reset the clamp spring compressor and now lift just the spring. Remove the retainer disc. 4) Remove the clamp and remove the spring. 5) Install new spring, use clamp to raise it over the lifter. 6) Place the retainer on the lifter and lower the spring. 7) Raise the retainer and spring together and stick the two keepers in place using a dab of grease to keep them in place. 8). Carefully lower the spring and retainer over the keepers. Be sure they set properly. (amazingly, usually the spring would slip out of the clamp at the last minute and "pop" into place. Relief and amazement ensues as I checked for proper placement. Yowzer!) That process can take 10 to 30 minutes per valve depending on access, patience, and technique. Avoid lowering the spring and retainer improperly on the two keepers. Un-doing jammed keepers is a real pain! (how do I know???) Also, I noticed that my exhaust manifold gasket was burned through in several places, allowing exhaust gases to leak out (bad!). The MMI valve cover plate studs were a big help, and I recommend them. I used extra, longer bolts to temporarily hold the heavy and unwieldy manifold in place, then one at a time installed the original bolts. Also did a carburetor clean/rebuild with a new gasket. New intake flange gasket too. I was very pleased to hear her fire right up and run quietly. No clacking valves! The broken spring was fixed, and the sticky valve was freed. The engine seems to be much happier with new gaskets = better intake suction, no exhaust leaks. Whew, I hope I never have to do that one again! Photo captions: 1. Original bad condition. Note stuck valve on cyl#2 and broken spring on cyl#3. 2. New springs in place with new plate studs. 3. Cover in place with studs and nuts. 4. Broken spring shown. 5. Burnt manifold gasket. (have you checked yours lately?) Anyhow, thanks to all (especially TomThatch!) for the encouragement and advice. Now I get to report back to Ken in Parts that I don't need those head gaskets after all... -Rick Last edited by rpowers; 01-17-2011 at 09:44 AM. |
The Following User Says Thank You to rpowers For This Useful Post: | ||
PWAusCal29 (07-01-2016) |
#2
IP: 24.224.206.117
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Good to hear you got it sorted out.
__________________
Mo "Odyssey" 1976 C&C 30 MKI The pessimist complains about the wind. The optimist expects it to change. The realist adjusts the sails. ...Sir William Arthur Ward. |
#3
IP: 71.129.235.22
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"Whew"
Rick,
Congrats on a job well done, I'll sleep better tonight knowing she's back together and running. Tom P.S. How'd you like to drive down to Oxnard and change out my springs for me?...Just kidding. |
#4
IP: 76.7.147.23
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Good info and congrats. Dan S/V Marian Claire
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#5
IP: 24.196.47.83
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Congratulations. Your patience is commendable.
Forgive me for backtracking , but briefly - the cause of and cure for the stuck valve in the original bad condition photo ? |
#6
IP: 71.134.240.155
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Cause-Cure
Hi Laker,
Not exactly sure of the cause of the sticky valve. Maybe sitting for 2 months not running. Possible moisture causing microscopic rust or varnish (?) When I got the spring off, I was able to move the valve by hand, but it was sticky. My hunch is that the old springs (1976) had lost their "spring" and that one was unable to press past light varnish. The new springs from Moyer are about 1/2" longer and are made from stainless steel. They should be able to keep things "hopping". Also, a footnote: I am now doing several changes of oil, with a high dose of MMO so that the solvents contained therein can do their magic on the varnish on the valve guide. Cure: New springs and MMO Btw, here are the ingredients of MMO: Naphthenic Hydrocarbons 70-80% Mineral Spirits 20-30% (Wintergreen!) Chlorinated Hydrocarbons 0-1% See attached MSDS sheet. Now, off for a day of full power motoring on the beautiful San Francisco Bay! -Rick Last edited by rpowers; 01-16-2011 at 09:08 AM. |
#7
IP: 68.126.189.201
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Rick, Great job. I saved your list of "How it's done." One thing about the A4...we will all one day make the same repairs. Your how to will make my (hope never) future spring change easy.
Domenic |
#8
IP: 142.68.240.30
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Rick, this thread deserves 5 stars, and I so voted. A keeper. I need to do the star-vote thing more often; this is my first time.
__________________
1974 C&C 27 |
#9
IP: 24.196.47.83
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Mineral spirits - now that is interesting. I think that goes a long way in seeing into some of the "Mystery" as to the curative properties.
Thanks , and congrats again. Laker |
#10
IP: 76.106.6.207
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Quote:
I love wintergreen! |
#11
IP: 24.136.77.31
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Yeh!
Rick, having done a valve job in the boat myself albeit with the head off I admire your fortitude. I'll bet your even better with your fingers than you were before unless of course you are a surgeon.
I'm still thinking of an engine running valve adjustment this off season to see if I can quiet her down a bit. Many other small projects in line and priorities are what they are. How did she run on the SF Bay? Dave Neptune |
#12
IP: 71.129.174.188
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Rick,
Sorry that the compressed air approach to holding the valves closed apparently didn't work in your case. We commonly use that method on race engines but are dealing with engines with less leak down and are probably using a larger cfm compressor. In your list of notes you didn't mention checking valve clearances, so if your engine was running quietly enough before the stuck valve issue, they are probably in the ballpark. Also, I would be curious to know if the change to stronger springs has had an effect on your compression readings. Tom |
#13
IP: 208.71.0.56
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Running report, and air compressor
Dave,
She ran great! Smooth as a purring kitten. Took her 1 hour out, sat in the bay and changed the oil (2quarts oil, 1 quart MMO), then powered back in. Speed was 6.5 mph at 2000rpm = good! What with new exhaust and intake/carb gaskets it seemed like I had much more power in reserve (2300rpm!). Is spoke with Don Moyer on the phone yesterday, and he too was amazed that springs could be changed with the head attached (much less engine in boat!). Tom, I had the air compressor working, holding 30psi at top piston, but I was pushing past the air pressure when applying force upwards on the valve stem. Therefore I fell back on making a special tool, a 12" medical forceps with the tip bent at a 1" long 45' angle. I was able to carefully apply downward force on both valves (even the smaller harder to see exhaust), as well as upward holding force under the valve top when pulling down on the valve stem. Compression seems great, but my test was invalid as I had cut the compression guage hose to make the adapter for the air compressor rig. Patching the hose back up had leaks, so all cylinders showed 50psi, the max the hose could hold. Anyhow, she runs great, and another thanks to all you great guys! -Rick |
#14
IP: 71.129.174.188
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"Head on, spring change"
Rick,
Glad to hear everything is running right. On another note, anytime we can help Don increase on his vast A4 knowledge, I would say that the (your) effort was worth it. Tom |
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