#51
IP: 107.77.97.81
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These A-4 don't wear out, they just go bad from sitting around and getting rusty and stuck valves. work things loose, lube it up, and put it back together. You are getting advice on this forum from probably the best source, and if we go wrong, Don Moyers and Co. would set us straight and you on the right path.
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Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" Last edited by lat 64; 05-18-2019 at 02:18 AM. |
The Following 3 Users Say Thank You to lat 64 For This Useful Post: | ||
#52
IP: 24.152.132.140
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Quote:
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#53
IP: 107.77.97.97
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Ok I finally have the long awaited valve video. Not from the valve cover.. I need to get a wire with a switch I can hold... but here it is from the top: [YOUTUBE]https://youtu.be/hYbFZg-5-Qg[/YOUTUBE] The YouTube embed tag doesn't seem to work... direct link https://youtu.be/hYbFZg-5-Qg |
#54
IP: 24.152.132.140
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Nice video but a feeler gauge is the acid test. It's also entirely possible that the simple act of turning the engine over could free up sticky valves too.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#55
IP: 24.53.89.131
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It appears to me from the video that #1 exhaust is not closing fully and, if I recall your very first post correctly, that was the cylinder with zero compression.
As Neil has noted, the feeler guages are "the definitive" answer. You could also probably get a good sense from examining the valve seats when the valves are fully open. Peter |
#57
IP: 107.77.97.97
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Looks like most of my valve keepers are jammed to the retainer tried pressure. Tried tapping on the valve head with the rubber back of a screw driver... haven't got the hammer out yet don't worry. Any ideas?
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#58
IP: 24.152.132.140
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What are you using for a spring compressor?
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#59
IP: 107.77.97.101
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Fork pulling up to the engine deck. I wonder if the fork is skewed..
I'm doing some feeler measurements on the cylinder head.. specs show .006 is acceptable. I meet that. But a .004 feeler will just barely slide through to the center. Going to see if I can get a quote from a machine shop tomorrow to do the flat head. If the price is reasonable I may go for it. If I can't justify it with a good $400 engine sitting in my garage I may consider swapping the heads. Or leave it as-is.. throw head gaskets on and check if I get compression back. If the book says .006 is ok I may just take their word. Last edited by infy; 05-19-2019 at 05:38 PM. |
#60
IP: 137.103.82.194
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The head has nothing to do with the valves sticking. I am not sure I get the connection
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#61
IP: 107.77.97.101
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If the head is warped it has to be machined or replaced because it won't hold compression when reinstalled. You use a feeler gauge and a straight edge in a cross corner to corner to check if clearance is in spec.
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#62
IP: 107.77.97.101
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Doing some initial cleaning on the block deck... the valve seats don't look great. I would bet the underside of the valve heads are cooked.
I'm going to try a new spring compressor to pop them off... I may just get the one from MM |
#63
IP: 24.152.132.140
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Quote:
This started as a zero compression issue with the general consensus of the forum membership that sticky valves were the likely cause. We talked about how to turn the engine to find TDC in a Catalina 30 and I don't recall any resolution to that discussion. We talked about using a feeler gauge to measure for stuck valves, no resolution to that either and then the valves are on their way out of the block without a diagnostic measurement. Now the head is going to a shop for possible facing/milling? What happened to the stuck valve hypothesis? We don't even know for sure if that was the problem and it doesn't look like we ever will. Sorry . . . .
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#64
IP: 107.77.97.101
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Quote:
Check out the photo above. The valve seats are cooked. Destroyed. No valve clearance adjustment is going to make this engine run again. Valve clearance is one of the last steps to a top end rebuild. You don't do that until after checking to make sure the valve seats, valves, springs, and etc are in good order... As for manually turning over the engine.. there were 2 resolutions: 1. Yes you can put it in to gear and rotate the prop shaft. 2. You can cut an access hole to the flywheel and modify a socket to adapt. Or buy the official tool from MM. |
#65
IP: 137.103.82.194
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All true, but an A4 does not have a "top end" like a car, the valve seats are in the block. If you have the head off anyway by all means have it checked for being warped, but that is a totally different issue.
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TimBSmith (09-26-2020) |
#66
IP: 73.83.157.183
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Here's another valve seat. They all look to be damaged. I showed the photos to a friend who works at a machine shop.. he's not optimistic on having the block machined at all.
I'm going to try and see if I can find anyone willing to quote the work just to see the bottom line. |
#67
IP: 192.182.133.60
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Thought I'd give anyone following a bit of an update. I called around to 5 or 6 machine shops. Almost nobody has the equipment to machine valve seats on a flat head engine anymore. Everyone has moved on to machining valves on heads. I did get referrals to shops who could potentially do it, but they all refused the work.
They said that from their past experiences, they are highly likely to strike water due to water jacket and other corrosion. But yes, this block can in theory be machined by drilling out and installing new valve seats. Last edited by infy; 05-20-2019 at 01:21 PM. |
The Following User Says Thank You to infy For This Useful Post: | ||
TimBSmith (09-26-2020) |
#68
IP: 107.77.97.48
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Wow, I stand corrected on the valve seats. What a weird bit of corrosion. It looks like rust, but wrong color. Was there any acidic rust stabilizer used in cleaning this?
Its disappointing that you can't get a machine shop to help. The equipment for grinding seats on side-valve engines is the same as overhead valves. The A-4 is particularly easy to do, just lift it up on the bench and have at.
__________________
Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" |
The Following User Says Thank You to lat 64 For This Useful Post: | ||
TimBSmith (09-26-2020) |
#69
IP: 107.77.97.100
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Quote:
Best guess is this engine was probably run for a long time on bad/wrong spark plugs or with carbon deposits. Damaged by detonation/pinging. Change your spark plugs people make sure they're to spec. |
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