#51
IP: 128.183.140.38
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This past summer, my tach started reading twice what the actual RPMs were. Even though the switch was in the "4 cyl" position, I rotated it back and forth several times through all the positions to clean the contacts. It came back to the correct readings and was fine the rest of the summer.
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@(^.^)@ Ed 1977 Pearson P-323 "Dolce Vita" with rebuilt Atomic-4 |
#52
IP: 24.74.202.154
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Removed the tach and worked the switch back and forth. Also sprayed with contact cleaner as best as I could. Did not seem to improve/change and I will replace the tach "some day". The tach has read this way since I got the boat so what ever the problem is has been there for 8+ yrs. Ran the A-4 hard enough at the dock to get the vac # to 10. I hope to do some on the water tests in a few weeks.
Helped a friend move her 40 ft Caliber up from Morehead City today. Nice, nice, nice boat and it was good to be on the water again. Dan S/V Marian Claire |
#53
IP: 74.162.82.28
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My previous tach was acting this way and I finally took it out and looked inside; the circuit board was full of corrosion so I had to replace the unit.
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#54
IP: 76.7.133.129
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Several questions. I have read a few posts on repairing cracks in the head and there seems to be several options, JB weld, epoxy and welding at a shop. Does this crack look to big to repair? What repair do you prefer? Would you keep a repaired head as a spare? Can the repair be tested? The head is 47 yrs old and has been in service for 40 yrs all RWC.
Also could I have opinions on the color variation on the valves shown? Mainly the white, #3 #4 versus the clean #2 exhaust valves. More pics here. http://www.moyermarine.com//forums/album.php?albumid=97 Dan S/V Marian Claire PS. Anybody got a early model head sitting around collecting dust? And yes the access is that good on the MC. I only had to remove the alternator, crossover and temp sensor to remove the head. Last edited by Marian Claire; 02-08-2012 at 03:41 AM. |
#55
IP: 71.90.53.237
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I jumped in at the end of this thread , sorry if If this has already been brought up - the location of the crack makes me wonder if it is lifting ring related.
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1966 Columbia 34 SABINA |
#56
IP: 76.7.133.129
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Laker: Several of the posts I have read about cracks mention the lifting ring. As best I know I am the only one to ever remove the engine. I did not use the ring but used a sling made of webbing to remove and reinstall. I do not know how it was installed by the original builder back in the 60s. The mechanic at the marina looked at it and simply said " old Age". Who knows, uneven heat, as mentioned by Ed, some time in its life, years of vibration from the alternator??? As old as it is I may be wasting time trying to repair. Dan S/V Marian Claire
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#57
IP: 67.78.241.34
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Dan - Any reason why you are limiting your search to an early head? You have plenty of room for the "thermostat bubble".
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#58
IP: 76.7.133.129
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HC: None other than my plug and play approach to spare parts. Would I have to modify my early manifold to accept a fitting for the hose/crossover or can the late head be changed/drilled to accept my early crossover tube? Dan S/V Marian Claire
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#59
IP: 67.78.241.34
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Dan - The only thing you would need to do is tap the manifold for 1/2" NPT and then cobble a tube to the "bubble".
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#60
IP: 24.152.131.155
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Dan,
If it were me I don't think I'd attempt a repair of any kind, it would be a source of stress and worry. And I agree with Hanley, any head will do. There has been much speculation over the lifting eye causing cracks. It may be a contributor in conjunction with other factors such as decades of salt water cooling and the ensuing corrosion substantially reducing the material thickness internally in that particular area but I suspect the lifting eye by itself isn't the cause. Dan's mechanic summarized this quite eloquently in two words, "old age." Dan's experience is an example. He's never lifted his engine by the eye yet he has a crack. Can't blame his on a lifting operation. Also, every one of our engines was originally installed with the lifting eye. If the eye alone causes cracks, why don't we all have them or at least a significant percentage? No, there are other factors involved.
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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 |
#61
IP: 76.7.133.129
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HC: I have zero experience at tapping. So could I remove my existing early crossover tube, tap the manifold on the boat and replace the early tube and run with the head I have on? Then have a spare late head set up with one T-state housing port plugged and the other set up with a hose and fitting to tie into the tapped manifold. No T-stat would be used, same as my existing system. Again I just try to be prepared for a breakdown in the boonies. Dan S/V Marian Claire
Last edited by Marian Claire; 02-08-2012 at 08:04 PM. |
#62
IP: 67.78.241.34
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Dan - Yeah, in fact I would get rid of that cast crossover tube even if using an early head - it is a nasty restriction. And I'm sure you could operate that tap.
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#63
IP: 108.23.219.10
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Hurry?
Dan what is your hurry that one only lasted 40 years or better. Yeh I must agree with the old age senario. As far as the lifting of the lifting eye I doubt that would cause any damage unless really haddled roughly. I like the sling idea better.
Your valves and such look OK and remember that this shut down wasn't a normal one. I'd give the seats a good look and maybe kiss them and the valves to redo the seats. Personally I would go for any "good" head I could find, the A-4 kind. Adapting one to the other is not rocket science. Welding via stitching is a good approach but for MY boat I would opt for the sure thing a good head! A welded head can last a long long time or a very short time no real way of knowing. My guess is since these heads are thin and flat I would stay away from any welding on the head where yours is cracked. If it were a small crack around a stud hole I MIGHT re-concider. Dave Neptune |
#64
IP: 76.7.133.129
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Good deal. On the late head I see that the early exit port is blocked but still "located". Can that port be drilled and opened? Just looking at all my options.
Dave: Thanks for that on the valves. They just looked so different I had to ask. Dan S/V Marian Claire Last edited by Marian Claire; 02-08-2012 at 11:10 AM. |
#65
IP: 76.7.133.129
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Anybody need a paper weight rated for high wind zones, hurricanes and Santa Anas. Dan S/V Marian Claire
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#66
IP: 71.90.53.237
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Niel ,
I agree with your comments and opinions regarding the lifting ring , including the fact that it is , in all probability, not a factor in the MC case. That said , I still believe that it is a stress source which is best to avoid. But then , we've all hashed this out before. Back aboard the MC ... PS - Wife looked at photo of heads in cockpit and said : "muffin tins?"
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1966 Columbia 34 SABINA Last edited by Laker; 02-09-2012 at 07:19 AM. |
#67
IP: 24.152.131.155
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A couple of members have come up with improvements on the lifting eye design, Thatch being one of them. He added an ear that picks up a third head bolt that resolves the twisting leverage on the original design. I don't think he'll mind me posting this picture of his work.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#68
IP: 99.41.59.47
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"Exposure"
I certainly don't mind Neil posting "almost" any of my photos. This bracket is similar to what "ILikeRust" had created, but is a bolt-on rather than a weld-on. Part of the reason for adding this part was to help insure good alignment of the alternator along with strengthening the lifting ring.... The only thing that I regret, is not having cleaned the grout better before taking that picture.
Tom |
#69
IP: 67.237.207.128
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Had a chance to get the MC out and run some tests. This time I had a properly functioning tach and in open water. It was not dead calm but what little breeze there was was always on the nose or beam. I averaged the speeds for each rpm.
RPM MPH Vac 1500 3.9 18+ 1800 4.4 17+ 2000 4.9 17 2300 5.7 15 2600 6.4 13 At this point the wind was up enough that I felt it would effect the test so I just had to sail the rest of the way home. Poor pitiful me. When I first started this thread I simply wanted more speed. Now I want more top end speed, good "cruising" speed at a good continues use RPM and no lugging of the A-4. I will monitor the #s in the future but my conclusion at this point is that I am indeed slightly under-propped. Dan S/V Marian Claire |
#70
IP: 71.118.13.238
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Good call
Dan, Hanley should be jealous of these numbers!! Yes they do indicate that you are indeed underpropped. At 2600 RPM I'd like to see between 5+~7" of vac. That would still give you a bit of reserve power, IE tha last few inches of vac without the worry of over-reving the beastie.
When re-propped you should achieve your 6.4 when clean around 2200 or less RPM with plenty of reserve power remaining to tow in a dead diesel while smiling profusely and sipping the beverage of your choice from your MMI coffee mug. Dave Neptune |
#71
IP: 67.78.241.34
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Yes, indeed
Hanley is paying strict attention to this discussion with a view to making a change. I want to cruise at 2000 rpm, however, and I am not real concerned about top speed. Staying tuned...
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#72
IP: 67.237.207.128
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Dave: The #s you suggest are very close to what I want to achieve. I will definitely post an update when I re-prop.
Hanley: I look forward to your results. Our boats and style of use are similar. Will be interesting to see where, prop wise, we end up. Dan S/V Marian Claire |
#73
IP: 71.77.145.154
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Dan,
I'll throw some more numbers in for you. These are from memory, I left my notebook on the boat last weekend, but I think they are correct. My boat is a C&C 38 with an A4, 2:1 reduction, 16x10 two blade. No vac gauge. WOT 2850 rpm, 6.7 knots 2600 rpm, 6.6knots 2400rpm, 6.4 2200 rpm, 6.2 My engine is a Stevedore model, and although I haven't looked yet, I am willing to bet that the restriction ring is still in the manifold. Your investigation is really tempting me to put a vac gauge on it just to satisfy my curiosity. Bringing the boat down from Maryland the last couple of weekends, we ran the motor a lot (close to 40 hrs) and ran it pretty hard at times. Never had a hiccup, she ran like a champ. It does burn about a quart of oil every 8 hours and we burned just over 1 gph on average for the whole trip. James S/V Delaney C&C 38 Oriental, NC |
#74
IP: 67.237.207.128
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JT: Thanks for the #s. As I have learned during this process RPM, speed and vac #s all add to the picture of how well the prop is matched to the boat/A-4.
I hope to be out and about on the MC around Easter so if you are down in Oriental give me a shout. Dan S/V Marian Claire |
#75
IP: 108.23.219.10
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Dah' head!
I was working on my beastie last evening and thought about your cracked head. We have seen a few of these and I am wondering if the alt bracket is working as a heat sink and drawing (rediating) heat off the head causing a "chilled" spot which is already under stress. The sides of the bracket work as "veins" rediating heat from a concentrated area. I'm kinda reachin' here but thought I'd toss this out for your thoughts. I have seen "odder" things happen in some cases.
Dave Neptune |
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