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Is there a rule of thumb regarding the height the hot section should rise above the exhaust thru hull
Len
Len
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old system
I think this needs work!!!???sigpic -
The hot section should rise as high as your boat configuration will allow without getting too close to the deck above. Also it should be wrapped as an extra precaution. Black iron plumbing fittings are the best material and you should be able to cobble something nice without having to do any threading. Start with the Moyer flange which has the port for pressure testing in the future.Comment
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As high as possible is right.
However, with a waterlift system there is no requirement the hot section needs to be higher than the exhaust thru hull. Mine isn't nor is any Catalina 30 of which there are several thousand, other boats too I'm sure.
The critical height for the hot section is above the manifold flange. A foot is heaven, anything more is gravy.Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few othersComment
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According to an earlier post, the top of the dry/hot section should be a minimum of 3" above the waterline at all angles of heel. Since most A4 installations (but not all!) have the waterline just at, or slightly above, the top of the head, 8" to 12" should be great, depending on how close the stack is to the centerline of the boat.
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4
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work in progress
this is the direction I'm heading any comments
have I made the hot section to tall, still working out the details
and I am going to add a water trap to the bottomAttached FilessigpicComment
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FWIW, 6500 Catalina 30's, both gas and every permutation of diesel were manufactured out of compliance with the above specification.Originally posted by edwardc View Post
We would all love to have that amount of rise.
Awful lot of galvanized pipe in the pictures . . . .Last edited by ndutton; 03-13-2012, 05:07 AM.Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few othersComment
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Looks like you're moving in the right direction. If you use all that pipe you will need some support so as not to stress the manifold casting. Should be able to get a 1 1/4"x1 1/4"x3/4" T to reduce weight a little. Have you ordered a new flange from MM?Comment
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If the manifold connection is on the left side of the picture, looks to me that the water would flow into the engine, The water injection point should be on the ride hand side as low as possible.
SteveComment
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The exhaust comes in on the right side of the picture, water comes in after the rise in the hot section, and yes I was concerned about the weight, had planned to support it with an exhaust hanger, I am hoping to reduce the height and the water intake is being changed to a barber copper fitting for the hose. I am going to retake some measurement and refit a few pieces. I will repost some new pics latter todaysigpicComment
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Steve, I was thinking the same as you were..since sleonhard reports it is the other way around, I think it might be a little overkill. I'll wait for better pictures..I can't believe where on earth all that pipe would fit in a boat!
I know everyone around here advocates the use of black iron and not galvanized. I used galvanized for mine and as long as you are aware of and take precautions during the first few hours of use during the off-gassing of the galvanized pipe, I have not seen any other adverse effects from using galvanized pipe.-Shawn
"Holiday" - '89 Alura 35 #109
"Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!)
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FWIW: Based on my experience try to avoid using short nipples. The ones that are totally threaded. For whatever reason they have been the first piece to fail on my systems. Thinner wall due to threading???? Dan S/V Marian ClaireComment
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Yeah, Pearsons too. When I got mine, it had NO riser at all! Fortunately, there was enough room to put in about 12" of rise. And I'm not sure even that maintains 3" when we're heeled hard with the port side down.Originally posted by ndutton View Post
Pesky reality keeps intruding on goals!
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4
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This might help you out. The image will be large because I can't seem to reduce the size with the new laptop....it works perfect on mine and I have no cooling or water intrusion problems.Attached FilesLast edited by Mo; 03-13-2012, 02:17 PM.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.Comment
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Shawn, I used black pipe for mine and it outgassed for awhile before it stopped.
Smelled Horrible, didn't want to be anywhere near it
SteveComment
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