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dont worry about what way the blades point when you install the impeller. They sort themselves out. It can be a tight squeeze at the cam.
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GOB
I know where you are coming from. When I did my first water pump rebuild it was in my per forum days. I turned the engine with a hand crank before I put the cover plate on to be sure the impeller blades were flexed in the correct direction before I started the engine after the rebuild. Even though later I learned it was unecessary (after I joined the forum) it made me feel better at the time.
I still do this after a water pump rebuild as a double check to be sure everything is right before I hit the pump with full engine power. Overly cautious? Probably so.
TRUE GRITComment
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impeller
I just dont think I have enough force from the stern exhaust .. I found i video on line showing the exhaust being expelled with great force .after cleaning the Elbows and the Acid flush installing the By pass
I just expected more .
this boat is new to me so I do not really have a barometer ..
If I could get a visual on the impeller it could give me an a base line , as I stated earlier the PO was a little fuzzy on when the impeller was changed last.S/V Gosling
Westport CT .
“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing- as simply messing about in boats.”
― Kenneth GrahameComment
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A word on the acid backwash, I did the backwash and still ran hot. I then backwashed only the exhaust ( reverse direction also) manifold and I couldn't believe what came out of that thing. Haven't run hot since then and water explodes out of the transom.Marker Dave
"Solitaire"
'75 Catalina 30 #65Comment
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GOBOriginally posted by goodoldboat View Post
You are doing good thing here getting to know your new love~I mean boat~better. I lost track. Is the engine running hot? Maybe a previous owner modified the exhaust system or there is rust\corrosion in the exhaust system somewhere that is causing the steam.
TRUE GRITLast edited by JOHN COOKSON; 08-10-2017, 01:22 AM.Comment
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Did you do the Thatch Modification by re plumbing so water enters the manifold at the low end? With this modification you will "back flush" the manifold cooling area every time you start the engine. Also the modification will eliminate air pockets in the manifold and slowdown rust formation.Originally posted by Nahart View Post
TRUE GRITComment
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Have you determined WHAT pump you actually have yet?
(See post #9)-Jerry
'Lone Ranger'
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1978 RANGER 30Comment
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impeller
The pump is an Oberdorfer , i think . The flush of the exhaust manifold sounds like a good idea . I will do it with the by pass valve open . so everything goes through the T stat Housing ,( T stat is removed ) .
I had a massive exhaust failure on Maiden voyage earlier in the year and replaced the entire hot section .At high revs the water still really only batches out the stern . I have been on many other boats and the exhaust is explosive .I have checked elbows , acid wash , by pass valve installed ?The last is the impeller ? and the water lift muffler ?
At 1600 RPM ,the speedo says 6.5 and I don't get any steam , So I'm happy .
I have by pass valve fully closed ( its actually not a valve but a c clamp ) , i am wondering should I open it up and send some water through the by pass?S/V Gosling
Westport CT .
“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing- as simply messing about in boats.”
― Kenneth GrahameComment
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Does it say Oberdorfer on it or look like the pic?Originally posted by goodoldboat View Post
I ask because you need to know to have the correct impeller.
Did you replace the EXHAUST HOSE as well?I had a massive exhaust failure on Maiden voyage earlier in the year and replaced the entire hot section
They can fail internally and collapse limiting flow.-Jerry
'Lone Ranger'
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1978 RANGER 30Comment
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impeller
looks like the top picture ..
Both hoses from the eater muffler are in good shape they have not collapsed
internally.
Which impeller do I need ?S/V Gosling
Westport CT .
“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing- as simply messing about in boats.”
― Kenneth GrahameComment
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Top picture?
They're side-by-side for me.1979 C&C 27 MkIII, Hull No. 780
Cygnet
North Saanich, BCComment
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Just tell Ken at MMI that you need a impeller for a Oberdorfer pump. He will fix you up.Originally posted by goodoldboat View Post
Also tell Ken you need a M7 cam shoe to increase the pump's output. P\N CSOB_8_69.
I'll explain as well as I can remember. If Ken or another member says something different go with what they say.
Anyway: The Oberdorfer pump comes with a 5 millimeter cam. Increasing the cam to 7 mm compresses the impeller blades more resulting in more pump output.
TRUE GRITComment
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gob..some pictures would help clear up the confusion a bit...and/or a short video of the exhaust uploaded to youtube.
-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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thanks guys and good advice .. I will get to boat this weekend and take video ..S/V Gosling
Westport CT .
“Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing- as simply messing about in boats.”
― Kenneth GrahameComment
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