photos of raw water pumps; bottom paint peel; rudder weep

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crieders

So I have posted photos finally:
1. I rec'd the Oberdorfer 3/8 inch raw water pump. When I took the elbows off the Sherwood they would not fit the Oberdorfer since they were 1/2 inch threads. That worries me since I am concerned that more water was capable of flowing thru the Sherwood than the Oberdorfer and that might affect cooling. Should the Sherwood elbows have fit the Oberdorfer? I also notice that the impeller on the Oberdorfer is smaller than on the Sherwood.
2. Bottom paint peel is shown. Does not look like blisters but question is how to deal with other than to soda blast the entire bottom.
3. One spot of rudder weep. Do nothing? Drill and fill that one spot? Remove and redo the entire rudder justified?
Thanks for any suggestions, particularly on the pump issue.
Cliff Rieders, c34 tall rig, 1990, hull #1022

Ron Hill

Cliff : I've posted this on this message board many times :
The Oberdoffer pumps about 1/2 the volume of water that the Sherwood pump does - according to Westerbeke Service Manager Joe Joyce !!!
That's why it's something to really look at if you have an M35 or M35BC engine, before changing raw water pumps.
As I recall you have a M25XP? and if so - should not be of concern.  The Obordoffer performes nicely on an M25XP!

To answer your questions;
1. The elbow nipples of the two pumps are not interchangeable. 
Yes, the Oberdoffer pumps less water than the Sherwood and that's why the Sherwood impeller is larger with more blades!!

2. Doesn't look like blister to me, rather it's the paint not adhering to the hull.  Not cleaned properly, still has some mold wax, barrier coat wasn't roughed up enough ??- anyway the paint didn't stick for any of a number of reasons !!

3. I'd drill out where it's weeping and below it to let the water out.  Don't forget to reseal the stainless column entry into the rudder layup in the spring

BTW, the Oberdoffer I had, did have the two hose nipples installed - so it was "ready to be mounted".   A few thoughts
Ron, Apache #788

crieders

What confuses me Ron is that the folks at Torrensen and the pump sellers all claim that the 2 pumps pump the same amount of water per minute. Also CatalinaDirect or CatalinaOwners ( I forget which, says the same thing). As to your pump, I did not appreciate that yours was the one with the new cam and the o-ring. My mistake; very sorry. As you can see, I have a lot to learn.  Where do you buy the elbows. By the way did you see the photo of the Oberdorfer with the "outline" of the impeller etched on it?
Cliff Rieders, c34 tall rig, 1990, hull #1022

Ron Hill

Cliff : You might be able to get the elbows at Home Depot. If not at a plumbing supply Co. for sure.

On the water flow - I just report from what I consider experts, that I know and trust. I have to agree from what I can see on my new engine that the water flow is greater with a Sherwood than was ever coming out of the exhaust with the Oberdoffer (about 23 years of observing).  Then I try to give the best advice.

My pump had the "paper gasket" as the "O ring" Oberdoffer was a model that wouldn't fit your engine. As it was for a gen set !

As for the marks on the face plate - from what I can see the "rubber" from the impeller blades is fused to the faceplate.  That tells me that pump assembly has been around for awhile.  Trash the impelled as - it's JUNK.   
Ron, Apache #788

crieders

The O ring model is the only one they sell for the engine now.
Well its all very confusing. I will call around again but Oberdorfer claims a flow rate the same as the Sherwood....so who knows.  I guess perhaps I will call Westerbeke.
Cliff Rieders, c34 tall rig, 1990, hull #1022

Bob K

Cliff,
I have had the same type bottom paint issues since owning the boat for past 5 years.  I just scrape off the loose stuff in the spring, scuff the edges a bit, and paint over it all.  No worries!  If I raced I guess I'd do differently.
Regarding your rudder, weeping generally happens at the rudder post entry point (see my recent and myriad posts from others on that topic - ugh).   I am assuming your pic "Boat001.jpg" is the weeping rudder ?  It looks like weeping somewhere in the middle of the rudder body.  I'm confused - did you drill holes first, and then saw the weeping or maybe these are blisters that popped?
Bob K
Prosit
1992 #1186
Northern Chesapeake Bay

Stu Jackson

#6
Quote from: crieders on January 11, 2012, 03:35:26 PM
The O ring model is the only one they sell for the engine now.
Well its all very confusing. I will call around again but Oberdorfer claims a flow rate the same as the Sherwood....so who knows.  I guess perhaps I will call Westerbeke.

Yes, this "which pumps more water" issue is getting rather repetitious, but perhaps new for some.

Cliff & Ron, perhaps we can look at it this way:

--- The Oberdorfer cools the engine adequately.  It works just fine with an M25 and M25XP.  If you have either a 160 or 180 thermostat, the raw water pump will keep the engine working just fine, unless you still have a 2 inch HX on your M25.  All M25XPs have 3 inch HXs.  I installed a 3 inch HX on our M25 years ago.  The Oberdorfer works great on my engine, 2480 engine hours.  The old 2 inch HX would overheat just a tad if the WOT was employed for an extended period of time with my Oberdorfer.  That's why I put in a 3 inch HX, which has been discussed in Mainsheet magazine and this board ever since M25XP engines were used in C34s.

--- The Sherwood works great, too.  So, even if it (does) (maybe does) or (maybe doesn't) pump the same amount of raw water as an Oberdorfer or more (in ANY proportion), from an engineering standpoint, it simply does not matter.  Why?  Because your engine will work just fine with EITHER PUMP.

Cliff, you can call Oberdorfer or Sherwood, but Ron has made it pretty clear over the years that the Sherwood costs dearly compared to the Oberdorfer, and my experience has been that the Sherwood access plate is kinda backwards.

My conclusion is rather simple: use either pump.  Both will work.  Don't "overthink" this 25 year old issue for M25 series engines.  DEPCO is your friend.   :D :D :D
Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  Cowichan Bay, BC  Maple Bay Marina  SR/FK, M25, Rocna 10 (22#) (NZ model)

"There is no problem so great that it can't be solved."

crieders

Thanks very much Ron.
As to the rudder, yes the rust and little blister is in the middle. I have not done anything about it yet.
Cliff Rieders, c34 tall rig, 1990, hull #1022