For those who were interested in the inquiry re: installing a larger heat exchanger on a M-35 for a 1992 C36, here is the reply from Westerbeke staff:
[I]Your email to Gerry at Catalina Yachts has been copied to me in his reply to you.
The thermostat in your Universal is rated at 160 F. I generally will hold the engine operating temperature, depending on the temperature of the sea water and engine load, in the 150F - !70F range.
I would for the sake of accuracy. Verify the engine operating temperature with the use of a heat gun monitoring engine temperature at the thermostat housing where the instrument panel’s temperature gauge sender is located. There can be a number of degrees of inaccuracy from gauge to gauge and sender to sender.
Diesel engines with a closed antifreeze cooling system operating in the 180F range is by no means detrimental to the engine. Your engine operating in shallow warmer water than found in the Chesapeake has caused the increase in operating temperature you are seeing with your engine.
Like a cars radiator increasing its size or that of the heat exchanger does provide for more cooling area and helps the engine thermostat to better control engine operating temperature at the rating it has.
[COLOR="Red"]Larger size heat exchangers for the Universal M35AC are not available and as mentioned above. The operating temperature of the engine in the 180 degree range is not detrimental to the engine.[/COLOR]
Very Best Regards,
Joe Joyce
National / International
Service Manager
[/I]
encore,
I am not sure what your point is. I have a great deal of respect for Joe, and our C34 skippers have been working with him for many years, as have your C36 skippers.
That said, Sendure and Seakamp can provide a LOT of different answers to the same question, if there was, indeed, one included in your OP.
Like this one:
[url]http://c34.org/bbs/index.php/topic,6920.0.html[/url]
I'm sure that someone experiencing "potential" overheating issues, in whatever waters they're sailing in, could well use a larger HX. It sure is a viable approach to heat rejection from a diesel engine. In our M25, I moved from the old 2 inch HX to the 3 inch model years and years ago.
I see no reason why the same shouldn't be true for M35s, regardless of the thermostat temperature selection. As far as I know, there are only two: 160 and 180.
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
Stu: You've commented that you went to a 3" hx for an M25. Is there a documented procedure for that on the forum? Any issues in the retrofit? I'm not sure how to measure if mine is a stock 2" or upgraded to a 3". Is it an o.d. 3" I'm looking for? The PO has done various upgrades on our M25 Universal Kubota, but this is one in particular,I want to check on.
Paul Lipsit,
Zatarra #406
1985 C36 Mk1 S/R F/K
M-25 Universal Kubota
Port Dover, Ontario
Paul and Stu:
I went to a SeaKamp 3" on my M25 in my C36 MK1.
There was no way to keep it in the same location with the factory, nor supplied, mounting brackets - so I moved it aft by about 3 feet.
I mounted in to the fiberglass-reinforced, fresh-water-tank box, which traps the fresh water tank under the rear double-coffin berth.
This simplified maintenance on the tranny and probably helps keep the exchanger a little cooler by virtue of it's relocation away from the top of the engine. I had to reroute some lines and add some hose. But it has worked.
I'll attach a pic.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
I as well replaced the OEM 2" HX with the 3" Seacamp a few years ago (the old one was shot), and contrary to what Mitch wrote, it will fit in that area, albeit with a lot of "persuasion" and foul language. I did have to remove the bracket from the engine and, after reversing it, bolted it onto the fiberglass crossmember instead. See photo at www.catalina36.org/comment/43086#comment-43086
(The fitting locations on the replacement HX are not exactly the same, either, as I documented back then: www.catalina36.org/comment/43087#comment-43087 )
But I must say I very much like the way Mitch did it instead. It is now a total PITA to reach the transmission plug and the HX's zinc fitting on mine (essentially its all by feel).
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Mitch/Matthew:
Thanks for the comments. I'd be interested to hear from others about your re-location, Mitch, as it sounds like a great location for maintenance and improved cooling. Does it transfer more heat into the aft berth at all? (There's a raw water filter at that location, on our boat, but, it could be relocated. See attached photo)
Am I measuring the outside diameter of the hx tube to compare 2" to 3" sizes?
Thanks again, skippers!
Paul Lipsit,
Zatarra #406
1985 C36 Mk1 S/R F/K
M-25 Universal Kubota
Port Dover, Ontario
[quote=Chachere] But I must say I very much like the way Mitch did it instead. It is now a total PITA to reach the transmission plug and the HX's zinc fitting on mine (essentially its all by feel).[/quote]
Updating: I just reconfigured the location of our HX the way Mitch did in his boat -- and wow, what an improvement to access!
Not a big job to do (mostly involving replacing a few hoses with longer ones), and while I was at it I took out all that hot water heater bypass plumbing that (apparently) serves no purpose (see previous discussions at www.catalina36.org/forum/technical-discussion/cooling-system-bypass-head... www.catalina36.org/forum/technical-discussion/reason-heat-exchange-bypas...). Now access to the transmission dipstick and the aft-starboard engine mount is easy (almost impossible before), as well as access to the HX zinc and end caps. (See pictures below)
[quote=paul.lipsit]I'd be interested to hear from others about your re-location, Mitch, as it sounds like a great location for maintenance and improved cooling. Does it transfer more heat into the aft berth at all? (There's a raw water filter at that location, on our boat, but, it could be relocated)[/quote]
To answer some of Paul's questions:
1) the raw water strainer on ours was in the same position as appears in your picture; I moved it over a few inches to starboard to make room for the HX. I glassed a small block of plywood to the box that holds the water tank so that there was something substantial to screw the HX bracket into.
2) I haven't noticed any excessive heat issues in the area where it is now located under the aft berth. Actually, when the engine is running, the outside of the HX is fairly cool to the touch, because the raw water is just below the exterior shell (the coolant loop is in the interior of the HX).
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Yes, logically, I would think that the berth is warmed by the re-location of the heat exchanger. This could be mitigated by running the vent blower or installing a heat shield though. When we return dock side, I usually run the blower to suck out the heat anyway.
However, I couldn't venture a guess by what degree the rear berth is warmed.
But to me, it was worth the trade off. The transmission is so much more accessible.
We spend zero time in the rear berth anyway. It's basically a storage area on our boat.
Mitch
1986 Catalina 36 MKI
S/V "Blessing"
Kema, TX
Hull: #584
M25 w/ Oberdorfer Conversion
Just did my winterizing chores this weekend, and was pleasantly treated to the ease in accessing the transmission filler and the heat exchanger zinc with the new configuration I did last spring by moving the heat exchanger. Eliminated those awful contortions.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Thanks for the suggestions . I am doing it now. Do you have the sizes for the pipes that go there?
My goal next week-end, if UPS is cooperative, is to install a new Seakamp 3" 200420 on my boat (http://www.mrcool.us/200420cn-universal-westerbeke-medalist-heat-exchang...).
I would like to fix it the exact same way Mitch did it? Like on this picture:
How do you connect it against the water tank box? Any advices on what hardware I will need to get this done?
Am I going to need to remove the water tank to complete that?
I know someone already ask for it, but if you remember the type of hoses you used to achieve the connection between a 25XPB and the Seakamp 200420, it would be great too :)
Ludovic François
Hotel Catalina - Catalina 36 Hull #883
Marina Del Rey, CA
[quote=ludo]How do you connect it against the water tank box? Any advices on what hardware I will need to get this done?
Am I going to need to remove the water tank to complete that?
I know someone already ask for it, but if you remember the type of hoses you used to achieve the connection between a 25XPB and the Seakamp 200420, it would be great too :)
[/quote] Ludovic -
When I did this modification, I epoxied a block of wood to the wooden box that holds the water tank, with bolts set in it to fasten the heat exchanger bracket (removed from the engine) to the block (its in the first of the photos my post #7 above). So no need to remove the water tank.
As to hoses, black heater hose -- available at any auto parts store or big box home improvement place -- will do just fine. I'm not on the boat so can't tell you the lengths or diameter -- but whatever sizes worked for one boat may not be the same anyway for yours. I do recall that for at least one hose I had to make up an adapter for different diameters between the relevant fittings.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY