Hey everyone,
My wife (Guen) and I just purchased a 1983 Cat 36. It has an M25 Universal and when I bought it the engine wasn't running...It is currently on the hard on our property. We are planning a full overhaul...hmm...
I have been researching and learning all about this specific engine. I have a few questions that I was hoping someone could help with or at least give me some good pointers to some resources so we can teach ourselves.
Here is what i know?/ don't know?...
1) For my own knowledge (What's the difference between an M-25 and an M-25XP?) I have learned that an updated heat exchanger is on the XP is at least one difference?
2) I was able to get the engine running today. The raw water inlet has a plastic sea cock that can direct water from sea/ lake water or through a hose that can be placed in your own source. I am unsure if i had this configured correctly. I do know that it wasn't in line with the through hull which tells me sea lake/water is isolated...but not sure if it allows suction to the short hose inside...
3) There was zero suction from the bucket of water I had. Nothing came out of the bucket.
4) I shut down the engine and tried to trace the direction of flow. The flow to the raw water pump was apparent...and the raw water to the heat exchanger is apparent. The pump seemed to have rotation...but I have not inspected the impeller yet. The pressure after the pump was of course quite substantial compared to before the pump...I assume this makes sense but I also feel water wasn't exiting as it should.
5) I see the siphon/vent i believe on the top of the heat exchanger/ same side as the raw water inlet.
6) I also notice a line going from the exchanger to the fresh water pump.
7) I am not completely confident i understand the others. It appears that there are two lines coming from the bottom of the exchanger that can be connected/ isolated through a valve with a bleed. Is this to heat potable water? I assume this must go to another heat exchanger? I assume hot raw water isn't pumped through the potable water taps or was this an option in the 80s?
8) I also notice a line coming from the heat exchanger right to the bottom of the fresh water reservoir close to the exhaust. Not too sure on the direction of flow here.
9) This is a great lakes boat...i don't see a strainer after the sea cock...normal?
Thanks for your help everyone! This is my first post. If i need to change how i ask questions or where this should be placed...please let me know! We love this boat. I sailed with a friend of mine who also had a MK1 on the east coast of NFLD for a few years...i know there are some quirks...but...overall a great boat.
Talk soon!
Luke
SV Plan "B" (To be renamed though as this is the previous owner's name)
Do you have the Catalina 36 MkI Owner's Manual? Page 48 has a coolant diagram & Page 49 has an exhaust diagram which might help you trace out the various hoses. Other manuals, including the engine manuals are here.
2.) That doesn't sound standard but I have heard that some people would modify the raw water intake to either allow for a fresh water flush or emergency engine bilge pump. I you have any photos of the set up it might help people identify.
There could be a clog or valves might be misaligned.
4.) Hard to say. If there is pressure after the pump then there could be a clog somewhere in the system.
7.) Mine has hoses with a ball valve to direct hot water to the the hot water heater & to adjust the temperature. I assume added by a prior owner. Not a great photo but you can make out the red of the old heat exchanger behind the piping Refer to the hot and cold water diagrams to get a better handle on tracing those various hoses.
9.) Mine (1984) didn't come with a sea strainer, it went straight to the raw water pump. I have since added a sea strainer.
Ultimately, it might take some time crawling about inside tracing the various hoses to ID them. Having a partner to help can make it easier since sometimes you can shake or jiggle a hose and they can confirm which one at the other end. I use a sharpie to mark an arrow showing the direction (and a label of what it goes to) once I figured it out.
There's a chance that the clog could be with the heat exchanger. I ended up replacing my heat exchanger and exhaust riser (mine had a yanmar style riser installed). Good luck!
Steve
SV Ringle
C36 MKI #358
Steve Orosz
s/v RIngle
1985 Catalina 36 Mk I #358
San Francisco Bay