[C320-list] Another Perkins M30 Overheating Help Thread

[Dan Winsor]

I believe it is possible to get an air trap in the heater hoses to/ from
hot water tank. Do you think a temp short bypass loop is worth a try?

On Sat, Jun 10, 2023, 10:51 Dave Hupe via C320-list <
c320-list at lists.catalina320.com> wrote:

> Don't  believe it is possible to "remove the raw water hose from the
> exhaust elbow and run it overboard". It is a very short rubber nipple
> attached to the exhaust elbow that is part of the rear rubber boot
> connected to the rear of the heat exchanger tank/tube.
> Dave Hupe
> 1994  C320 #32
> Holland,  MI
> Sent from Yahoo Mail on Android
>
>   On Fri, Jun 9, 2023 at 9:18 PM, Dan Winsor via C320-list<
> c320-list at lists.catalina320.com> wrote:   Hey all, this is a good one.
> So.... now that we have confirmed fresh water
> flow via clear hose section (great idea), let's focus on heat transfer. The
> fresh water gains heat from circulating around the cylinders and dumps heat
> by transferring to the raw water via the heat exchanger and the hot water
> heater via a coil located within. Those two circuits are parallel flow and
> the hot water heater will get less flow due to smaller hose size. Does the
> hot water heater get hot?
> The engine heat exchanger is the primary heat dump of course. Although I
> have not had cause to open mine, I assume it to be a shell and tube type
> exchanger where raw water runs thru tubes from the fwd end to the aft end
> of the exchanger and the tubes are surrounded by fresh water being
> circulated by your new engine water pump. The radiator cap being on top of
> the exchanger shell insures that if the water level is near to the top then
> the likelihood of airbound condition is minimal. The expansion tank being
> even higher pretty much guarantees it. Have you run with cap removed and
> seen flow thru the shell?
> The wet exhaust is a good indication of raw water flow but can be somewhat
> hard to differentiate good flow from low, especially with the pulses from
> the muffler. I would second the suggestion to resort to a contact
> thermometer and start tracing the heat. I frequently grip the hose leaving
> the raw water pump (cool to touch) and the hose entering the exhaust elbow
> (quite warm) during my engine testing prior to launch.
> Here are some additional suggestions....
> 1. monitor the expansion tank and verify that level rises as engine heats
> and returns to prior level as engine cools. this will verify proper
> operation of the radiator cap and the plumping between the cap and the
> tank. should eliminate air concerns.
> 2. when eng temp starts to climb, try running hot water and see if that
> stabilizes or slows the rate of increase.
> 3. remove the raw water hose from the exhaust elbow and run it overboard.
> Cob some plug on the elbow where the hose was attached. This will minimize
> back pressure on the raw water pump and create more flow thru the tubes
> thereby transferring more heat. This will also eliminate the exhaust line
> from being a cause. Of course exhaust flow will be louder and get hotter so
> don't run that way too long.
> 4. remove the large rubber end caps at one or both end of the heat
> exchanger and clean the inside of the tubes with a bottle brush. fouled
> tubes cant transfer heat well.
> 5. verify indicated eng water temp with contact thermometer.
> Sorry if I repeated any testing you have already done. I also have the
> perkins and have a vested interest in your issue. Lets solve this thing and
> save your trip!
> Dan Winsor
> Lucky Devil #109
> Mattapoisett, MA
>
> On Fri, Jun 9, 2023 at 1:20 PM Paul Hetherington via C320-list <
> c320-list at lists.catalina320.com> wrote:
>
> > Jeff and Dave thanks for your comments.  Thanks for sticking with me on
> > this.
> >
> > Dave, you are correct we are in Salt Water and have replaced the exhaust
> > elbow.  It was relatively inexpensive and easy to do so it was high on
> the
> > list.
> >
> > Jeff, we may very well have air in the system it sounds like.  After
> other
> > fixes we may not have been focusing on getting it all out well enough,
> > giving us the impression other fixes didn't work?  Going to play with
> ways
> > to eliminate it.  I'm not sure I understand the funnel method you
> mention,
> > but I am doing some research.  Also looking into whether a pressure
> tester
> > would be of value.  Dave mentioned 7psi.  Gonna chase that down.
> >
> > We did think perhaps we were over propped (good suggestion), but after
> > working with the outfit that built our prop up here in Naniamo (he was
> very
> > helpful) it actually appears we may be under propped which is resulting
> in
> > our not achieving expected speeds and thus wanting to push the revs up.
> We
> > are working with that as separate issue and will be re-pitching after a
> > haul out in 2 weeks.  Hopefully that doesn't exasperat our overheating
> > issue, but at least we will be able to achieve a higher speed at the
> lower
> > rpms we are currently forced to operate under.
> >
> > Will report back.
> > ----------------------------------------------------------------
> > Paul Hetherington
> > Seasun, 1994, Hull #155
> >
> > On Fri, Jun 9, 2023 at 8:48 AM Jeff Smith via C320-list <
> > c320-list at lists.catalina320.com> wrote:
> >
> > > You might try running the engine without the cap on (apologies if this
> > has
> > > been suggested). It sounds like air in the coolant. There is also a
> > > no-spill funnel that you can use with coolant to make sure there is no
> > > trapped air. This involves filling the funnel with coolant and running
> > the
> > > engine and letting air bubble out. It might be getting into the system
> > > through the cap.
> > >
> > > Is it also possible you are over-propped? I know you just installed a
> new
> > > prop and the problems also just started. Either too much pitch or
> size? I
> > > am sure, based on the list of stuff you have replaced, that this is not
> > an
> > > issue. But, I have a max prop with adjustable pitch, and the previous
> > owner
> > > (or me the last time I serviced it) set the pitch too low.
> > >
> > > Good luck. Let us know if you figure it out.
> > >
> > > Jeff Smith, #121
> > >
> > >
> > >
> > > On Fri, Jun 9, 2023 at 9:54 AM Dave Hupe via C320-list <
> > > c320-list at lists.catalina320.com> wrote:
> > >
> > > > Looks based on your photos like some minor coolant leak around the
> > > > "radiator cap" neck on the heat exchanger tank. The cap looks
> > > > original/rusty. So, wouldn’t hurt to replace it (7psi is what is
> > spec'd).
> > > > However, without seeing a trail of coolant leakage there, I am not
> sure
> > > > that is your problem.
> > > > I have heard about blockage in the exhaust elbow causing overheating.
> > Any
> > > > consideration of that?  I replaced my entire heat exchanger tank
> > because
> > > > the "radiator cap" neck on the tank had a piece cracked off where the
> > cap
> > > > should seal.  I had to remove my exhaust elbow attached to the tank
> and
> > > > remount it on the new tank.  I carefully inspected my elbow and it
> was
> > > very
> > > > clean and seemed fine to reuse.  My boat has always been in
> > > freshwater.  I
> > > > don't see on the hull roster or your posts where you are located
> > > > (saltwater??). That can make a significant difference related to
> items
> > > like
> > > > this.
> > > > Dave Hupe
> > > > 1994 C320 #32
> > > >
> > > > Sent from Yahoo Mail on Android
> > > >
> > > >  On Fri, Jun 9, 2023 at 1:42 AM, Paul Hetherington via C320-list<
> > > > c320-list at lists.catalina320.com> wrote:  So still trying various
> > > > suggestions here and have ordered a fresh water
> > > > pump.  But we put a clear hose on the fresh water loop today and it's
> > > very
> > > > obviously circulating water.
> > > >
> > > > We thought we had maybe fixed the overheating after really running at
> > > high
> > > > revs the other day for testing of the prop (dislodged something?) so
> > did
> > > > some measurements/testing.  Unfortunately the temp climbed to 200
> after
> > > > about 30 minutes at 2700.  It dropped back down to 180 after 20 min
> at
> > > > 2000, and then climbed back to 185 after 30 minutes at 2500.  Not
> sure
> > if
> > > > it had plateaued because we had to come in.  But clearly still have a
> > > > problem.
> > > >
> > > > Any chance a small leak in the rad cap could cause this?  Here are
> some
> > > > pics.  We can't see  a leak, or water coming out but it looks
> corroded
> > > and
> > > > we are trying anything at this point.  What is the best way to test
> > this
> > > > out?
> > > >
> > > > Pics here:  https://photos.app.goo.gl/E83NV9cPXe6JFXXZ8
> > > >
> > > > We are getting pretty discouraged at this point.  The boat is usable,
> > but
> > > > the month long journey we have planned for this summer is going to be
> > > tough
> > > > with 4 knots through the water.  Especially because some of the
> passes
> > up
> > > > here can be 8 knots (really have to time it!).
> > > >
> > > > Thanks, Paul.
> > > >
> > > > ----------------------------------------------------------------
> > > > Paul Hetherington
> > > > Seasun, 1994, Hull #155
> > > >
> > > >
> > > > On Mon, May 29, 2023 at 7:27 PM Paul Hetherington <paul at heth.ca>
> > wrote:
> > > >
> > > > > Some good thoughts here. Thanks to all.  Will be trying a few
> things.
> > > > >
> > > > > One thing that has come up, how would we best confirm the non-raw
> (so
> > > > > fresh) water pump is working well?  There is no impeller that I
> know
> > > of,
> > > > so
> > > > > not entirely sure how the water is 'pushed' around the circuit. It
> > > would
> > > > > stand to reason that if this water isn't moving well then the
> cooling
> > > > > transfer won't be efficient and the temp would rise.  I'm just not
> > sure
> > > > how
> > > > > to best test this.
> > > > >
> > > > > Cheers.
> > > > >
> > > > > ----------------------------------------------------------------
> > > > > Paul Hetherington
> > > > > Hull 155, 1994 Seasun.
> > > > >
> > > > >
> > > > > On Mon, May 29, 2023 at 1:08 PM Dan Winsor via C320-list <
> > > > > c320-list at lists.catalina320.com> wrote:
> > > > >
> > > > >> Here's my two cents worth...
> > > > >> If the engine can't transfer its heat to the raw water then the
> raw
> > > > water
> > > > >> would be cold when it enters the exhaust elbow. If that's the case
> > > then
> > > > >> swap out your new water pump. I don't believe in coincidences like
> > > that.
> > > > >> Dan Winsor
> > > > >> Lucky Devil #109
> > > > >>
> > > > >> On Mon, May 29, 2023, 15:41 P.F. Ross via C320-list <
> > > > >> c320-list at lists.catalina320.com> wrote:
> > > > >>
> > > > >> > Paul,
> > > > >> >
> > > > >> > Your experience sounds very much like mine.  I run at 190 at
> 2700
> > > rpm
> > > > >> > cruise (I have an Autoprop) and have done all the things you
> have,
> > > > >> except
> > > > >> > for doing the temp testing with a non contact thermometer.  It
> has
> > > > been
> > > > >> > this way for many years and over those same many years replacing
> > the
> > > > >> temp
> > > > >> > sender has been on my list.  I figure it is the only thing I
> have
> > > not
> > > > >> done.
> > > > >> >
> > > > >> > I watch the temp gauge like a hawk, but it has always held
> steady
> > at
> > > > 190
> > > > >> > except for once when I sucked a plastic bag into the raw water
> > > intake.
> > > > >> So
> > > > >> > at least I know my temp gauge moves!
> > > > >> >
> > > > >> > Frank Ross
> > > > >> > Beta Wave #206
> > > > >> > Naples, FL  34102
> > > > >> >
> > > > >> > On Mon, May 29, 2023 at 2:26 PM Dave Hupe via C320-list <
> > > > >> > c320-list at lists.catalina320.com> wrote:
> > > > >> >
> > > > >> > >
> > > > >> > > https://www.parts4engines.com/perkins-perama-m30-water-pump/
> > > > >> > > This would be the engine water pump.
> > > > >> > > Dave Hupe
> > > > >> > > 1994 C320 #32
> > > > >> > >
> > > > >> > > Sent from Yahoo Mail on Android
> > > > >> > >
> > > > >> > >  On Mon, May 29, 2023 at 3:02 PM, Paul Hetherington via
> > C320-list<
> > > > >> > > c320-list at lists.catalina320.com> wrote:  Yes our M30 is
> running
> > > > hot.
> > > > >> > > 2500 rpm = 190, much over that and it pushes
> > > > >> > > over 200.  Haven't had the guts to push it right into
> triggering
> > > the
> > > > >> > > overheating alarm (203? - not totally sure it's functioning).
> > But
> > > > we
> > > > >> > used
> > > > >> > > to be able to run at 2700 with no overheating (185-190) and
> now
> > it
> > > > >> heats
> > > > >> > up
> > > > >> > > very quickly.
> > > > >> > >
> > > > >> > > I am pretty sure I have read all the previous threads and
> tried
> > > many
> > > > >> of
> > > > >> > the
> > > > >> > > suggestions but we are still stuck, so posting our detailed
> > > approach
> > > > >> is
> > > > >> > > only to clarify it to myself, but hoping to get some
> > insight/ideas
> > > > >> from
> > > > >> > > your experience.
> > > > >> > >
> > > > >> > > Here is what we have tried:
> > > > >> > >
> > > > >> > >  - Checked the raw water intake and all was clear.
> > > > >> > >  - Removed hose between seacock and water filter and confirmed
> > > good
> > > > >> > water
> > > > >> > >  intake flow through seacock
> > > > >> > >  - Diver conformed no obstruction from below at the entrance
> of
> > > the
> > > > >> > >  seakcock
> > > > >> > >  - Topped up the coolant
> > > > >> > >  - Replaced the impeller
> > > > >> > >  - Replaced the thermostat (Even though the old thermostat was
> > > > >> working
> > > > >> > >  fine when I tested both of them in boiling water)
> > > > >> > >  - Took out the heat changer and cleaned in a bath of muriatic
> > > acid.
> > > > >> It
> > > > >> > >  was then very clear.  It was not that clogged up to begin
> with
> > > > >> though
> > > > >> > >  - Replaced the exhaust elbow (after ordering one with current
> > > > >> > downstream
> > > > >> > >  tube diameter)
> > > > >> > >  - Replaced the raw water hoses between the intake seacock,
> > > between
> > > > >> the
> > > > >> > >  raw water filter and the water pump with new reinforced hoses
> > to
> > > > >> make
> > > > >> > > sure
> > > > >> > >  that they are not collapsing
> > > > >> > >  - Kept testing the engine in forward gear, tied to the dock,
> > and
> > > > >> > >  measured temperature with heat gun all over engine block, to
> > > > >> confirm it
> > > > >> > >  wasn't a gauge issue.
> > > > >> > >  - When engine was ran at 2500 rpm or higher, measuring
> > > temperatures
> > > > >> > >  between 195 and 200 around the coolant pump
> > > > >> > >  - Always seemed to have good water flow coming out of the
> boat
> > > > >> > >
> > > > >> > > Right around the time we started to have overheating issues
> two
> > > > other
> > > > >> > > events happened that may or may not be related.  We switch
> from
> > a
> > > > >> tired
> > > > >> > and
> > > > >> > > chipped 2 blade prop to a 3 blade Campbell Sailer prop AND the
> > > water
> > > > >> pump
> > > > >> > > was leaking so we replaced it with this one from
> parts4engines:
> > > > >> > >
> > https://www.parts4engines.com/perkins-perama-m30-raw-water-pump/
> > > > >> > >
> > > > >> > > Any help is appreciated.
> > > > >> > >
> > > > >> > > Cheers.
> > > > >> > >
> > > > >> > >
> ----------------------------------------------------------------
> > > > >> > > Paul Hetherington
> > > > >> > > Hull 155, 1994 C320
> > > > >> > >
> > > > >> > >
> > > > >> >
> > > > >>
> > > > >
> > > >
> > > >
> > >
> >
>
>