Done so far:
Prop clean
Hull clean
Thru-hull clean & clear
Strainer clean
Hoses apart and clean
Rebuilt pump with new impeller
Heat exchanger clean and shiny
New thermostat (tested)
Flushed coolant Came out clean
New radiator cap (tested)
Added coolant resevour

I am interested in mickey's bypass he has for the water heater and how it is
plumbed. I think I want to be able to isolate the water heater anyway.

Next: Exhaust manifold to talepipe comes out.

Thanks again - Allen

how did you clean the heat exchanger? I've heard anything up to and
including muriatic acid. How old is you exchanger? A new exchanger for
about $150 may be an investment, at least so you can keep your old one
as a spare, but first try to see if you can get good water flow through
it.

Email me directly about the bypass,p lease, and I'll try to send you
pics.

cheers
mickey

I took the heat exchanger off with the intent of sending it to the radiator
shop but it was very clean and all tubes were clear so I gave it a quick
bath in some phosphoric (?) acid I had on hand. It came out very shiny. I
capped the ends and pumped in some air pressure let it sit over night for
each side to check for leaks. I would like to have a spare if you know of a
good used one.
-Allen

"bushman" wrote in
m:

Thanks again - Allen



Armed with all this new information, let me ask you how bad does it smoke?
Black or white smoke?

You've eliminated all the cooling system problems I know of in this simple
diesel. Now, I'm wondering if you don't have an injection issue or an
overloading problem....

I assume this prop used to work fine and didn't overheat the engine, right?
Has anyone been under the boat to see how bad the prop is fouled?

When you rev it up with the transmission disengaged, does it rev up much
better than when it's engaged?

An observation we all made after Cutter Doc in Daytona worked on the
injectors was how much COOLER the engine ran. I'm talking about 30 degrees
cooler! All that was done was to fix the injectors, besides getting the
seawater out of it. It still just opens the thermostat even if you run it
wide open throttle! Does yours seem to knock harder than usual, an
indication of bad spray pattern on the injector? Has anyone checked the
injection TIMING on the Perkins?

This injector difference also showed up on another friend's Hatteras 56
with twin 8V92TAs in it. One engine ran hotter than the other and the
thermostats had been in it quite a while so I changed them. Didn't change
the problem. I noticed the port engine seemed to labor more than starboard
and ran hotter. The diver said everything under the boat was fine when he
cleaned the Charleston off her. We got a diesel shop to pull the injectors
and take them in to test them. One of the injectors on that port engine
wasn't spraying properly and the TIMING was out of specs! They replaced
the bad injector and reset the timing and the engines sync'd better and
pulled more evenly. Both engine temp guages in the engine room and at the
helms were even after that.

--
Larry

Larry:
I think you are right that I do have injector issues, but I think they are
just old. The engine starts as soon as the key is turned. The only smoke is
a black puff when you floor it and maybe a little black when at full
throttle. The prop is clean and from all acounts was correctly sized by the
boat builder 17X17. Hull speed is reached at about 2K at one gallon per
hour, full throttle in gear is 3K, in nuetral is 4K+ (max rpm per Perkins).
My plan is to replace the injectors myself then hire a mechanic to adjust
the valves and check the pump timing. I hope this will get me more economy
as I have more than enough power now. The more I work on it the more I think
of pulling it out and rebuilding. The savings in leaking oil would pay for
it in 5 years or so.
- Allen

"bushman" wrote in
m:

Larry:
I think you are right that I do have injector issues

There's your overheat problem. The sooner you fix it, the sooner it will
stop overheating. Lionheart's 4-108 barely opens the thermostat, even at
WOT, now.

I didn't learn about this injection from boats. I have a 1973 Mercedes
220D taxi cab I restored. Before the restoration, at about 350,000 miles,
the engine ran about 85-90C in normal driving. When it was restored, the
mechanic said we should put on a rebuilt pump from an old German guy in
California who's been rebuilding them for 40 years. I agreed and am glad I
did. The restored engine gets 38mpg on a 5000# car and never reaches 80C
on a really hot South Carolina day with its AC running full open. Although
it's only 57hp, virtually the same size as the Perkins, at 70 mph it no
longer sounds labored cruising along. It has more power and doesn't smoke,
at all, until you're accelerating wide open. Injection timing is
controlled by a lambskin diaphram and a bellcrank to the throttle...totally
mechanical. I expect it to outlive me, easily.

--
Larry

too bad you don't see many Mercedes diesels in boats this side of the
pond. I've a 1985 300SD just shy of 300K, and it runs like a dream.

"mickey" wrote in
oups.com:

too bad you don't see many Mercedes diesels in boats this side of the
pond. I've a 1985 300SD just shy of 300K, and it runs like a dream.



Me, too. 1983 (European 82) 300TD estate wagon. 428K on it this morning.
The shift knob on the automatic transmission needs replacing...(c;

--
Larry

"bushman" wrote in
m:

I am interested in mickey's bypass he has for the water heater and how
it is plumbed. I think I want to be able to isolate the water heater
anyway.



Ours is a T of 3 valves. Two valves shut off the hoses to the water heater
in case it ruptures or a hose fails. The other valve is the bypass valve
across the engine side of the other two valves.

-----------T--V-----------
Engine V Water heater
-----------T--V-----------

I'm not sure the bypass valve across is really necessary. It came on the
boat. All the cooling water can't go through the water heater, just like
all the cooling water in your car doesn't go through your heater
core...same idea. The water heater just bypasses the thermostat and heat
exchanger and I'd think the bypass valve would make the engine run hotter,
not cooler, if the thermostat were normally near open where it couldn't
compensate. Other than when the heater was replaced and moved OUT of the
engine room into the lazerette so we could get to the front of the engine
and belts easier, the valves have never been closed. Maybe I'll fool with
them and see what the effect of shutting down all 3 valves does to engine
temperature some time.

--
Larry

Larry
I've a similar setup, but without the valves from the Tees to the
heater. (I figure if a hose breaks, I could just replumb the existing
hose. Actually, I didn't figure anything--it came that way! I
leave the valve across (the middle in your diagram) open most of the
time. (if it's winter and cold and want some hot water fast, or the
engine is not getting up to temp, I close it, but that's rare.)

It sounds like your valves a little different though--If I had three
valves and shut them all off, then there would be no coolant
circulation on my system or engine. I'm also not sure I understand how
the water heater bypasses the thermostat and heat exchanger. My
coolant runs:

engine - water heater (with bypasses) - heat exchanger

part of my problem is that the wtaer heater hoses are smaller than the
engine hoses, so obviously I need something to give there, thus the
bypass. Here's a diagram: (best viewed with a fixed-width font)

WATER HEATER
: :
: :
engine......____L___/___L____......heat exchanger (to engine)

Of course, the heat exchanger is mounted on the engine, but it's hard
to loop with these text diagrams Here ... and : are hoses, _L_ is
a T and _/_ is a valve. I have no valves between the _L_ and the heat
exchanger.

mickey