"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