This week has been quite the ride on the Good News/Bad News Rollercoaster of life and we have the two most recent examples to share of how we spare no expense of time and energy In our relentless quest to bring you non stop entertainment.  I’m going to divide this up into two separate posts; this one for the ride up to all new highs with my trip up to Gardner Marine Diesel GMD on Monday to join them for the dynamometer testing of Mr. Gee 2.0 and then I’ll do the second post on the ride down to some new lows at the end of the week.  Hang onto your hats boys and girls, it promises to be a wild ride!

Bonus!  Captain Christine has kindly taken all the video I shot during the dynamometer testing and compiled a summary video that I will put down at the end of this posting so for those who can’t wait or just aren’t that interested in all the technical details you can jump to that at any time.

Gardner History

I won’t dwell on it too much but a quick review of the history of the Gardener company and the engines it produced does seem in order to provide a bit of context before we get into my most recent visit to Gardner Marine Diesel in England.  Incredible as it may seem, the L. Gardner & Sons company began 127 years ago (not a typo), starting with the production of gasoline engines in 1895, moved into Barton Hall Engine Works, in Patricroft, Manchester seen in this photo, and began producing diesel engines in 1903.
For any history buffs out there, you can find more details on the history of Gardner engines HERE and HERE

It is difficult to wrap your head around some of these historical dates but to put them into perspective Rudolph Diesel (1858-1913) first came up with the idea of a combustion ignition engine and applied for patents in 1893 and after years of different prototypes and attempts the first commercial diesel engine was produced in 1898 and the first diesel engine of the “trunk piston” type we know today was built in 1901.  Gardner started producing diesel engines in 1903 and so it is not hyperbole on my part to say that Gardner was in the diesel engine production business quite literally from the VERY beginning. 

Gardner & Sons were in business producing diesel engines for more than 100 years but the actual production of Gardner engines ended as did the company, in 1995.  This meant that the large aluminium and cast iron castings of engine blocks, crank cases and heads were no longer being made but all other parts have continued to be manufactured by various companies, most notably Gardner Marine Diesel or GMD which have been my go to Gardner supplier of all parts and expertise since they first found Mr. Gee for us.

It is estimated that there are still several hundred thousand Gardner engines in service around the world on boat land and sea but most are marine.

Putting Mr. Gee 2.0 through his paces on the Dynamometer

Jumping from past to present, this week began reaching new heights on the Good News portion of the roller coaster ride when I flew up to Canterbury England on Monday to spend Tuesday and Wednesday at the Gardner “works” as Gardner Marine Diesel and my British friends refer to it. 

It was an amazing eXperience for me and I’ll do my best to not go too far overboard and bore you with too much detail so please join me for the ride through my visit and all the dyno testing.  If it gets a bit too much for you, they do make the scroll bar for a reason right?
Like most commercial buildings the exterior doesn’t provide too many clues as to what’s inside but this was my fourth visit so I had a bit better idea of what to expect.

I’ve been in almost daily communications with Michael and James at GMD during the whole build of Mr. Gee 2.0 but you can imagine how delighted I was to have THIS mechanical masterpiece greet me as I walked in.
I timed my visit to be there just as the new Mr. Gee 2.0 had been finished and was ready to be put through its paces on the dynamometer for the initial breaking in and full set of testing and measurements of the engine’s overall performance before it was shipped back to Möbius in Greece. 

Here he is all chained up and ready to be transported into GMD’s dynamometer room in the building behind.
Every engine GMD builds is thoroughly tested on this dyno so it didn’t take them long to get our Mr. Gee connected bolted onto the LXB cradle, connected to the dyno itself as well as cooling water, exhaust, start battery, etc..
A dynamometer is a relatively simple device which essentially allows you to connect an engine’s output shaft to a large turbine like wheel inside a housing filled with water such that you can put a load onto the engine when it is running.  Similar to how a pedal type exercise bike works where you can change the resistance to your pedaling to get more or less of a workout.

The two directly measured values on a dyno are Toque measured in pounds feet and shaft RPM measured in Revolutions per Minute.

Here you can see how the dyno shaft is bolted onto the flywheel of the Mr. Gee with a drive shaft transferring the rotation back to the dyno.
The other end of this shaft is connected to the input shaft of the dyno which in turn is connected to the water wheel inside the housing behind which allows you to adjust how much resistance or load is being applied to the input shaft. 

There are two gauges on a dyno as seen here; the large round dial is the “weight” of the force aka Torque, being exerted on the torque arm you can see in the bottom Left and the smaller rectangular gauge is the shaft or engine RPM which we will need to convert torque to Horse Power that I will get to in a bit.
Torque is simply a a force that tends to cause rotation such as the twisting force you apply to the lid of a jar or to the wrench you are using to tighten a bolt. 

Note that there is no motion or speed involved in measuring Torque, just the Force in pounds X length of lever in feet = Torque in Lbs.Ft.  often referred to as “Foot Pounds”

Just like the arm on old weight scales you might remember from your doctors office, the Torque arm attached to the dyno water wheel needs to be balanced out to zero the scale and so these old pistons are used to counteract the weight of the Torque arm to zero it out such that it “floats” in place and the gauge reads zero pounds.
You can see how the torque arm is then connected up by these rods and joints to the scale itself. 
End result is that this large gauge shows how many pounds of force is being applied to the lever.  At the time I took this photo, the force on the lever arm was 11.0 pounds. 

This weight or torque on the lever arm is the one value that is directly measured on a dynamometer and this value can then be plugged into a simple formula to produce the calculated value of the Horse Power or HP that the engine is producing at that moment.  Without getting into the details there are several different kinds of HP such as Brake HP and Shaft HP to name a few, but what makes these water wheel type dynamometers particularly well suited to measuring the HP of marine engines is that they measure what is known as Propeller Absorption HP.  This tells us what we really want to know which is the power that will actually end up being transferred to the propeller and the water rather than the other more theoretical HP ratings.

For the final bit of the calculation puzzle then, this plaque on the dyno tells you that the factor that takes into account the Length of the Torque arm which you need to use to calculate the Propeller HP from the weight scale.  For this dynamometer that factor is 400

Putting this all together, the formula for calculating the Propeller HP or PHP is:

 Weight Scale readout in LBS x RPM

400

Therefore, in this example the PHP would be: (click to enlarge any photo)

22.8 LBS x 1220 RPM

400

= 69.54 PHP

With the maths all sorted out we can now run Mr. Gee through his paces on the dyno by measuring the Torque at different RPM, convert this to PHP as above and then plot these readings out on this original graph from the dyno at the Gardner Factory in 1989 for a 6LXB Marine Propulsion Continuous Duty rated 150HP @ 1650 RPM to see how the numbers compare.

For those interested in PHP to BHP comparisons you can check the intersections of any vertical RPM line to the upper Shaft HP curves #2 and then look down on PHP curve #3.  At 1400 RPM Shaft HP is about 135 and Propeller or PHP is about 80HP.  As you can see these curves come together at the upper RPM of 1650 where both are 150HP.
Each fuel injection pump has this stamped plate affixed after the pump has been fully calibrated to show which rating this engine has.  Mr. Gee has now been set up for a Continuous 100% rating of 150HP @ 1650 RPM.  The 100% Continuous rating is what we need and care about on Möbius as this is the HP that the engine can run at 24/7 on our multi day/week passages.  Of course we will normally run at a lower RPM, usually around 1200-1400 in order to have the Goldilocks Sweet Spot combination of load, fuel consumption and boat speed.
Depending on the load applied, the HP at any given time on the dyno will be somewhere between Prop HP and the Shaft HP because Gardner engines control the amount fuel injected using a a governor rather than a direct connection to the throttle levers as with most engines.  This governor is normally fully sealed inside an Al housing that was left off so that the throttle settings could be adjusted during testing.

This “set it and forget it” type of throttle is a particularly great feature when teamed with our CPP Controllable Pitch Propeller in that we can set the RPM to whatever speed we want and the governor will automatically adjust the fuel as the load changes due to wind and sea conditions and keep the RPM at that same amount. 

All the HP in any combustion engine originates with the amount of fuel it has to burn and so more or less fuel means more or less HP.

First order of business before starting the dyno testing was to do the initial break in and get the engine thoroughly warmed up.  Michael aka Mr. Gardner in White and James the Master Gardner builder in Black.

After an initial warmup run for about 45 minutes at 800 RPM with mid load of 12-13 Lbs until the thermostats opened, the speeds and loads were increased in stages.  In this shot you can see there is 22.6 Lbs @ 1210 RPM so that would equate to an output of about 68 PHP (22.6 X 1210 / 400 = 68.37)

We started the engine for the first time at 12:15 and he started right up in less than one rotation of the crankshaft which was a great start to the testing. (sorry couldn’t resist) 

Then it ran with this 800 RPM low load for about an hour until the thermostats had fully opened and the engine oil was getting nice and warm at about 42C / 108F.  As you will see below, this oil temp will go up to the normal range of about 55-60C / 130-140F as more RPM and load is applied during the testing.  Oil Pressure is 38 PSI which is a bit higher than the 35 PSI it will settle into.

For those familiar with most other diesel engines will note, the oil and water in these large volume slow speed Gardner engines run much cooler and lower pressures as they are under much less stress and load and this is part of why these engines are so much longer lasting.

Exhaust Gas Temperature EGT measured here on the outside of the exhaust manifold is also mid range at 297C / 566F at this mid load and RPM.

We also kept a close eye on the exhaust as it exited the dyno room.  Even during the first startup and there was nary a hint of any smoke which is a great sign of a good rebuild with the rings seating quickly.

Readings from the dyno, water + oil temps and oil pressure were noted throughout the four hour dyno run.
All that data was transcribed into this spreadsheet after the dyno testing was all done.  Click to enlarge if you’d like to go through all the numbers.

Continuing to go up in stages, this is now a notch higher at about 25.5 Lbs @ 1350 RPM = 86 PHP and run at this stage for about an hour.

Up to the next stage of 1500 RPM at about 30.2 Lbs = 113 PHP

All the way up to max rated RPM of 1650 which netted about 35 lbs = 144 PHP and ran it here for about 30 minutes.
EGT nice and toasty at 487C / 909F, about as high as we will go.
Water temp at this top stage of testing reaching its designated maximum temp nicely of 66C / 150F
Last run in the series was to go above max rated speed of 1650 to about 1700 RPM and hold it there for about 15 minutes just to make sure everything held its own when fully maxed out. 
James kept a close watch for any signs of leaks throughout the whole testing and we were all delighted to find none.
Then the process was reversed bringing RPM and loads back down a notch at a time to gradually bring down the temperatures and check outputs throughout.  Down to about 1350 RPM and 71 PHP here.
Down to 1000 RPM for the final cool down before going to idle.
Water cooled down to 64C at the lower speeds and loads now.
And oil pressure pretty much spot on at 36 PSI, factory spec is 35 PSI @ 1000 RPM when fully warmed up.

Dropped it all the way down to set the idle speed to be the desired 480 RPM and shut down the engine off at 16:00 so total run time of the dyno testing was just short of 4 hours.

The all new Mr. Gee 2.0 passed all his tests with flying colours and we all left with very big smiles on our faces.

Next day, James soon had Mr. Gee out of the Dyno room, securely strapped onto his wood pallet ready to be shrink wrapped for shipping.  The engine was picked up the next day and on Friday morning he was on the ferry out of the UK then down the continent by truck and onto another ferry to Piraeus/Athens.  Then clears customs and with some luck *might* be on the final ferry from Athens to Kalymnos by next Friday.

Fingers crossed that the return trip will be MUCH shorter than the 8+ weeks it took to get him from Kalymnos to Gardner in the UK now that the crush of the summer tourist traffic is winding down.

Hurry home please Mr. Gee, can’t wait to put you back home in your engine beds on Möbius so we can head back out to sea again soon.

Bonus Video compilation:

As promised, Captain Christine took all the videos I shot during the dyno testing and put them together into the video below.   Enjoy!

Thanks for tuning in here again and be sure to leave any and all comments and questions in the “Join the Discussion” box below.

– Wayne