Generator and Lehman Engine Projects and Notes

Random Engine Notes:

Other random Engine Notes from Brian at American Diesel:

Exhaust Elbow Replacement

Hoses:

Small hose (transmission cooler?) - 1"

Main exhaust hose:  3.5"

If replacement is needed, use rubber hose (per Brian at American Diesel), not silicon.

Replacement elbows ship as raw steel, and should be painted.  Brian recommends just painting with regular paint.  The paint will burn on the bottom, and turn black, but will be better than having raw metal oxidize.  He suggested that normal paint is ok, as either normal or even high temp paint will likely burn on the lower portions of the elbow.

Steps for replacing the exhaust elbow:

1)  CLOSE the main engine seacock.

2) May need to pinch off shaft log exhaust water hose.

3)  Need to drain coolant down several gallons.

a)  There are two drain plugs at the bottom of the heat exchanger.  The one furthest from the cap is the coolant.  The other one is sea water.

b)  With the petcock at the top of the manifold still closed, loosen the furthest drain plug - some coolant will start to drain.  Remove plug, and replace with hose as quickly as possible.  Hopefully with everything closed up, not much coolant will spill out.

c)  With a hose on the drain opening, going to a bucket, open the petcock at the top of the manifold and open the fill cap on the top of the exchanger to allow air in  (and water out).  Drain ~3 gallons.

4)  With the coolant drained, remove the exhaust hose and the secondary hose on the elbow.  Then loosen the bolts holding the elbow in place.   The large hose on the stbd engine elbow was stuck - ended up removing elbow, then using hose puller, followed by driving  long screwdriver into hose to loosen.  The upper two bolts were much easier to remove than the lower two bolts on both elbows.  The starboard lower bolt required lots of PB Blaster, lots of tapping, and then use of a standard length 9/16" socket, with a socket extension, and a 24" breaker bar to loosen.   Note that 3/8" drive sockets and extensions must be used.  1/4" extensions sheer due to the forces required in breaking the bolts loose.

5)  Install the elbow for the heat exchanger hose.  Anti-seize was used on this fitting.  The fitting was screwed mostly in, and left for final tightening / positioning until the elbow was bolted to the manifold.

6)  Replace the elbow, using the new supplied gasket in the kit (and new bolts).  Use anti-seize on the bolts (?).   NOTE:  Use Permatex #2 Form-a-Gasket Slow Drying / Non-Hardening sealant on the MANIFOLD side of the gasket to seal the gasket.  Do NOT put Permatex on the ELBOW side of the gasket - this will allow the elbow to come off easily, then the gasket may be peeled off the manifold.

7)  With the petcock open and the cap open, re-fill 


Port Engine exhaust elbow was started 2/12/22.  A 1/4" fitting  and addapter was used to drain coolant from the heat exchanger into a 5 gallon collapsible water container.  One of the four bolts on the elbow sheared off, leaving a stud of about 3/8" long protruding from the exhaust manifold.  Attempted penetrating oil and use of an external bolt extractor (not an "easy-out" - did not yet resort to drilling out the bolt).  That did not work.   However, at Steve's suggestion (Dock 18 friend), lots (~5 min+?) of tapping on the stud with a hammer, and repeated applications of PB Blaster finally loosened the bolt enough that it could be extracted with a pair of vice grips.

In further discussion, Brian (American Diesel) suggested using studs and nuts to install the new exhaust elbow, rather than the supplied 4 bolts.  That would remove the potential issue of the bolts sticking in the future.  2" x 3/8" studs were ordered and used on the upper bolt positions.  Unfortunately, due to the lack of space between the bolts and the elbow body, the standard bolts (not studs) had to be used in the lower two positions - which are also the most problematic to remove (this is where the water is...).    Actually - in retrospect - Studs were used in all 4 positions on the port engine, but only the top two positions on the starboard engine.   Let's hope that the generous amount of anti-seize will help if this job needs to be repeated within my lifetime (or ownership) of the boat.  The rest of the assembly went without issue.   Installation of the port elbow was completed on 2/19/22.  Total engine hours at that point were 4274.8 hours.  Drained coolant was poured back into the system, and about 1/3 to 1/2 gallon of distilled water was added to top off the tank.   Engine was run for 30 min with no leaks and no issues.

Replacement of the starboard elbow was started and mostly completed on 12/28/22, at 4305 engine hours.  For whatever reason, this elbow was not as severely rusted as the port elbow.  From the exact color match of the old elbows to the engine paint, one might guess that these may have been the original elbows - though Brian from American Diesel said that couldn't be - as the elbows only last ~1500 hours.  Perhaps we got lucky?


Oil Change

At about 4280 hours (mid July, 2022), I finally took the time to sop up the oil that had been accumulating under the engines.  It had been there since I bought the boat.  Not a lot, not enough to be a major concern.  But definitely something that I should have gotten around to much sooner than later.   When I finally got around to cleaning up the mess, I discovered that there was a lot of water in the oil (not surprising, as water could get in the pans under the engines rom any number of places).

I then checked the oil in the engines.   Both engines showed plenty of oil.  In fact, they showed that the oil lever was closer to the factory mark on the dipsticks - well above the scratched mark that was probably made when the engines were installed, or at least by a careful previous owner that was aware of the slant of the engines and took that into account.

The more alarming issue that I saw was that the starboard engine oil had a tannish brown color to it, not the jet black color of the oil in the port engine (that just needed to be changed).   I haven't been as good at checking the oil as I should have been.  I haven't taken the boat out a lot, and the several times I've checked the oil, there was always plenty of it, and it seemed to be ok.   So I have my fingers crossed that something hasn't gone terribly wrong.   At the very least, it's time for me to probably do a couple of oil changes on the starboard side, and definitely give the port side a good oil change as well.

OIL SELECTION:

According to Brian at American Diesel, and "Bob" (experts on Ford Lehman engines), the preferred oil for a Ford Lehman 120 is straight SAE 30 oil.  Unfortunately, these days it is challenging to find straight 30 wt oil in large quantities.   The FL 120 engine capacity is stated to be 12 quarts - thus requiring 6 gallons for the two engines, plus another gallon or two for the injectors.   That's a LOT of oil.    In mid year 2022 with the Russian invasion of the Ukraine, fuel prices skyrocketed.   Diesel jumped from $3/gal to over $5/gal.  Rotella 15W-40 oil is running at $20-$28/gal!   After price checking Walmart, Sams, Costco, AutoZone, Advanced Auto, O'Reilly's, NAPA, and Amazon, the best price that I could find in quantity was at Walmart, where they only had gallon jugs (not the 2.5 jugs or 5 gal buckets that would have been a better price).  I ended up paying $15.34/gal for Rotella 15w-40, and $13.47/gal for 4 gallons of no-name (Ultra Plus?) oil just for flushing the engine.

By the same token, Fram PH8A filters (I was cautioned to avoid NAPA and WIX filters) were $4.20 at Walmart, less than half the price listed at auto parts stores.

I agree with the opinion expressed on Trawler Forum that while SAE 30 is the oil recommended by the EXPERTS, that no harm will come from using Rotella 15W-40 oil, given that I cannot find a sufficient quantity of Rotella SAE 30 (or other major brand).  My personal belief is that if the oil is API certified, it should be fine.   I'm not planning to run my engines hard, and I probably typically won't run them all that long at a time.  For my engines, my thought is that changing the oil regularly is far more important than sweating whether it's SAE 30 vs. 15W-40 - as long as it's a well known, trusted manufacturer, and the oil is changed regularly.

Fuel Filters

I finally got around to changing the fuel filters.  I had been putting off this project for far, far too long out of fear and intimidation at the thought of needing to bleed the fuel filters / lines / injectors.  This turned out to be a nightmare project from hell.

Each engine has 3 filters.  There is a Racor 500 filter mounted on the aft bulkhead of the engine room.  This fixture houses a 30 micron filter, along with a water separator.  Each Ford Lehman then has two fuel filters that are engine mounted.   Many believe it is better to have a course filter on the Racor to catch the big stuff, and then let the engine mounted filters be small to catch the little stuff.

I started with the port engine because the Racor was easier to get to, and the fuel filters on the engine were on the starboard side of the engine - meaning they were easily accessed in the passage between the two engines.  This allowed me to more easily discover what I was doing (i.e. bend down and look under to discover o-rings, etc.) before moving on to the starboard engine, where the engine mounted fuel filters were between the engine and starboard wall.

The bowls of both of the Racor 500 primary filters were cloudy.  Opening the spigot on the bottom of the port filter did nothing.  When I opened the top lid, I saw that the filter was completely full of sludge.   This was BAD.  No one should have ever let the filter get this bad, and I realized that this should have been a first priority when I initially bought the boat. I honestly have no idea how the engines were still running (and yet, they had been running just fine).  I had ordered the rebuild kits for the Racor filters.  But after seeing how full of sludge they were, I decided that I'd rather replace the filters than take a chance on getting them completely cleaned and put back together correctly (lots of parts, lots of o-rings, lots of opportunity for leaks).  A pair of new Racor 500's was about $500.  That was the start.  

I discovered that over the past 30-40 years, Racor had changed the design.  The filter was the same.  The body was essentially the same.  The mounting is now different, and the inlet and outlet port threads are different.  I also discovered that my engines had been plumbed so that the copper tubes from the fuel manifold went outboard to each fuel filter, and then from the further outboard part to the engine.  The Racors designate one side of the filter as input, and the other side as output.  Since my filters were plumbed to be mirror images of each other, the port engine had fuel going in to the output port, and out of the input port to the engine.   Apparently, this didn't matter much, as the engines both ran fine.  When I replaced the Racors, I fixed that issue - though it did mean that the hose replacing the copper tubing had to cross sides.

As mentioned previously, the Racor ports are different from the original threads on what I removed.  Racors currently have ports that are threaded to 3/4"-16 UNF SAE J1926 (need to check this...  I got it from the spec sheet, not from the part I actually bought to mate to the new Racor body).  This is NOT a standard fitting size.  My local Marine store (Blackburn Marine in Kemah, Texas) happened to stock fittings that adapted the unusual Racor threading to a more standard (1/4 or 3/8" NPT) fitting.  The next challenge was the copper fuel line from the fuel manifold to the fuel filter.  I ended up replacing the copper line feeding the port filter with a piece of 3/8" rubber (A1-15 rated, USCG approved) fuel hose.  This had it's own set of fittings to find.   On the other side, the outlet of the fuel filter already went to a 5/16" hose (that turned out to also be A1-15 rated, USCG approved,) running to the fuel pump on the engine.  Unfortunately, I didn't realize  it was 5/16" hose, instead of  the ubiquitous 3/8" hose, until I was ready to attach the hose to the 3/8" barb fitting I had specially ordered for the filter housing...   ARRRRRGGGGH.  Yet another trip to Blackburn Marine.

Once the Racor was replaced, I went ahead and fired up the engine to ensure everything worked before moving to the next step.

In addition to the Racor 500 for each engine, the Ford Lehman 120 engines have two engine mounted fuel filters.  The fuel filters were replaced with Fram C1191A fuel filters.  The filter comes with the 4 (yes, FOUR) o-rings that must be replaced when the filter is replaced.  

When I removed the filters, there was some sediment / sludge in the aft of the two filters, but the forward filter seemed pretty clean.  Given the condition of the Racor, that was a huge relief!

Getting all the o-rings in the right places is a little intimidating the first time.  The good news is that they are all different sizes, and will generally only go in one place.  The smallest one goes on the long screw that secures the filter.  I found the previous o-ring all the way at the top of the bolt.  My understanding is that it should only extend up as high as the threads of the bolt.  I need to check this with Brian, the Lehman guru, at American Diesel.

The output bolts on the filters are for bleeding / filling the filters.  The inboard bolts go all the way through the filter to the bottom cup, and hold the filter in place.

HINT:  A turkey baster is excruiatingly slow, but works well for filling the fuel filters with fuel through the vent ports on top.   Once the filters were filled with fuel, the engine got past the air bubbles and ran normally fairly soon.  The manual paddle on the fuel pump didn't seem to do much at all.   

Having replaced the port Racor, and the two engine mounted filters - the port engine was now done.  It was run for a solid 30 minutes to ensure all air bubbles in the lines had been purged.

Now for the starboard side.  After the experience with the port filter, much understanding was gained, and I had already survived the parts circus of trying to find all the required fittings.  Instead of hose, the starboard engine has copper tubing going from the Racor to the engine.   While I did replace the copper tubing from the engine manifold to the Racor with rubber hose, I decided to leave the copper tubing going to the engine.  It was working, and replacing it would have required getting places that would have been VERY challenging to reach.

Unfortunately, this required finding the fitting that would adapt the Racor to the copper tubing fitting.  This is not a Home Depot / Lowes fitting.   Three plumbing supply houses later, I tried Grainger.  They were helpful, but also didn't have anything that matched.  However - they DID suggest trying the Hydraulic House in Austin, across the freeway.   The Hydraulic House finally was able to supply the right fittings!   It appears the copper lines on the Ford Lehman of the '83 Ocean Alexander were -6 and -8 JIC threads (???) - apparently common for diesel engines?  One of the other threaded fittings appears to be a -6 SAE fitting (though I don't think I ended up needing that).  With parts from the Hydraulic House, I was able to "Frankenstein" a series of connections from the Racor to the copper tubing feeding fuel to the starbard engine.

After installation, the starboard Racor was filled with fuel, and the starboard engine miraculously fired right up!  After a few seconds, it died.  It took a little cranking, and several attempts, but eventually the engine started and ran.  On to the engine mounted filters.

When I changed the port mounted engine filters, I noticed that the forward filter had an acorn nut on the bottom of the retaining bolt  (turns out it's not the bolt, but rather a fitting in the cup).  The stud has a hole through it, and the acorn nut can be loosened to drain fuel out of the filter.   The aft filter didn't have an acorn nut - rather, it had a plastic knob to accomplish the same purpose.

In removing the starboard filters, I immediately noticed that while the cup on the stern filter had an acorn nut similar to the one on the forward port filter, there was no nut at all on the forward starboard filter cap.  Upon removing the filter and examinging the cup, I discovered that the retaining bolt screwed down into the cup, but that the acorns / knobs were threaded onto a stud in the bottom of the cup.  The aft filter had a hole through the stud for draining.  The forward filter had no hole, and no nut or knob.   Other than that, the filter replacement was fairly straight forward - other than working on the difficult side of the engine where one had to lean over the engine and attempt to look up into the filter housing to see what was going on...

Once the filters were replaced, I used the turkey baster to sip diesel fuel in through the bleeding ports.  It took about 4 cups of diesel to fill the  filters.   Again, the engine started easily, but died soon.   More cranking, and eventually the engine came to life and kept running.

Both engines were run for about an hour and 20 minutes to ensure everything seemed to be running well.

Engine Shaft Packing

About mid March, 2023, while replacing the engine fuel filters, it was noticed that the starboard engine shaft seal had a stead stream of water with the engine stopped.  Having never worked on shaft seals, I decided to hire someone to repack the seals so that I could learn how to service them.  It took about 2 weeks for someone to finally show up.  Thankfully, by that time, the stream of water from the seal had dropped back to a drip about every 4 seconds.  Reference for the seal work:

Jake Kay

Kemah Boat Repair

281-698-7752

$115/hr, 2 hr. minimum.

3/24/23 - When Jake arrived, I explained the issue, and that I wanted to repack the seals on both engines, as they had never been serviced since I owned the boat, and no idea how long prior to that they were last worked on.

Jake stared with the port engine.  The first nut sheared off immediately.  The boat was rusted through.  This stopped work - a haulout would be required to dis-assemble the coupling, replace the broken bolt stud, and see what else needed to be done.

Jake noticed rust and some pitting on the port engine shaft, though he thought it might simply be surface rust.  He would not know until the job had progressed.  Worst case, both shafts and both couplings may have to be replaced.   Jake also commented that the port and starboard couplings did not match.  Apparently, at least one of the shafts had been worked on before.

Seeing these issues, and understanding that the port prop was bent (this was seen at the original purchase survey), Jake expressed concern that the rudder seals may also need to be serviced, and that the rudder could be bent.   As per survey, bottom job, and pressure wash haulouts, the rudders seemed fine.  Jake checked the rudder posts and said that the rudder seals appeared to be fine.

Fuel Transfer Pump

A fuel transfer pump was rigged to transfer fuel from the stbd tank to the port tank to compensate for the natural list of the boat.  This resulted in the stbd tank now being 1/3 or less full, while the port tank is almost full.

There were copper main and return fuel lines from the manifolds to the generator.  At the generator these lines transitioned to rubber hose.  The rubber hoses were removed.  Shutoff valves were installed, and then fuel hose was run from the shutoff valves to the diesel transfer pump.  The transfer pump was rated at 11g/min - but this seems to be very optimistic.

Starboard Engine Fuel Problem

On 11/4/23, I started having problems with the starboard engine dying.  It sounded and felt like it was somehow getting starved for fuel.  Note that this was after I had transferred fuel out of the starboard fuel tank to the port side, to compensate for the boat's natural list.  I was still running both engines on  only the starboard fuel tank.

I had also noticed at the starboard Racor appeared to have some water in it.  I drained some of the fuel (and water?), which was just before the first failure of the starboard engine, about halfway out into the Watergate channel.  Eventually started at the dock, ran fine at low speed.  Failed a second time out past Kemah boardwalk when the throttle was increased.  Racor and engine mounted filters changed.  Engine would still fail in the dock when ramped up to high speed.  Checking the engine mounted filters showed that they had at least a lot of air, with little or no fuel, explaining why the engine died.  Changed the manifolds to draw fuel off the port tank.  Worked at the dock, but didn't have a chance to take it out for a good shakedown.  Brian suggested running the engine a while, then taking the lid off the Racor to see if it had air.

Discussion with Brian at American Diesel:

Replacement fuel pump is about $70 - however, 1) Brian said the pumps almost never fail, and 2) there is one nut/stud that is very difficult to get to.  Offset wrench would be very helpful for this.  Brian, of course, thought replacing (and especially) or supplementing the mechanical pump with an electric fuel pump was a HORRIBLE idea - more connections, more points of failure, dependence on 12V when nothing else on the engine needs 12V power...

Brian believes the problem is most likely either in the Racor, or in the fuel lines.

Ordered two fittings from American Diesel to adapt 5/16" SAE Recessed Flare (what goes to the lift fuel pump) to 5/16" barb.  Also ordered 10' of Coast Guard Approved A1-15 fuel hose.

The fuel line from the Racor to the engine is original - copper line changing to jacketed tubing for the last foot or so to the fuel pump.   Fittings to convert the fuel line to 5/16" Coast Guard Approved fuel hose have been ordered...

Fuel problem put on hold mid December to focus on the breaker replacement project.

Starboard fuel hose replacement

The boat appeared to have the original starboard copper fuel line from the Racor 500 fuel filter to the engine mounted mechanical fuel pump.  At the engine, the copper line transitions to a braided fuel hose that goes to the lift pump.  Brian at American Diesel STRONGLY recommended replacing this line, as the braided hoses can eventually leak (or almost as bad - allow air to be sucked in, starving the engine of fuel).

2-4-24  Replaced starboard engine fuel line from Racor to engine fuel lift pump.

To replace the copper line with 5/16" USCG approved A1-15 rubber hose, new fittings were required.  Blackburn marine had the metric (?!!!) fitting that works on the Racor.  American Diesel is quite proud of their fitting for the engine side (or was it really the ridiculous shipping cost that made it seem painful?).  The fitting for the engine side is a 5/16 SAE Recessed  Flare fitting that goes to a 5/16" barb.  Brian also suggested that the Racor could use 2 micron filters.  Small filters in the Racor prevent stuff from getting to the engine mounted filters.  The Racor filters are MUCH easier to replace than the starboard engine mounted filters  (and also much easier to pre-fill with fuel)!!