Preparing for Sea Trial

Last week we finished up some minor electrical connections, such as the green neutral lights on the shifters and the transmission pressure gauges – although they’ll need new sending units to register correctly.  We ran both engines at between 1500 and 2000 rpm until they both came up to temperature so the thermostats would open and circulate coolant to wherever it needed to go.  We added some coolant to the starboard engine to compensate for the long lines running to our hot water tank and back.

When we did the first start a few days prior, we noticed a puff of smoke from the port engine when it first started.  It did that again, and with it running for 30 or 40 minutes we could notice a definite exhaust leak smell, even though there wasn’t much smoke.  Further examination the next day, after all had cooled off, revealed a leak between the turbocharger and the exhaust riser.  We tightened those bolts in the hope that they weren’t quite tight enough, but that didn’t improve the situation at all.

 

We decided to disconnect the riser, which required removing the insulating blanket as well as the raw water hose to the injection elbow.  What was revealed was that the flange of the turbocharger was in no shape to support a good seal to the flange of the riser.  It was pitted and corroded to the extent that the ridge on the metal compression gasket did not fully engage with the housing. 

Our choices as to fixing it seemed to be to either machine the housing down to a flat surface, or replace the turbocharger.  Mechanically, the turbocharger was fine, spinning freely with no bearing play at all, but I wasn’t too keen on the machining, as it appeared that the pitting  was caused by water damage in a previous lifetime for this unit and there may be other issues inside waiting for us.  Also, the amount we’d have to take off to square it up would reduce the bolt hole depth and thus weaken the connection to the riser.  I sent photos to Seamaster Marine in Florida, where we purchased the engines, and they agreed to send up another turbocharger, which should be on its way today.  We’ve removed this one from the boat and will pack it up and send it back.  Unlike the turbochargers on the old Perkins engines, these units are water cooled, so we had to drain all the coolant from the port engine – we’ll be going through the thermostat exercise again.

So, our initial sea trial has been delayed by at least a week while we wait for the new turbocharger.  That’s when we’ll find out if we can reach the engines’ rated maximum rpm of 2600.  According to some online calculators we should be able to, or at least come close.  This will tell us if our props are the right size.  If we are substantially below max rpm, we may have to have the props re-pitched – otherwise the engines could be overloaded even at the lower rpms. 

We did get the roof panel we removed bolted into place so it wouldn’t go flying off as we headed into the wind.  Patching the saw kerfs will come later, so our sea trial will be on a dry day – perhaps another unreasonable requirement this time of year.  Irv from Gallery Marine warned us that we should expect smoke and burning smells from the paint on the engines as manifolds and other various parts come up to operating temperatures.  He told us that they usually don’t even take customers along on an initial sea trial run for this reason, adding “whatever you do, don’t bring the womenfolk along – they always freak out.”

The turbocharger weighs close to 50 pounds, so Ray made a shipping box for it from some scrap pieces of plywood and 2x2s.  I'd say this box is pretty well engineered!

Erin and I did some weekend work at the boat while waiting for our replacement turbocharger.  Our above average rainfall has made an appreciable change to the lake level, as the boat has risen well over a foot over the last month or two.  So, we brought along the steps that we’ve been bringing home each fall.

Erin busied herself polishing chrome while I inflated the dinghy and washed off some of the grime that has accumulated on the boat – one of the benefits of mooring under the I-5 Ship Canal Bridge.  In an attempt to keep water from pouring through the saw kerfs of our roof hatch and into the salon, I covered the openings with tape. 

For the most part it worked, except for a drip in one corner.  So now we’ll at least look somewhat respectable from a distance when we head out into the lake for sea trials once our replacement turbocharger arrives.  Ray and I recently reconnected the lines to the air horns, so at Erin’s urging, of course, I gave her a brief demo, being careful to not signal the University Bridge to open.

While waiting for the replacement turbo to arrive we set about installing a pair of coolant reservoir overflow bottles, which I had purchased on Ebay.  Just as in your car, these allow expanding coolant to collect and then draw back into the cooling system as it cools.  The automotive versions of these overflow bottles come in all shapes and sizes to be tucked into the car’s engine compartment, but these are universal bottles and needed brackets to secure them.  The engine block had some conveniently placed threaded holes just behind the expansion tank, and Ray made some steel brackets that we could bolt on there.

Ray is preparing the port engine to receive the new bracket, which you see in the foreground.  He had to add on the offset piece with another pair of bolt holes, as, unlike the starboard engine, the port engine had a brace to the expansion tank bolted there.  The kitty litter bucket contains the coolant we drained to remove the turbocharger.

Our replacement turbocharger arrived on 3/29, but on that same day Chief Engineer Ray was ill, and eventually was checked into the hospital for abdominal surgery to repair a hernia as well as some strangulated bowel.  The good news is that Ray has since recovered, and we delayed any sea trial attempt until he was ready to participate, hear the roar of the exhaust and smell the paint burning off the manifolds as we accelerate to maximum rpm out in Lake Washington.  It’s a big step in the fruition of our labors over the past several months. 

Here are photos of the old and replacement turbocharger exhaust housings.  The replacement turbocharger appears to have a brand new housing on the exhaust side.  It had so much more metal on it that I double checked the number in the casting to make sure it was the same part.  While I’m glad they sent the replacement without question, I’m a bit surprised they let the first one leave the shop. 

I was pretty sure Ray wouldn’t be interested in hefting the 45 lb. turbocharger anytime soon, so while he was recovering I got it bolted into place.  New gaskets came with it as well, and I added some high-temp silicone sealer between the manifold and turbo, and some lithium grease to the exhaust port.  Once the turbocharger was securely in place I could add the coolant back into the engine. Rather than mess with a funnel and trying to clumsily pour from the bucket into the smaller bottles or the expansion tank, I found some hose and started a siphon to fill the engine.  It worked great and I poured the individual jugs of coolant into the bucket as the level was siphoned down.  You can see the reservoir bottle bolted into place and yes, the overflow hose has since been connected to it.

With the exhaust and raw water systems reconnected, and coolant back in the engine I started it up for a test.  No exhaust leaks, and enough coolant found its way into some additional areas that I could add nearly another gallon to top it up.

Diesel engines need to be able to achieve their maximum rated rpm at wide open throttle under load to assure that they are not overloaded throughout their working range.  In actual use, we will seldom, probably never, run at the maximum rpm, but if the engines are unable reach their maximum, in this case 2600 rpm, it will mean the boat is “over-propped” – the diameter and pitch of the propellers take too big of a bite for the engine to handle properly (no pun intended).  While we could easily cruise at our usual 8 or 9 knots even when over-propped, it could be likened to driving around in a stick shift car in high gear at 15 or 20 mph – you can do it but it’s not good for the engine to be lugged down like that.  We’ve used calculators available online that indicate we are pretty close to being just fine based on our horsepower, boat weight, length, beam, reduction gear ratio, and diameter and pitch of the propellers.  But the real test will be when we head out on the water to see how she performs.  If we end up topping out a couple hundred rpm short of max, then when we haul the boat out for maintenance we’ll take the props to the prop shop and tell them we need a couple hundred more rpm.  They’ll know how much pitch needs to be taken out if that’s the case.

With the engines pretty much ready for sea trials, I decided to focus on some other chores while Ray recovered from his surgery.  As part of opening up the hatch in the roof we had to cut through some wires as well as the copper tubing to the air horns.  The wires were to the stereo speakers further ahead in the roof.  They are shielded pairs, and required some nipping to get to the individual wires inside. They’ll be rejoined with compression splices.  Ray and I had already reconnected the horns using plastic tubing, but the tubes needed to be secured so they wouldn’t cause a bump once we put the headliner back into place.

I had reused the transmission oil pressure senders for our new gauge configuration, since they were working in the old configuration.  What I didn’t take into account was the scale on the gauges.  The gear pressure gauges on the Perkins panels ran from 0 to 400 psi.  The transmissions actually operated at pressures between 90 to 130 lbs, and I used new VDO gauges with a 0 – 150 lb scale.  The old sending units work exactly as designed, and for 100 lbs of pressure they move the needle one fourth of the way through the range – so what registered as 100 lbs on the old gauges registers as about 35 lbs on the new gauges.  The old sending units were equipped with half inch pipe thread for attaching to the transmissions.  Most of the new sending units use 1/8 pipe thread, although the half inch was available.  The problem was that the same sending unit that cost $24 with 1/8 thread was priced at $56 with half inch thread.  Yikes.  I bought the new units with 1/8 thread, and for 68 cents apiece got these threaded bushings to convert them.  These will go on the transmissions in the next day or two, and then the gear pressure should register correctly.

I continued working on the boat during Ray's recovery, and noticed there was some fresh fuel in the bilge.  I had been swapping out oil absorbent pads there ever since the Perkins injector pump had its leak, so I noticed the new fuel right away.  With the engines running I discovered a fairly significant fuel leak on the starboard engine.  I could see it running down the side of the block and dripping off the bottom of the engine.  I’m pretty sure it wasn’t doing this when we first started them up, but we’re still under 3 hours total run time. 

  It was coming from the injector pump, and I was hoping I could just find a loose fitting somewhere to tighten.  But, it was coming through a pinhole in a diaphragm that protrudes from the block side of the pump.  It’s about 2 or 3 inches in diameter and is in the center of the 2^nd photo below.  I talked to the folks at Seattle Injector, and they said on this particular model pump (model 3062F541) this device, a fuel pressure damper, regulates the fuel to prevent smoke when accelerating.  They said it would run without it if it were removed and the hole plugged, but that it would likely cause the engine to “hunt” and not hold a steady rpm if it were missing.  The diaphragm inside the device has failed, causing the fuel to leak through the pinhole.  Actually, it spurts out in pulses with the pump’s rotation.

 I wrote to SeaMaster Marine in Florida with pictures and a video of the leak, and Ron said to buy the part at Seattle Injector and he would reimburse me.  I did and he did.  The part, pictured above, was a little awkward to remove and replace, as one can only get one finger on it at a time.  It went quicker than I anticipated, however, and once replaced the engine ran fine and the leak was gone.

Speaking of leaks, we also had a leak on the port engine - this one with coolant.  I had noticed some coolant leaking earlier around the overflow hose under the expansion tank cap, and assumed it was because we didn't have a clamp holding that hose on.  I had put a small clamp on it while replacing the turbocharger, but the next time I ran the engine it was still leaking.  Closer examination revealed that the neck coming out of the expansion tank was cracked and that's where it was leaking.  The cooling system was not pressurizing or sending overflow coolant to the recovery bottle - it was just leaking out, running to the underside of the expansion tank and then dripping down onto the serpentine belt, which in turn sprayed it out across the aisle between the engines.  I drained two or three gallons of coolant from the engine and removed the tank. 

With the tank in the trunk I headed north on Hwy 99 trying to find a shop that could repair it or put on a new neck, either brazing or pressing on – not quite sure how it’s supposed to be connected.  I had remembered a small radiator shop north of Lynnwood because it had a sign that read "The best place to take a leak!"  Of course that was several years ago, and now they were nowhere to be found.  I did get the addresses of a few radiator shops in that general direction before I left on my quest, but quickly discovered that most places that now advertise being a radiator repair facility merely remove plastic radiators from cars and replace them.  A couple places recommended Performance Radiator in Everett, but when I called them, they said they’d send it to their shop in Tacoma to evaluate.  Finally I was sent to Greenwood Radiator in North Seattle, where they’ll heat it up, remove the neck and see if it’s reusable or if it needs a new one.   

By now Ray was well on the road to recovery, and he and I went back to Greenwood Radiator the next morning, with the thought that if they weren’t going to get to it for another day or two we’d just buy the new neck and do our own repair.  We showed up about 10 o’clock in the morning and it was already repaired.  He had cut out the old piece, ground off a bunch of pitted metal around it, welded on the new neck with overflow tube and pressure tested it.  All for $45 in labor, plus a few more bucks for the neck and tax.  What a deal!  We took it to the boat, bolted it on, slapped a little paint on it, filled it up and ran the engines up to operating temperature.  Works great – another problem solved!

 I had written to Seamaster Marine about this as well, and although they said the tank was fine during their dyno test they had offered to do whatever I thought was right.  From the looks of the crack in the neck, I'm pretty sure it got stepped on either in transit or by someone here in the months of preparation before our first start. I told Ron at Seamaster not to worry about it - that I'd save the good will for a more expensive future problem that we both hoped would never occur.