Updated on March 21, 2016
Engine Part 3b: Converting to Closed Cooling (the end)
At the end of my last post, the real time was early April 2015; I left off at a point where I was angry and frustrated at a small, hard-to-see, very stubborn piece of bronze. Sometimes there is no way out but forward. After my initial defeat I desperately needed a “win” before I started phase two of the bushing battle. The flywheel was right there staring at me, so I decided to go for a quick victory and remove it. It took me a while but I finally came up with a way to keep the motor from turning over while I unscrewed the large flywheel bolt.
With one minor victory under my belt, it was time to go after that bushing. I thought if I could drill out the majority of the bushing, then I would have a little more room with which to work and maybe I’d be a little more successful with the hacksaw blade.
I scrounged up this antique right angle drill. Not variable speed, and the power cord looked like an electrocution waiting to happen. After repairing the cord, the bronze was ready to fly.
The drill-out worked really well. It took me about two minutes to drill this hole, including the time to take photos. It also reinforced my idea that I should have started with drilling out the bushing, and then I could have simply used a tap to cut new thread; however, this was no longer an option as I had already gone too deep with my relief cuts. The other thing the drill-out did was let me indirectly see (still using the camera to see what is going on) into the now bigger hole a little better. I could see that my relief cut at the 12 o’clock position still had a little ways to go. I got out the hacksaw blade and ran it back and forth for about ten minutes. I checked that the cut was parallel to the bore hole in the block. It was looking good, and after about 15 more strokes I heard a soft but distinct “click”. Could it be? I put a cold chisel on a flat spot and hit it with a hammer to spin the grommet counter-clockwise…and it moved!!! I added penetrating oil and, using the cold chisel and the hammer, I managed to spin it about four revolutions–but it didn’t unscrew. Was it not threaded? I used a little screwdriver and gently pried while I spun it and out it came!!! The dang thing was a pressed in bushing.
Now I needed a way to go from hose barb to smooth bore hole. My new plan was to cut threads in the side of the block. I wasn’t sure if the hole was the right size for a tap, and there was no way I could precisely bore out that hole with the engine inside the boat.
Let’s move on.
The conversion kit came with two different gaskets for the water pump; the amount of metal overlap on the upper edge of the pump seemed awfully skinny. After a run to the hardware store for some mounting bolts (not in the serpentine belt kit), I selected what I thought was the correct gasket and bolted on the pump. There was a little rubbing when I spun the water pump over by hand. I took it off and sanded down coolant passage in the area where it was rubbing, after that it spun smoothly. Then I bolted on the new flywheel. I had just gotten the new alternator three days earlier, so now was a good time to lift it up an see how it fit.
It didn’t fit.
The large Racor 500 Turbine fuel filter I put in last year was in the way. I spent the rest of the day running back and forth for parts, and finally managed to move the filter aft to make room for the big alternator.
The next day I tried to lift the new heat exchanger/exhaust manifold in place.
It didn’t fit.
Come on, every other Beneteau First 38 has this exact heat exchanger on the same Perkins motor, it has to fit! I was laying in T’s berth working through the starboard side access hatch; from there I couldn’t see what I was getting hung up on. From the front of the motor I could see the sea water strainer was in the way–out it came. The new heat exchanger did not come with a way to connect to the exhaust hose, or add the cooling seawater to the exhaust line. The final problem (ok, not really the final one) was that the metal flanges on mounting feet of the new manifold are about 1/4 inch thicker than the flanges on the feet of the old exhaust-only manifold. The 30-year-old studs screwed into the exhaust side of the engine block were 1/4 of an inch too short. These studs would have to be removed and replaced with longer ones.
I used the two nut method to take out all of the studs: thread a nut onto the stud; then thread a second nut on while holding the second nut with a wrench; back out the first nut until the nuts bind on each other. I had doused all four of the studs with penetrating oil the night before and tapped on them lightly with a hammer. I have found that it sometimes helps with a stuck fastener to slightly tighten before you loosen. The idea is to break the seal made by the rust and not to break the bolt or stud or whatever you are removing. Once it wiggles, keep adding oil and keep wiggling, and it will eventually come out. The first stud came right out, and the next one came out with a little heat. Studs three and four were stubborn, but I had time to let the penetrating oil soak, so I moved on to other projects (fresh water system) and would return every couple of hours to apply more heat and oil.
At home I had to deal with the geometry problems of the exhaust. Maybe I should explain wet exhaust. On the VW diesel car the hot exhaust travels through a metal pipe led under a metal car. It gets hot. It will burn you. Luckily, it is out of the way unless you decide to crawl under you car. On our boat, the hot exhaust travels out through a rubber hose which snakes its way from the motor to the transom. If water is not added to cool off the spent gasses, the exhaust would melt the hose. The other option would be to have a hot metal pipe running through the boat. I took the old exhaust elbow, which has passages to add water to the exhaust, off of the old manifold. I then spent the money at a local welding shop to have a small aluminum extender made, as well as a flange for the elbow so I could plumb in the water.
I returned to the boat in the middle of May. The hole in the side of the block was 1 1/8 inches, which is just about the right size for cutting one inch pipe threads.
Two days later, I could screw a hosebarb into the side of my motor. At first I was nervous about the tap going in off-center, but once it got started, it cut smoothly. Pipe thread is tapered, so the deeper the cut, the more cutting surface of the tap is engaged. It gets a lot harder to turn the tap. In the beginning I was cutting little chips; then at the end, I needed so much pressure that I was worried I would break the tap. So, I mostly wiggled it back and forth, each time moving it a little more forward, now making more of a grey metal paste instead of chips. Way slower then simply cranking on it; also way safer.
I got the last exhaust stud out using paraffin wax. I put a wet rag on the stud and heated up the block around it with the MAP gas torch. Then I removed the rag and rubbed the solid paraffin on the base of the hot stud; the heat melted the wax, and the cooling action of the hotter metal engine block wicked the melted wax into the threads. The stud slid out like butter. It worked so well, I used the same system to swap out the thermostat housing studs. Paraffin wax for stuck fasteners from now on!
The cross flow pipe was in–but in the configuration intended by the guy who designed the kit, I was unable to swing the alternator on its hinge. The alternator has to be able to move in and out in order to adjust the belt tension. I went to bed thinking if only the pipe was hose, then I could bend it wherever I wanted.
I am notoriously bad at brazing pipe–it always leaks. After the soldering was done and the hose clamps were tight I did a test run, filling the engine with water and… then the water came pouring out from behind the circulating pump.
The tan gasket fit the motor, but it didn’t fit the pump. The black gasket fit the pump but it didn’t fit the motor (tiny gap at the top). When I first installed it, I held the gaskets up to the pump and I selected the black one; like a doofus, I never checked the fit against the engine block. I remembered the little bit of interference when I first bolted it on. I rang up the diesel parts guys and explained the problem.
Perkins guy: So, you say it doesn't fit and it's really leaking. We've never had that problem before. Are you sure it's a Perkins 4108?
Me: Is there an adapter plate that goes between the water pump and the engine?
Perkins guy: Let me see... Yep, it looks like there is.
Me: I'll take one.
Perkins guy: Do you want to know how much?
Me: Sure. *Thinking...what other options are there, anyway?*
Perkins guy: Twenty-five dollars.
Me: Great. Send it.
Now it was early July, and, adapter plate in hand, I made another trip. I was thinking about the anemic water flow the last time I winterized the engine, and how much scale had built up after 30 years in lake Texoma. So, I also brought up an electric pump and a gallon of concentrated engine de-scaler.
July 15th, two weeks after last year’s launch, I finally had the whole thing put together. I fired up the engine on land, drawing cooling water from a bucket with a running garden hose in it. Three and a half months and maybe 50 hours; maybe more, and now we have a closed cooling motor. To be fair, in the previous three months I also removed three unneeded through hulls, glassed in the holes, built the new mast from parts, did a full bottom job (five coats of barrier coat and two coats of antifouling paint), and I rebuilt the entire freshwater system.
Next up in Engine Part 4: The Frankenstarter.
Trick I learned from an old mechanic about taps – turn it in 1/2 to 3/4 turn, back it off about a 1/4, until you feel/hear a “click” of the cut chip breaking off. Though that would have been challenging in the space you had to work!
I’ve not heard the paraffin trick before! Going to remember that – thanks!
Good job all around!
Doing the same thing to my 4108, indirect cooling is so much better ! The last part that had me puzzled was that big brass bushing , I had a feeling that it was not screwed in as I have the donor motor ( 400 Euros ) and had tried getting the pipe out of that one with a wrench , which only chewed it up ! Thanks for putting this information on line . Great !