MD17C in A25

[WillieC]

Kerry

Thanks for asking, so much of this is in my head I may blow past something blatantly obvious, but not necessarily to the casual observer.

The compression ratio on these diesels is supposed to be 17.5:1. To attain that, the air gap between the bottom of the head and the top of the piston at TDC is supposed to be somewhere around .031". This is adjusted by the size and number of shims underneath the water jacket. Raising the water jacket, with a thicker or multiple gaskets, raises the head above the piston, since that is a fixed number determined by design stroke AND the level of the raw crankcase above crankshaft centerline. These blocks were evidently milled to different levels, probably due to variations in casting process. The amount of shim originally designed to be installed under the water jacket is stamped into the top of the crankcase, off to the corner of the water jacket. Metric, of course, so mine says "3" which is .3mm which equates to .012". My engine with the original water jacket was supposed to have a .012" shim under it which, when all is said and done, factory original head gasket, head torqued to book values and probably retorqued. The resultant gap between the top of the piston and the bottom of the head (which actually sticks down into the cylinder a bit) is supposed to .031" plus or minus to give the desired optimal 17.5:1 compression ratio for designed combustion blah, blah, blah.

Long answer, sorry. The odd thing about mine, one I have asked before somewhere in my posts, is that my spare engine, the block I am using, while stamped "3" actually had "2" shims installed. .008" instead of what one would assume to be the necessary .012" shim. After meticulous cleaning of rust and scale and using new gaskets, with no binding, etc.etc. it turns out that the .008" shim gives me about .035" smush gap. OH YES, your question!! I knew I would come around. The manual describes a confusing way to measure the gap with micrometers. Since the piston is recessed in the cylinder, and the top of the liner is slightly above the top of the water jacket and the head sticks down into the cylinder, there is nothing simple about measuring, adding, subtracting, carry the one, etc. and then coming up with what size shim to stick under the cylinder. The MD3B manual and Matt Morehouse, my VP mechanic hero of yore, says to just stick a piece of solder in there, either through the injector opening if the head is already on, or in my case, right on top of the piston before installing the head. torque the head. Run it by hand through a couple revolutions, you will feel the solder at TDC, give it a bump. Pull the solder back out the injector hole, if you are lucky it doesn't break off. Or in my case, remove the head since I used the old head gasket for this test and mike the hunk of smashed solder. That is your gap. Another side note. Not all head gaskets are the same. The Montana engine had much thinner head gaskets (aftermarket from Asia?) than the Spare Engine I started with. The old Spare head gaskets and my brand new $150 gaskets are both Swedish VP with matching numbers, construction and thickness (Give or take after 40 years of use on the old vs. new. I called them the same.)

That's all I know! Sorry you asked? Don't blame you. Now you know how my The Commander feels when she asks me about my day!

[kerrye]

So like plastigage?

[WillieC]

Soldergage. I like that. I have not used plastigage. Seems like .030" +/- is a bit thick to measure, but again, not familiar with it other than what I have read. Basically, the solder gets crushed between the rock and the hard place, and that is the gap that determines the compression ratio. Also, there is a minimum protrusion of the valve heads above (below) the bottom of the head surface. Part of that is in relation to sealing surface between valve and seat, but also, that valve in the combustion chamber takes up volume which affects compression ratio. One could really dial in that gap by milling the crankcase or water jackets or head surfaces, but hey, this is a 40 year old boat. We'll save the dialing for the big boys in a hurry.

[WillieC]

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Need parts and possible machine work, Tacoma area.

Funky old pumps with no bearings and no replaceable bushings. Shaft is worn, and you can see wear marks of impeller in body.

I can find seals and gaskets, but not shaft. Depco says it is irreplaceable, but they will give me an estimate for rebuilding it. All I have to do is ship it to them in Fla. Huh? I like challenges, but my dad was the machinist, so I'm not.

Thanks.

[DesertAlbin736]

Ouch! Hold onto your wallet!

[WillieC]

Actually, I have three set-ups for moving raw water and anti-freeze. I was poring over Peter Boldt's Alanje articles, looking for some pictures of stainless steel mixing bowls used as vent covers, when I found a post by the guy I bought the Montana engine from. The post was from '08, I think. Around $600 for this dual pump set up new, which I can't seem to find anywhere today, but with three sets, I'll be fine.
Anyway, Peter rigged up a regular old off the shelf pump and drove it off the flywheel with another pulley bolted out in front of it. I have all these parts and just need to weld up some kind of adjustable bracket to make it all work. I like the piggyback pumps, but not for $600. So, yes, Steve, I continue to hang onto my wallet.
Did I see an electric pump next to your Vetus strainer? That is another excellent solution. Does it run when the key is switched on? Through a relay I presume? Since it is next to the strainer, i assume it is the raw water pump, with the antifreeze pump somewhere on the engine, cam driven. More than one way to skin a cat. Nice to see you back.

[DesertAlbin736]

Did I see an electric pump next to your Vetus strainer? That is another excellent solution. Does it run when the key is switched on?

That's our main electric oscillating diaphragm type bilge pump. The suction hose goes into the bilge sump & has a small inlet strainer. Discharge is routed up to the side of the hull and exits outboard of the helm station. It's manually switched via it's own dedicated house circuit with a toggle on the DC fuse panel at the dash board. When it's on I can look out the pilot house side window & see the water shooting out & know when to switch off. If we ever do get to the point of keeping the boat in the water full time, which at this point is not very likely, I'll have to add a float switch in the bilge & a 3 way fused On-Auto-Off switch (of which I have a West Marine one laying around in my stash box at home) to the dash board.

Bilge pump switch is the third toggle from the right on the black switch panel to the right of the wheel in this picture. Just below that is the on/off toggle for the solar panel. To the left of the wheel is the digital continuous voltage read out display that can individually monitor voltage levels on the house & start battery banks & the charging output of the 20 watt solar panel that is mounted on the hardtop roof. On a good sunny day the solar panel puts out about 1 to 1.6 amps at 15 to 16 Volts. The controller allocates charge from the solar panel proportionally, more to the house bank and less to the start battery, and limits the charge voltage going into the batteries to the proper level for AGMs. Most of the time I leave it switched off since these batteries hold their charge pretty well. If we stayed anchored out for several days while cruising or we haven't taken the boat out for awhile and I see the voltage start to drop from self discharge then I switch it on and let it trickle charge for a few days at a time. From the department of redundancy department, since the Yanmar does not have a way to hand crank start I also keep a Harbor Freight automotive jump start battery pack on the boat so in case everything went flat I could still jump start the engine. And of course be able to help out another boat with a dead battery.

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[WillieC]

Yet another draft shot to, hello there!

Steve, I don't know why I was thinking that might be a seawater pump for the HX, maybe just what I have been fixating on. Oh, I see the red hose lying down in the bilge. DOH! Nice set up. The skinny little pump that came with ours clogged up so fast and so many times it finally quit working, so I installed another pump as low as I could get it, but not low as I would like, so we end up using the manual Whale pump periodically, not wanting to wait until the bilge fills clear up. Your type of pump will actually lift so you can stick a hose down in the Krakatoa. Nice solution.

I finally got one of my lingering questions answered in the last couple days. The MS style transmission that came with the Spare Engine utilizes the rubber baby buggy bumper input shaft to the tranny. The RB transmission, on the derelict 3B engine, uses a gear direct drive off of the crankshaft. I could probably swap parts but that requires special pullers and expertise I don't want to fool with. So I will be using the MS transmission which being 1-1/2” longer, will require modification of the engine drip pan so it all fits. And shaft mods, and whatever else. The Starfleet Commander reminded me today that since this is a New Year, all the budget categories are full of their allotment. Spend, baby, spend! I can do that.

To verify the transmission sich-ee-a-shun, I had to raise the 3B, still in the boat, in order to remove the transmission and drag it over to the shop for side by side comparison. So the engine is about 1/3 out of the boat. I had planned to thoroughly clean and paint and pinstripe the engine compartment, but now I have some fiberglass work to do elongating the drip pan to accommodate the longer transmission. Point being, if I end up using a crane or forklift or some sort of Mobile Power Unit, it will be done in two stages with the accompanying two payments. Which I don't like if you have been following my cheap a$$ ways. And the rains have returned until mid-July so it looks like a temporary shelter is in my future once I remove the hardtop. Still awaiting inspiration for exactly how I am going to Repeal and Replace these engines. But I know it is going to be very, very great. Trust me.

In the meantime, when it gets too bad, I light the fire in the shop stove and listen to the deluge hammering the tin roof and wonder how I ever held a paying job.

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[WillieC]

Has anybody with the A25 dug deeply into the embeds for the motor mounts? Mine are encapsulated nuts that are flush with the fiberglass. Shims and a steel plate bolt onto that and the rubber VP mount threads into that 3/8" or so thick plate. The excess thread on the bottom of the rubber stud is cut flush with the bottom of the heavy steel plate.

The reason I am asking is that I am trying to find a simple way to accommodate the 1-1/2" longer transmission. I suspect the original cast-in-fiberglass nuts may be welded to a plate which was then embedded in the fiberglass which would prevent them from any possibility of spinning after 40 years of rust. They are solid. I could whack off the shaft, but since the coupling moves aft the same 1-1/2", it starts to hit the rise in the engine pan. Trimming the shaft would also require lengthening the keyway.

OR, I could move the engine forward, thus my question. I don't see a simple redo of the embedded nuts a viable solution so today I will be looking closely at mods to the engine mounts to gain that 1-1/2". The alignment shims also come into play adding to the complexity of this. Stand by!

[Beta Don]

When I installed my Yanmar I had to fabricate all 4 motor mounts - The engine sat lower in the engine beds than the OEM Yanmar mounts could accommodate and the engine beds were also about 1 1/2" too wide. I thought the cast factory 'legs' which went between the block and the rubber mount were cast iron but I learned they were actually cast steel so I was able to cut them and weld them to a short piece of 3" angle iron which I drilled to fit the stud for the rubber mount. Could you use a piece of angle bolted to the transmission which would extend forward 2 or 3 inches so your longer transmission could still use your factory mounting points? My 3" angle was 1/4" thick and completely up to the task for a 100 HP engine

Don

[WillieC]

Don, thanks for weighing in. The transmission hangs off the back of the engine with no visible means of support, you get my drift, only the four bolts that hold the tranny to the crankcase. All the weight is carried by engine mounts. I looked closely today and by simply redriliing the flat plates and retapping for the mount studs I can gain about 3/4". The original shaft saver, between the transmission flange and shaft flange is about 1-3/8". I am considering using another type of shaft saver, R and D engineering I think, and I need to verify how thick it is. I have about 7/8" between the end of the shaft and the leading edge of the rudder, so I can gain some there as well. I think I can get it, but it will be a combination of things to do it.

It would be nice re-powering with the new lighter engines and gain all that space. But, but... here I am. I looked into swapping mounts, but they have 4" OC bolt up dimension and the old A25s are metric 4", around 4-1/4". Hard to move a hole 1/4". 3/4" on a 1/2" bolt is hard enough, but doable. Before I get much farther, one set of stringer bolts, the right front, came out hard. I hope enough thread got left behind or I will be doing the angle iron and new mount arrangement so many of you swappers have done.

Thanks again. I will take pics once I have a plan.

[WillieC]

Engine is coming out. This is about as far as I will go without a Mobile Power Unit. Crane or forklift or stinger or something. Top is coming off. My plywood legs works pretty good. I was able to just scoot the engine aft on my 4X8 skids without rollers or pinch bar. Now my new hip is killing me, so maybe that wasn't so good. Oh to be young again.

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Am I the only one who thinks that running raw saltwater through the transmission might not be the best idea? I found what looks like may have been a zinc on the bottom side of the MS transmission, but it had super fine metric threads so i tapped it out to 1/4" NPT. I keep scraping crud out of the cooling passage, also soaking it with CLR and rinsing and soaking and scraping. Took an old file and screwdriver to it and crap keeps breaking loose. I think I got most of it, but it sure seems like some more could bust loose and head straight for the heat exchanger. Thought about installing the strainer after the transmission, but don't want to suck geoducks, octopi and seaweed into the transmission. And I don't think having two strainers is common practice. Any thoughts?

[Beta Don]

Well, saltwater has done the job fairly well now for 40 years and it evidently didn't plug up completely. You've cleaned it out really well so you should be good for another 10 or 15 years at least I would think - Are you really worried about having to clean it out again 15 years from now?

I guess you could install a tiny heat exchanger and run an anti-freeze solution through the trans, but you would need to set up a small pump to move it . . . . and an alarm to let you know if it quit moving

It's 50 year old technology which is still working - Trying to modify it to bring it into the 21st century is probably more trouble than it's worth, IMO

I used a forklift with a stinger when I re-engined my 27. A friend owned the forklift and I had it sitting here for a couple months. After the removal, I had to set the new engine in there 2 or 3 times to get the motor mounts modified to fit the engine beds

Don

[DesertAlbin736]

Rick, goes without saying you're my hero for going through all this effort! But that said I would still say complete your MD17C rebuild then sell both engines for whatever the market will bear and go with a more modern new or rebuilt Japanese engine such as a Kubota/BETA or Yanmar. At least something that doesn't necessitate fiberglass work to lengthen the engine bed. And of course the AquaDrive CV joint/thrust bearing set up would be a big plus. Yes it's expensive, but IMO even if you had to take out a loan would be worth it in the long run & would adds a lot of resale value to the boat when somewhere in the distant future that dreaded day arrived to sell the boat. Not to mention better reliability, parts access, less vibration & quieter running.

This article, while pertaining more to sailboats, makes a lot of good points, some of which apply to your situation, others not.

http://www.soundmarinediesel.com/pdfs/R ... ilboat.pdf

Far as getting the old engine off the boat, I wonder if it can be (carefully) slid aft somehow on some sort of track arrangement past the wheelhouse to the open part of the cockpit where it can be lifted clear with a forklift or some sort of cherry picker crane? That way you wouldn't have to remove your hard top.

Anyway, when the day comes to align the new engine & shaft, here's a tip for building a plywood jig

Albin25_6 motor template.jpg

This is part of the text accompanying the picture

One picture shows the plywood engine template fitted into the engine space, with a dummy prop shaft of black iron pipe supporting it. Note the actual flexible engine mounts installed on the template. This method makes engine bed modification [ if needed ] obvious and straightforward. Once the template fits the engine bed, the engine will also fit.

http://www.soundmarinediesel.com/Albin25Repower.shtml

By the way, I looked up the engine spec weight of the MD17C including transmission, and according to the Volvo manual it tips the scales at 640 lbs. A Kubota based Beta 38 weighs in at 374 lbs, 41% less than the Volvo. The slightly smaller 3 cylinder, 28 HP Beta 28 weighs even less at 330 lbs, just over half the weight of the MD17C.

Just more food for thought as the saga continues. Whatever the case I hope we can get back up there to the Pacific NW in 2018 & do some cruising together.

[WillieC]

HEADS! DONE! This was a very good day. My mechanic neighbor, new best friend ever, called this am, had some time to kill so let's do the valve seats. He dropped off the hard seat grinder yesterday, and got my hopes up. He builds race engines for boats, dragsters, stock cars, you name it. And he recently retired, so he is very busy. After talking to him for 15 minutes last fall, I knew this was the guy to salvage my heads. At $150 a pop for replacement VP valves, I didn't want someone falling asleep at the wheel and I got him. He was extremely meticulous, checking the margins against the shop manual, gave me a three grind profile as needed, felt imperfections in the seat that my old eyes could barely make out, checked everything for full contact seating and was done in about an hour, with me taking the brunt of his time asking questions. Better than I could have asked for and extremely reasonable in his request. As a bonus he also gets free oysters for life from my back yard.

See if you can tell the difference.

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(Hint, you can just make out the red sharpie ink used for checking fit.)

The nick in the copper injector sleeve was caused by previous sloppy work, not my guy. (Did I mention three grind??!)

Don, I like your assessment on the transmission. 15 years would be wonderful. I am thinking of calling in a few favors and get some help removing the old engine. I am certain that it would not be too much to slide it out on a ramp with a friend to offer an "Oh, Sh#$%^!" when it goes sideways. Then go drink some beer.

Steve, your points are well taken, but I gotta see this baby run in the boat. I will likely leave the boat to my kids so they won't have to dig into ancient history to find something to blame on their dad.