Thoughts on my planned engine rebuild?

[Cool Beans]

One project (out of 1,254 and counting). . .rather large project. . .I'd like to accomplish over winter is to pull the engine and reseal it and to replace all the engine mounts (all rotten and frozen). The poor thing leaks like a sieve and there is engine oil everywhere. I have several diapers in the engine pan and have kept the bilge clean. . .until I left a cockpit hatch open during a rain storm and the deluge that ran thru the engine compartment rinsed a lot of sludge into the bilge

Since I rebuilt the fuel system a couple years back, the engine has ran fine. Not sure what a "great" running atomic 4 is like, but this one hasn't let me down yet. In fact, the longest run this year was a motor sail into 2-3 foot seas across the mouth of the bay. . .6 hours that engine ran Only hiccup was at the end and it developed an occasional miss at idle. . .hasn't happened since though.

I haven't checked the compression yet, couple years back I think it varied from 85 psi to 95 psi. Starts in a couple cranks with choke when cold, starts almost immediately when warm. Oil pressure at idle is 20 psi, WOT it's 32 psi with 20w50 oil. I've never adjusted the valves or oil pressure thingy. . .hell, I've never had it opened up at all. Life time raw water cooled in saltwater. Already electronic ignition. She's old and worn, but still kicks hard.

So, how far do you think I should go or need to go? Not that I'm cheap or lazy, but I'm kinda cheap and lazy

My immediate concern is replacing all the paper gaskets, rear seal, cleaning up the rust, and painting it. The head has a couple paint bubbles with dried rust stains bleeding through, so that needs to be repaired at a minimum (or replaced). Head gaskets need to be replaced. Water jacket needs to be investigated and cleaned out (I know it's bad, but not how bad). If the block isn't rotted out, Fresh Water cooling is a option. Also need to redo the exhaust (has 8 90* elbows, lol). That isn't dependent on me having the engine out though.

Since it is out, and will be apart, is it worth while to go full bore rebuild? Any advice on a just a refresh? Or just fix what I planned and get it back in the boat before it becomes one of "those" projects?

Thanks!

[ndutton]

Here's my take on whether or not to go the full Monty while the engine is out of the boat.

Several years ago on the last day of a BVI sailing vacation I was asked if I was going to take a last dive on a new shipwreck on the same side of the island where we were moored. I said nah, it's 6 A.M. on a Sunday morning, everyone else is asleep, we still have to do breakfast, clean up, repack and have the boat returned to a neighboring island in 6 hours. Besides, it's a deep wreck and I have only a half tank of air remaining. It's just not in the cards.

Then he asked a question that summed up the situation as clear as crystal: "How often do you get here?"

[hanleyclifford]

Well spake, Neil. IMO the most important thing you can do for an A4 is convert it to FWC.

[Cool Beans]

Yeah, I know I should. . .and probably will to an extent. . .I just don't want to drop thousands into a full rebuild on a boat I might sell in a couple years. Full rebuild vs old, but well maintained seem to fetch the same price, ie. less than a diesel model of the same model/year

Just how much can be reused? My engine building experience is car/truck related. Engines were always worn out; over bore for pistons, under sized crank bearings, new cam shaft bearings, lifters, camshaft, etc. . .basically a rebuild kit and machining would leave you with a brand new motor.

I've never opened a motor and mic'd out the tolerances and made judgement calls on what is still good. Automotive motors, it's not really cost effective. But after leafing through the Moyer catalog, I'm willing to give it a shot

Yes, if I get this far into the motor, FW Cooling I think is a given.

Thanks!

[ndutton]

I did not understand the engine project was for resale purposes. That's different. As you already know you'll want to end up with a good running, good looking engine that starts easily and doesn't smoke out either end. Whatever it takes to achieve that goal, even the addition of (Gawd I can't believe I'm about to say this) a PCV system to manage excessive blowby if necessary.

[BunnyPlanet169]

IMHO - the full monty is when you take out the crankshaft. I wouldn't do that unless you have a compelling diagnostic reason, or you're committed with time and money. Separating the major castings to replace gaskets is a project, but more like orthopedics, not open heart surgery.

You mention the head gasket needs replacing. Why? You don't mention a compression check. I'd do a compression check first, and then think about the head gasket and valve lapping, and then rings, in that order. Your oil pressure is on the low side of normal, but you haven't tried to adjust it. If you can get it to 40 psi running, you probably don't have excessive internal wear on crank bearings.

There is a saying - if you take something apart on a 40 year old boat, it's broken. The A4 is a robust beast that will take a lot of abuse, but when you start taking it apart, things tend to mushroom. Heads round over, fasteners shear off, pipe plugs get stuck, threads strip.... If you plan on reselling in a few years, I would limit myself to what I had to do based on diagnostics.

The A4 can and is rebuilt - but it's not inexpensive, and won't be cost effective if you sell in a year unless the alternative is no engine at all - I.E. if a boat with a running A4 is worth $5000, the same boat with a rebuilt A4 is also worth $5000. That $5000 boat without an engine is only worth maybe $1500.... and that $3500 is the rebuild.

[ndutton]

Regarding budgets and expenses, there are ways. No matter how deep you go there will be expenses.

Within a month of acquiring my spare A-4 (described in another thread) I also picked up a seized Universal M25XP 3 cylinder diesel. Both were free for the taking. I parted out the diesel and trashed the block, spent some dough on the A-4. As it turned out I spent about $100 more on the A-4 than I got selling the diesel parts and saved the alternator and heat exchanger off the diesel for myself. I'm calling it a wash, net zero invested in the now finished A-4.

[lat 64]

I think not completing an engine rebuild is much less fraught with hazards than not completing a deep dive. It's not like someone else can finish it for you.
Staying with that metaphor though, I understand Neil is a very experienced diver. Some of us are experienced engine fixers and can see the requirements of time and aggravation to fix it up for sale—or not.
I think a running motor is a running motor. The prospective buyer can do sea trials with the existing setup and fall in love with it all the same.

New owner probably just want's a diesel anyway

[BunnyPlanet169]

Regarding budgets and expenses, there are ways. No matter how deep you go there will be expenses.

Within a month of acquiring my spare A-4 (described in another thread) I also picked up a seized Universal M25XP 3 cylinder diesel. Both were free for the taking. I parted out the diesel and trashed the block, spent some dough on the A-4. As it turned out I spent about $100 more on the A-4 than I got selling the diesel parts and saved the alternator and heat exchanger off the diesel for myself. I'm calling it a wash, net zero invested in the now finished A-4.

I agree, but it's time, and time not on the water. I bought a salvage A4 for $400 (also in another thread), for the block, but it came with the $250 MMI stainless waterlift. Turns out that motor was rebuilt and nearly pristine, so now I have parts and spares, and maybe (yet another) project in the old engine.

Like Russ and his small two cylinder - it's a divine madness.

[hanleyclifford]

I did not understand the engine project was for resale purposes. That's different. As you already know you'll want to end up with a good running, good looking engine that starts easily and doesn't smoke out either end. Whatever it takes to achieve that goal, even the addition of (Gawd I can't believe I'm about to say this) a PCV system to manage excessive blowby if necessary.

Gotta save this blasphemy for posterity.

[ndutton]

Gotta save this blasphemy for posterity.

Hey, fair is fair. This is a great example of what the PCV is for - mitigating a problem without the time and expense of proper repair. That's been my position all along.

And again, in Cool's case - if needed.

[Cool Beans]

I don't think PVC is needed, the engine doesn't smoke or burn oil as far as I know. . .no smoke out the back, none in the engine room. . .it just leaks like a holed boat

Hopefully with the amount of oil seeping out of all the seams, the engine will come apart "easily".

The head gaskets need replacing because there is a constantly forming salt crust around the edges. I think I posted about that earlier in the year.

I will perform a compression test as soon as I get the gas tank back in the boat.

This isn't expressly for resale, but it will help. I want to keep oil out of the engine room and bilge. It all needs to be cleaned (and I doubt it would sell all gunked up) and I'd like to gel coat it or paint it and make it purdy

If I planned on having the boat for at least 5 more years I'd go full monty on the entire boat. Right now I live on 'er and I'm looking forward to another boat that's more live aboard friendly in the next 2-3

[ndutton]

If you decide to gel coat the engine space please talk to me first.