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flyingfin · 02-04-2017, 12:36

I second the Marvel Mystery Oil option. But here is you big problem - you don't want to just un-freeze the motor, you have to make sure the rings are not locked up. Let sit for a week, then rock the pistons. Once you feel movement, stop and add more MMO and wait a day or two. Proceed with caution. Don't put the starter to her until you feel free piston movement.

Second option- Declare the motor dead, yank her and stick in a new or rebuilt Yanmar or other motor that you know will run and can buy parts for. Pissing away money and time on a seized diesel will leave you and your wallet stretched to the max

Cheechako · 02-04-2017, 12:53

Hopefully not this:

Jesse · 02-04-2017, 13:14

The Perkins 4108 has precombustion chambers that will prevent inserting a camera to view the situation. WD40 was developed as a water displacement agent and it does that very well but there are much better lubricants, some designed to serve your purpose. The bolt on the end of the crankshaft can be sheared if too much force is applied as the threaded portion on this engine is unusually smaller than the hexagonal head so be careful using a cheater bar. After draining the coolant remove the head and find the problem. These great old engines are ultimately repairable and simple to work on. Cover each piston with penetrating oil and let it sit for a couple days, the acid in penetrating oil will work on any rust between the pistons,rings and sleeves and hopefully start percolating through to the sump. Replace any missing oil and gently with a breaker bar and socket try to turn the engine in both directions (I'm not certain but I think the bolt is left hand threaded) spend a couple minutes going back and forth and hopefully you will detect a slight movement. Each time you change direction the crank will move a tiny bit more, it will take time so if you get tired just add some oil and come back later. If there is no movement let it soak a few more days and try again. Repeat as often as needed.

PigZen · 02-04-2017, 13:32

I am bringing a gallon of Marvel Mystery Oil to Staniel Cay with me. I'll have a 1 1/2 inch socket, ratchet and small cheater bar and will carefully try to move the engine after 5 days to a week of sitting with the pistons covered. I will pull the injectors and almost certainly the head - though I'm concerned I'll need a new gasket (oh well what's another $70). Will I need mostly metric or standard wrenches and sockets? I had thought metric but it's a 1978 so standard? I'll bring a craftsman $50 set with both plus a bunch of extras...
Is there any magic to re-installing the injectors correctly? Thanks for the advice so far it has been a big help.
Quick second question - can you repack the rudder post stuffing box while in the water? Rudder won't drop out will it? That would be a hoot.

**Lepke** · 02-04-2017, 13:53

A few months ago I freed a 4108 for a friend. The boat had been on the hard for years - divorce. Anything is better than WD40 for lubrication. The rings are most likely rusted to the sleeves. Penetrating oil alone won't break the rust. What I try 1st is an electric impact wrench on the crank bolt, then a breaker bar with a pipe extension. As a last resort, I pull the head, put a piece of 4x4 on each piston top and hit them with a sledge. The sledge is usually gas engines. Diesels don't rust up as hard. I have rebuilt several sunk diesels.
Once the engine is free, change the oil, flush out the old diesel and bleed. It should start if you have enough compression and the injectors and pump work. Adding heat helps. Block heaters is best, but hair dryer in the intake can help. Have some way of cooling the engine on the hard.
If money is no object, rebuild it. 4108s are easy. But... you could get several years out of the engine if you're not a purist. Maybe a little smoke and a slight sheen. Smoke may even go away with some hours. It's not necessarily any less reliable than any other 4108.

buzzstar · 02-04-2017, 15:22

May optimists. So you have secondary plans?

PigZen · 02-04-2017, 16:18

I don't believe this engine is beyond reviving. But if it is not within a reasonable financial expense I might consider moving the boat with an outboard, or importing an electric engine...I am in contact with a guy who claims to be able to provide an electric motor alternative for under $2K. Or i could import a running 4.108...bring it to the boat in my friend's boat...hoist it aboard with some kind of chain hoist and clever use of halyards, dinghy davits etc. and repower it where it sits. That is something I would really rather not contemplate. It'll run.

oldcal46skipper · 02-04-2017, 16:24

Based on our ten+ years specializing in rebuilding 4.108's, the chances you can free it up w/o total tear down is about 10%.

Most of the engines we get for rebuild are seized as yours is. This primarily comes about from the exhaust water injection elbow corroding so badly that when you shut the engine off the water remaining in the exhaust will run back into an open exhaust valve. If the engine is not run often, the rings rust to the cylinder liners. If the engine fires on one of the other cylinders and there is a significant amount of water in one of the cylinders - POW! Water is virtually not compressible.

We have a "Aw Shucks" table with proof of what can happen. So, if you are ever up Pensacola way, call and drop by. We are not looking for work as we have 9 engines waiting for the laying on of hands. We have shipped 4.108's to several Caribbean islands, Mexico and South America, but Bahamas customs duties are difficult.

Ma Perkins built over 500,000 of the 4.108's. Why? Because they are well designed, well built and with proper maintenance 10,000 hours of use can be expected.

Good luck! Let me know if I can help. We recently shipped a circulating pump to Staniel.

Sputnik · 02-04-2017, 16:58

Sorry to say you won't get it up and running without taking the pistons out, even if you can get it to turn.
IF there is seawater in cylinder there will be substantial corrosion at the piston/cyl' wall. The piston rings will be corroded into the ring lands, and you will not have any compression, or massive blow-by.
Heaving on the crank pulley will be very unlikely to get it to turn unless the corrosion is minimal, and will most likely damage a rod (a conrod works in compression, if you pull on it you will distort it.)
The only way to possibly retrive the engine will be to remove it and strip it.
If possible to get to the big end caps you will be able to remove the crank, once that is out of the way a wooden plug on the piston crown driven by a mallet may get it down the bore a way, so you can then polish the bore and drive the piston/rod assembly out (using a wood block against the big end, making sure it is a similar dia' to the big end so not to damage the rod).
If you can get the pistons out then heat them to about 150 deg C to free off the piston rings and remove them...you may if you re really careful get them out without breaking them...but you are going to need to polish the bore or have it re-bored, so will most likely need new rings anyway.
There are special tools available to hone the bore if it is not too badly pitted.
Good luck, but unless the corrosion is minimal you are unlikely to be successful.
BTW, coke (the liquid kind !) is great for unsiezing the pistons.
Neil

01kiwijohn · 02-04-2017, 19:37

take along a head gasket kit, just in case you can't free it up by external means.

Matsubob · 02-04-2017, 20:09

As one who has revived two Yanmar engines from immersion, one by rainwater and one by seawater, I wouldn't run any engine that has seized. I would pull the head for a good clear look inside. It's not that hard, and that way you know for sure what you have.
Because with an engine, there are so many variables. Most of the possibilities are mentioned here.
I would recommend removing the pistons and inspecting them, then hone the cylinders with a hone chucked into a drill, replacing the rings while at it, as well as the rod inserts, while they are accessible and then come back up with it.
Yes a new head gasket will be necessary, as the old one will be unusable. Diesels fire on compression, so the best compression possible is top priority!
That is the only way to know what you have and that you can rely on it. All of that would be precluded, of course, by draining the oil and checking for presence of water.

Capt. Tom · 03-04-2017, 05:49

Why not just sail it back to the states. From Staniel it's not that hard.
A dink with an outboard would be a big help. But get it to a convienient inlet and havi towed from there. Lots of experience with 4-108 and breaking one loose is very difficult.
Capt. Tom
S/V Chardonnay

PigZen · 21-04-2017, 16:12

Update:
The pistons were only corroded to the cylinder walls, not rusted by saltwater. This was a big lucky break and as of now the pistons are free and the crank has a full smooth rotation. I changed the oil and filter. The injectors are corroded into the cylinder head and do not want to come out. They have been soaking in a combination of diesel fuel and ATF. I soaked the cylinders with ATF for two days before using a breaker bar to get the pistons to move. The marvel oil is stuff with the rest of my cargo in transit.
I am hoping the fuel is good (two years sitting though had an additive stabilizer added prior to leaving it. I hope the injectors are good. Will let you know how it turns out.