4-108m

[Dirk Williams]

Recently obtained a Hallbery RASSY 33" Mistral". Has a Perkins 4-108m motor upgrade. We received this boat about a month ago, and the first thing we discovered was fresh water in the crank case.

Pulled the motor at Moss Landing, and have the motor here in Oregon, where we have dissected the motor looking for evidence of where the fresh water could have come from.

Nada, nothing zilch. We did find evidence of water inside the bell housing and a rust stain across the fly wheel, and inside the starter housing. The motor is down to the Pistons and crank, in the cases. Cylinders seem clean, tops of the Pistons have zero signs of water on them. The head gasket appeared to be intact.

We have found a very very small amount of unusual sludge inside the block, up under the # 3 sleeve. 3 being third from the front of the motor.

We're frankly scratching our heads, we can find nothing wrong internally. I'm slowly cleaning every piece, and inspecting for evidence. Tomorrow I'll go over every single bolt hole, and clean every set of internal threads on the motor, with a tap and die set.

The interior of the boat shows zero signs of water damage. Their is some spots of oil in the bilge, and the crank case does show signs of the same spotted oil splotches, on all four sides.

We're new to the ocean boats, and want this motor solid before we need to apply it should we need to.

Anybody seen this before, we're open to ideas, and solutions.

Regards,
Dirk Williams

[skipmac]

Hi Dirk and welcome to the forum.

Lots of members here with 4-108s and more than a few with experience in maintaining and overhauling them.

As I read your post I had a few ideas but the more detail you provided the fewer of my ideas seemed likely. They just didn't hold water.

Since the boat is new to you I assume you have no historical info on the engine, any loss of water from the fresh water system or other details from previous use.

Was the oil/water milky IE the oil emulsified in the water or straight water in the bottom of the oil pan with straight oil floating on top?

How long since the engine has been run?

[pcmm]

Wouldn't a rust line on the flywheel indicate that the motor sat in water up to that level for a while? When we purchased our morgan, it had been flooded at some point and we had a rust line across the flywheel that was exactly the same as the level that the water got up to.

[DeepFrz]

Sludge up by cyl. #3 could be evidence of cracked block. But that would be leaking coolant and not fresh water I guess. The oil on the engine and bilge is just likely "Perkins".

[skipmac]

Originally Posted by pcmm

Wouldn't a rust line on the flywheel indicate that the motor sat in water up to that level for a while? When we purchased our morgan, it had been flooded at some point and we had a rust line across the flywheel that was exactly the same as the level that the water got up to.

This was my first thought but the OP said he didn't see any signs of water in the boat? I would look closer at this possibility myself.

[skipmac]

Originally Posted by DeepFrz

The oil on the engine and bilge is just likely "Perkins".

Originally Posted by DeepFrz

Sludge up by cyl. #3 could be evidence of cracked block. But that would be leaking coolant and not fresh water I guess.

If the PO had not added any anitifreeze to the fresh water tank then wouldn't coolant be fresh water? I guess that begs the questions, was the cooling tank filled and did it have antifreeze in the mix and was there any evidence of antifreeze in the water in the engine?

[Lepke]

The 4108 is a good engine. I have one running a generator. I have rebuilt several. Most likely path for water into the crankcase is a head gasket failure allowing coolant into an oil path. Also there are o-rings sealing the bottom of the sleeves. With a head gasket failure a less common path is water into the cylinder making it past the rings or between the sleeves and cylinders and past the 0-rings.
If it was my engine and I had it outside the boat, I would buy a complete gasket kit and change everything, including removing the sleeves and installing new o-rings.
What I think happened (not seeing the engine) is a small head gasket leak allowed water between the sleeve and cylinder on #3. Compression forced the water between the sleeve and cylinder and down past the o-rings and into the crankcase. Probably at a very low rate.
If you do take any of the pistons/sleeve assemblies apart, record each part, bearing, and piston position within the engine. Because of British manufacturing practices, each piston is fitted and the top milled to fit the sleeve/cylinder. An option would be to buy new rings and have the sleeves lightly re-honed (to restore crosshatching) and you would have a cheap overhaul.
The 4108 is an older, more heavily built engine than most yacht engines of today and will last longer. Mine is 40+ years old. They are used in industrial and farm equipment, too.

[model 10]

The 108 has dry liners so no O rings. Even if it did there are 2 O rings in a 107 and water leaks out between the 2, out the side of the block, outside, not inside. There is a pathway through the rear main seal housing but it's usually sealed up. Some Perkins used a common oil supply for the transmission and the engine. The bell housing will hold water. It would flood the starter too because the common sump starter has O rings. There is a soft plug behind the flywheel but Factory perkins used a stainless plug.

[westwinds]

It's obvious water intrusion caused the rust on the flywheel, starter and water in the oil pan. It appears the engine is not leaking freshwater into the pan so consider all of the symptoms. Better check the rest of the sailboat cabin for water signs. Rainwater probably flooded the sailboat. Here in Wisconsin, a boat has to be pulled out every winter because of lake ice, and finding water inside when spring comes does happen.

[Dirk Williams]

Thank you for the replies.weve considered most of what's been noted here. The fresh water coolant/ tank was empty., we have been thru the boat closely looking for evidence of a flooded interior, nothing noted, except for the bilge are and the engine compartment.

We are thinking freshwater entered the cabin, filled the low areas of the boat, and possibly entered via the crank case dip stick reciprocal.

We've considered the coolant system. With zero anti freeze in the cooler, and only fresh water. The boat was in Santa Cruz for several years, we even considered possible damage from the tsunami in Japan. That would be salt water though.

The boat is a really clean boat, was missing the boom,a servey, noted a hard jibe, causing the loss of the boom and main sail. I don't buy that non sense, and the motor had water in it. A new main sail, and an aftermarket boom fixed that problem, and we're slowly working on identifying the motor issue.

I've got to plastiguage the rod end caps in the morning. If they measure properly we start buttoning the motor up, with TLC, and a keen eye for anything that needs replaced or cleaned.

So IF the water was to have come from the heat exchanger/ radiation, what would be the likely path from the exchanger into the crank case? I can't see how ?, for the fresh water to get their minus a head gasket, or a cracked block, or maybe a cracked head. Again no physical signs of any of these three avenues.

Although we are not intending a NDI " non destructive inspection" of the head or the block, due to costs, well put it back together, fire it up, let it run for an hour, or so, drain the oil change the filters again and probably drop the pan again for another look.

Last question sorry to be so long winded. I'd like to get away from the existing air cleaner. I'd like to go to a K & N style, cleaner, with the intent of providing better air flow, for better optimal engine use.

Any thoughts on the after market air cleaner, pro/ con.

Thank you in advance for,your help. I'm greatful, I have zero experience on the 4-108m.

Dirk

[shakey doug]

Double check that you have a 4.108 not a 4.99 or 4.107, you would not be the first to be caught. Serial number on flat next fuel pump. Earlier models known for water in sump.

[DeepFrz]

Any thoughts on the after market air cleaner, pro/ con.

No personal experience but others on CF have spoken highly of the "Walker AirSep".

Perhaps using the "Google custom search" would turn up some posts.

[Dirk Williams]

Thank you all again for the advise. been up researching the walker airs sep. think I'm going a similar route. Frankly the filter looks exactly like the K & N filters I put on my vintage motocross bikes I build.

Is their a difference I. Specifically the filter, filter construction and intent?

Dirk

[gjordan]

Many engine rebuilding shops can pressure test your cylinder head and probably your block. Call around and see what you can find before you put it back together. I finished a rebuild on a 4 cylinder generator that had been started by a previous mate/engineer and when started up it got water in the oil right away. The West Indian machine shop didnt pressure test the head and it had a crack that could not be seen. This all started with the idea that it was a blown head gasket. Having to do things over again is a PITA. Just my 2 cents worth. ____Grant.

[model 10]

I use a round/ conical K&N filter but on the end of a piece of exh hose to move it away from the engine a little bit. Hooking up a breather is the only problem. I put a hose barb fitting in the base of the K&N filter.