Perkins 4-108 Life Expectancy ?????

[cburger]

I have the opportunity to purchase a Perkins 4-108 with a Hurth gear. The engine is reputed to have 5700 hrs. on it. It has never been rebuilt and is 20 years old. The owner has indicated that he has been good regarding maintenance and that outside of some of the normal Perkins issues ( leaks a little oil) that the engine and gear are operating well.

This is a two part question, does 5700 engine hrs seem like alot and does anyone have any insight as to the life expectancy in terms of hours of the 4-108?

Cheers,

CB

[CSY Man]

This is a two part question, does 5700 engine hrs seem like alot and does anyone have any insight as to the life expectancy in terms of hours of the 4-108?

The 4-108 should have a lot more life in it than 5700 hours.
I have the same kind of engine with the same kind of hours and it is healthy as a horse.

A guy in St. Croix have been running a charter boat for years with a 4-108 and he finally had the engine overhauled at 15,000 hours. There was nothing wrong with the engine the, he just got nervous.

The Perkins on my boat has been overhauled once but that was because the anti-siphoning valve failed and filled up the engine with salt water and it sat for weeks..Not good.
This happened in the 80s, but interestingly enough I had the same problem last year: After a night for anchor the engine did not start the next day. I found the problem and blew the salt water out, cleaned the mess and changed oil/filter etc and it started right up. Nowadays I always close the sea-cock when I shut the engine off.

You should be in good shape with a used 4-108, but as always, a compression check would not hurt before ya do the deal..

[Chief Engineer]

5700 hours divided by 24 hours = 237.5 days divided by 20 years = 12 days a years.

I would see if you could find out who did the maintenance on it.

Failing that compression/leakdown tests would tell you some things.

Oil sampling would be of questionable value, as you need to get a baseline from which to start.

All in all they are solid engines, I had one in a Navy Whaleboat that was 25 plus years old.......other than some surface rust and a LOT of Navy Paint, it ran great.

[cburger]

Motor was from a real world cruisers boat, maintenance was performed by the owner, repairs where made in many places, the usual Perkins stuff, rear main seal, leaking oil pan gasket.

[svHyLyte]

Try this link Foley Industrial Engines, marine engines, engine rebuild kits, marine rebuild kits, marine engine parts, replacement engines, rebuilt marine engines, wisconsin engine parts, continental engines, perkins engines parts, perkins diesel engines, zenith c . If anyone can answer your question, its the boys a Foley. My own mechanic opins "...between 10K and 20K hours" depending upon whether the engine has good or very good maintenance and up-keep.

Cheers,

s/v HyLyte

[cburger]

I have spoke with the folks at Foley engines before, very eccentric to say the least. I don't have a strong comfort level with anyone who goes by the name of Dr Diesel and won't give his real name.

I drove from NY to Newport, RI last weekend and seatrialed the engine. the motor runs very smooth, no evidence of smoke or knocking of any kind. Very easy starting, of course the engine was already warm when I got there. Upon starting the oil pressure alarm comes on for a couple of seconds then shuts off. Owner would only run the motor at very low rpm, otherwise the motor overheats. When I did a visual inspection of the motor there was coolant under the oil pan. As I can get the motor for a very reasonable price I am hoping the couple of issues are just simple fixes. Any thoughts?

[svHyLyte]

The alarm for the first few seconds is usual as it takes a moment to get the oil pressure up. If the engine heats up at higher RPM's running in neutral, ask for a look at the maintenance log to see when the impellor was last changed. That's frequently a source of problems and a thrown vane can get itself into the water-lines and restrict the flow to the heat exchanger. (A pain in the neck but not a difficult fix.)

If the engine heats up in gear, find out if the running gear is clean. If not, that's commonly a source of overheating as the engine is straining to maintain it's RPM's.

The coolant leak can be more of a problem. Firstly, check the point at which the line from the expansion tank connects to the throat of the coolant filler, under the cap. If the paint on the top of the heat exchanger in the vacinity of the cap is missing, either the cap or the hose connection are suspect. (I had that problem on our engine and learned that because the former owner had used a replacement filler cap from an auto-parts store, rather than a proper Perkins cap, the top of the filler throat was bent enough to allow seepage.) If that's not the source, next check the area around the temperature sensor, next to the thermostat housing--where leakage can occur around threads, the base of the thermostat housing itself for leakage around the gasket; and, the fresh-water coolant pump and hoses, especially if the hoses run to a hot water heater that uses engine coolant to heat a domestic hot water supply. A leak in any of those or their connections could be the source of the coolant under the engine.

In conclusion, if the engine starts easily and runs smoothly, at $1,200 is probably a deal. A rebuild--i.e. rings, bearings, valve-job et al once it's out of the boat--would not be very costly, nor would cleaning out the heat exchanger and replacing all of the gaskets, hoses and seals. With that you'd have a very good deal--probably under $4,000 for a really good engine that--properly cared for, could easily last another 10,000 hours.

Good luck!

s/v HyLyte

[northiceman]

I have had MANY bad thoughts about my Perkins 4-108 (all unfounded); things like...how long before I need to overhaul, etc. The longer I keep this engine (since 1996) the more I like it!
I'm more concerned with whom I should bequeath it to when I pass than when I should get it over-hauled.
I have run it for 17 days consecutively (12 hours per day) on a cruise - at 2,800 RPM - no overheating, no problems at all. I did this on the advice of my cousin who is a diesel mechanic - he claims that a diesel should always be run at its power curve (3000 is top for 4-108). However, I will be throttling back soon - at the cost of diesel these days.
ENJOY THAT PERKINS !