Life span of a Perkins 4-108

[bern74]

Hi all!
I have been looking at a sailboat that is advertised as having a "well" maintained, Perkins 4-108 (original Motor) with 4400 hours on it.
With these type of hours what would be a realistic time frame before a rebuild / replace would be needed?

[Cheechako]

That engine COULD go to 15000 or more. But it really depends on the type of use; short runs without fully heating up may be harder on it than higher hours.... but being run for long periods.
Kind of hard to say.
If it runs well, doesn't smoke, doesn't leak (they do often have a real small drip tho'), starts right up without excessive cranking, and doesn't have black build up/goo inside the rocker cover/on the rockers etc, it's probably pretty good.


If it passes those tests give it a compression test as part of the inspection/survey. There are people on here that rebuild them, maybe they will chime in.

[DeepFrz]

Well maintained? Is there an engine or maintenance log with the boat that you can read? Is the engine and engine compartment clean? When was the heat exchanger last cleaned, the injectors rebuilt, the impeller changed, the injection elbow replaced, etc. etc. What shape are the hoses in? Has there been water dripping on the solenoid/starter? How does the belt look? How does the engine start after sitting over night? How much smoke and what color is it? What do the engine mounts look like? Are they clean or are they all corroded and dirty. It might be worth your while to have an engine survey done.

[Cooper37]

I've got 5800 hours on my 108, and recently had a mechanical survey. The mechanic gave it a 8 out of 10. It does smoke a little a minimum idle, but starts easy, and has been well maintained. So I have the same thoughts ... how long? I'd hate to learn the hard way that
" I should have ". I'm changing out all the hoses next week, and the hot water tank. I'll also change the engine oil and coolant. The manual says to change oil every two months!! Don't think so .. but maybe salt water has more corrosive meanies at work.

[deblen]

Originally Posted by Cooper37

I've got 5800 hours on my 108, and recently had a mechanical survey. The mechanic gave it a 8 out of 10. It does smoke a little a minimum idle, but starts easy, and has been well maintained. So I have the same thoughts ... how long? I'd hate to learn the hard way that
" I should have ". I'm changing out all the hoses next week, and the hot water tank. I'll also change the engine oil and coolant. The manual says to change oil every two months!! Don't think so .. but maybe salt water has more corrosive meanies at work.

Might pay to pull the head & do valves & seals.This would give u a look at cyls for ridge,etc.

[CSY Man]

I know a CSY guy that ran his 4-108 to 15,000 hrs and it ran just fine, but he had it overhauled because he got nervous with the high hours.

Like the above posters said: Check compression, log for an engine log, etc.
You can tell if the boat/motor was taken care off: If a cheap slob owned and maintained the boat he would probably have ignored the maintenance and abused the boat. If everything is meticulous with an extreme attention to details, and if the engine starts right up when cold, does not smoke, delivers the RPM, etc., then it is probably in good shape.
(Look for fresh spray paint on the engine with over-spray on hoses and hose clamps, it may make the engine look "fresh" to some, but a warning sign to others)

I loved my 4-108, gave it a hug several times, always started in 14 years of ownership and delivered the power. Only thing it asked for was clean fuel, regular oil and filter changes. That and valve adjustment every 1000 hours and injectors every 400 hrs. Heat Exchanger boiled in acid every 2 or 3 years, fuel tank cleaned on the inside once in a while, fuel filtered before going into tank,
New hoses and hose clamps every 10 years, impeller serviced, etc, etc, etc.
Many owners probably ignore the scheduled maintenance as per the book and those owners have the problems we hear about occasionally.

[zeehag]

perkins can run forever., 4400 hours on a decent running diesel is nothing. treat it well and make sure you have oil and not too much, make sure the oil is not more than put into the engine-diesel fuel in the oil means FIX something, ie, lift pump--keep it maintained and running well and should be forever. is a diesel, not a gasoline car with limited lifespan.
to answer your question-- it is good until you crack the block. if you let it runaway, you WILL need to repair it. it will look inside like an erector set town got run over by a freight train. will need rebuilt, as only sound will be ka lunk, as i have previously posted.
make sure injectors are clean and injector pump is working properly. isnt rocket science--is an air pump with attitude. treat it well and it will live forever, or damn close to forever.

[Eddiefuego]

I am replacing my Westerbeke with a perkins 4-108. It is used with 400 hrs. I will need to replace the motor mount bushings but I believe I can use the same motor mounts. Can I just replace the bushings?? What info do I need to supply a supplier to get the correct bushings? Who would you use or not use? Any other info would be appreciated since this is my first repower.

[Boatyarddog]

Recommended, major services or refits are 12000 to 15000 hrs.


Sent from my iPad SV Cloud Duster

[btrayfors]

It's kinda like with fiberglass: how long does it last?

For a 4-108, truth is, nobody knows. They run forever, given modest maintenance.

Mine starts fast and hums along just fine after 26 years of ownership, and it was 8 years old when I first met with it.

Seriously, it's a very good idea to get a professional engine survey before buying so you won't have any serious surprises.

Bill

[Stonefloat]

Any good recommendations for a Perkins survey person in Seattle area ?

Cheers, Stonefloat

[leftbrainstuff]

A well maintained Perkins diesel will last indefinitely. 15000 hours as another poster mentioned is not unrealistic.

That being said most sailboat diesels either don't get much love or don't get to run long and hot.

Love for a diesel is clean fuel, clean air, clean oil and run under load at normal operating temperature. Most wear occurs at start when cold.

My own Perkins 4-236 has 3800 hours. It was maintained by an aircraft mechanic for the last 22 years. He also ran a pre oiler before starting. This is key to minimising wear as it ensures oil at pressure is present to all oil galleries.

I did an oil analysis at purchase. Something you should consider. Transmission too. This will tell you a lot about the internal condition. I do oil analyses often. Oil changes are 50 hours for me. Oil and filters are cheap.

I completed a compression test and visual inspection. Clean coolant, no sludge visible, no significant oil leaks and not much rust are all good indicators. These are all simple checks and it will give a good idea of the overall condition.

I might add the engine room was spotless. I ensure its clean enough so you can eat your dinner of it. I began my career in motorsport so dirty mechanical systems don't exist in my world. It also makes casual inspections very effective.

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[evm1024]

Get an oil sample and send it off to Blackstone. The analysis will tell you volumes.

[pmgpmg]

I am looking at a 1976 Tartan T34c with an orginal Perkins Perama M30 with 4500 hrs. The boat and eng look very clean. I have not heard the eng run yet but will 8-24-15. Should I expect to have to rebuild/replace eng and what should I look for when broker shows the boat. I'm new to this and he knows it. Thanks Mike

[Lepke]

I have a 40+ year old 4108 generator engine. 20,000 hours.