Perkins 4-108 Nightmare

[cburger]

I have my Perkins which was out of the boat when we bought her with a mechanic who specializes in diesels. Of course the motor according to him is a complete wreck. Got a figure for an entire rebuild $7,200.00 and almost had a coronary. (See his email to me below) This does not even include paint or looking at the reduction gear. I have got so fed up that I will just repower with a new motor. I would like opinions on Yanmar, (I have had them in past boats and they where phenominal). The model I have been looking at is the 3JH4 puts out about 40hp at the crank, does anyone have experience with this powerplant?. I would also like an opinion on the mechanics bill for inspection and cleaning. As the motor was in pieces when I delivered it to him this seems expensive also.

2nd email from mechanic after I told him his estimate was to high: Currently I have 9 hours at 85.00/hr in this engine, dis-assemble time and cleaning all parts, so I have 765.00 in it now. I am not charging out the steam and jet washer or bead blaster material. All parts were cleaned for inspection and prepping for overhaul, I don't charge time for generating a estimate, looking up parts and so fourth. Let me know what we are doing here.

1st email from mechanic:

Ok , here we go.. I read the info you had sent to me, and I see a wide variety of opinions. I am not a believer in replacing gaskets with RTV, gel gasket maybe but not RTV. Your engine as you can appreciate came with and is designed with gaskets. I also don't know how much oil is leaked out of this small engine on some of the people in these postings. We were told by Detroit Diesel leaks are listed in three categories: weep, seep, drip. A lot of engine don't leak at all, although new are designed with modern materials and design, for example using o-rings in place of gaskets. Over the years I have seen Perkins engines that were dry as well as damp. The side tappet cover and rocker cover are just sheet metal, tin, and have only so much crush the can give a gasket. Enough of that, brass tacks time

I apologize for the delay in sending this estimate, I did not have all my ducks in order, now we do. We bead blasted everything for the most parts to see what we need, after all that engine was rusty in and out. This is not a in-expensive proposal, but necessary I don't have a scanner at the shop and since you don't have a fax, I have listed what this estimate has on it. I did not add oil, primer, paint. This estimate should cover most everything engine related:

Labor estimate, teardown, cleaning, bead blasting, overhaul with listed parts, assemble, test run

labor 2720.00

machine in new liners 100.00

miscellaneous hoses for oil and fuel
system (estimate) 100.00
Perkins overhaul kit 854.41
reman injection pump 942.30
reman injectors 139.72
reman starter motor 222.50
set of injection pipes 181.87
fresh water pump 118.08
fuel transfer pump 44.60
raw water pump parts 237.51
engine heat exchanger asm 681.49
timing cover 261.10
pump drive bushing 150.86

total with tax would be 7294.80, for the engine alone

The overhaul kit from Perkins is a complete parts kit for major wear items and has: pistons, rings, liners, all gaskets and seals, filters, oil pump, and all items to re-build the cylinder head, only re-using the casting it self, rod and main bearings, small end bushings. Let me know what you want me to do, or call me with any questions you may have

Thanks

Perry

[never monday]

His estimate and current costs don't seem unreasonable.

[AnchorageGuy]

Nothing unusual that I can see here and the mechanic seem to be reasonable in his charges and expectations. A re-power will probably be in the neighborhood of twice the cost of your rebuild. No nightmare here, just the costs of boat ownership.

[cal40john]

Originally Posted by never monday

His estimate and current costs don't seem unreasonable.

I have no experience dealing with marine mechanics and so I don't disagree with what you have said, but should there have been more communication before this point? Personally I would have been upset with a $750 bill to evaluate whether I wanted to keep this engine or buy new, unless I had been told upfront before work started what the cost was of the evaluation. Also I would have expected to be told a couple of estimates before a $750 evaluation began. There could be one for the everything is dead you need a complete rebuild, and maybe one for everything except the lower end. Expensive ancillaries such as the injector pump and starter motor should have been listed as separate possibilities.

Or am I completely out of it and 3/4th of a boat buck is normal just to ask? I tend to fix most everything myself, so I normally only have to shudder at the price of parts.

John

[AnchorageGuy]

There is no way to determine how bad any engine really is and to what extent you need parts, etc. till you tear everything down and that takes time. You pay for a mechanics time. How could you possibly receive a couple of estimates for repairs that are unknown till someone pulls the engines apart. The mechanic is neither a mind reader nor able to see through solid steel. You pay your doctor to determine what is wrong with you before he begins treatment. Try telling him he should have given you an estimate before he charged you for your visit and exam. That mechanic spent much more time examining that engine then your doctor will checking your latest symptoms.

[Morgan Paul]

Get an outboard, or scuttle her. Good luck.

[btrayfors]

Perry,

I've lived with a 4-108 for 18 years now. It's one hell of an engine. Has it's drawbacks, of course, but a great engine.

Repairing your 4-108 or replacing it with a new engine might not be your only options. For example, you should be able to pick up a rebuilt one for about half the price quoted to rebuild yours. Check around.

I think the comments about the costs of diagnosing problems are about right. You can't expect a good mechanic to be a soothsayer...he needs to pull the thing apart to see what's needed, and proceed from there.

I'd do some checking on availability of good rebuilt 4-108s and, certainly, have a conversation with your mechanic about this. A rebuilt engine has lots of benefits, including not having to alter the engine bed, controls, wiring, etc. for a new engine.

If you do go with a new one, check out the Beta engines as well as Yanmar. They have a great reputation. Also, remember that the 4-108 is WAY overrated in HP (37, 42, 50HP claims, and all that). It's a small engine, and only develops that kind of HP at high RPMs. IMO, it should be rated at about 25 shp.

Good luck.

Bill

[AnchorageGuy]

The average 4-108 is approx 27 HP at the prop with the most common set up. The usual replacement for the Perkins in the Yanmar is the 4JH? series which will be 56 HP for the naturally aspirated or 72 for the turbo. If installed and geared properly they will deliver their rated HP at the prop. Even a rebuilt Perkins is only going to deliver 20 something. If that is satisfactory for your boat and needs, go for it. But if this puts you in a position of being under powered, than by all means upgrade, but it ain't gonna be cheap.

[cburger]

I got a price on the Yanmar JH that delivers 40hp for $8600 new including gearbox, when you measure that against having the current rebuilt for $7,600.00 for a motor that is 30 + years old and would still retain alot of the old components it seems like a new Yanmar is almost a no brainer?

[AnchorageGuy]

About average price for the engine. But don't forget you will need to factor in all of the modifications for the new engine and changes, if needed to exhaust, prop shaft, etc. Will you be doing the install yourself? If not then you might be looking at that much again before it is all over.

[cal40john]

Originally Posted by Chuck Baier

There is no way to determine how bad any engine really is and to what extent you need parts, etc. till you tear everything down and that takes time. You pay for a mechanics time. How could you possibly receive a couple of estimates for repairs that are unknown till someone pulls the engines apart. The mechanic is neither a mind reader nor able to see through solid steel. You pay your doctor to determine what is wrong with you before he begins treatment. Try telling him he should have given you an estimate before he charged you for your visit and exam. That mechanic spent much more time examining that engine then your doctor will checking your latest symptoms.

I can call most any auto mechanic and ask what would you charge for a complete rebuild and he knows the parts and time to do it. There would be qualifiers, such as if the head or block is cracked that would not be included in the price. Once you pull an engine apart, for most parts it makes no sense to put them back in worn. After all look at his list, what is missing from a complete rebuild?

You could even spend a little money and get a leakdown test, or even since it's out of the boat, pop off the oil pan and look at a couple of bearings before doing the whole thing.

John

[never monday]

John,
Were not privey to the conversation that went on when the engine was left with the mechanic.
Personaly, I do set a number for teardown and inspection.

[cburger]

I would do all the work on the repower myself. Any opinions Yanmar versus Beta?

[never monday]

I extremly biased to Yanmar.
but, Universal also makes a nice unit.
What is the boat the 4-108 is in?

Also, going from 4-108 to 3/4JH you shouldn't have to do anything to the engine beds. you will need a new prop when every thing is done.

[Alan Wheeler]

There are several issues being smuge'd together here. Firstly, I am assuming you are in the US. So this is US prices. Correct us if this is wrong as it can make a very big difference.
Secondly, this is a little more than an engine rebuild. The engine rebuild part is actually very well priced. The additionals are a new Starter, (does this need to be renewed??) a new heat exchanger (does this need to be renewed?) water pump">Raw water pump (does this need replacing?) Coupling(does that need replacing?). These are items that are beyound the engine rebuild cost and taking them off the quote and I assume the labour for them off, I think it brings the cost down to a very realistic price.
So you need to look at the cost of a Yanmar, that comes with most of the above, factor in any extra's that still need replacing. Like does the Yanmar price include heat exchanger and so on.
And finaly, the Hp ratings. It's not all together correct to say a Perkins 108 is 20Hp and the Yanmar is 40Hp. The Hp is not measured the same on both engines. You need to look at figures and compare apples with apples. Look for a common rating like SHP, or BHP or DIN or what ever, but make sure both are the same. By the way, Hp is supposed to be measured at Max RPM. What you need to compare is the point at where the Hp and Torque curves cross. This is the point where maximum propellor swinging energy is developed. It maybe that one develops that energy at 2000RPM and the other develops it at 2400RPM.
Um.. actually this is finaly....to repower with another engine, you can open up many cans and some are full of worms. But double the engine price to give you are close ball park of new engine install.