Perkins 4.108 repair/replacement options

Engines, Drive trains, Propellers, Steering, Ground Tackle and other mechanical system
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monroe
Posts: 29
Joined: Wed Dec 04, 2013 6:33 pm
Location: La Paz, BCS, Mexico

Perkins 4.108 repair/replacement options

Post by monroe »

Hello,

We have a 1983 Freedom 39 deck salon with a Perkins 4.108 engine, 3400 hours. Two problems with the engine: It's loud and it leaks oil out the rear engine seal and pan gasket, about a quart every 15-20 hours depending on RPM's. Otherwise, the engine starts and runs well, only belching smoke on hard acceleration (e.g. I'm about to hit the pier, back up NOW). Adding oil and mopping up underneath has become "not fun", and I'd like to fix the problem. One positive is that it encourages us to sail more than motor.

Option 1 is to have the engine pulled and the seals, gaskets, and hoses replaced. This should fix the leaks but won't fix the noise.
Option 2 is to re-power with a more modern marine grade engine, such as a Yanmar or Beta. This should take care of both issues but will be expensive.

Has anyone done option 2? What did you replace with, what was the cost, any problems or pitfalls in the installation, and did it significantly reduce the noise?

We do plan on keeping this boat for a while.

Thanks,

Doug and Cindy
s/v Spartan, 1983 Freedom 39 DS, Hull #27.
Currently lying San Francisco Bay.

rds
Posts: 50
Joined: Mon Jul 06, 2009 9:32 pm

Re: Perkins 4.108 repair/replacement options

Post by rds »

I would try to repair the old perkins, if it were me. Parts are still available as far as know .
I got Yanmar 4JHTE, 3500 rpm in my boat, which is high revs and noisy diesel as well.
Actually two friends of mine have 4.108 perkins in their boats and I always been a bit envious of this low revs engine ( 2600 vs. 3500 rpms ?).
4.108 is almost silent in one of these boats (provided it has good sound insulation ), it is barely noticeable in the cockpit and down below during operation.
I might be wrong on this, but if I recall correctly one of my friends always complained about leaking rear end as a deficiency of design of this diesel, but the other guy always argued that it has been rectified now (something like real rubber seal instead of packing in rear crankshaft journal ) so no oil should been leaking at all.
Winter is coming so it looks like a doable project.. I suspect the engine replacement is gonna be expensive (probably 10-12K just of the diesel with transmission) plus installation costs,
You probably have to tinker with the prop and with exhaust as well. (new transmission gear ratio in tranny and diff. exhaust diameter / flange , e.t.c.
I also recall the second friend bought his rebuilt engine somewhere from CT and had some problems with leaking head gasket (it was supposed to tighten in 50 hs. ?)

Capitan Sardina
Posts: 41
Joined: Mon Dec 15, 2008 9:14 pm

Re: Perkins 4.108 repair/replacement options

Post by Capitan Sardina »

I installed a Beta 37 to replace the perkins in a F-40.
Main reason was to meet European emisions and to prepare for an atlantic crossing.
The Beta is marginally less powerfull than the perkins, but will run all day without overheating. Much smaller foot print and lower weight.
I was able to use the same tranny (ZF) and changed the pitch of the feathering prop (11x19 I think).

There is an option to order "custom feet" for a drop in installation.
The engine is priced quite reasonably (around $8-9K depending on options), but installation by a prestigious east coast yard cost me more than the engine, after I did most of the work to remove the perkins myself!! Just to find out on the eve of our departure to cross the Atlantic, that they neglected to tighten the engine mounts...

cheers

Freedom44
Posts: 8
Joined: Wed Oct 07, 2009 4:33 am

Re: Perkins 4.108 repair/replacement options

Post by Freedom44 »

i have a F44 which had a Perkins 4107 - Yes i know, it should have been a 4108 ,but the original 4108 engine was badly renovated by a company in Massachusetts and in the end I had to re-engine it with a 4107 just before crossing back to UK. A very long and painful story.
However eventually (ie 2 years ago) having become increasingly fed up with a foul bilge and deafened into the bargain, i decided to bit the bullet and replace it with a modern alternative, and that is when Betty came into my life. She is quiet and very red. Even more economical than the Perkins and just lovely.
I selected the 2 alternator version so I now fairly buzz with amps. She pushes us at 6+knots when clean. I dithered about the size and eventually decided on the 50hp, a new gearbox and a pumped water prop shaft seal.
The best decision I have made on the boat.
I even sold the old perkins on ebay to a chap in france who was re -engining a canal boat so the expense was not as bad as I imagined!
We had a bit of a fight fitting it all in; I would definitely choose the small sump option.
All in all, a no brainer as long as you anticipate keeping her for a few years.
Freedom 44 "Windwalker" located Plymouth UK

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