Restoring Perkins 4.108 after years of disuse

[Marathon1150]

We have two boats, one with a Perkins 4.108 and one with a Volvo Penta 2003. They are night and day different in terms of noise, vibration and starting. The Perkins will start instantly no matter what the temperature. It is super quiet (bystanders sometimes wonder if the engine is running) and when the idle speed is set properly and there are no leaking injectors (a separate story) it is essentially vibration free, considering that it is a diesel. The Volvo is the opposite of all of the above.

I bring this up because of some of the comments in this thread - Perkins 4.108's are noisy, vibrate, etc, etc. Ours doesn't.

But it has had its fair share of problems (it seems to eat the seals on the raw water pump) and getting the injector pump timed correctly has been a challenge. But it is super quiet, doesn't vibrate and is incredibly easy to start.

Every engine/boat combination is different so it seems that we might be at the very happy end of the spectrum in terms of these particular attributes.

[doog]

I just wanted to conclude the discussion with a couple comments, the gear driven starters which are lighter and powerful and have an internal clutch (delco type) work great. This is what I was supplied by the parts store but they had no info on installation details. These have various spacing requriementst to adjust the distance to the ring gear which requires a spacer and the guys at TAD (transatlantic Diesels) are the gurus to call. They fixed me up with a costly but properly sized spacer that will allow the use of a cheap Chinese starter with perfect results instead of the burned-up bushing that caused my crazy rattling sound. I suspect there are boats out there using this starter and no spacer and as long as the engine is used at low rpm and infrequently its okay but on the first high RPM run up there will be bad news and the smell of scorched bearings. These starters and others are for sale on dozens of websites and E-bay sellers, and I tried the NW marine supplier people and they too had no real idea of what the issues were. I'd call them and get a $900 quote one time and the next I'd hear they just couldnt tell without the original starter what would fit. At one point I called one supplier and left a message and got the return call from the other number. It seems one company has two names and some sort of shell game going on.
And I also discovered there are tons of useful archives on Crusisers Forum which may come up with a Google search but they dont come up searching in the website search tools. Anyway its a great resource and thanks to everyone for reading and comments.

[doog]

Final update after removing the cylinder head and lapping the valves to restore original compression. I found #1 exhaust with a noticable leak and pitting in the first three. #4 was perfect and I didnt touch it. I found the original timing marks stamped on the fuel pump drive gear and got the valves perfect, then secured all the injectors and noticed some of the hold-down yokes were upside down, they seem to work either way. But its all about meticulously clean mating of the crush washer and surfaces. Can be stubborn and tricky. Anyway I no longer feel the Perkins is a noisy shakey clatter-bang engine but rather its as smooth as a Kubota or Yanmar! And now mine is! It seems it had the timing advanced too far to prevent smoking and now there is a far smoother feel and sound and less smoke too. Smokes some, its a diesel. But sounds like a Mercedes!

Here is the clip of the engine freshly restored and purring sweetly!

https://www.youtube.com/watch?v=k66CQIbuO0U

And I'm totally with the fellow above who commented to this effect as well.

[Finalee]

Thank you for the final.

[marcjsmith]

Well done sir.

[doog]

One final observation is that the strange clank on shut-down is totally gone, the cause Im feeling was that the timing had been set too far advanced to inhibit smoking as a result of the low compression cylinder. Now with the compression even and the timing on the spec it doesnt smoke and the clank is totally gone. Anyway diagnosing an engine by sound is only possible with great experience and I knew something was going on with this Perkins and got lucky that it held up for 600 hours with the issues it had, and now finally its in proper running condition and its like a totally different beast. And Im feeling a lot of these other more clattery engines may have similar timing issues because they are set too far advanced to make them smoke less. And then things get fouled with carbon and ... About oil, Im using a 15-40 synthetic multi vis and I also like Lucas oil treatment in moderation, and when I poured a bit of that in the valve cover, the idle speed picked up by a substantial degree as the Lucas drifted down and hit the camshaft helping reduce friction as it pushes the lifters up against those strong valve springs. Anyway that's what I think. And Im so pleased to be done with that awful clank on shut down!

Now just to run it 6/8 hours and re-torque the head and check the valve adjustment and change the oil again. And get out on the water!

[PUDDLE JUMPER II]

Has anyone-- owning a Perkins-- 4-108 or 4-107 UPGRADED away from the rope seal?

I had heard a few years back that there was an upgrade out there for the Perkins to get away from the whole dam rope seals-- I am kicking myself for not buying the upgrade kit back then--- but looking now for this option...

Cheers,

[PUDDLE JUMPER II]

So I purchased this to try an avoid the crazy rope seal replacement at ridiculous intervals...

https://www.parts4engines.com/perkin...l-upgrade-kit/

[skipperpete]

It’s still “the crazy rope seal” just a better rope!

[PUDDLE JUMPER II]

Originally Posted by skipperpete

It’s still “the crazy rope seal” just a better rope!

Sadly... That is the ugly truth of the matter... One leaks more, one leaks less... (Shrug)

[doog]

The cure? A drip pan.

[stormalong]

If you have a lot of crankcase pressure due to blow by - worn rings there is little you can do short of an overhaul to fix the problem.

I had that problem on my 4-108. Replaced the seal and it did not help. Built a drain into the bell housing to capture the oil. That helped a bit but in the end decided to replace the engine. It was also under powered for my boat and the delta between a simple rebuild vs replacement wasn't that much.

Since I was in England at the time and dealt directly with the Beta factory I got a significant discount. If the engine had been torn down and something significant, like the crankshaft had to be replaced the cost of the rebuild would have exceeded the cost for replacement.

[doog]

Oh not the case at all in my situation. (blow-by and all) I have a low-time engine with good compression and high oil pressure with little wear. It had some corrosion in the valves that was easily repaired with lapping and doesnt use oil. But sounds like you made the best choice, stormalong.
I was looking at the Perkins 3 cylinder engines which are now available on Ebay for around $3K and yet they still need marinized for installation in a boat. But looks like a great deal. This, too, would be too small for your boat Im sure from your comments.
I got to the bottom of my engine issues and the issue was DIS-use, not excessive use but sitting for years only run once or twice a year and corrosion and neglect. So the engine was not worn out at all. Still a relatively low-time engine.
Thanks for your comments and glad you got sorted out. Your Perkins would have made someone a good rebuilder just needing a parts kit and some machine work, and ready to go again. The Beta are a great engine!

[rbk]

Yours now sounds like mine.

To help reduce crankcase pressure and reduce rear main seal leaking install a proper air filter, it does make a bit of a difference. K&N filter with a rubber coupler and is an easy mod for $100. They make a similar kit that runs around $350, think Foley was selling those.

I replaced the rear seal with a new one, got it partially assembled then covid hit and it sat and dried out over 2 years. Leaked like a sieve this summer so tore into it again and replaced, leak gone (for know…)

Look for ‘rust’ or oil based paints like Tremclad, Rustoleum or Armor coat etc. usually ‘farm equipment blue’ that are very close or better in colour. Paint parts as you replace or service them. I went a bit brighter than the oem and have no regrets. The original looks dingy and muddy compared to the new colour.

I highly recommend upgrading to a serpentine belt especially if you’re considering an alternator uograde. Way less belt dust.

[doog]

More good tips! I would love to do a serpentine belt, but the Foley system is ridiculously priced. I did get a serpentine pulley with my Mechman alt, and I see reasonably priced engine drive pulleys and that's a great idea, if only the whole conversion were reasonably priced. I do get some squealing and belt stress with the high output alt when adding a substantial load with just the stock V belt. I replaced with a Mechman that makes about 150 amps and will work with V drive but serpentine is preferred. And I think mine must be the only 4-108 that doesn't leak from the rear seal. Never did. I do get a little drizzle from the front seal but it's really not a bad leaker in general. But that air filter is a really good idea. So did you spring for the high dollar foley serpentine system or is there another option? (Involving also the water pump)
Thanks again.