Restoring Perkins 4.108 after years of disuse

[doog]

Thanks so much Marcjsmith, sounds pretty similar and for some reason my engine has that definite clank at shutdown. I changed the balancer disc on the transmission which indeed was getting sloppy but it still clanks on shut-down when the engine turns over its last stroke and kicks back a little. But yes I think Im right in there in the range of typical engine condition. These things are amazing how they can sit and still come to life with no issues.

[doog]

Originally Posted by donradcliffe

Go with 30 wt non synthetic oil and it will leak less. I ran 40 in the tropis.

Makes sense in the tropics. Yes.

I would have chosen this until I read the workshop manual and its a good point given the tendency to leak. But I was able to fully seal the timing cover with permatex copper gasket silicone and a new front seal which did the trick. My engine runs so cold, I havent measured the temp but its always in a range you can put your hand on it without discomfort so likely around 110. And in the NW coastal climate where 70 is the peak in August I'm feeling the 20w makes sense for this region.

[stormalong]

Idle speed of 400 is low. Should be over 600. This may be contributing to your bucket of bolts noise.

When I had a 4.108 I used straight 40 weight oil. When I was making the rebuild/replace decision I spoke with a 4.108 guru in England. I was wintering in London at the time. He said that I should have been using a multi viscosity oil and that the engine would have lasted a lot longer than the 6500 hours I had on it. In the end I decided to replace it. Partly because it was under powered for my 12 ton (measured at 15 ton) boat. I suggest that you have a conversation with Trans Atlantic Diesel and get their input on oil and anything else you have questions about. They are the Perkins experts.

https://www.tadiesels.com

[Searles]

Note ,idle speed stated at 400 rpm ,should be 750 to 830 rpm idle if set at 30 hp rpm 3000 max w.o.t 4000 ,56 hp at flywheel not prop shaft ,good flex mounts ,help alot,injection timing is critical .⛵️⚓️

[Searles]

P.s the clunk on shutdown maybe wear in the flywheel to g / box drive plate .⛵️⚓️

[W32Glorious]

Looks and sounds just like mine and mine is over 40 years old. Just keep the fuel clean and change the oil and trans. Fluid regularly.

Can anyone tell me where to get some Perkins Marine Blue paint, so I can freshen up my engine? It is hard to find.

[W32Glorious]

Also, I meant to mention that your idle sounds low…mine runs nicely at around 800rpm.

[doog]

Originally Posted by Searles

P.s the clunk on shutdown maybe wear in the flywheel to g / box drive plate .⛵️⚓️

Yes, thanks. That was my fear and I changed that part. It did have significant wear and was loose but then the clank remains with the new part. This is the 'damper plate' you're referring to and available in the original form, and I did have one of those very small bolts holding it coming loose and was nice to correct that issue. I used thread Lock this time.

[Finalee]

They sound the same way with spun bearing. I just got mine going again after blowing the sensor line. It froze up. I was able to get her going again but did not trust it. Upon disassembly there were 2 spun rod bearings and severe scuff on all 4 pistons. Oil analysis showed high iron,aluminum. Pressure was 10 at idle 40 at 2000 rpm.

[Finalee]

Oh and the crank was cracked. Now after rebuild oil psi is 40/60. Sounds pretty much the same.

[doog]

Yes, and if you had not rebuilt but just run the engine, it would have failed catastrophically and destroyed the block. I know my crank and mains are good because I had that inspected and I also replaced the main bearings but the top end is original and I could have issues in the rod bearings and pistons although compression is beautiful after 600 hours.
My feeling is that a boroscope check and or oil analysis is my best bet at this point. And with the injectors out one could also rotate the engine carefully and observe piston movement to detect a lost rod bearing. Each rod felt totally tight when I assembled the motor but it has the same history of losing the oil pressure line and its oil when it was new at 60 hours. I bought it as salvage for core value and its run beautifully for its whole history of about 600 hours.
Anyway oil analysis sounds like a very good idea at this point and its those rod bearings Im concerned about. Thanks for the details.

[stormalong]

Originally Posted by Finalee

Oh and the crank was cracked. Now after rebuild oil psi is 40/60. Sounds pretty much the same.

Finalee: Please tell us what your rebuild cost. Did you DIY it?

When I chose to replace my 4-108 rather than rebuild it one of my concerns was that the price would skyrocket if the crank or some other major parts needed to be replaced.

[1affiah]

Originally Posted by W32Glorious

Looks and sounds just like mine and mine is over 40 years old. Just keep the fuel clean and change the oil and trans. Fluid regularly.

Can anyone tell me where to get some Perkins Marine Blue paint, so I can freshen up my engine? It is hard to find.

Try Ford blue engine spray paint.

[ttex]

Doesn't sound like my engine. I have a 4108 as well. Yours has a lot more higher pitched rattling sounds. If that makes sense. Mine is a deeper more consistent sound.

Edit: If everyone elses sounds like this and mine is the weird one maybe mine is broken, lol.

[Finalee]

Originally Posted by stormalong

Finalee: Please tell us what your rebuild cost. Did you DIY it?

When I chose to replace my 4-108 rather than rebuild it one of my concerns was that the price would skyrocket if the crank or some other major parts needed to be replaced.

All in $3500. That included $1200 machine shop and a $500 donor engine .
I supplied the labor. It got new pistons,bearings,crank,rebuilt injection pump, oil pump, cam, and pumps.