Restoring Perkins 4.108 after years of disuse

[rbk]

Originally Posted by 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.

No I only buy from TAD and Parts4engines. I got mine from TAD, they also has some good emerg kits and things like a flexible emergency HP injection line. Biggest thing with the serpentine kits is the new water pump. The pulley is pressed on with something like 20T so not something you can likely replace DYI. I kept all the old V belt stuff and can swap it back in case the water pump ever goes I’ve got a spare.

[doog]

Yes, TAD is a great source. They helped me sort out the starter issue requiring the correct spacer, and advised on injection timing and the Standodyne fuel treatment which also helped. Im just going to upgrade the V belt as possible for now, hmm, a machinist press should be able to change the water pump pully and I will look into the serpentine belt options. Clearly a nice upgrade.

Running now with Delo 400 the engine seems happier and starts okay with the help of the electric primer.

Im also running a Chinese diesel heater and thought about ducting it into the engine compartment as pre-heat. These things can get a small compartment really warm in short order with low electrical consumption and are fairly economical on fuel as well. I'm in a marina currently but the aim is self-sufficiency on my own systems. Almost there..Between our short days and cold weather my 400 watts of solar needs supplemented with a lot of run-time, in summer I would barely need any.

Happy Sunday.

[col50]

Originally Posted by Rumrace

I’d hate to be accused of being able to fix by sound but tinkle tinkle says valve lash, lifter wear, weak old springs,leaking guides, rocker arm wear, cam bearing, gear wear..
All upper end stuff.

I have rebuilt several of these engines and that's what it sounds like to me.
One thing to watch is rocker arm wear, where it contacts the valve stem, as this will give you a wrong reading when using a feeler-gauge.
The clanking when the engine stops is probably a different issue.
Also, as far as I remember, the idle speed should be 700 RPM.
Increasing the idle speed will increase the oil pressure at idle and reduce the shaking. My engines have always idled very smoothly.

[doog]

col50,

You'd do better to read the whole thread and find you are way off. The springs and valve train are fresh, this is not a worn engine if you note it says "Years of disuse" not years of use...Its been sitting and I found the issue and described what it was in the starter gear train, due to an omitted spacer which is critical to ring gear engagement/disengagement.
The oil pressure remains above 60 at any rpm. Again is not a worn engine, but unused for years. Its all in the discussion including the good-running result after pulling the head and valve lapping. No the rocker arms were not worn.
The engine has a rock solid idle but this perkins has high compression and it will shake with the typical 4 cyl rhythm rather powerfully. It doesnt miss at all. I do wish it had hydraulic lifters as you can hear them tapping but its old technology.

[col50]

Originally Posted by doog

col50,

You'd do better to read the whole thread and find you are way off. The springs and valve train are fresh, this is not a worn engine if you note it says "Years of disuse" not years of use...Its been sitting and I found the issue and described what it was in the starter gear train, due to an omitted spacer which is critical to ring gear engagement/disengagement.
The oil pressure remains above 60 at any rpm. Again is not a worn engine, but unused for years. Its all in the discussion including the good-running result after pulling the head and valve lapping. No the rocker arms were not worn.
The engine has a rock solid idle but this perkins has high compression and it will shake with the typical 4 cyl rhythm rather powerfully. It doesnt miss at all. I do wish it had hydraulic lifters as you can hear them tapping but its old technology.

Sorry, I guess I missed post # 48. Glad you have it all resolved.

[skipperpete]

Originally Posted by col50

Sorry, I guess I missed post # 48. Glad you have it all resolved.

You make a good point about the wear on the tips of the rocker arms, sometimes the only option is to use a dial indicator to adjust the clearance.

[doog]

Thanks col50 and skipperpete, good information. Yeah its a long conversation and I learned a lot, thanks for looking back.

[rbk]

Originally Posted by doog

Yes, TAD is a great source. They helped me sort out the starter issue requiring the correct spacer, and advised on injection timing and the Standodyne fuel treatment which also helped. Im just going to upgrade the V belt as possible for now, hmm, a machinist press should be able to change the water pump pully and I will look into the serpentine belt options. Clearly a nice upgrade.

Running now with Delo 400 the engine seems happier and starts okay with the help of the electric primer.

Im also running a Chinese diesel heater and thought about ducting it into the engine compartment as pre-heat. These things can get a small compartment really warm in short order with low electrical consumption and are fairly economical on fuel as well. I'm in a marina currently but the aim is self-sufficiency on my own systems. Almost there..Between our short days and cold weather my 400 watts of solar needs supplemented with a lot of run-time, in summer I would barely need any.

Happy Sunday.

Early season or winter I’ll throw the space heater in the engine room overnight to heat the block all the way through. After that we make sure we start every morning and evening until fully warm. Usually that time of year we’re motoring anyways. The diesel heater plumbed into the engine compartment is a great idea, I’ve been throwing around the idea of installing one. Curious where you are with short days and cold weather. We’re officially down to less than 6 hours of daylight.

[doog]

Astoria, Oregon. I see you're in Canada. It's usually very mild here in Winter with the usual SW flow, but this year we are getting a few snow-storm/freezing systems. I was so glad to finally install a wood stove but its so much work and messy, and the diesel heater is truly the ticket to convenient, on-demand warmth. And fairly frugal on fuel and very clean burning. I chose a 5K which is good, but with a dual heater system you could have either one or two going and really heat a fairly large boat well. And Im sure your knowledge would be more than equal to a first-rate installation.
If I were in a climate consistently as cool as this winter has been with repeated freezing, I'd definitely install two of these heaters.
Ordinarily its only needed in the early AM and cool evenings, and always turned off overnight.

[rbk]

Originally Posted by doog

Astoria, Oregon. I see you're in Canada. It's usually very mild here in Winter with the usual SW flow, but this year we are getting a few snow-storm/freezing systems. I was so glad to finally install a wood stove but its so much work and messy, and the diesel heater is truly the ticket to convenient, on-demand warmth. And fairly frugal on fuel and very clean burning. I chose a 5K which is good, but with a dual heater system you could have either one or two going and really heat a fairly large boat well. And Im sure your knowledge would be more than equal to a first-rate installation.
If I were in a climate consistently as cool as this winter has been with repeated freezing, I'd definitely install two of these heaters.
Ordinarily its only needed in the early AM and cool evenings, and always turned off overnight.

We live in northern Canada but keep our boat just across the border in Alaska. Try charcoal briquettes in the wood stove. Higher btu in a smaller package with less smoke and soot. Easy to keep a bag of it in the bilge. Easier to keep going and you can always ad a few sticks to get it roaring again. We have propane heater for off grid which does really well along with meal planning (use the oven when it’s cold). I like the forced air diesel heaters as you can let a bit of warm air ‘spill’ into the bilge via a few holes in your duct runs to get airflow and reduce moisture.

[malbert73]

I know these are really revered engines- but in reality they are pretty underpowered (need 4000 rpm to get 50hp) so most folks overprop them to get some performance out of them at lower cruising RPMs

https://www.cruisersforum.com/forums...e-52046-2.html

[rbk]

Originally Posted by malbert73

I know these are really revered engines- but in reality they are pretty underpowered (need 4000 rpm to get 50hp) so most folks overprop them to get some performance out of them at lower cruising RPMs

https://www.cruisersforum.com/forums...e-52046-2.html

Underpowered for which boat…

[doog]

Re malbert73, yes, low for a power boat upwards of 35 or 40 some feet, but the primary use is aux sail, and I over propped in order to get the low rpm power which gives me almost hull speed at under 2000 rpm and around .5 gallon per hour economy with a 2.8/1 transmission to keep the prop RPM low. (Im no expert but I feel I got really lucky with this combination)
The actual HP needed in my application is around 25/30 so its perfect, although a small Japanese diesel would be technological superior but twice the cost..I suspect over-propping is a British tradition where they know the larger, slower prop is more efficient, since the old Seagull outboard days.

[ocean686]

Sound is normal for Perkins 4.108. Idle should be adjusted to the recommended 625RPM. Oil pressure should be a minimum of 30lb at max engine speed. Looks like excessive engine movement(or very shaky hands!) suggesting new engine mounts needed.

[Cheechako]

Originally Posted by malbert73

I know these are really revered engines- but in reality they are pretty underpowered (need 4000 rpm to get 50hp) so most folks overprop them to get some performance out of them at lower cruising RPMs

https://www.cruisersforum.com/forums...e-52046-2.html

Interestingly, the boat in my avatar, a 44 ft cutter had a 4-108 in it with Hurth gear.
It would push the Yves Marie Tanton 44 at 8.5 knots in flat-ish water at 2500+/- rpm. (Max Prop) I kept fuel records and for the life of the boat under my ownership, it burned only .65 gallons per hour. I never felt a need for more power.