Perkins 4107: Rebuild or Replace??

[Chasing Summer]

I also go for the rebuild. I'm in the middle of a rebuild of my own Perkins 4-107. I sent the head to Hill Head Shop in Seattle, WA to have new valve seats pressed in.
New sleeves and bearing through out. It's not completely back together yet but it should last me a long time .... at least the the plan.

[atmartin]

We're leaning towards a total repower at this point. Our long term goals have use shoving off for much further shores than mexico in the (hopefully) near future.

Either way, rebuild or replacing: I gotta get this damn thing outta the bilge and to my shop. Working at the slip it's been slow, but I'll hopefully have it out tomorrow. Need to rewire while I'm at it. Nothing criminal, but convoluted.

Pix pending. Something hillbilly is gonna be required for me to get this thing from the bilge to the dock. Even with the tranny and accessories off I figure 300lbs? Probably use the boom if I can get comfortable with the idea.

[SimonV]

I recommended that when you do the motor rebuild, do the gear box as well.

[Nemo55]

I can tell ya from a Mechanics point of view,,,if your dead set on repowering (something i think is overkill) then stay with the same series engine.
Or open up Pandora's box of head aches.
Personally i would just put a rebuilt head on her after a thorough inspection of your bottom end, and save yourself some grief.
The Perkins has a well deserved GOOD reputation.

[MacG]

The 4.107/08 is a widely used engine that served all sorts of automotive/industrial as a source of power.
The main failure is the weak cylinderhead - if the engine drops out it is in most cases due to the cracking of the head. Which leads inevitably to a costly repair.
The engine is quite outdated and there is no guarantee at all that a rebuild will save you from further misery.
I would opt for a Beta, Nanni or similar engine. Get a suitable marinised powerplant, not a piece of automotive transplant.

[zeehag]

you can find parts for 4-108 in mexico. the 4-107 has wet sleeves in all models, and 108 does not have same. is slightly different engine-same block and some accessories, but starter is different and some other parts, as you will see if you interchange them as i have..LOL....the 4-108 is used in many fishermans rigs here and is readily repaired and replaced if you so need.
i left sd with a used 4-108 and i am very very happy--we finally got the air knock to be gone by repairing a fuel line tubing, and she purrs sweetly now. i even have gauges and redundant gauges mounted over engine doghouse--this is heaven.

[malbert73]

Does the OP have any update on final engine choice and outcome?

[Chasing Summer]

Malbert73 ... they did a re-power with, if memory serves, a Yanmar. I bought their old engine. It's very rebuildable. Needs a new head as theirs was cracked. It has new sleeves, pistons, newly machined crank ... the works. They could have saved a lot of headache by just getting a new head or a used one and sending it to Hill Head Shop in Seattle and having it rebuilt. Heads is all they do. They grind out the old seats and press in new, harder seats.
Are you interested in the old engine? I need to get rid of it and the Borg Warner transmission.

[malbert73]

Nope- not currently. My boat has a fairly new yanmar. Know someone with old 4-107 thinking of re powering...

[Farlander]

Bump: I have a Perkins 4.107 in a 41' sailboat which has a Paragon transmission and reduction gear, meaning the driveline drops about a foot from the engine crank to the coupler. Looking for a replacement engine / trans combo that closely matches the driveline offset. My Perkins runs great but uses 1 qt of oil per 8 hrs, and is noisy as hell (top end tick, rattley like a spark plug knock) not sure why but at certain rpms it smooths out. Noisey valves?

[Ambler]

I would do a rebuild of the Perkins for the experience.

But this engine in my opinion is too big for your boat. Diesel engines love to work so I think your best option is to repower with a smaller engine say 25hp. I rebuilt my perkins due to glazed bores, she wasn't working hard enough. I then did a re engine with a 3 cylinder 30hp Kubota and sold the Perkins to guy with a 50 footer. The 30hp is a much better match for my easily driven 37ft IOR 1 ton yacht.

[skipperpete]

Originally Posted by Farlander

Bump: I have a Perkins 4.107 in a 41' sailboat which has a Paragon transmission and reduction gear, meaning the driveline drops about a foot from the engine crank to the coupler. Looking for a replacement engine / trans combo that closely matches the driveline offset. My Perkins runs great but uses 1 qt of oil per 8 hrs, and is noisy as hell (top end tick, rattley like a spark plug knock) not sure why but at certain rpms it smooths out. Noisey valves?

Your Paragon could fit on any other engine, flywheel housings and flywheel bolt patterns conform to various industry standard sizes, SAE and DIN are 2 of the most common. You could use your old drive plate and gearbox to get the 1foot drop. Alternately a ZF “MIV” vee drive might do the trick if the Paragon is nearing end of life.

[more]

Originally Posted by Ambler

I would do a rebuild of the Perkins for the experience.

But this engine in my opinion is too big for your boat. Diesel engines love to work so I think your best option is to repower with a smaller engine say 25hp. I rebuilt my perkins due to glazed bores, she wasn't working hard enough. I then did a re engine with a 3 cylinder 30hp Kubota and sold the Perkins to guy with a 50 footer. The 30hp is a much better match for my easily driven 37ft IOR 1 ton yacht.

and your opinion is wrong,this engine is to week for his boat. what when hi come in high current,strong wind ecc.

my 1 bavaria 38 have 55 hp and from entry bay i have 3 nm to marina. couple time on full throttle i for this 3 nm i need somtime in storm 3-6 hour ,or return 15 nm on next island on big vave.

[Farlander]

The boat weighs about 25,000 lbs and the 39 hp motor has to run at 2500k pushing an 18" x12 3 blade prop, 2.5:1 reduction, to do 6.5 knots in flat water. So yea it works hard, but the previous owner put gasoline in it which I think glazed the cylinders.

[Lepke]

Always cheaper to rebuild. It's a PIA to change engine brands and get aligned and everything hooked up.

The 4107/4108 was widely used in farm and industrial applications. I believe heads can be swapped between models. Check tractor junk yards.
Also engine kits and other parts are cheaper from a farm supply than Perkins or most marine companies. Parts are the same.

The problem with Westerbeke is they overprice everything. They don't make the basic engine, just the bolt on stuff. W40 = 4107/4108.

Found this: https://www.tractorpartsasap.com/cat...erkins%204-108