Perkins 4108 leak and engine upgrade

[deweymt]

It appears that the oil leak in my engine is from the front of the engine, the seal around the timing chain cover. I've read some troubling posts about unsuccessful attempts to address that issue. Anyone else have experience replacing/upgrading that gasket? The boatyard wants to pull the engine to replace the seal, in part because they want to be sure that there isn't another source of leak (apparently, rear crankcase seals often leak on the 4108) and because I also need to the pull the prop shaft to repack the stuffing box - no room to get at it. What else should I consider replacing/upgrading when the engine is out?

thanks for any thoughts/experience on this![/size]

Dewey

[camroll]

You might have them check the damper plate as long as you are in there. As long as you have the shaft out you should probably put in a new cutlass bearing. And you might want to look at GFO packing for your stuffing box. Its a set it and forget it packing. The Coast Guard recommends it for all commercial vessels. I have in my boat and I haven't needed any adjustment in 3 years. No leaking and the stuffing box is cool to the touch. Good luck
Russ

[gonesail]

if you have the shaft out you should probably replace the transmission coupler as well. and take a close look at the shaft too.

[deweymt]

Thanks for the advice on upgrades. Much appreciated.

[Jeff Barnes]

The projects you describe can all be done without removing the Perkins. The timing cover seal is a typical source of oil leak, but that, and the front seal around the crank shaft pulley are not difficult jobs within the engine in place. If the rear seal is suspect, then that is obviously a different scenario. I fully agree with using GFO packing. Great stuff. There is not a lot of real estate in the area of the coupling so, yes, the shaft should come out. Removing the existing cutlass bearing can be challenging (I have done two on a CD36)) but recommended if the shaft is pulled.

[Matt Cawthorne]

You can replace the rear seal with the engine in place. You need to support the aft end of the engine and remove the transmission, aft engine mounts, bell housing, and flywheel, but it is doable.

The thing is that removing the engine is not a trivial matter, but you might find that it is worth it. When I pulled my engine in 2015 I ground away some fiberglass to see what the steel underneath looked like. This is typical of what I found.

20160116_121922.jpg

When placed upside down in my shop, this is what was left.

20160117_180424.jpg

. Needless to say, it was a very important find.

Since the engine was out and its compression was marginal, I just had a complete rebuild done. Then I put the engine back on new mounts. With the full rebuild, the engine leaks less than 1% of what it used to. Perhaps 0.1 %. When I get back to the dock, I just don't know what to do with the time that I used to spend cleaning up oil.

Matt

[John Ring]

Engine Bed, old small file.jpg

Engine Bed, new small file.jpg

My experience with engine beds is similar to Matt's. About 10 years ago I lifted the Perkins out & blocked up in the salon, then cut the old bed out with a Dremel. I had a local shop make a new bed from 316ss & I tabbed it in on the old footprint. The old Perkins went back in and all good now.

John Ring
CD36 Tiara