Rebuilding Westerbeke W30, aka 4-91

[sanibel sailor]

Been delayed waiting for parts, then it got breezy here a week or so ago. Had to order a new timing chain and as long as I was waiting for that to arrive from the UK, I ordered a correct front plate gasket (part 14570) from my local Westerbeke dealer. I believe this may be the first Westerbeke brand part I have ever purchased. Only $7 and they could put it in as a routine order so no shipping charge. Supposed to be less than a week. Took three weeks then Irma, finally I go to pick it up yesterday. $20 shipping because Westerbeke. I squawked and they cut it to $10, I take my lumps, chain arrives same day, tonight I get a chance to work on it. Gasket does not fit. It is same as MGA gasket! In Westerbeke packaging. I wound up making my own after all.

Installed front plate, cam retainer, Chain wheels and timing chain. Had to add an extra shim behind crank to adjust end play of crank sprocket. Very careful to get marks lined up. New chain tensioner as old one was shot. I then temporarily installed crank pulley and timing mark bracket. Stuck tappet and pushrod in cyl #1, allowing me to set correct position and installed fuel pump drive spindle in correct orientation. I had been a little worried about that task and it was easy.

[sanibel sailor]

Picture of tan MGA gasket on top of grey Westerbeke gasket (identical) with my homemade one on top. Notice different distance to cam hole position.

[sanibel sailor]

Installed new gasket

[sanibel sailor]

At end of evening, feel like I made some progress.

[CS Cruiser]

Great to be making progress!
How many hours do you have on the W30 prior to rebuild?

[sanibel sailor]

No idea how many hours, $400 craigslist deal, running takeout. Guy in Miami with 3 sailboats in his backyard, I think one was a Cal 34.

[sanibel sailor]

Got the timing cover installed last night. Since the distance between the cam and crank is different, the timing cover is different from the gasoline engines as well. This required making a new gasket for it as the one in the kit did not fit. Installed new seal in the timing cover. Got it all bolted together, using the crankshaft pulley to center the timing cover prior to tightening. Got it all tightened down and was ready to install the crank pulley when I discovered the oil slinger plate that has to go on prior to the timing cover. Took it all apart and reassembled. The oil slinger has a mark on it to ensure correct orientation.

[sanibel sailor]

Oil pump tonight. I didn't remove the upper part of the pump from the block initially. Machinist said it would be OK. The pump cover had some scratches in it and I had lapped it nice and smooth. Old pump had too much clearance so I bought a new one. First step of reassembly of us to look through my box of gaskets, did not see the correct one. There are apparently two different styles and using the wrong one is catastrophic. I proceeded to make a gasket, blew the first one and made a perfect gasket second time through. Kept thinking to myself "The end clearance of the pump rotor is important, is this gasket the right thickness?" The more I thought about it, the more anxious I got. Went back and read the technical guide and the parts diagrams. Turns out there is no gasket. The important one is between the upper part of the pump and the block. Easy to reassemble after that wild goose chase. Put lots of assembly lube on the pump rotor so that it should prime right away.

[sanibel sailor]

Got the oil pan tentatively installed. Had to clean it first. Bottom of sump was dented from mishandling the engine. I knocked that back into shape.
I then installed the cylinder head studs and tightened them down. Temporarily placed head on. I will do some more reading before installing it. This is starting to look like I might be able to complete this project.

[sanibel sailor]

Installed cylinder head tonight. Bit of a delay getting new head nuts. I had beat up a couple of the originals getting the studs out. Took one to a bunch of different places looking for replacements, without success. It is an oddball, 7/16-20 fine thread, and 1/2" tall rather than the usual 3/8". High grade alloy I assume as well. Impossible to find locally. I managed to lose my example somewhere in my travels, so had to order some. Found a very close match at Fastenal. $9 shipping. Gotta pay for being dumb. Should have just reused the old one, or better yet, get a couple of standard nuts to pull the studs.

The engine design hides 3 of the nuts under the rocker arm shaft. Requires a special wrench adapter for the torque wrench. The original adapter is obsolete of course but SnapOn made a similar item. Fortunately, I had picked one up on eBay years ago.

After torquing the head to specs, I installed the rocker arm nuts and adjusted the valves. Nice to do that task in the shop rather than curled up in a locker with an anchor and 3 fenders trying to hump me.

This brings me back into familiar territory. Everything else on this engine I have done before. Not in a rush, but barring missing parts etc, I should be able to button it up soon.

[sanibel sailor]

For future reference, here is the cylinder head nut that is hiding and the Snap-On tool model S-8663-A used to tighten it

[model 10]

Originally Posted by sanibel sailor

For future reference, here is the cylinder head nut that is hiding and the Snap-On tool model S-8663-A used to tighten it

That is an aircraft cylinder base nut wrench. I thought they were unique to air cooled aircraft engines.

[OneMist8k]

This article has been so helpful. I have the very same engine and have to decide between re-power and rebuild. I won't be doing it myself as you have done, but you have pretty much confirmed what my mechanic has told me about parts availability and quirks about this engine. Still haven't decided yet, but your postings have me leaning towards a new engine.

I'm looking forward to reading how it turned out, if you have any final thoughts about the amount of time, effort, and money spent on a rebuild. I'm especially interested to see if the performance of the rebuilt engine is anywhere near what you expected.

[sanibel sailor]

It is still setting, I have most of the accessories mounted. I just have haul my engine lift out of the storage unit so I can pick it up off the engine stand which mounts to the back of the block, then to get the flywheel, bellhousing and engine mounts on, then it will go on a new stand and be ready to test start. Major expenses, machine shop 800, pistons 400, bearings, small parts and supplies 300, injectors rebuilt 150, I am sure there is some other stuff. Probably around $2000 including purchase of engine.

[CS Cruiser]

Hey John hope you are well, any progress with your rebuild?