Author Topic: Westerbeke 40 Rebuild?  (Read 2071 times)

S/V Deo Volente

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Re: Westerbeke 40 Rebuild?
« Reply #45 on: March 04, 2020, 07:52:17 AM »
Dale is right, grade 8 is what you need. I made a similar puller for some bushing work and had to get a grade 8 rod. Dry ice is what I would suggest as a first step before the torch. I assume the new liners will require boring though.
"S/V Deo Volente"
Pearson 365 Pilothouse
Hull #17 1980
Duluth Minnesota
Bob

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #46 on: March 04, 2020, 08:23:07 AM »
This part of the project is a bit nerve wracking, but I am hopeful that a thoughtful, slow and steady approach will get me through. And I cannot believe the depth of knowledge on this forum-it is such a great resource. Even simple things like what you just taught me about different strengths of threaded rod is invaluable. As you can tell, this is not my day job..

I've weighing all options,  Couple of issues:
1. I don't have gas-at least not now...

2. My jig has stepped discs at the bottom AND the top of the liner-this to ensure the discs stay centered and don't skew in the liner increasing risk of scratching the bore or binding-but it imposes some constraints.

3.Have heard about dry ice-am planning on that approach for the installation of the new liner, but given the "two disc" enclosure for removal, I think that precludes the dry ice for removal. By the time the ice is packed in and the jig reassembled the whole area would be chilled.

4.Then there is this.....Harbor Freight sells a little portable 120Volt AC inverted to DC ARC welder that has recieved great reviews for short money ($150).  Seems like that would be an inexpensive way to learn stick welding (always wanted to and who doesn't like a new tool?) and less likely to generate the heat to thru weld the liner.  And given that the first liner is stuck halfway out, I can practice on the segment that is not in contact with a cylinder bore. If its too wild/unstable I still have a tool to play with and I fall back to the option below.

5. I have ordered the hollow ram-for only $120 and am picking up a hydraulic pump-10 or 20 tons today. Again, Harbor Freight- if the welder works I can return the hydraulic....Ram wont be here until next week.

This is kind of an expensive learning curve, but its probably less than using a machine shop and given they quoted 45 days I think its an overall reasonable approach.

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #47 on: March 04, 2020, 08:32:00 AM »
Bob-my understanding is reboring is required if the bores are out of spec or damaged. Is that true or am I being too optimistic? My liners were .003 out (.006 is considered the wear limit)if not for a broken piston skirt I wouldn't be rebuilding at all-I am hoping to get the liners out, measure the bores and find them as manufactured.  If I did, then I was hoping to install original replacements.  The goal is to bypass the machine shop. Block is flat, crank and cam are perfect. Head will probably need combustion inserts and maybe some valve work-haven't measured then yet-though visually they look great). Again, this is not my day job...what am I missing?

S/V Deo Volente

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Re: Westerbeke 40 Rebuild?
« Reply #48 on: March 04, 2020, 09:42:30 AM »
I was told that they will need a clean up bore because the dry liners are thin and can distort while assembling. Maybe the supplier can tell you. Dry ice is -109F so you need to be careful handling. It will disappear fairly fast but leave the liner cold for awhile.   
"S/V Deo Volente"
Pearson 365 Pilothouse
Hull #17 1980
Duluth Minnesota
Bob

Dale Tanski

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Re: Westerbeke 40 Rebuild?
« Reply #49 on: March 04, 2020, 02:10:51 PM »
Dry Ice will transfer the cold to the liners and be long gone before the cast block starts to cool.  Besides, the numbers on the thermal conductivity of the steel liners say they will conduct the cold at half the rate that the cast iron will, meaning any cold that escapes the liner will travel through the cast iron at twice the rate and therefore be half the temp differential and contract at half of the rate.  This means that the greater the differential in temperature the cast iron block and will never catch up and the liner will shrink at twice the rate.  The coefficient of expansion for the two materials are so close that the liner is going to shrink before the block has half a chance.

Up here we can buy dry ice at any good welding supply and can it be transported in a good cooler.  Yes... because of the ultra low temperature you have to be careful while handling it.  If you had a source for liquid nitrogen at -300+F you could just squirt some of that into the liner and they would probably fall out on their own.  As far as inserting the new liners, a couple of days in a good freezer or a a nap in dry ice would be a big help. 

Keep going! We are all living vicariously through you.

Dale
"Maruska"
Pearson 365 Cutter Ketch
1976 Hull #40
Buffalo, N.Y.

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #50 on: March 04, 2020, 07:27:31 PM »
I am very happy to report the liners are out.  The little AC welder I bought allowed me to run beads up and down the liners and the result was I was able to tap them out. No burn through anywhere but  I did get one knick down at the bottom of one cylinder where a piece of slag bound to a cylinder. Its small, about  0.2 inches but I hope one localized divot should not equal a rebore. Hoping emery cloth will smooth it well enough for liners. The rest of the cylinder is spotless and on spec. .  Other than that divot, the bores seem to be as manufactured and on or within .0005 of spec. Will call TransAtlantic Diesel to get there recommendations regarding reboring tomorrow. Thank you all for the support!

S/V AMITY

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Re: Westerbeke 40 Rebuild?
« Reply #51 on: March 05, 2020, 08:37:10 AM »
  Great education for the some of us.  Thanks for taking the time to post your progress log. 

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #52 on: March 05, 2020, 12:42:26 PM »
Sigh-just spoke with clerk at TransAtlantic Diesel-they are a big Westerbeke/4-107/4-108 parts seller. The nice lady  tell me their liners need to be installed and then bored-which means I probably will not avoid the machine shop with its attendant cost and 45 DAY LEAD TIME!!  Its strange because the origianal liners are very thin-like 0.125 inches.  When I mentioned that they said it was probably due to inability to source the originals. That sounds odd because the ones I removed are dead simple-no flange straight liners, steel not chrome.  Why would progress in liner design yield thicker liners and require the use of more raw materials?  Clearly I need to do some shopping around.
Its even more frustrating because the parent bores measured as new (just like almost everything else on this engine).
Jim

S/V AMITY

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Re: Westerbeke 40 Rebuild?
« Reply #53 on: March 05, 2020, 01:01:51 PM »
Try Mack Boring:  http://mackboring.com/.  In past years I've gotten Perkins parts from them.


jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #54 on: March 15, 2020, 07:55:00 PM »
Liner update-my local Napa put together a rebuild kit for me. I received lots of conflicting advice about liners-to bore or not to bore. My local Napa guys assured me it could be done with out boring so i gave it a shot.  I bought some dry ice and let them chill to about -13 degrees and the first one went about halfway in and then tightened up-I suppose it had warmed up but steady tapping with a bearing plate and a hammer finally sent it home, I was really concerned about the potential for damage to the liner and in fact, I may replace the first one because it chipped ever so slightly at the top.  After that experience I got smart and suspended the block over my wood stove for a bit-brought the block up to 170 degrees and still kept the liners on ice-they slid in almost effortlessly.
So for it looks like I am staying out of the machine shop.

S/V AMITY

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Re: Westerbeke 40 Rebuild?
« Reply #55 on: March 15, 2020, 09:00:52 PM »
   Excellent!!!

   I've used more or less that same technique for rebuilding my raw water pump.  Housing in the oven to about 175 deg. and the bearings in the freezer for several hours.  Yours is likely the first block that's been heated over a wood stove. 

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #56 on: March 15, 2020, 09:09:35 PM »
Yankee ingenuity is alive and well. Next challenge is honing the cylinders-hopefully parts guy got it right and only honing is required.

S/V AMITY

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Re: Westerbeke 40 Rebuild?
« Reply #57 on: March 15, 2020, 09:21:55 PM »
Yanks always find a creative solution  8). One step at a time... you're doing fine.  Once she's honed the rest of the job is reassembly.  How do the valves look?

jpendoley

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Re: Westerbeke 40 Rebuild?
« Reply #58 on: March 17, 2020, 05:49:46 PM »
Taking a detailed look at the valves tomorrow-first pass is little immediately detectable wear. Hoping I can confine this adventure to just the lower end...

S/V AMITY

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Re: Westerbeke 40 Rebuild?
« Reply #59 on: March 17, 2020, 07:56:20 PM »
   While enjoying the adventure, lapping the valves is an important part of the experience whether they seem to need it or not.  Can't hurt and will assure solid compression.  Depending on the hours on the engine you may also want to replace the valve springs.  When you're done you'll have an "as new" mill and will be able to sleep soundly.  Cheers!