engine repower

[asea]

I'm looking for info regarding re-powering. I have a M-25 and it does work fine, but am thinking of dropping out for a couple of years with the wife and would like a little more H.P. I was looking at the M-25XPB. Has anyone done this and if so is the transmission compatible?

[Stu Jackson]

Where are you located?

This is about an XP, but shows what can be done by a reputable and helpful local service fellow: 

http://www.c34.org/wiki/index.php?title=Rebuilding_the_M25-XP

The difference between the M25 and M25XP is only two horsepower (21 vs. 23) and, quite frankly, is simply not worth the effort unless you have serious problems with your existing engine.

Is there anything that is wrong with your existing engine?

[Craig Illman]

I expect your older M25 has a Hurth HBW50 transmission. I believe they no longer make them and now Westerbeke uses the ZF10 (HBW 100). It's one inch longer. You might have a little fiddling to align the shaft and exhaust riser. Also, the M25XPB has a different style exhaust flange, potentially ncessitating a new riser (which probably might be due for replacement anyway.

I'm pretty sure Ron Hill has done this upgrade, I expect he would chime in on his experience.


Craig

[Stu Jackson]

Also, the M25XPB has a different style exhaust flange, potentially ncessitating a new riser (which probably might be due for replacement anyway.

I'm pretty sure the M25XP has the same exhaust flange as the M25.  I don't know about the XPB, but I'd check at www.marinedieseldirect.com, easy enough to do.

IIRC, Ron installed an M25XPA to replace his M25XP.  You could look it up in the Knowledgebase and then/or Tech Notes Online. 

[Ron Hill]

asea : I've fixed the old M25XP (a waste of time & $$) and then finally installed a new M25XPB engine.

If you look in the Mainsheet tech notes you'll find an extensive article w/pictures on that installation.

As I've mentioned numerous times, most C34 owner questions have already been answered in the Mainsheet tech notes. 

Bottom line is - it's great to have the 26hp and the reliability of an ALL new engine (not a rebuild with old starter, old injection pump, old internal water pump, old etc. etc. - you get the idea!!

A thought.   

[Stu Jackson]

Ron, have a great trip.

IIRC, Ron had over 5,000 engine hours on his original engine.  I doubt if many of us "regular" sailors have even half that many.  We just hit 2,500 last month, 1986 boat, 888 hours when we bought it in 1998.

Ron's right about all the "old" parts vs. a new engine, you should also consider the # of hours you have and the # you intend to add on your trip as part of your decision making process.

Ron's excellent engine replacement tech notes are November 2009.

[Ron Hill]

Guys : Stu is correct - I had 5000hrs on the engine, but don't kid yourself as it was also 20+ years old. 

Somewhere the engine hour curve and the age curve cross.  The crank oil seal started to leak - was the first indication. 

Engines don't last forever, especially the seals   A thought

[David Sanner]

Ron makes some good points... and as we all know the years do add up.

As I've mentioned before I like Beta Marine's Kubota
conversions better than Westerbeke.  25 & 28 3 cyl models.
http://www.betamarinenc.com/enginemodels.html

Thread on the subject.
http://c34.org/bbs/index.php/topic,6033.0.html

[asea]

I appreciate the input. I am just exploring at this point. My diesel does run fine. I just would like a little more power. I do have a 2 blade prop and maybe changing just that might be the way to go. I need to get info on the self adjusting props and find out if they work as well as they claim. So it looks like I have some homework to do.
Thanks all

[Kevin Henderson]

I have a 3 blade prop (25XP) and don't really feel I'm lacking in maneuverability and speed.  I have a feeling if I had a 2 blade prop I may be having the same thoughts as you.  A prop is a far sight cheaper than a whole new engine, and as noted in a quote I found in another forum, the change can be pretty dramatic.

With my racing background all I wanted was a nice, sleek, folding, feathering, furling proplett that wouldn't disturb the boat speed.....

Then I turned my engine on with its BIG FAT 3 BLADES churning the water! Man, my boat moves!  6 kts at 2,000 rpm and into any sea theres still plenty of power where and when you need it.

Who gives a tinkers cuss about loosing 1/4 of a knot sailing when you can hit 8kts if you want?


When you are tired and pissed off and just want to get somewhere you have the option to do so. Save the extra thousand dollars for a new comfy bed mattress (or beer!)
I love my fat 3 blades!

[Les Luzar]

What are you trying to accomplish? More speed under power? Every thing in sailing is a trade off. If you want more speed under sail, reduce your drag with a folding prop. The trade-off will be a bit less efficiency under power. If you want the most bang under power, then go with a 3 blade fixed prop, but you will have more drag, and a little less speed under sail. Why would you replace your engine if it is running fine? You will have enough expenses repairing and replacing things on an ongoing basis. It's a lot less expensive to upgrade your prop than to replace an engine, and a few extra horse power will be negligible.

[Ralph Masters]

Does a three blade walk to port less then the two blade in reverse??

Ralph

[Les Luzar]

Ralph,
Don't know, never had a two blade prop.

[Stu Jackson]

Arnie and I had a nice offline pm discussion.  I thought it might be helpful to those of you who can help him to be aware of the great things he's already done with his boat.  Here it is:
********************
You are right about the difference between the m-25 and m25-xb. I was looking at a m-25xpb it is rated at being a 26 h.p. with the same physical dimensions as the m-25. That's 5 hp more or 25%.
I am not planning on doing this right now but looking out a couple of years. My boat sails well as I have done many upgrades and feel comfortable with her as long as i stay not more than 25kn. miles from shore. I feel also it's cheaper than going out buying another boat and doing upgrades all over again.
That said I would love to have a little more beef when I have to buck sea's, current, and head winds. Getting another 5 hp and changing the prop ( i have just a two blade)might give me another knot and more thrust when needed.
I live in Belmont Ma. outside of Boston, and summer my boat at a mooring in Plymouth ma. We sail pretty much from Maine to Long Island.
North on year South the next. As we are nearing retirement, we are thinking of spending more time on the boat and probably dropping out for a couple of years.
I have to do more homework on the info i am looking for but thought asking on the Catalina site might be a good place to start.

Thanks
Arnie Corazzini

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Arnie,

Glad you posted, good discussion.  I wasn't aware of the 26 HP for the XPB, always nice to learn something new.

I still feel that unless you have some significant issues with your M25 that you find a "better" place to "invest" your boat bucks.  I know, I know, boats aren't an investment...but there are other things to consider as well.

For example, if you switched, you would most likely have to consider your prop and perhaps repitching it.  If it was my boat, I'd go for a three blade right away.  Why?  'Cuz my PO did exactly that when he first bought the boat.  While when I was racing I knew I was dragging a bucket around behind me (!) I did get a break on the PHRF.  You may find the prop change to be a wise option to consider.

Another thing you could do to "regain" some HP is to install an external regulator on your alternator to be able to either use Alternator Management or Small Engine Mode (http://c34.org/bbs/index.php/topic,4454.msg27149.html#msg27149)

This essentially "gives you back" anywhere from 1 to 3 hp right away if you reduce the alternator load.

I wouldn't put an external regulator on an OEM 55 amp alternator, although some have done so (I shudder, but the few I've heard of say it's fine – I can't figure out how).  I just don't know what you have as an alternator.

I also don't understand the 25 mile limit.  On my boat I have a 23 gallon fuel tank, say 20 usable at 5 knots @ ½ gallon per hour measured fuel consumption (over the course of 13 years – my fuel gauge is inoperative and I wouldn't trust it anyway! – will fix it if I ever sell the boat!!!) is 40 times 5 or 200 miles.  Maybe you can help me understand that.

Another issue, of course, as you mentioned, is space.  Lots of my friends have Mark II C34s with M35 engines in the same compartment.  I have NO clue as to how they work on their beasts!

FWIW, I put a larger 3 inch HX on our M25.  I also did the alternator bracket upgrade (necessity!!!).  Hope you have done the bracket at least.  Have you read our "Critical Upgrades" page?  It has a lot of engine info.  http://c34.org/bbs/index.php/topic,5078.0.html

The C34 Tech wiki also has tons of engine info, just click on it on the Message Board page.

Bucking currents:  You are aware that we sail on San Francisco Bay and in and out of the Golden Gate.  I used to have a Catalina 25 with a 7.5HP Mercury outboard, and we sailed her in the ocean.  I have NEVER felt a need for more power on our boat.  When we motored up river to Petaluma a few years ago, all the guys with Mark IIs could get a ½ to a knot faster in smooth water.  To me, no big deal.  I simply don't personally share the concern about time & distance with our M25.  Besides, the larger engine has got to have higher fuel consumption, I'd bet doing the math would get you a pretty even tradeoff with the same size fuel tank, slightly higher speed with higher fuel consumption could well turn out about equal.  I do, however, understand the additional torque you would get with a larger engine to buck heavy duty headwinds and seas.  Whether or not a few extra HP would do that I just don't know.  An M35 compared to an M25 – now you're talkin'!

"I feel also it's cheaper than going out buying another boat and doing upgrades all over again."  I agree wholeheartedly.  I don't know what you have done to your boat, but because of my interests in both safety and "creature comforts" I've found a solid reliable electrical system takes a much higher priority to me than a few extra HP from the engine.  And electrical systems are things that seem to befuddle and antagonize more people than engines (except for when it comes to bleeding!!!).  My thoughts on Electrical Systems are included in the sticky "101 Topics" thread on the message board.  I'd add more batteries before I'd repower if my engine was working OK.

Ron Hill's M25XPA swap did this for him in 2009, he had had over 5,000 hours on his OEM M25XP:  I'm in the break-in mode so can't go above 2500rpm, but very impressed with the boat speed so far.  With the old engine - clean bottom, no wind I was reading 6.7kts on the knot log(thru the water) @ 2650rpm.  With everything the same the new engine is showing 7.2 kts @ 2200rpm!!  There was no water in the aft tank and I'm not fully loaded, but I'm still impressed.

If you go that much faster, though, you're pushing more water once past hull speed.  Maybe there's something I'm not getting, but sometimes I think it's like putting a V8 in a VW Beetle!!!  Maybe I'm just crazy and a traditionalist who's just happy with what he's got, and with blinders on!!

I always love talking boats, so please feel free to continue our discussion anytime.  Email might be easier:  mraquaq att aol dott com

Best regards,  Stu
************************************************************
I found this today on the C36 forum

Pos M25-xpb
The PO repowered his 1987 C36 with a M25-XPB. It is a terrible application for a marine auxiliary. The damn thing will not idle smoothly below 1150 RPM, and is really hard on damper plates and engine mounts. Check out the C310 Owners' website, since Butler & Co used that engine in those boats, and the vibration at idle is a well known problem.

He had ordered a Yanmar, but upon further investigation the yard told him it would require modification of the engine cowl/companionway ladder to get it in there. He cancelled that and went with the Universal/Westerbeke engine.

I owned this boat, in what now seems a previous life, and its M25-XP purred along at an 850 RPM idle, smoothly ticking over. The XPB will "run" below 1000 RPM (the published idle is 1000-1200), but acts like it wants to crawl out into the cockpit with you.

The XPB was not entirely a "drop in" replacement for the XP and the PO reported some issue with the engine mounts. I'm not on the boat, and can't recall what had to be done to get the new engine in there and aligned. The heat exchanger had to be shifted to starboard in its brackets to fit, resulting in its end cap rubbing up against the throttle and engine kill cable sheaths. The heat exchange zinc wound up nearly inaccessible (directly above the engine mount) and can only be changed with liberal application of the f-word.

Westerbeke used the deservedly much-malinged backwards facing Sherwood raw water pump, the impeller in which would be a real PITA to change anywhere but at the dock. One of its hoses must be removed, spilling saltwater onto the lower engine pully, when changing the belt because some rocket scientist figured it wasn't important to employ the Oberdoffer off to the side of the engine as in the M25-XP.

I was in a 3-way partnership in a 2005 310 before reacquiring my 36. With under 700 engine hours, we had already gone through two damper plates and an engine mount. That engine exhibited the exact same reluctance to idle as does the XPB in my boat.

Not being a bit fan of shifting the transmission at 1200 RPM, I reduce the throttle to around 950, grit my teeth while the engine rumbles around, shift and quickly reapply power to 1150 to get it to run smoothly. Makes for a jerky approach to the dock. The old XP could stay at 850 and shift back and forth effortlessly as needed to get into the slip.

As much as I have misgivings about rebuilt diesels, that might be a consideration, depending on what's wrong with the existing engine. Doubt one would save a lot of money and, to my way of thinking, sailboats are about beauty and relaxation, absent the worry of a rebuild going TU.

Had it been my call, I would certainly have tried to get a Yanmar (or something?) in there, even if it required downsizing the HP to fit. I have no experience with the Beta or other offerings, but would only go with the XPB if there was no alternative.

Can't remember the exact figure, but recall the yard bill being around $13k, including new transmission, dripless shaft seal and flexible coupling in 2008.

Hope this is helpful.

Jack
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Nimue Nimue is offline
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Yanmars have a great reputation for reliability but they are also notoriously expensive to buy parts for.

Also, they are philosophically different from a Universal/Kubota/Beta type engine. A Yanmar 3GM in a typical 36' boat cruises in the mid 3000's RPM vs. my old Universal M25 at 2250. That's like the difference going down the highway between my 1963 Chevy II 2-speed vs my wife's 2004 Toyota - I can tell you which one I'd rather sit in for 8 hours straight.

I probably have one of the oldest C36's around and my engine will be coming due for attention soon. I think I'll buy a used unit and rebuild it, then swap it out and sell my old while it is (hopefully) still running. Although the M35 sounds nice for the odd time I have to motor into a strong headwind, really the 21 HP M25 is plenty for this boat under most conditions.
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Nimue
1983 Catalina 36
Hull #75
Vancouver, BC, Canada

Stu Jackson, C34 IA Secretary, #224 1986, "Aquavite"  San Francisco Bay, SR/FK, M25, Rocna 10 (22#) (NZ model)

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Much appreciate the responses i have received. As I mentioned I have done numerous updates. My C34 is a 1986 and I have owned her for 10yrs. I recently had a survey because I changed insurance companies. I was pleased to be told that by the surveyor that my boat was one of the better ones he has seen for it's age. Also the depreciation was only 5 thousand from what I originally paid.

I did do an electrical upgrade several years ago. I changed the cockpit seaward engine gauges and harness. Originally the boat came with a fused panel at the nav. station and I changed it out to a seaward breaker panel. I also changed all power lines to new tinned 1 awt wire. along with upgrading the alternator to a 110 output balmar (i think that was the brand)and a new voltage regulator. I put in 4 golf car Batteries for the house with a separate engine battery. I did get the general planning from tech notes. However those that did similar upgrades used lighter wire. I believe that to be a mistake. Also no  mentioning of fusing the golf car batteries either. That said I did so for my free standing Engel refrigerator. works great can freeze if i set the tstat low enough. And it can hold plenty. The nice thing is no need to tear apart the gally and put in condensing units. The Engel only draws between 3.5 to 5.5 amps depending on load. i can leave it on for 3 day before i need to charge the batteries, but i don't. i have left it on for a weekend without recharging. the other good thing is it cost only $800.00 and can work on a 30degrre heel.  I also have a electric main halyard wench. My wife can't get me up the mast so this was the solution. I use it to put my inflatable up on the bow as well and of course to bring up the main. I have done many other upgrades Like all new standing rigging, new bottom, electronics. new portals, new traveler, etc. etc. etc.

As for the 25 mile limit I misspoke and was referring to the Catalina being a coastal cruiser and not a blue water boat. And yes I know you can take her father than 25 miles off shore, but we rarely have.

Currents in New England especially Maine are fierce. We have sailed up rivers and have had 5 knts going under us while we were at a mooring or anchor.You can see nuns and cans get sucked under during tide changes. The bay of Funday has a 50ft. tide. As you go up the coast you see some pretty funky stuff especially on a spring tide. The gulf of Maine, Buzzrds Bay, or Long Island sound all have currents that we try to play to our advantage. But when when we get stuck in something that wasn't predicted and the wind and seas are on the nose I always felt it would be nice to have a little more diesel.

My diesel does run fine. I have replaced the heat exchanger, and both fresh and salt water pumps. When I bought the boat the previous owner had the engine rebuilt. I usually run it around 2000 to 2400 rpms. But have pushed it up to 2800 when I had to plow through seas wind and current. Or when it is just damn miserable out there and you want to get back to port quickly and safely. I'm not sure how long you can push it at those higher rpm.s?

I appreciate the other email you sent regarding the upgrade. I need to find out from people like that who have done this. Re powering may not be the right way to go. Maybe be just changing the prop to one of those 3 blade self adjusting might be a wiser investment. And even with those I hear they are overprice and don't work as claimed. So I have a lot homework to do. But as I have said I don't plan on doing this right now, so I am in the exploratory phase.

One other thing I plan on putting on as a future upgrade is heat. There are some nice kerosene heaters available in Maine. As long as they are vented properly. Not that we plan on being in N.E. in the winter for sailing. But in Maine spring and fall can be cold at night, or you get those lows with rain and rawness. it doesn't take much heat to take the curse off and warm  the boat to make it more comfortable.

Thanks for your earnest interest
Arnie Corazzini

[Ron Hill]

Guys : If and when you RE engine there are a bunch of things to consider:
1. Will it fit?
2. On which side will the throttle and shifter attach?
3. How will the exhaust system interface with the existing muffler?
4. Will the raw water system be compatable with the existing thru hull/hose routing?
5. And a bunch of other things ie. electrical hook up and length of existing wires?

Don't get me wrong, if you have enough $$ you can change everything to make a new engine fit, rewire and operate.
 
In my mind -The whole idea is to do the least amount of changing - to get the job done, for the least cost !!

Maybe you can even improve on the factory's installation !!  ie. everybody pisses and moans about the intake raw water being captive of the drive belt on the M25XPB ,M35A and M35BC engines.
I looked at that problem and took that intake hose and ran it next (above) to the exhaust raw water hose.  OR you could have done as Bill Nuttall wrote in the Mainsheet Tech Notes (late 1990s) and cut that hose and placed a simple garden hose connection so you could easily disconnect to change the drive belt.  
As I've said MANY times -- the answers are out there if you just want to do some reading!!

Enough said, on a few thoughts.