Repower or repair?

[jibes138]

A knot is a speed of one nautical mile/hour. Thus, an "extra knot an hour" would be an extra nautical mile/hour/hour--i.e., an acceleration. At the end of an all-day run you'd be travelling at 15 to 20 knots!

I stand corrected. Thanks for pointing this out. Although at twenty knots I would be going less than HALF the speed of the new Americas Cup boats!

 

[jibes138]

Well I spent all day getting to the marina at 2 knots, barely above idle and a favorable current. That bolt and fender washers held it together. Met with the engine guy to finalize options and gave go ahead to purchase. Then started ripping everything apart between the boat to have access and the motor to get it out. Went well and I just need to remove fuel lines and battery cables and the old Universal can be hoisted out. Looks like a new prop will be recommended otherwise shaft and coupling should be OK if not scored inside the stuffing box. I'll take some pics for your viewing pleasure. Getting the motor mount bolts out was tough. Luckily they weren't rusted up and the nuts all came off. Trying to get at bolt heads under the stringers is quite challenging.

 

[jibes138]

I understand. And used this on the way up the coast last summer. I normally would cruise at 2450 but bumped it up to 2800 (3000 is WOT). I gained a half a knot.

Good luck, Dave. Good choice.

Thanks Stu and thanks for all the good advice over the years!

 

[jibes138]

Here's a few pics. Notice the motor mount shifted after I removed the mounting bolts and disconnected the shaft coupling so the fracture is much more pronounced. That 5/8 bolt actually held the motor up so it wasn't bouncing up and down and vibrating too severely. Did a 10 mile run up to the boatyard like that.

 

[jibes138]

New phenomena for interested parties. The fuel drained from my return line after the injectors is a different color than the fuel going into the secondary (on engine) filter or the fuel in the secondary filter. Any idea why it changes color in the engine pump or going by the injectors? Heat?? The cup on the right is the from the return line right after the injectors.

 

[eherlihy]

Looks more like the fender washer held the motor up. It is a shame that the bell housing cracked because judging by the picture, your motor looks like it is in good condition. I have had to reach in the stringers to remove the old motor mounts on my M25. It was an uncomfortable, greasy, dirty job.

Again, I would seriously consider replacing the cutlass bearing while you are doing the repower because it has likely been damaged from the motor mis-alignment. The prop shaft should be inspected to assure that it is true, and that there is no scoring.

I would love to know how the motor is eventually removed from the engine compartment. I have had the oil pan off of my engine in order to refinish it (eighteen 10mm bolts), but it seemed that there would only about an inch or so clearance to fit the oil pan over the motor mount, and the valve cover under the companionway. I am sure it will be tight.

Also, if it is not asking too much, could you give us an idea of which engine that you selected and what the new engine will cost (+/- $1K)? My guess is that it will run you about $12K for the complete repower with a Beta 25, and the options that I outlined above.

 

[eherlihy]

Is it possible that you have added road use diesel into the last tank?
Off road (marine, construction and home heating oil) diesel contains a red dye that is used to identify that the road use tax has not been paid. If your Kenworth shows up with red dye in the fuel filter you are in deep trouble.

 

[LeslieTroyer]

The fuel should all be the same color. It is constantly being pumped out and back into the tank by the lift pump.

 

[jibes138]

Regardless of where the fuel came from I ran the boat for four hours on Saturday. The fuel still in the lines is a different color after the injectors than the color after the secondary filter. My picture shows the difference. I buy my fuel in 5 gallon tanks and pump it through a Racor going into the tank.

 

[jibes138]

I removed the counter top on the piano hinge to help with access. Also to avoid damage. New motor is a little over 9 grand plus installation costs that are variable. Beta 25 is the model. I will need a new prop and exhaust is 2 inch versus Universal using 1.25 or so. Also pump inlet is 3/4. I was told warranty depends on both being to spec. For options I wanted a panel with coolant temp and hot water heater fittings. Basic panel is a tach and idiot lights.
I already put in a 3/4 seacock when I removed the OEM 1/2 inch clamshell slotted strainer. So I'll just need some hose and a few barb fittings. I'll probably replace battery cables while I'm at it. The OEM cables were never sealed with heat shrink tubing so they look pretty bad, not tinned wire either.

 

[jibes138]

Oh yeah the exhaust riser will be custom made also and may need a water lift muffler for the 2 inch hose size.

 

[Stu Jackson]

and exhaust is 2 inch versus Universal using 1.25 or so.

the exhaust riser will be custom made also and may need a water lift muffler for the 2 inch hose size.

A really wonderful sbo member did a repower just like yours. When he reported on the need for the 2" exhaust, I questioned him. By then he'd had the new engine in and his old muffler out. Once I learned about the Beta's requirement for a 2 inch exhaust, I understood. He was kind enough to send me his old muffler for the cost of shipping!!! Lovely. I installed it last year, works great. I needed it 'cuz my OEM muffler intake port was dying. I'd seen all sorts of repair options for that, both here and elsewhere, but his was in fine shape, and worked flawlessly on our trip up the coast. I forget whether he replaced the box muffler with a Vetus or some other. As far as I know, those old box Catalina-style mufflers only came with 1 5/8" ports.

 

[Stu Jackson]

Stu - on my Leece-Nevill 90 Amp alternator, I have been using the 8MR (dumb) regulator, and it serves my needs with a 220AH house bank nicely. My energy needs are modest (all LED lighting. No windlass, inverter or refrigeration. SOC monitored by a SmartGauge. I have never dropped below 50% SOC.). Of course, I'm not using it to it's fullest potential, but the Leece-Nevill is FAR better and more reliable than the stock Motorla 55A alternator.

Good system for your requirements, great alternator. I think you are using it to its full potential because of your system.

 

[jibes138]

As far as I know, those old box Catalina-style mufflers only came with 1 5/8" ports.

The system constrain on the M25 is only 1.25 based on the exhaust flange attached to the manifold. It's a big change to go up to 2 inches in terms of area, the 2" is 2.56 times larger in cross section.
http://shop.toadmarinesupply.com/ships_store/index.php?p=details&mfc=Universal&sku=298599

 

[eherlihy]

2" muffler is ~$135 at Jamestown Distributors; http://www.jamestowndistributors.co...pid=11694&familyName=Vetus+Waterlocks+Type+LP

 

[rajhnsn]

Beta makes a 20, a 25, they made a 28 but I don't see it listed on their site, and they make a 30 - all of these are 3 cylinder, and I believe that any of which would be applicable for our O'day 34/35.

If I had the funds, I would probably opt for a Beta 25 with my own alternator upgrade (40A is too little, and so is 75A), I would have Beta install the hot water fittings on the thermostat bypass and I would opt for the CW control panel (with a recess).

When I spoke with the guy from Beta at the Annapolis Boat Show last year, he told me they had a 28HP and not a 30 but maybe they have made a change since then. If I were repowering, I would go with the 28/30. The extra knot pays off on long passages and would give me more confidence in tight situations.

 

[eherlihy]

Regarding the power requirements - I had this rule of thumb ferreted away in my files;
A Diesel Engine produces about 20lb of thrust per horsepower
In the case of the M25 in an O'day 34/35, 21hp= 420lbs of thrust @ 3000RPM

" Detail; the very approximate calculation goes like this:
Take the engine power in Watts. If it is given in HP, then multiply by 746 to obtain the power in Watts. Call this power BSP (brake shaft power).

Multiply BSP by transmission and propeller efficiencies. You can assume around 0.5 as a maximum total efficiency of such a small prop. Call this power PE (effective power).

Convert the speed to meters per second (m/s). To do that, multiply the speed in knots by 0.514 . Then multiply again by 0.95, to approximately take into account the eventual effect of the hull wake. Call this speed Vp.

To obtain thrust given by the prop, divide PE by Vp: T = PE / Vp .

This will be the available thrust in Newtons, for that speed and engine power. I'm using all SI units, to avoid errors related to inconsistent units. To convert this thrust to lbs, multiply by 0.225 .

That's all.

If you think you'll need to do more such calculations in future, and/or have them more precise, I suggest you buy the excellent Dave Gerr's book "The Propeller Handbook". You can find it at Amazon for $12, a real bargain for the knowledge it contains: http://www.amazon.com/gp/offer-listi...condition=used"

 

[odaydokay]

I see talk about years of use, but use is not use. Some folks take 10 sails a year, put maybe 25-30 hours on a motor, others take many sails or longer ones and put 300 hours on a motor or more. Would one not want to look at the hours per year situation with regard to a fix or buy new decision? Not taking a stand on fix or buy in this case, just saying.............

 

[Scott Fox]

I THINK YOU SHOULD REPOWER IT.