Indigo

[tenders]

sastanley, how are you going to fix that?

The "right" way would be to cut out the log and replace it. That involves removing everything, cutting a big hole in the boat, and a fair amount of precision alignment and fiberglass/epoxy work.

Another way would be to grind off all the surrounding paint, coat the existing log with a nice thickened batch of epoxy, slide the next largest size log over the existing log, and thus epoxy it very thoroughly all the way around the existing log.

If you cut a slice out of the bottom of the aft end of the new log (so that it was shaped more like the end of a quill pen than a squared-off cylinder), it would fit right over the existing rot back to the hull, and you could epoxy it securely to the hull with cloth or roving. It would be easy to dry-fit and adjust this before applying the epoxy.

It might involve some additional hardware with the stuffing box or shaft seal, but might be worth avoiding the precision work.

Just a thought - this would be a real pain in the neck to tackle in February but is both a pain in the neck and a disappointment to have to tackle in June.

tenders

[Mark S]

Preliminary Indigo results

Shawn,

It wasn't much of a test this morning, only coming down the Danvers River to Salem Harbor, but I noticed some huge differences between today's Indigo propulsion and former 12x7 two blade propulsion. (Reference NOAA chart 13275.)

First, the boat crawls in forward at idle speed very slowly, much more slowly than with the two blade. I had complete control at not much more than drifting speed getting out of the slip at the yard.

Second, I could get 5.5 knots in calm water with not much wind at 1900 RPM. This is through the water speed. Before, I couldn't ever get past 1500 RPM which gave me 6.0 knots in calm water. I didn't have any need to go faster today so I don't know what the top RPM would be or what RPM would give me 6.0 knots. That's for another day. Once past the MBTA bridge in Beverly, we got into some headwind and slight wave action. The through the water speed did not change and I stayed at 1900 RPM into Salem Harbor. Engine temperature stayed at a steady 160 degrees the whole way. Exhaust appeared visually the same as always.

Third, and quite delightfully, I could approach the mooring at idle speed, keeping the engine in forward, and shift into neutral only at the ultimate moment before Alicia hooked the pennants. Previously with the two blade, there was a lot of shifting from forward to neutral to keep the speed low which could, in headwinds like we had today, make steering control somewhat difficult. I can't report anything as to reverse as the only reversing I did was to stop the boat when the pennants were picked up. That's also for another day.

Nevertheless, the Indigo so far does what I had hoped: gets engine speed higher for a given boat speed and seems to give more punch for chop and headwinds. I'll find out as time goes on what impact this has on fuel consumption and what performance is like compared to the two blade in heavier seas and winds.

Mark

[Dave Neptune]

easy does it

Mark, I to had a very positive reaction to my slow speed performance however after I got over the shock of how slow I was going for a given rpm particularly below 1600rpm's. I tow a 10' lapstrake dinghy every where I go and I notice it a lot less with the Indigo. My fuel figures dropped everywhere I keep records for however I do feel that they are better across the board. I use a vac guage and the changes in manifod preassure were significant.

I just finished motoring for 9 1/2 hours over Mem. Day weekend and used under 8 gallons of fuel @ 2000 rpm's for at least 8 hours of the motoring.

Enjoy!

Dave Neptune

[Mark S]

Dave,

My fuel figures dropped everywhere I keep records for however I do feel that they are better across the board.

Do you mean your fuel efficiency is better with the Indigo? I was prepared to sacrifice some economy for more power, but to have it both ways is too good to imagine!

Mark

[sastanley]

Mark, I think the answer to Dave's comment is yes. I guess with the engine not so 'loaded' with a lower pitch/smaller prop, it isn't lugging and thus needs less fuel to function at a higher RPM.

Sometimes it is too good to be true!

[Dave Neptune]

Loads

Mark, once the motor is tuned the amount of fuel you use is pretty proportional to how much powerl you are using plus the additional rotational friction of the engine. In many cases getting the engine to turn at a more efficient rpm (for a given Motor) can more than offset the additional friction. Yes I too am operating at more rpm however the "load" on the intake is ruduced due to the efficiency of the engine. Before the Indigo I was cruising @ 1600+rpm @ 7" of vac @ 5.2~4 kts---now to cruise at 5.2~4 kts the engine is at 1800+rpm @ 10" of vac and uses a bit less fuel. When pushing the engine back to the same manifold load of 7" of vac I get 2100rpm's and 6kts and at that I am using about .8 gph of fuel. Since the engine likes the Indigo better it is working more efficiently at both vac settings and increased rpm. The increase in rpm at a given "load" also reduces bearing loads and cylinder preassur as well; ie you have a series of smaller burns happening faster reducing stress on parts.

Dave Neptune

[Mark S]

Thanks for the clear explanation, Dave. It all makes great sense the way you put it.

Mark

[sastanley]

ah ha!

Well, I am plugging away at the shaft removal. I got the shaft to start moving with the socket/coupler press method. I ran out of bolts, so I stopped at the hardware store on the way home to continue tomorrow.

However, I got the stuffing box assembly loose and pulled it out to expose the shaft log.

Recall the earlier pictures I showed the little black hole is the same hole....This new hole was under the hose. The only thing keeping the boat afloat was the 34 year old hose & a single clamp.

Only had my cell phone with me today, so this is the best pic I have.

[Mark S]

The only thing keeping the boat afloat was the 34 year old hose & a single clamp.

You're a lucky guy, Shawn. You could have discovered this in a much, much worse way.

Mark

[keelcooler]

It looks fixable! A little glass and a hose and your back in the saddle...rawhide!

Just don't let the boy's at BP try to fix it.

[rigspelt]

Recall the earlier pictures I showed the little black hole is the same hole....This new hole was under the hose. The only thing keeping the boat afloat was the 34 year old hose & a single clamp.

Phew. A good lesson for all of us. Only sure fire way to know for sure is to look.

[sastanley]

You got it keelcooler. I am good with glass work! In a weird sort of way it is comforting to at least know the main culprit.

This shaft removal is a S-L-O-W process. 1/4 turn on each fine thread bolt at a time takes a while. Then I have to back them out one at a time to keep the alignment right, and add a washer to get a little more travel before bottoming out in the engine half of the coupler, more 1/4 turns, back out again add more washers, etc.. Once I get to 3 lock washers thick (regular washers won't fit, the collar is too close) with a bolt bottomed out, I can move to the next shortest bolt, which is 1/2" shorter. My first trip to the hardware store I guesed on the lengths, and missed the next longest of the original bolts, which is where I am now.

I could almost rotate the shaft, set up the pry bar and turn the bolts with my eyes closed. It's moving though!

edit - so thinking ahead, which is what my brain was doing while I was straddling the engine bay and mindlessly spinning 3/8" fine thread bolts yesterday with my beer just out of reach on the chart table......what is the procedure to insure alignment of the shaft in a dry-run type of way? Can I put the coupler on the shaft & temporarily pin it with the set screw, get the engine aligned with no stuffing box, and then easily pull the shaft off to add the stuffing box components? I assume that once this is all in pieces and cleaned up, the shaft & coupler will slide apart easily.

[hanleyclifford]

alignment sans shaft log et stuffing box

Shawn - Couldn't help it: this is going to be interesting. Yes you can do the alignment with just strut bearing and engine. Remember, though, the tail wags the dog. In fact, this could make for a real quality alignment because the tension from the stuffing box won't be there to confuse the issue. But as I recall you have some work to do on those engine mounts. When the alignment is complete and you are ready to put in the new log, do just as you said: unhook the coupling, slip on the new log with half round cut internal bushings to snug it up to the shaft, put the bushed log into position, epoxy it in, then remove the bushings. You will have the best shafted, logged, and aligned boat in Maryland. Keep talking.

[thatch]

"The frosting on the cake"

Shawn,
Hanleys method of getting the propshaft centered is right on. Since I haven't seen the question asked iguess I will do it; is a new strut bushing in the cards? If you can get the motor mounts to cooperate and verify that the shaft is straight you have the opportunity here to give the old girl a like new feel.

P.S. On another note, I took "Kari On" out yesterday to test my new wheel steering setup and it performed beautifully. The effect of the 2 blade is not nearly as bad with a wheel compared to the tiller. As soon as I add the tach and vac guage and get some accurate baseline numbers I will make the switchto a 3 blade. I'm still waiting for some input on peoples reaction to the Campbell prop that Dave N. mentioned, on a cat 30.
Tom

[sastanley]

HC,
I sprayed all the mounts yesterday...all the lag bolts move, I just can't get the 'proper' tool squarely on anything to help coax the mounts to move athwartships. I may not need it, but, it seems likely the shaft was waaaaay out of whack., but I hope I can just move the corners up and down...Don't worry, if I am going thru this process, she'll be smooth as butter when she floats again.

I'll keep spraying them..maybe the PB BLaster will help loosen up the metal mounts from the glass beds.

I'll get my sledge hammer out too