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#1
Main Message Board / Re: ? Sudden overheating?
Last post by KWKloeber - Today at 01:07:26 PMQuote from: Ron Hill on Yesterday at 02:51:53 PMGuys : Before you start tearing things apart - spend a few $$ on a heat detection gun and see what the temperature of the engine really is!!
A thought
Ron
Perhaps you can post a link to your info about the engine cover grounding out the Temp switch. I could not locate it. Given what was explained so far that's the only explanation I see that makes any sense.
#2
Main Message Board / Re: Keel Bedding Survey
Last post by High Current - Yesterday at 08:26:16 PMQuote from: KWKloeber on May 05, 2024, 10:42:35 PM@High Anxiety
I've previously posted about my same experience re: the fingertight aft nut and keel bedding so many times that my head hurts every time I repost about it.
Well, thanks for doing it one more time. I found your post quite helpful. I've read a lot of posts about keels, including a few of yours, but managed to miss the similarity with the aft nut.
QuoteAre you thinking that CTY bolted-up the keel nuts/washers into wet gelcoat? Doesn't seem logical to me. What does, is the known issue on C-30s of torquing the nuts so many times that the washers compress the glass and bury themselves in the gelcoat.
Maybe it's not gelcoat per se, but whatever brittle white material coats the bottom of the sump partially covered all of the washers, appeared to be original, and cracked free easily when I disturbed it. Photos below
QuoteThat said I'm unsure whether I would trust the yard with anything. Someone who blocks jack stands with 2x4s has (IMO only) questionable knowledge/conscientiousness and at worst doesn't care about their customers' yachts. Gimmeabreak -- don't they have lumber yards in ME?
No kidding. I have stories....
If I had time to do the work myself it wouldn't hesitate to DIY, but it's 4 hours away and I have young children who need me to pick them up from school every day. My main reason to re-bed NOW would be to preserve integrity of the bolts. BUT if I weren't going through this process I probably wouldn't be worrying about it...
QuoteSee above for (IMO) the danger of too-often and too-tighting of the keel nuts.
Keel nuts that are 40 ft-lbs shy do not cause the Catalina smile.
Does it crush the solid glass or only the wood core that I don't have?
I used to think similarly but managed to convince myself otherwise. Loose keel nuts put extra stress / strain on the keel-hull joint that could lead to cracks and water ingress. On the other hand, I agree that 65 vs. 105 ft-lb is probably enough pre-load either way; at 105 ft-lb = ~10,000 lbf, a single bolt could hold the entire keel if it were in pure, static tension.
Reasons in favor of re-torquing that I can think of:
1) Lead creep and other factors (see: corroded washer in my previous post) can reduce bolt tension over time
2) Low bolt tension can lead to uneven loading of the keel and excessive stress/strain in the joint, possibly compromising the joint / bedding
3) If a keel bolt has been severely corroded, I would rather have it snap off when I try to torque it on the hard than have it silently stop holding my keel.
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(1) made me wonder: What's the coefficient of thermal expansion of our hulls? Does it matter at what temperature one torques the bolt? Were my bolts loose simply because it was April?
I'm going to assume the keel stub is one inch thick (0.0254 m).
This says CTE of fiberglass is 25E-6 m/m-C: https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html 10 degC @ 1" would be 6.35E-6 m of expansion, or 0.025%. Stainless is pretty close but let's ignore that for now to get a worst-case.
If I assume some lubrication (because anti-galling), then 105 ft-lb is about 10,000 lb of clamping force ≈ 44kN. https://www.engineersedge.com/calculators/torque_calc.htm
The washers are 1 7/8" diameter. Crudely, that amounts to 0.00178 m^2. 44kN / 0.00178 m^2 ≈ 25 MPa of stress.
Finally, looking here, one presumes strain is fairly linear at about 1% per 40 MPa: https://www.researchgate.net/figure/Stress-strain-cure-for-fiberglass-Figure-6-The-stress-strain-curve-and-tyre-strip-for_fig4_305627338
Assuming I did it all right, 10C change in temperature causes 0.025% change in thickness which causes 1.8 MPa change in stress out of 25MPa total, before you consider that the stud is also contracting. So no, temperature isn't a huge factor. But that was fun!
#3
Main Message Board / Re: What's under the stern lad...
Last post by High Current - Yesterday at 05:19:48 PMI can also confirm there's an embedded, threaded something on my 1990 mk1.5. I got really nervous when I first looked under there and the studs had no nuts or washers, but I eventually put 2+2 together...
#4
Main Message Board / Re: ? Sudden overheating?
Last post by Noah - Yesterday at 03:29:51 PMI assume Ron is suggesting using an "infrared thermometer" to measures heat, NOT a "heat gun" that creates heat. Both are good inexpensive tools to have onboard.
#5
Main Message Board / Re: New Video from Mainsail
Last post by B. Samartino - Yesterday at 03:29:33 PM
Wow, Great to see he is recovering so well.
#6
Main Message Board / Re: ? Sudden overheating?
Last post by Ron Hill - Yesterday at 02:51:53 PMGuys : Before you start tearing things apart - spend a few $$ on a heat detection gun and see what the temperature of the engine really is!!
A thought
A thought
#7
Main Message Board / Re: Oil/temp warning
Last post by KWKloeber - Yesterday at 11:20:07 AMEdit - I've said it previously in this thread but will again. Tie down the wires so that harness movement doesn't get transmitted to the oil pressure switch terminals. They fail too many times on the B engines. Wb doesn't put a spring-coil of wire on the sender wires to absorb vibration/movement.
***
David where exactly where the two ends disconnected? Were they quick-disconnect terminals?
Does she still have the black rectangular Westerbeke plugs on the harness near the back of the engine?
When did the fuel gauge stop working?
I would be rethining my choice of a mechanic if one claimed that I didn't need a harness ground wire connected!
***
David where exactly where the two ends disconnected? Were they quick-disconnect terminals?
Does she still have the black rectangular Westerbeke plugs on the harness near the back of the engine?
When did the fuel gauge stop working?
I would be rethining my choice of a mechanic if one claimed that I didn't need a harness ground wire connected!
#8
Main Message Board / Re: ? Sudden overheating?
Last post by KWKloeber - Yesterday at 11:14:51 AMEDITED
Craig this makes no sense to me. Pinning high is due to zero resistance at the gauge S terminal and you have 970 ohms there. The R measured on the S wire should be very close to the R of the sender (depending on what gauge S wire you ran.) However, you are measuring the two Rs by referencing two different grounds (directly to the engine block vs. the path back to the gauge G terminal, therefore, that could account for the difference***. (That might mean your ground up to the panel needs checking/ohm-ing/attention.) ***Remember when you are measuring R using that method, you are measuring R of the entire circuit (i.e., from the panel, S wire to the sender, the sender, through the engine block to wherever the connection is for the ground wire going up to the panel, through the panel wiring, and to the gauge G terminal. 70 ohms difference corresponds to about 30 feet of 14 AWG stranded wire, so you are definitely in the ballpark given the theoretical resistance of the S wire and return circuit.
Still, the gauge should read a little lower (not pin high) if the R is higher at the gauge than at the sender.
You saw my questions about your engine cover?
Craig this makes no sense to me. Pinning high is due to zero resistance at the gauge S terminal and you have 970 ohms there. The R measured on the S wire should be very close to the R of the sender (depending on what gauge S wire you ran.) However, you are measuring the two Rs by referencing two different grounds (directly to the engine block vs. the path back to the gauge G terminal, therefore, that could account for the difference***. (That might mean your ground up to the panel needs checking/ohm-ing/attention.) ***Remember when you are measuring R using that method, you are measuring R of the entire circuit (i.e., from the panel, S wire to the sender, the sender, through the engine block to wherever the connection is for the ground wire going up to the panel, through the panel wiring, and to the gauge G terminal. 70 ohms difference corresponds to about 30 feet of 14 AWG stranded wire, so you are definitely in the ballpark given the theoretical resistance of the S wire and return circuit.
Still, the gauge should read a little lower (not pin high) if the R is higher at the gauge than at the sender.
You saw my questions about your engine cover?
Quote from: Schulcb on May 12, 2024, 08:03:34 AMAfter removing the S wire from the gauge, the resistance from the S wire to the panel ground (checked using the G post on the temp gauge) IS 970 ohms. Checking the resistance at the sender again (cold this AM) is 900 ohms.
When the gauge started displaying inaccurate readings it was sporadic with it going from "pinned" high to reading normal. Then the frequency diminished until it always reads >240.
This morning with the engine cool, when I engerize the panel the gauge reads ~170'F.
Not sure it this tells you anything...
Thanks,
Craig
#9
Main Message Board / Re: Oil/temp warning
Last post by dclintonbaker - Yesterday at 09:27:24 AMProgress report.
Yesterday I reconnected all of the wires of the harness.
The "tan" wire had become disconnected. I think that this one goes to the temperature switch. Difficult to spot that the two ends were not connected as it was at the back of the bundle.
The red wire with red stripe spade connector on the engine side had a poor crimp. The wire could be easily pulled out even with the heat shrink. I replaced both the male and the female sides.
Fired her up and the low oil pressure buzzer promptly stops!
But...none of the instruments working.
The black wire was not connected at the harness. Mechanic told me not needed. I connected it anyway. All the instruments now work with the exception of the fuel gauge.
I am currently trouble shooting the fuel gauge.
Again Ken, thanks for staying with me on this.
David.
Yesterday I reconnected all of the wires of the harness.
The "tan" wire had become disconnected. I think that this one goes to the temperature switch. Difficult to spot that the two ends were not connected as it was at the back of the bundle.
The red wire with red stripe spade connector on the engine side had a poor crimp. The wire could be easily pulled out even with the heat shrink. I replaced both the male and the female sides.
Fired her up and the low oil pressure buzzer promptly stops!
But...none of the instruments working.
The black wire was not connected at the harness. Mechanic told me not needed. I connected it anyway. All the instruments now work with the exception of the fuel gauge.
I am currently trouble shooting the fuel gauge.
Again Ken, thanks for staying with me on this.
David.
#10
Main Message Board / Re: Air Conditioner size .... ...
Last post by rmjohns - Yesterday at 04:15:34 AMI have a 16k unit, though it's an older unit. It does blow pretty cold air. It's adequate in the summers of NC, but I wouldn't say it would freeze you out of the cabin. If the sun is shining on the deck, you can feel the heat radiating from the ceiling when you're down below. I made some deck shades that help dramatically.
Rob.
Rob.