Amen. One of the symptoms of an overloaded belt is it turning over in
the sheaves.

bob
s/v Eolian
Seattle

Dennis Gibbons brought forth on stone tablets:
Skip,
a couple of observations:
repeated belt failure is unlikely cause by chance. Sounds like you are over
stressing the unit. If you have( as I suspect) a high output alternator and
a smart regulator), you have options
1. most smart regulators have a belt load adjustment. Adjust it
2. You may require a dual belt system to carry the load.
My point is that you have had this problem continually and want to solve it
once and for all before you go far afield

regards,
Dennis Gibbons
S/V Dark Lady
CN35-207

Skip wrote:
And, of course, if the 3/8-10mm route
works, that will save me having to buy new pulleys, a route I'm sure
will be horribly expensive as they're no longer made...

Skip,
I may have missed it in past posts, but have you checked carefully to
see that the V-angle on both pullies as well as the belt are all identicle?
Balmar at least has supplied slightly different V angles on pullies
with their alternators to suppliers using the same part numbers. If any
one is different it would eat belts.
Red

Skip,
IIRC the Gates kevlar belts were solid green.

"Skip Gundlach" wrote in message
ups.com...
Hi, Garland,

I don't know - they are Napa's "heavy duty FHP" 4L490W. Certainly
that's a possibility.

I really think it's got to be the pulleys, which are demonstrably
smaller than 1/2 other than on the alternator. I also have a new 3/8
pulley, and the current belts I'm trying are 10mm, as recommended by
one in another list as lasting him more than hundreds (plural) of
hours, so I'll mount that after this one fails. Currently, it just
goes into both of the engine sheaves, and sits low in the alternator,
though well off the bottom. It's also cogged on the bottom, cited as
better for tight turns as well as heat dissipation.

I've felt the engine pulley, and I believe that it's potentially at
fault, too, in that the edges, while not rough (sandblasted during our
refit, and repainted, not rusting before reinstallation), are slightly
pitted. In any case, the speed of wear on the new belt will tell us -
and, for those better connected than I to the world of belts, it's a
25 Xl 7483, which is a tiny bit longer than I need; I'm going to get
the next shorter one today, along with another of these as a spare,
and if the shorter one doesn't go on in the next change, exchange it
for a 7483.

I tried Top Cogs, but I'd been told I needed a 50" belt, and while it
went on easily, there wasn't enough stretch room, and they quickly
started slipping. I've been trying to find another source after the
one I found in Charleston and haven't succeeded yet, but will lay in
some of those as well, if I can. And, of course, if the 3/8-10mm route
works, that will save me having to buy new pulleys, a route I'm sure
will be horribly expensive as they're no longer made...


L8R

Skip

Morgan 461 #2
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"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
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hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

On Oct 30, 6:40 pm, "Garland Gray II" wrote:
I used to use Gates, but now I've been using Dayco Topcog belts that are
sold at Advance. They were recommended as better, and certainly seem
tougher.
BTW, you aren't using the Gates belt with Kevlar are you ? I tried them once
resulting in rapid, repeat failure. From a call to Gates I learned that if
any sheave is below a certain diameter, kevlar reinforced belts will not
last.

More on the subject:

Update and probably a conclusive answer to my earlier question...

I went and talked with the kind folks at Zahnheiser's in Solomons
today. They dragged out the Perkins manual and specific belts
information as well. They had different belts for "old" and "new"
4-154s. New was defined as post-1981, which makes mine the "old"
model.

The specific Perkins belt for our engine is a 9.5-10mm (25/64") X
1260mm (49 5/8"), and equates to a Carquest XL 7490. It's skinnier
than the ones I'd been using, so fits in the sheave correctly, rather
than riding on top as the others I'd used did.

That Perkins part number equivalent in Carquest is a cogged belt (not
that it drives via teeth, but that it isn't solid), and matches the
one I have just bought from NAPA, their # 7480. The one I have on now
is a 7483, which is 1/4" longer, at 48 7/8" and I returned the even
longer one, a 7485, at 49 1/8".

So, apparently the original belt is almost 50" long. That, on my
engine, anyway, would run out of adjustment almost immediately.
However, the significant information is that it's a 25/64th belt, and
cogged, presumably working to greatly reduce heat due to more surface
area and better flex characteristics. I'll see how long the one I
have lasts, and return the longer belt if I can get the shorter one
on, as I presume I'll be able to do.

The "new" Perkins belt Perkins part number is 2614B040 and there was
not a translation on any other belt, nor did they stock them, so I
don't know the specs on it - but at least, there's the part number for
those who may not have it.

Also, it's the opinion of the mechanic that the main pulley could
likely be machined out to a 1/2" profile (sufficient material), but
they didn't do that sort of work there, feeling it was too highly
precision for them. If I had the luxury of doing it in a layover, I
could make that happen, probably, by removing it and taking it to a
machine shop. Using a similarly cogged belt in a 1/2 sheave would
likely last longer - but I have the feeling that this will resolve
most of my challenges. Between a heat problem killing similar belts
to that which I was using, and the wrong sized belt for the drive
pulley, I can see why I'd kill the belts I was using...

So, keep reading my logs for further analysis and reports - but for
now, that's the skinny (pardon the expression).

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
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"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in its
hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

On Thu, 01 Nov 2007 02:55:26 -0000, Skip Gundlach
wrote:

Also, it's the opinion of the mechanic that the main pulley could
likely be machined out to a 1/2" profile (sufficient material), but
they didn't do that sort of work there, feeling it was too highly
precision for them. If I had the luxury of doing it in a layover, I
could make that happen, probably, by removing it and taking it to a
machine shop.

Before you do all that, try to find a double sheave pulley for both
the engine and alternator. Long term I think that's the real answer.

I concur.
You can't rely on the stock engine belting when you are using a high output
alternator.

Dennis Gibbons
"Wayne.B" wrote in message
...
On Thu, 01 Nov 2007 02:55:26 -0000, Skip Gundlach
wrote:

Also, it's the opinion of the mechanic that the main pulley could
likely be machined out to a 1/2" profile (sufficient material), but
they didn't do that sort of work there, feeling it was too highly
precision for them. If I had the luxury of doing it in a layover, I
could make that happen, probably, by removing it and taking it to a
machine shop.

Before you do all that, try to find a double sheave pulley for both
the engine and alternator. Long term I think that's the real answer.

More on the subject from one of my mailing lists posts:

From: cherev
To: morgan
Sent: Thursday, November 01, 2007 4:25 PM
Subject: [morgan] Perkins 4-154 fan belt info, again

What would it cost, both in money and time, to simply replace
the sheaves with a matched set that uses a broader belt? A common
type, such as the kinds used on diesel trucks?

In the process, the alternator and pump shafts could be slotted
and keyed so that these would be easier to maintain, i.e., no
need for a 1.5-tonne press to press on a sheave, nor a special
tool to extract one.

Seems to be a mite of angst being spent on a simple mechanical
problem, unless the alternator(s) are also wonky.

I don't think it possible that I have 5 wonky alternators...

New pulleys is one of the remedies I've considered. The trick is
in getting all the offsets right, in addition to all the
different mounts.

The alternators have a shaft which is hex keyed to keep it from
turning - but I haven't the strength (and I routinely break stuff
because I'm too strong on a bolt, tool, etc.) to get my 3/8
pulley off the other alternator to swap it on to the one
remaining functional (of 5) alternator.

The driveshaft is splined and keyed - held on by a massive bolt -
and has some dishing and other shape potential issues, plus it
has to have the right face for the PTO end which drives the raw
water pump with its sheave (1/2" - go figure, it's bigger than
the alternator belt, and doesn't have nearly the required force),
which PTO bolts to it.

The freshwater pump is essentially a bowl of stamped steel, with
a ring pressed on to it, and a resultant offset of 3-4 (I've not
measured it) inches.

All these would have to be duplicated. If you've got a
comprehensive source for such pulleys, I'm all ears. Otherwise
the next best thing might be to have the main shaft pulley, solid
steel, machined to the same size/angles as the alternator's 1/2"
belt, and buy the appropriate cogged belt in 1/2 (giving me
whatever the resultant greater surface area [and strength]
resulted)...

For now, the 10mm belt is what was specified, and is much less
hot after running, so between the fact that it actually fits in
the drive pulley, and isn't as hot (better tight turns? more
surface area? I don't know why), I'm going to expect a better
life from it.

So, I'm going to see how this one lasts. If it's not an
improvement, then I'll bite the bullet and get the pulley off and
turned, and go to 1/2" belts. The freshwater pump shouldn't
matter, I don't think; it's just a stamped dish with a ring
pressed on; clearly it's not intended to carry any load, so I
expect the 1/2" would drive it just fine, and not negatively be
impacted by its smaller size.

I can say for sure that after some heavy charging last night, I
felt the belt after over an hour of running. It was hot, but
nothing like the prior belts I'd been using. I've also heard
from several, now, who say that the solid belts I'd been using
were disintegrating on them, too, and changing to the cogged -
whether topcog (Dayco) or internal) seemed to dissapate the heat
better, as well as, perhaps, give better close-radius
performance.

However, I have all of perhaps 5 hours on this belt. I've
tightened it once, and both that and the first were extremely
tight - a recommendation from an alternator vendor (Hotwire) and
others - to cope with the higher output. Given how many belts
I've been through, though, some experimentation is in order; I'll
not tighten again until I hear squeal or smell smoke. I check it
literally every time I stop the engine and again before I start
(other than panic modes, of course), so I'll have a good feel for
what the tension was before squeal and smoke occurs.

I'm triangulating on the failure modes as well as the solutions.
I know about the wallet mode; I could probably get a backyard
hobby guy to turn me a brand new set of pulleys cheaper than
buying something used, and get a 1/2" set in the bargain :{))
One of the guys I was working with in St. Pete (Erkki, from my
logs if you recall the first leg of this trip) was such a guy.
He'd enjoy doing it - but I don't have one of those to hand, nor
do I have the time, now, to do it. However, I might do some
downtime this winter, to address my atrocious electrical system;
if I did that in St. Pete, I'm sure he'd not only help with that
but enthusiastically participate in the other stuff. Best news
is he's a retired rocket scientist (used to design satellites for
Canada) and does it free for lunches - cuz he likes it...

And, finally, I got the proper Perkins "old" part number. It's
NA003439, and 25/64 x 49 5/8, or 9.5-10mm X whatever that works
out to. That would be long enough that I'd not get more than one
tightening on it, so I'm using one quite shorter.

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
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"You are never given a wish without also being given the power
to make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in
its hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

On 2007-10-30 10:57:50 -0400, Skip Gundlach said:

The next day we expected to go to Solomons Island, but the
weather was forecast (see above comment on NOAA, and see below
for more) at 20-25 knots with gusts to 30, and straight behind
us, along with relatively large waves, which would have been very
uncomfortable. So, we decided to stay in Cambridge for another
day. Of course, given NOAA's track record so far (see below), it
might have been a fine day to sail south.

I can't quite figure out which day you're referring to here, but
Friday, Saturday and Sunday were solid 20-25 with a regular higher
gusts. Moderated a bit Sunday afternoon to 12-15 with some gusts.

Our raft-up of "corks" (very light & buoyant boats) broad-reached at
hull speed north on Saturday, south on Sunday (How often does the wind
do *that*?), one logging about 15 nm, the smaller doing about 30 nm.
'Twas a wonderful downhill sleigh ride.

You probably would have been fine jib-sailing, but you're cruising now,
so not moving for any or no reason is just fine.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

On Oct 30, 11:07 pm, Jere Lull wrote:
On 2007-10-30 10:57:50 -0400, Skip Gundlach said:

The next day we expected to go to Solomons Island, but the
weather was forecast (see above comment on NOAA, and see below
for more) at 20-25 knots with gusts to 30, and straight behind
us, along with relatively large waves, which would have been very
uncomfortable. So, we decided to stay in Cambridge for another
day. Of course, given NOAA's track record so far (see below), it
might have been a fine day to sail south.

I can't quite figure out which day you're referring to here, but
Friday, Saturday and Sunday were solid 20-25 with a regular higher
gusts. Moderated a bit Sunday afternoon to 12-15 with some gusts.

Our raft-up of "corks" (very light & buoyant boats) broad-reached at
hull speed north on Saturday, south on Sunday (How often does the wind
do *that*?), one logging about 15 nm, the smaller doing about 30 nm.
'Twas a wonderful downhill sleigh ride.

You probably would have been fine jib-sailing, but you're cruising now,
so not moving for any or no reason is just fine.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages:http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips:http://homepage.mac.com/jerelull/BVI/


Hi, Jere,

Sunday was the day we passed on. It had been forecast, all the way up
until early that morning, for 20-25, 30G, 3-5, straight on our tail.
Lydia and I would have done it, but in consideration for our
passenger, we took a lay day. Your report of the reality would have
been a very nice run - but not having feet on the ground out there, we
could only go on the NOAA stuff and all the other internet stuff we
could find...

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
See our galleries at www.justpickone.org/skip/gallery !
Follow us at http://groups.google.com/group/flyingpiglog and/or
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"You are never given a wish without also being given the power to
make it come true. You may have to work for it however."
(and)
"There is no such thing as a problem without a gift for you in its
hands. You seek problems because you need their gifts."
(Richard Bach, in The Reluctant Messiah)

On 2007-10-31 08:06:34 -0400, Skip Gundlach said:

I can't quite figure out which day you're referring to here, but
Friday, Saturday and Sunday were solid 20-25 with a regular higher
gusts. Moderated a bit Sunday afternoon to 12-15 with some gusts.

You probably would have been fine jib-sailing, but you're cruising now,
so not moving for any or no reason is just fine.

--
Jere

Hi, Jere,

Sunday was the day we passed on. It had been forecast, all the way up
until early that morning, for 20-25, 30G, 3-5, straight on our tail.
Lydia and I would have done it, but in consideration for our
passenger, we took a lay day. Your report of the reality would have
been a very nice run - but not having feet on the ground out there, we
could only go on the NOAA stuff and all the other internet stuff we
could find...

Hey, Pat and I lazed in the anchorage until about 2, not wanting to go
out in *that* and betting that it'd be less sloppy later -- and we only
had 3 nm of open water and half an hour.

You've got the time, pick your battles.

We have stayed in the Solomons a couple of times with a mere 15 knots
on the nose. The first time, after a half hour of escalating mistakes
and frustration, we turned around: Best decision we could have made.
The geometry of that area can make some strange waves.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/