[Amel Yacht Owners] Re: Volvo Turbos
Dear Stephan, What a useful note. I was hoping to change the belt myself until I found out the price of the belt tension guage ( somewhere in the region of $6-800).Interestingly, my prophet on the mountain in La R. , M. Selo, has recently emailed me that 2,000 hours before a change was OK, whilst cautioning that an amateur attempt to change should not be undertaken lightly.I have noticed a few Volvo trucks on(and off)the road in Ecuador so I am now hunting down a knowledgeable Jose to lend me his tools and ride shotgun on my very cautious first change
Marine Express Parts recomend 1000 hours, which I think is in the latest handbook. They also say that in their experience unless there is something wrong with the fuel pump they would not check it when changing the cam belt. Ian
From: "Stephan Regulinski" <stephreg@...>_________________________________________________________________
Hotmail messages direct to your mobile phone http://www.msn.co.uk/msnmobile
Ian and Judy,
Good grief! I didn't realize that the belt change tool kit was so
expensive! You may try ofering to "rent" the tools from your local
Volvo mechanic. This could work for both of you. Good luck on your
By the way, as to the question of 1000 versus 2000 hours, this is
usually settled on two pieces of data. First is the point at which a
significant number of failures begin to occur. When the engine is
first developed, it is estimated based on prior experience with
similar engines plus engineering "judgement". In time, this estimate
is updated using data from the actual engine.
"Significant" in this case is a function of the cost of repairing in
the event of running to failure as compared to the cost of replacing
the belt prior to failure. Since the engine overhaul is likely to
cost on the order of ten times the cost of a belt change,
a "signifcant" number of failures would be anything greater than ten
percent of the belts failing between 1000 and 2000 hours under normal
The second piece of data is the effectiveness of inspection. If
inspections were perfectly effective in identifying belts that will
fail before the next inspection, than you would have no "hard time"
limit on the belt. Instead, you would inspect on the interval and
replace only when the belt failed inspection.
With things that slowly wear out and then catostrophically fail, we
mix the two ideas and inspect through the part of the life where
failure is unlikely and then as the probability of failure increases,
we replace the part and start over.
Stainless steel is a good example of substance that does not yield to
visual inspection. It is hard to observe minute cracks in stainless
and it fails quickly after the formation of small cracks. Belts,
however, seem to be of the other sort. Evidence of belt wear is easy
to observe and failure happens well after the first signs of belt
I am inclined to believe that the original maintenance program is
correct. But remember it has two parts: Inspection and
replacement. Inspecting the belt requires that the inspection port
is opened and the belt is rotated through its entire circumference.
You are looking for "teeth wear and damage" and "cracks in the belt
and oil contamination" (from the maintenance manual). Oil degrades
the belt material and causes the fibers in the belt to begin to pull
Jay, who wrote in earlier (759 and 762) may shed some light on the
question of whether belt inspections are useful if he can tell us
what was observed when his belts were inspected prior to their
Stephan G. Regulinski
--- In amelyachtowners@..., "Ian & Judy Jenkins"
Dear Stephan, What a useful note. I was hoping to change the beltmyself
until I found out the price of the belt tension guage ( somewherein the
region of $6-800).Interestingly, my prophet on the mountain in LaR. , M.
Selo, has recently emailed me that 2,000 hours before a change wasOK,
whilst cautioning that an amateur attempt to change should not beundertaken
lightly.I have noticed a few Volvo trucks on(and off)the road inEcuador so
I am now hunting down a knowledgeable Jose to lend me his tools andride
shotgun on my very cautious first changethe latest
handbook. They also say that in their experience unless there issomething
wrong with the fuel pump they would not check it when changing thecam belt.
IanVolvo-From: "Stephan Regulinski" <stephreg@y...>
thePenta, 1998) page 28 says that the timing gear belt (also called
2000cam belt) should be inspected every 200 hours and replaced every
particularlyhours. This is twice the interval recommended by Joel.
isthe maintenance findings on the last belt inspection prior to
hours)capable of picking up premature belt wear in time to replace the
isgiven he is operating under more extreme conditions. The question
beltwhether this program is necessary for the rest of us. A timing
newchange is neither cheap or fast.
bolts.belt ($40 in Gibraltar), a workshop manual or copy of the relevant
shop.I was able to borrow all of the above from a cooperative Volvo
aThe were made more cooperative by the fact that I had just spent a
andtighten alternator belts. An assistant wouldn't hurt to hand tools
flywheelinserting an anti-rotation tool. My mechanic advised me that this
Allis a little tricky. Use a socket wrench with 31/32 socket to turn
pulley.is well if the "B" on this pulley lines up with the notch in the
beI am told that it can seize and that early evidence is a failure to
tensionreused and dispose.
inso that the belt, which rotates clockwise, pulls the pulley into
anthe maintenance procedure. I did not attempt this operation.
LOTimportant part of any good maintenance program.
governedofrequested power to function. To check:OPEN.
afterand youwill never get into the boost limit in cruise power conditions.Only whenasking for more than you should, like at avoiding a crash. Hopethis helps.important.
properlyrevcounter, both at crazy Volvo prices.Power output is fine and Itake careto
getsis apressure control valve that opens up if the turbo pressure
backtheresistance of a spring.I have been advised to move this rod
itmanuallyfrom time to time ( with engine switched off) to ensure that
movement onis freemoving and it has always been free when I have moved it.
openthe turbopressure doesnt reach the point where the valve opens.( thiswouldn'tprevent the turbo from working ok as mine seems to be)should not be
http://docs.yahoo.com/info/terms/Stay in touch with absent friends - get MSN MessengerService.
Jay Jones <selector6501@...>
Stephan, Ian et al
In my expierience we noticed some lateral cracking in
the surface rubber but nothing penetrating to the
fabric plies. In failure the belts simply disintegrate
and you are left with some string, a coating of rubber
dust and a bad smell.
Due to design deficiencies (underestimated need for
power) we were running these engines at wide open
throttle locked against the govenors for weeks at a
time in conditions that could only be labeled extreme
35C to -40C extremely dusty. The gensets were
contracted and the contractor ran a rigorous
maintenance programm including weekly inspections by
factory trained mechanics. We did not expect these
failures nor were they anticipated by the contractor.
I have no complaints about these motors though. As you
can see from the above description we had
unintentionally fallen into a torture test not
imagined by the contrator, manufacturer or ourselves.
After repairs and in 1 case replacement these motors
continue to serve but now in thier intended backup
I do not feel that any amount of inspection short of
that by someone with massive amounts of equipment and
expierience would detect a failure in progress. This
is why I reccomend rigorously adhereing to the
manufacturers schedule of maintenance (they have the
time and equipment to do the testing/failure analasys)
By the way volkswagon diesels have exhibited the exact
same failure only with less damage (7 of 8 valves
bent) possibly Herr Diesel smiling on us. I believe
this to be a sudden onset failure which wont be caught
by routine inspections unless you get lucky.
On to injector pumps. These pumps are extremly
sensitive and should not be worked on outside of a
pump shop. The tolerences in these devices are in
millionths of an inch and they require special
handling. Pump Timing: in a diesel engine the pump is
timed the way a distributor is in a gasoline engine.
In some cases the Cam belt also runs the pump. in
order to ensure correct pump timing there will be a
procedure outlined in the maintenace manual to
reestablish this timing. Other than correctly setting
the timing when you reinstall the belt there is no
maintenace that can be performed on a pump on the
boat. Incorect timing in a diesel normal results in an
engine that simply will not run, however if you get
the timing off by 180 degrees some diesels will
happily run backwards. Detroit deisels are famous for
this among other things (runaways, wet stacks,
excessive blow by, rack adjustments etc) and Detroit
uses this technique (along with some rotationally
specific parts) to make left and right hand engines
for dual marine mountings.
I believe from your decription that when you "lined up
the B on the fuel pump with the notch on the cover"
after installing the the timing pins you set the pump
timing. The operation is usually accomplished in such
a manner. On the larger engines the timing is done
with gears and you simply line up witness marks on the
gears (one reason Detroits are famous is that many of
them had both sets of marks on the gears, left and
right hand rotation, so if you were in a hurry of
course murphy stepped right in and you had a truck
with 16 reverse speeds and 4 forward, entertaining but
not very useful).
In summary I would religously follow all engine
manufacturers guidelines on belt replacement and other
services to include the procedures in the service
manual. I would also check for service bulletins from
time to time as they will contain the newest guidance
derived from continued testing and failure analisys.
--- Ian & Judy Jenkins <ianjudyjenkins@...>
Dear Stephan, What a useful note. I was hoping to=== message truncated ===
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