Reliability of an oldish BMC diesel engine
Daniel
I recently visited a boat that looks quite neat.
A heavy displacement hull, neat rigging. And a
great shape overall.
Only one critical issue to raise, the engine.
From what I could see the model is a marinised
BMC 4cyl. engine given for 38HP.
The block looks very clean. Build date is unknown
but the thing was fully overhauled when installed
in 1990, date of the boat launch - including a new
mechanical hurth gearbox.
I intend to get the engine (and the whole boat
surveyed). Any general view on those BMC engines,
specifically on reliability?
Daniel
Graham Frankland
news:43bfa5c5$0$14745$79c1...@nan-newsreader-06.noos.net...
were imported from India by AMC at Preston. They may be outdated but being
low tech are generally reliable, easy to source parts, cheap to repair etc.
Graham.
Daniel
> many of the later ones were imported from India
> by AMC at Preston. They may be outdated but being
> low tech are generally reliable, easy to source parts,
> cheap to repair etc.
Graham,
Thanks for the speedy and comforting feedback.
I'm going ahead with the boat!
Daniel
TonyB
I can concur with that view. Many of the hire boats on the Broads used BMC
engines, they are generally very reliable and as said before, parts easy and
cheap. The starter motor is low down on the ones I've seen and if the bilge
floods it tends to knacker the starter, but that may be the same with many
engines. You need a pump to change the oil, again as with many engines, some
BMC's have a pump fitted already. Otherwise one of those Pela vacuum things
may well do the job.
TonyB
Guy Fawkes
I preferred the 2.2 to the 1.5, but both were very very tough provided
you changed fluids and filters regularly and watched the revs, eg treat
red line continuous running as 80% of non marinised max rpm..... inline
pumps were better than distributor ones, some boat installs were prone
to core plug leaks in bad places like inside the benn housing because
there WEREN'T changed when marinised, and poor on engine anodes etc.
make sure it has an engine oil cooler if using it in anger.
TBH the only thing I personally wouldn't trust in your installation is
the hurth box, which were pretty crap, keep your eyes peeled for an old
borg warner in the meantime.
oh yes, fit a day tank, extra filters, road going CAV filters clogged
real fast on boat tanks, lots more condensation inside the tank etc.
Tony Brooks
Sorry to miss this post
All I would add is that is this is a direct/raw water cooled engine I would
avoid it. They do have a tendency to "fur up" their hotspots, but I suppose
any automotive based engine will do that if run without pressurising their
cooling system.
They are fine on keel or heat exchanger cooling. However if this uses a raw
water pump that is foot mounted and driven by a pulley they can be difficult
to change the impellor without removing pulley and pump and also, depending
on exactly which pump is fitted, the pumps can be prone to wear.
--
Tony Brooks
www.TB-Training.co.uk
Daniel
Thank you for dropping in
> All I would add is that is this is a direct/raw water cooled engine I would
> avoid it. They do have a tendency to "fur up" their hotspots, but I suppose
> any automotive based engine will do that if run without pressurising their
> cooling system.
I did commit for the boat yesterday ! The truth is that I like
the boat a lot.
I committed for this motorsailer for its overal build quality
and would definitely have preferred a more recent engine and
more marine stuff. But the engine is a part of the whole trade.
I understand that the engine is "direct water cooled" (as far
as I could see and undestand it). It is given for 500 hrs
since full overhaul and the set up has been treated with a
lot of care by the ex-owner and builder who is alas not
available due to health issues.
Knowing next to nothing about motors, i have mostly sailed
up to now, I'm a bit scared here by your feedback concerning
"fur up" (not being a native English speaker, i understand
that means lime stuff locking up in the cooling system ..).
The boat engine is easy to access. Any way to secure the
engine cooling system ? Pressuring stuff?
> They are fine on keel or heat exchanger cooling. However if this uses a raw
> water pump that is foot mounted and driven by a pulley they can be difficult
> to change the impellor without removing pulley and pump and also, depending
> on exactly which pump is fitted, the pumps can be prone to wear.
Any issue I should make the surveyor aware (he is supposed
to have mechanical skills) ?
Thank you for your time and helpful support.
Daniel
Nick Temple-Fry
wrote:
>Any issue I should make the surveyor aware (he is supposed
>to have mechanical skills) ?
>
>Thank you for your time and helpful support.
>
>Daniel
Be very careful about what the surveyor will do, by default a surveyor
is unlikely to more than look at the engine and say
its red
the engine mounts are rusty
the battery stowage is adequate
there are signs of oil leakage in the bilge
we recommend a mechanical survey by an engineer.
ie they will tell you what they can see by a brief external look.
If you want more then you need to make sure you have commissioned more
or get a diesel engineer to do an agreed survey on the engine.
Nick
k
tough and reliable marine conversion. I fitted a supposedly 'fully
overhauled' one 2 years ago to replace my corroded out Bukh 36 and it was
the worse mistake I ever made.
Difficult staring, rough smokey running, oil leaks developing everywhere,
loss of power when hot, air in injector lines, corrosion even through the
timing case cover with more oil loss, and I'm just waiting on the infamous
rear engine oil seal failing when I'm miles offshore. Oh and a starter
burned out too trying to start it with brand new glo plugs!
Maybe you get good ones, and I sincerely hope yours is one, but you can
certainly get bad'uns too - sorry but I wouldn't touch one with a very long
stick unless it's been completely overhauled with all seals bearings and
gaskets replaced by a professional......Keith
"Daniel" <daniel...@caramail.com> wrote in message
news:43bfa5c5$0$14745$79c1...@nan-newsreader-06.noos.net...
Graham Frankland
news:-YydnYFvZLvImU3e...@brightview.com...
> Hi - I'd present a contrary view to all those who consider the BMC to be a
> tough and reliable marine conversion. I fitted a supposedly 'fully
> overhauled' one 2 years ago to replace my corroded out Bukh 36 and it was
> the worse mistake I ever made.
> Difficult staring, rough smokey running, oil leaks developing everywhere,
> loss of power when hot, air in injector lines, corrosion even through the
> timing case cover with more oil loss, and I'm just waiting on the infamous
> rear engine oil seal failing when I'm miles offshore. Oh and a starter
> burned out too trying to start it with brand new glo plugs!
> Maybe you get good ones, and I sincerely hope yours is one, but you can
> certainly get bad'uns too - sorry but I wouldn't touch one with a very
> long
> stick unless it's been completely overhauled with all seals bearings and
> gaskets replaced by a professional......Keith
>
with a load of secondhand junk, which could have applied to any make of
engine.
Graham.
Daniel
>>I'd present a contrary view to all those who consider the BMC to be a
>>tough and reliable marine conversion. I fitted a supposedly 'fully
>>overhauled' one 2 years ago to replace my corroded out Bukh 36 and it was
>>the worse mistake I ever made [...]
>>
>
> A bit unfair to rubbish BL engines based on someone having fitted you up
> with a load of secondhand junk, which could have applied to any make of
> engine.
I've taken Keith's statement as "BMC engine are not marine
engines à la Yamnar but automotive-industry engines converted
for a marine usage... Carefully check the stuff around the
engine itself". That's what I'll do.
I'm getting a lot of support both on the forum and and off
this forum (incl. a very detailed feedback by Tony Brooks).
Thank to all of you:)
Daniel
Guy Fawkes
Daniel wrote:
> I've taken Keith's statement as "BMC engine are not marine
> engines à la Yamnar but automotive-industry engines converted
> for a marine usage... Carefully check the stuff around the
> engine itself". That's what I'll do.
Yanmar are not marine engines
Graham Frankland
news:1137777530....@g44g2000cwa.googlegroups.com...
>Yanmar are not marine engines
>
There are actually very few true marine engines around for small boats.
Most of the smaller modern ones are high revving industrial plant engines
and many older Volvo are marinised car & van engines such as Peugeot.
Graham
Guy Fawkes
Martin wrote:
> The Volvo MD1, MD2, MD3 are pure marine diesels
I ___DO___ hope you were joking....
Graham Frankland
news:rvl2t1t2quvrn02v0...@4ax.com...
>
And when did they stop making them 15?, 20?, 25? years ago.
Graham.
Dennis Pogson
True "marine" diesel engines are just an excuse to charge the sailor double
or triple what he would pay for a marinised car engine. If it's a really
good car diesel, it will probably make a good marine diesel, since the
technical development of car diesels has been quite dramatic over the past
few years.
The best and smoothest marinised diesel I have experienced is the Perkins 4
cylinder Sabre Leisure engine, but as this is not made in the smaller sizes
to suit the miserly pockets of yachtsmen, who think that paying 50-quid per
season for fuel is outrageous, the Perkins tends only to be fitted to larger
vessels.
BMC? My god! How quickly we forget!
Dennis.
Guy Fawkes
Dennis Pogson wrote:
> True "marine" diesel engines are just an excuse to charge the sailor double
> or triple what he would pay for a marinised car engine.
bzzzt, sorry, gonna have to pull you up on that one.
A true marine diesel is built from the ground up for the marine
application, some aspects of this will mean.
a/ rated maximum power = something it will do all day, not a peak.
(torque, not bhp/shp)
b/ entire induction and fuel system designed knowing it will never
operate at any altitude
c/ ALL materials carefully chosen with an eye to corrosion and
electrolysis
d/ crankshaft & main bearings designed to last the life of the engine
e/ separate heads and access doors in the block
f/ separate pump and injector per cylinder
g/ motor doesn't experience prolonged acceleration, but does experience
short acceleration and does experience rapid changes in inclination
h/ oil is a significant thermal rejection medium and oil system
designed with this in mind
i/ throttle response almost irellevant
j/ I could go on, you get the picture....
Fact is, most "sailors" simply have no use for anything engineered that
well, and as you say the cost benefits of using a marinised traction
diesel when the motor is only an auxiliary anyway.....
FWIW I don't class gardners as marine diesels, though I personally
would be quite happy to use them in a TSDY even if I was planning a
round the world voyage.
The true marine diesel comes into its own when you plan on using a
large proportion of its rated output 24 hours a day, so tugs,
fisheries, cargo etc, basically anything with displacement lines marked
on the hull, the savings on fuel and maintenance will make it more than
worthwhile.
My objections to the "toy" motors such as the volvo 2000 series are
that they are SO crap even a knackered old hull is likely to outlast
the motor and leave you powerless with a dead donkey on a lee shore
somewhere.
I have another objection to tiny underpowered diesels being fitted to
hulls that could do with 3 or 4 times the power, this isn't directly
related to toy diesels, but because both are driven by the same motive,
money, they tend to go hand in hand.
Alan Frame
> Daniel wrote:
>
> > I've taken Keith's statement as "BMC engine are not marine
> > engines à la Yamnar but automotive-industry engines converted
> > for a marine usage... Carefully check the stuff around the
> > engine itself". That's what I'll do.
>
> Yanmar are not marine engines
I'll bite.
What are the non-marine uses for 381cc diesels?
Water pumps - a la coventry climax?
Aviation service vehicles, like the HD servicar?
Millitary 3X3s like the Moto Guzzi?
> these are
> http://www.kelvindiesels.co.uk/index.htm
Well, yes :-)
rgds, Alan
--
99 Ducati 748BP, 95 Ducati 600SS, 81 Guzzi Monza, 74 MV Agusta 350
"Ride to Work, Work to Ride" SI# 7.067 DoD#1930 PGP Key 0xBDED56C5
k
"Graham Frankland" <gfranklandattiscalidotcodotuk> wrote in message
news:43d03883$1...@mk-nntp-2.news.uk.tiscali.com...
was against a Bukh DV36, which was a smooth, quiet, reliable, and economical
MARINE engine of the same power. The thing about BMC 1.5 and 1.8 D engines
is that they are 20+ years old and as terrestrial engines they won't endure
the rigours of wet salty bilges in boats. Even when new, they were pigs to
start from cold and that trait only gets worse with age.
I'm constantly amazed by the prices that these BMC units still command on
websites like Boats and Outboards - people are willing to pay £2K or more
for these venerable heaps of trouble! If I could afford to replace it with
another Bukh, I'd defray the cost by selling the BMC to a
masochist...Enough...I've said my bit and I'm trapped in BMC misery
now....cheers...Keith
Ronald Raygun
> I suppose thats a fair point Graham, but my comparison of the BMC 1.5D
> was against a Bukh DV36, which was a smooth, quiet, reliable, and
> economical MARINE engine of the same power. The thing about BMC 1.5 and
> 1.8 D engines is that they are 20+ years old and as terrestrial engines
> they won't endure the rigours of wet salty bilges in boats. Even when new,
> they were pigs to start from cold and that trait only gets worse with age.
Well, I have a Bukh DV20 in one of my boats and a BMC 1.5 in the other.
The BMC (almost certainly more than 35 years old) has never been a
problem to start, but of course it does have glow plug preheaters
and I always use them except for warm starts.
The Bukh (25 years old), although never difficult to start from warm,
anything up to about 4 hours after having been run, has been a total
pig to start from cold these last few years, and getting worse. Then,
a couple of months ago, I fitted the "cold start accessory", a massive
glow plug let into the air intake (the neck onto which the filter fits),
and it's now a delight, starting as keenly as it always has done for
warm starts.
The real criticism of the BMC which I have, is that the marinisation was
done in a somewhat cack-handed way. I can only hope that others out
there have been done better, and that mine was a one-off amateur hack
job. The problem is that the sea water pump is mounted in such a way
that the cover plate faces towards the engine with only about half an
inch of clearance. This means that in order to change or inspect the
impeller, you have first to remove the pump, and re-tighten the belt
after re-fitting it.
My pump actually packed in last season and Jabsco, in their wisdom,
had decided to obsolete their trusty old 6490 series. Their replacement,
the CW403, is a different shap and size, and as a result I to modify
the fitting arrangements as a result of which there is now even less
clearance. Sigh.
> I'm constantly amazed by the prices that these BMC units still command on
> websites like Boats and Outboards - people are willing to pay £2K or more
> for these venerable heaps of trouble! If I could afford to replace it with
> another Bukh, I'd defray the cost by selling the BMC to a masochist.
Defray? You could probably buy two second hand Bukhs for that.
Maybe these "masochists" are intent on de-marinising them and putting them
into their old lovingly maintained Austin 55 or Morris Oxford.
k
"Ronald Raygun" <no....@localhost.localdomain> wrote in message
news:l9pBf.8232$wl....@text.news.blueyonder.co.uk...
Thanks for these comments Ronald and I can agree with some of your points,
particularly on the deficiencies of some marinising systems. I've got a
Thorneycroft Marininsed version of BMC with a separate belt driven jabsco
seawater pump, heat exchanging header tank and Captain watercooled manifold.
From your description you must have a front end mounted pump driven off the
timing assembly in some way. The ease of starting on the Bukh was stunning
compared to the BMC - Bukh combustion chambers are 'direct injected',
whatever that implies, and the heavy flywheel helps too. Mine was a DV36 and
these babies retail new at around £6K (depending on exchange rates, gearbox
options etc). The 36 HP are 3 cylinder mills and seem almost unobtainable
second hand or for under £2K.
Note what you say about the efficacy of inlet manifold heating for sluggish
starters - that system was effective for the Perkins 4108 with a raw diesel
burner on the inlet manifold. Propane blow torch is best of all, but it's
hard
pushing the stater in the wheelhouse whilst training a propane flame into
the inlet manifold 10 feet away!
cheers....Keith
Ronald Raygun
> Thanks for these comments Ronald and I can agree with some of your points,
> particularly on the deficiencies of some marinising systems. I've got a
> Thorneycroft Marininsed version of BMC with a separate belt driven jabsco
> seawater pump, heat exchanging header tank and Captain watercooled
> manifold.
Mine's the same except I'm not sure about the "Captain" bit. I inherited
both a BMC workshop manual and a Leyland Thorneycroft user manual, but
when I spoke to Thorneycroft they reckon from the serial number it's
not one they would have marinised themselves.
> From your description you must have a front end mounted pump
> driven off the timing assembly in some way.
There is a large pulley at front bottom on what is presumably the
crankshaft. There is a three way belt joining this first to
another largeish pulley directly above it, on what must be the
fresh water circulation pump, and second to the alternator
mounted off to starboard. There is a small pulley attached to
the front of the first pulley I mentioned, and there is a two
way belt from there to the Jabsco seawater pump which is to port,
low down, and attached to the front of the engine's structural "wing"
which terminates in the bit which attached to the rubber mount.
How's your seawater pump mounted?
k
"Ronald Raygun" <no....@localhost.localdomain> wrote in message
attempted to trace authenticity on the Thorneycroft marinising and it could
easily be a 'home brewed' set up. The seawater pump is belt driven directly
off the main crank pulley like yours (I have 3 pulleys available, 1 large
diam and 2 small). It's a foot/pedestal mounted Jabsco 4900 unit, I think. I
was cautioned that these are not really designed for belt drive as they
don't have a proper main shaft bearings. They are designed for axial drive,
I believe. Anyway, it's mounted very simply on a piece of angle iron which
is bolted and pivoted to the front engine mounting bracket, with a simple
threaded rod type of belt tensioning device to adjust the pivoting position
of the angle iron mounting. Easier to draw than describe!
To add insult to injury today, I took delivery of a BMC workshop manual on
cd. Cost me nearly a tenner on e-Bay, and it's absolutely hopeless... full
of unhelpful instructions like 'dismount the rotary fuel distribution pump
and all ancillary equipment'. I expect they just call up the tooth fairy to
do that kind of routine mechanicing! Also, I actually went for a short
cruise around Oban Bay in the boat this afternoon - it started easily for a
change, but continued to belch bluish smoke at tick-over, which eventually
clears when underway at around 1500rpm, but returns at tick over. I think
it's a timing adjustment needed on the injector pump, but I cannot get
access to the lower mounting nut to loosen the pump and rotate it for timing
adjustment. Of course, the blessed manual makes absolutely no mention of how
to set the injector pump timing. It looks as if I'll have to remove the
starter to get at this nut and to get the starter off, I'll need to remove
the oil filter mounting assembly first!!! It just gets worse - I've never
see a worse design, exacerbated by being below decks and difficult enough to
access without all that. From that, you may understand my continuing
disaffection for the BMC1.5D. I'd gladly consign it to the seabed as a
supplementary mooring....Keith
Tony of Judicious
SNIP
>I think it's a timing adjustment needed on the injector pump, but I
> cannot get access to the lower mounting nut to loosen the pump and rotate
> it for timing adjustment.
I had this problem with my old MD7A (which has now been scrapped). There is
an extension for a socket which has the male end slightly rounded so that
it can go in at an angle. Don't know the correct name (something like a
wonky extension) but my local motor tool shop had one. Solved what I
thought was an big problem.
As to smoke, have you tried stuff to clean up the injectors. My diesel car
failed its MOT on smoke, dosing the fuel and a blast up the motorway in 4th
reduced the smoke reading dramatically.
Graham Frankland
message news:43dcb2c1$0$3615$ed2e...@ptn-nntp-reader04.plus.net...
> There is
> an extension for a socket which has the male end slightly rounded so that
> it can go in at an angle. Don't know the correct name (something like a
> wonky extension) but my local motor tool shop had one.
Wobble Bar
Tony Brooks
snip
. I think
> it's a timing adjustment needed on the injector pump, but I cannot get
> access to the lower mounting nut to loosen the pump and rotate it for
> timing
> adjustment. Of course, the blessed manual makes absolutely no mention of
> how
> to set the injector pump timing. It looks as if I'll have to remove the
> starter to get at this nut and to get the starter off, I'll need to remove
> the oil filter mounting assembly first!!! It just gets worse - I've never
> see a worse design, exacerbated by being below decks and difficult enough
> to
> access without all that. From that, you may understand my continuing
> disaffection for the BMC1.5D. I'd gladly consign it to the seabed as a
> supplementary mooring....Keith
I know about the access problems for the injector pump nut, but that's
better than having the starter solenoid hanging in the bilge like the early
3 bolt starter maximisations did. (most have probably now been modified with
a different starter drive end bracket).
Now to the timing
Look at the injector pump mounting flange and you will see it is bolted to a
"triangular housing" set onto the block. One of the upper corners should
have an adjustable pointer mounted on it. The mating face on the pump flange
should have a line scribed on it during manufacture or overhaul. The pump
body should be twisted to make the pointer and line line up.
This is the correct procedure and should be fine as long as:
1. Noone has moved the pointer.
2. The pointer was set during engine overhaul.
3. Wear in the timing chain and camshaft/injector pump drive skew gears is
minimal.
If you suspect any of the above you need a special gauge that fits into the
pump drive (having first removed the pump) and is twisted (anticlockwise
from memory) to take the backlash out of the drive system. The pointer is
then adjusted to line up with the line scribed on the gauge.
Where you obtain one now is any body's guess - I have no idea. The best
thing may be to loosen the lower nut and refit the starter then use the to
two nuts to release and lock the pump whilst trying small alterations in
position. It will be easy to put those pointers back in line if you can not
make an improvement.
There is another problem owners need to be aware of and that is the skew
gears require extra lubrication that is provided by an oil jet and strainer
located under the back of the exhaust manifold. look for two largish nuts,
one vertical and one horizontal. Take these out and ensure they are clean..
I have known the left blocked with debris after overhaul and also by oil
residue that builds up over the ages. If they are blocked it would be as
well to draw the pump drive shaft to inspect the gears.
If you go onto the website below and go to the links at the bottom of the
first page you will find a link to a Dutch manual site. Go to the site and
click on the union flag (unless you can read Dutch) and follow the links to
the engine manuals. There is a combined BMC 1.5 & 2.5 one there for you to
print out. Unfortunately I do think its just for the engine with no marine
bits.
I hope this helps and feel free to contact me on or off group if I can help
you any more.
Tony Brooks
www.TB-Training.co.uk
Owner of smoky on low power DV36, but would have had a 1.5 if the Bukh was
not in the boat.
k
"Tony Brooks" <to...@tb-training.co.uk> wrote in message
news:drlron$7fv$1...@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...
being able to slacken off that wretched lower nut underneath the CAV pump. I
just can't see how to do that without all the rigmarole of removing the
starter and oil filter etc. That may be my only unhappy option. Surely there
must be some way of slackening that nut loosened without having to dismantle
half the ancillary equipment on the engine!!
The CAV pump is accurately timed at least by alignment of the scribed line
with the marker on the block - so maybe it's wear in the rotary pump skew
gears, like you suggest. I'd like to try simply twisting the CAV pump a few
degrees either side of the alignment mark just to see if I can reduce the
tickover smoke and increase the power under way. All that before getting
into nightmare territory of trying to deal with excessive backlash in the
pump drive - that sounds way beyond my league of mechanicing! I've got a
couple of spare CAV rotary pumps though - just can't get the old one off.
Thanks also for clarifying the function of these large nuts below the
exhaust manifold - I pay little heed to that side of the engine as all the
trouble is on the pump/starter side! I though these were maybe something to
do with oil pressure release valving on the oil pump.
Thanks also for the link - I'll explore that later this evening and see if I
can get a better manual for the BMC than the cd version I got off e-Bay.
I'd gladly swap a smokey Bukh DV36 for the BMC 1.5, but I had 12 years of
trouble free service from my last Bukh and I don't think I've had 12 minutes
of comfortable and confident running with this BMC since I fitted it 3 years
ago..... Luck of the draw, I suppose.
Cheers....Keith
Guy Fawkes
k wrote:
I had 12 years of
> trouble free service from my last Bukh and I don't think I've had 12 minutes
> of comfortable and confident running with this BMC since I fitted it 3 years
> ago..... Luck of the draw, I suppose.
been watching this thread for a while.
"k" needs to understand one thing, it is NOT luck of the draw, if a BMC
1.5 has "issues" then it wasn't set up properly in the first place, and
your "issues" will not go away unless it is sorted properly.
blue smoke is oil
pissing about with the timing isn't going to do anything except give
you bigger problems, assuming the timing is right, which is a separate
matter
tuppence to a tenner you're burining oil at revs too, but you just
aren't noticing it because other factors are masking it, but ticking
over on the mooring it's hanging around
unless it's something silly like valve guides (head changed recently)
then it's glazed bores / stuck rings / worn out, the first two of which
can be fixed in situ with the head off.
in my (considerable) experience of these things what this sounds like
is someone who does not feel in control of the situation because he
lacks the required knowledge (not trying to insult you, but it's self
evident) and has shifted that to make the object the problem, which it
isn't really, but the important bit here is this, even if this engine
is put back to factory spec and perfect in every way YOU are never
going to trust it, someone could sell you a less reliable bukh, but you
would be happy and not see it that way.
if you hate the motor get rid of it now, save yourself a lot of grief.
Tony Brooks
>
>> "k" <posei...@madasafish.com> wrote in message
>> news:SYKdnTz1Frh...@brightview.com...
>>
>>
>> snip
Some comments in main text.
> Thanks for that advice Tony - yes, the key to all my woes could well lie
> in
> being able to slacken off that wretched lower nut underneath the CAV pump.
> I
> just can't see how to do that without all the rigmarole of removing the
> starter and oil filter etc.
I really do not see, in the great scheme of things that removing one spin on
filter (if the engine has been converted) or the two bolts securing the
filter head to the block (new gasket should be used) plus removing one or
two upper starter bolts and slackening the lower one to let the starter
droop downwards is a great problem (idiot boat builders causing access
problems excepted). Its a sight easier than removing the jabsco impellor on
my Bukh!
That may be my only unhappy option. Surely there
> must be some way of slackening that nut loosened without having to
> dismantle
> half the ancillary equipment on the engine!!
> The CAV pump is accurately timed at least by alignment of the scribed line
> with the marker on the block - so maybe it's wear in the rotary pump skew
> gears, like you suggest. I'd like to try simply twisting the CAV pump a
> few
> degrees either side of the alignment mark just to see if I can reduce the
> tickover smoke and increase the power under way. All that before getting
> into nightmare territory of trying to deal with excessive backlash in the
> pump drive - that sounds way beyond my league of mechanicing! I've got a
> couple of spare CAV rotary pumps though - just can't get the old one off.
The most likley cause of backlash, if there is any, is the timing chain
and/or adjuster but I would expect to hear a bit of metalic clatter from the
front of the engien if this was too bad.
Please note that the official BMC mariniser Newage (later Tempest) marine
fitted an injector pump that had a different test card to the automotive
ones, so unless you are 100% sure those spare pumps are in good condition
AND set up for marine use please send them top a specialist for
testig/re-setting before even considereing using one.
> Thanks also for clarifying the function of these large nuts below the
> exhaust manifold - I pay little heed to that side of the engine as all the
> trouble is on the pump/starter side! I though these were maybe something
> to
> do with oil pressure release valving on the oil pump.
I think you will find the relief valve under the big nut between the
injector pump and oil pressure switch - never be tempted to pack or stretch
the spring!
> Thanks also for the link - I'll explore that later this evening and see if
> I
> can get a better manual for the BMC than the cd version I got off e-Bay.
> I'd gladly swap a smokey Bukh DV36 for the BMC 1.5, but I had 12 years of
> trouble free service from my last Bukh and I don't think I've had 12
> minutes
> of comfortable and confident running with this BMC since I fitted it 3
> years
> ago..... Luck of the draw, I suppose.
>
> Cheers....Keith
I go with Guy about confidence in your engine. I operated a hire fleet full
of BMCs and had very little trouble (unlike the Listers we also had). You
have to understand what you have got.
Indirect injected so it will be difficult to start from cold unless the
auxiliary sprays hole in the injectors are working and the glow plugs are
also working and carbon free (remove glow plugs every two to three years,
test with jump leads on battery, and drill out the hole to remove carbon
7/64 drill I think, but check). The engine is likely to be less long lasting
than a true marine engine, but I can not see that being a problem in a
sailing boat as long as its well looked after - they do years in hire
fleets.
Once warm, the exhaust should be cleaner at low speeds and powers than a
direct injected engine like the DV36, however if you do have bunged up spray
holes, carboned up or faulty glow plugs all the time you are trying to start
the engine you are filling the cylinders and exhaust with unburnt fuel. When
it eventually starts the fuel vaporises and produces white (in theory, but
often with a slight blue tinge) "smoke"
The 1.5 will run with horrible things wrong with itself, but have a very
lumpy, smoky idle. I do wonder if your rough running is an injector or
compression problem. Much depends upon the quality of any "overhaul" before
sale.
The DV36 on the other hand is direct injected (have a look in the
Maintenance notes on the website) so uses a simpler injector nozzle and
inherently will start well from cold. The down side is that it will tend to
produce exhaust smoke at low speeds and power - which is why I do not worry
too much about mine. Being a three cylinder I expect it would produce worse
engine vibration than the BMC if it did not have balance shafts inside.
As Guy says , I also doubt you will ever be entirely sure of the BMC, so
replacing it with something you trust more may be the cheapest way forward.
As far as I can see no-one knows the internal state of the engine or the
injection equipment so you may spend a lot of money or time on it.
--
Tony Brooks
www.TB-Training.co.uk
mgc...@gmail.com
Good luck
Graham