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Engine alternator issues.....any suggestions?


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6 hours ago, Eeyore said:

Is this one any use to you, it's 55mm dia. Located in Great Haywood.

E12EBB52-9B77-4C95-9FFB-4984609DFD5E.jpeg

I've arranged to see Ed of Four Counties Marine tomorrow, I'll see what that throws up. 

 

I'll measure the pulley that I currently have on the alternator to see if that one will fit but just with a cursory look both of my alternators have 4 'v' belts whereas that looks like a 6 'v' pulley so first impressions would be that it will be too wide. If what we are looking at is the outside edge of the pulley I'm not sure how it would be fitted as I use a ring spanner to tighten the nut and an allen key to hold the spindle whilst tightening it. With that pulley I'm not sure how the ring spanner would fit into that depth. It cannot be tightened with a box spanner or socket because the spindle has to be held with an allen key and my allen key isn't long enough to go right through a box spanner.

 

If it looks as though it will work, after tomorrows discussion with Ed, I'll let you know.

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12 hours ago, Wanderer Vagabond said:

It cannot be tightened with a box spanner or socket because the spindle has to be held with an allen key and my allen key isn't long enough to go right through a box spanner.

You could use an allen key head for a socket set along with an extension bar.

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13 hours ago, Wanderer Vagabond said:

I've arranged to see Ed of Four Counties Marine tomorrow, I'll see what that throws up. 

 

I'll measure the pulley that I currently have on the alternator to see if that one will fit but just with a cursory look both of my alternators have 4 'v' belts whereas that looks like a 6 'v' pulley so first impressions would be that it will be too wide. If what we are looking at is the outside edge of the pulley I'm not sure how it would be fitted as I use a ring spanner to tighten the nut and an allen key to hold the spindle whilst tightening it. With that pulley I'm not sure how the ring spanner would fit into that depth. It cannot be tightened with a box spanner or socket because the spindle has to be held with an allen key and my allen key isn't long enough to go right through a box spanner.

 

If it looks as though it will work, after tomorrows discussion with Ed, I'll let you know.

You can do up and undo these things with an impact driver, the inertia of the rotor means that a very short pulse of torque tightens/loosens before the spindle turns much. Something I learnt from Ed!

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8 hours ago, David Mack said:

You could use an allen key head for a socket set along with an extension bar.

I think you slightly misunderstand. The spindle has an allen key hole in it for you to hold is stationary whilst you tighten nut on the thread of the spindle. It cannot be done with a socket although it might be possible with a long allen key through the centre of a box spanner, my allen key ain't long enough:unsure:

8 hours ago, nicknorman said:

You can do up and undo these things with an impact driver, the inertia of the rotor means that a very short pulse of torque tightens/loosens before the spindle turns much. Something I learnt from Ed!

I never feel comfortable belting something with a bearing behind it with an impact driver, but I digress.Ed has been along today and we think we've cured the problem, but wont be sure for a few days yet. To run through the options, we found a very minor diesel leak (I say we since I saw it as I was taking the internal cover off the engine to give access to the alternator). That seems to be a bit of a red herring since there didn't seem to be any trace of diesel on the belt. Interestingly when Ed turned the pulley of the alternator, the belt was in fact slipping over the engine pulley which was a bit unexpected although since the belt has now been slipping for as long as I've been out I would guess the belt itself was shot. He has fitted a slightly larger pulley on the alternator but when he checked the v's of the pulley they were as clean as a whistle so it wasn't a 'crud in the pulley' issue. When checking the engine pulley there is a very slight dig in it, my guess is that someone (not me) has dropped something (nut, bolt) whilst the engine was running and it caught in the drive belt and passed through the pulley (other opinions are available). When checking the alignment of the pulleys it seems that they were about 2 v's out of alignment so he has removed the shim behind the pulley and a thinner one in to re-align the pulleys. When all that was done and we fired the engine up, there was no squealing, the real test comes in the morning since it has always been at it's worst on a cold engine. Fingers crossed and quietly hopeful:rolleyes:

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5 minutes ago, Wanderer Vagabond said:

I think you slightly misunderstand. The spindle has an allen key hole in it for you to hold is stationary whilst you tighten nut on the thread of the spindle. It cannot be done with a socket although it might be possible with a long allen key through the centre of a box spanner, my allen key ain't long enough:unsure:

I never feel comfortable belting something with a bearing behind it with an impact driver, but I digress.Ed has been along today and we think we've cured the problem, but wont be sure for a few days yet. To run through the options, we found a very minor diesel leak (I say we since I saw it as I was taking the internal cover off the engine to give access to the alternator). That seems to be a bit of a red herring since there didn't seem to be any trace of diesel on the belt. Interestingly when Ed turned the pulley of the alternator, the belt was in fact slipping over the engine pulley which was a bit unexpected although since the belt has now been slipping for as long as I've been out I would guess the belt itself was shot. He has fitted a slightly larger pulley on the alternator but when he checked the v's of the pulley they were as clean as a whistle so it wasn't a 'crud in the pulley' issue. When checking the engine pulley there is a very slight dig in it, my guess is that someone (not me) has dropped something (nut, bolt) whilst the engine was running and it caught in the drive belt and passed through the pulley (other opinions are available). When checking the alignment of the pulleys it seems that they were about 2 v's out of alignment so he has removed the shim behind the pulley and a thinner one in to re-align the pulleys. When all that was done and we fired the engine up, there was no squealing, the real test comes in the morning since it has always been at it's worst on a cold engine. Fingers crossed and quietly hopeful:rolleyes:

Two grooves out of alignment is HUGE. No wonder it squealed.  Out of alignment is more detrimental with polyvee belts than with v belts.

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3 hours ago, Tracy D'arth said:

Two grooves out of alignment is HUGE. No wonder it squealed.  Out of alignment is more detrimental with polyvee belts than with v belts.

I would tend to agree, particularly as it's only a 4 v pulley, but it doesn't really explain why the squealing stopped as soon as the tacho became live (or alternatively the tacho became live soon as the squealing stopped;)). With that sort of misalignment you would expect constant squealing until the belt wore out. It is nothing that I've done since replacement alternators have been like for like so the misalignment has been there since I've had the boat.

Edited by Wanderer Vagabond
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Just to clarify, there are impact drivers and then there are impact drivers. In my yoof I used to use an impact driver on Japanese bikes to remove the screws. Big screwdriver kind of thing you whacked with a hammer.. So I suspect that’s where you’re coming from. But one can also get cordless (electrical) impact drivers, same sort of thing they use in a garage to get wheel nuts on and off, but those are air powered of course. No hitting or axial force required.

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23 hours ago, nicknorman said:

Just to clarify, there are impact drivers and then there are impact drivers. In my yoof I used to use an impact driver on Japanese bikes to remove the screws. Big screwdriver kind of thing you whacked with a hammer.. So I suspect that’s where you’re coming from. But one can also get cordless (electrical) impact drivers, same sort of thing they use in a garage to get wheel nuts on and off, but those are air powered of course. No hitting or axial force required.

The impact driver that I've got is of the 'big screwdriver' kind, it has a half inch square drive on it so sockets can be fitted but, as I found out to my cost, they have to be really good ones. Trying to free a very stiff wheel nut with it some time ago which even a long lever on the wheel brace wouldn't shift, failed when the impact driver was hit and the socket shattered!

 

Final update on the alternator, I think we've achieved about 97% success. When the engine was fired up this morning there was probably a second or even less of slip on the drive belt (compared with over 2 minutes beforehand). There is clearly something that makes a big draw on the engine alternator on start-up, the manual states that the manifold glowplug is a 345W unit plus a short burst on the starter motor I suppose is quite a biggish draw. The tacho doesn't completely freeze any more, but still takes about 3 or 4 seconds to become fully operational. As long as things stay like that, I can live with it.

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11 minutes ago, Wanderer Vagabond said:

The impact driver that I've got is of the 'big screwdriver' kind, it has a half inch square drive on it so sockets can be fitted but, as I found out to my cost, they have to be really good ones. Trying to free a very stiff wheel nut with it some time ago which even a long lever on the wheel brace wouldn't shift, failed when the impact driver was hit and the socket shattered!

 

Final update on the alternator, I think we've achieved about 97% success. When the engine was fired up this morning there was probably a second or even less of slip on the drive belt (compared with over 2 minutes beforehand). There is clearly something that makes a big draw on the engine alternator on start-up, the manual states that the manifold glowplug is a 345W unit plus a short burst on the starter motor I suppose is quite a biggish draw. The tacho doesn't completely freeze any more, but still takes about 3 or 4 seconds to become fully operational. As long as things stay like that, I can live with it.

Very pleased that you have succeeded and thanks for telling us, it all adds to the learning experience. 345W is a heck of a load at 12v, how long is it on for?

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To be honest, I don't see why it needs to be on after the engine has started. It's not a car where they consider pollution and engine noise. If t is a timer relay, I would be trying it with a starter solenoid that de-energised a soon as the key jumped back to run.

 

Although 375 Watts seems a lot, it's 30 amps and with an operating time of 30 seconds it would draw less than half an amp hour from the batteries, so any discharge should not involve a high charging current once started.

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50 minutes ago, Tony Brooks said:

To be honest, I don't see why it needs to be on after the engine has started. It's not a car where they consider pollution and engine noise. If t is a timer relay, I would be trying it with a starter solenoid that de-energised a soon as the key jumped back to run.

 

Although 375 Watts seems a lot, it's 30 amps and with an operating time of 30 seconds it would draw less than half an amp hour from the batteries, so any discharge should not involve a high charging current once started.

I don't know for certain whether it is, I turn the ignition key, the light showing the glowplug is operating comes on, it goes out and I fire up. My assumption was always that when the light went out the glowplug went off. I don't know numerically what the output of the engine alternator is when the slip occurs, but I would guess it must be high, the domestic alternator, according to the battery monitor puts out something like 55A on startup but the belt doesn't slip at all. The difference is obviously that the domestic alternator only has two pulleys on the belt so has 180 degree wraparound whereas the engine alternator has three pulleys on the belt (engine, alternator and water pump) so only has 120 degree wraparound. Add to that the fact that I'm less bothered about over-tensioning the domestic alternator belt since the only thing that might get wrecked is the alternator whereas on the engine alternator belt it would be the water pump bearing that would fail.

 

ETA Having given it some additional thought, I suppose that there is a possibility that, since the glowplug in the manifold is essentially heating static air, it may remain on after the warning light goes out so that the heated air is sucked into the cylinders over the hot coil for a short time when the starter motor is fired up. By comparison, diesel engines with the glowplug in the cylinder have a hot unit inside the cylinder itself. Not saying the idea is correct, but it is a possibility.

Edited by Wanderer Vagabond
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On 21/09/2021 at 18:33, Wanderer Vagabond said:
On 21/09/2021 at 09:30, David Mack said:

You could use an allen key head for a socket set along with an extension bar.

I think you slightly misunderstand. The spindle has an allen key hole in it for you to hold is stationary whilst you tighten nut on the thread of the spindle. It cannot be done with a socket although it might be possible with a long allen key through the centre of a box spanner, my allen key ain't long enough:unsure:

I am suggesting you use these up the middle of a box spanner:5207V_P&$prodImageMedium$

 

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 Put alternator on the ground. Plonk boot on it. put flat or slightly cranked ring spanner on nut. Enter Allen key or Allen socket and bar Fully into spindle end. Lay Allen key handle or bar on ground, left hand side looking face on at pulley. Position ring spanner at top. Keep boot on it. Give the spanner a sharp whack with a hammer again towards left hand side=undo. 

Edited by bizzard
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14 hours ago, Wanderer Vagabond said:

The impact driver that I've got is of the 'big screwdriver' kind, it has a half inch square drive on it so sockets can be fitted but, as I found out to my cost, they have to be really good ones. Trying to free a very stiff wheel nut with it some time ago which even a long lever on the wheel brace wouldn't shift, failed when the impact driver was hit and the socket shattered!

 

Final update on the alternator, I think we've achieved about 97% success. When the engine was fired up this morning there was probably a second or even less of slip on the drive belt (compared with over 2 minutes beforehand). There is clearly something that makes a big draw on the engine alternator on start-up, the manual states that the manifold glowplug is a 345W unit plus a short burst on the starter motor I suppose is quite a biggish draw. The tacho doesn't completely freeze any more, but still takes about 3 or 4 seconds to become fully operational. As long as things stay like that, I can live with it.

I use a pneumatic impact wrench to shift pulley nuts. Don't ever use the hit-it-with-a-hammer type as it's very likely to cause internal damage. The glow plug in the manifold sounds like a "thermostart" or "flamestart" type of device which lights a little fire in the manifold. 

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14 minutes ago, Sir Nibble said:

I use a pneumatic impact wrench to shift pulley nuts. Don't ever use the hit-it-with-a-hammer type as it's very likely to cause internal damage. The glow plug in the manifold sounds like a "thermostart" or "flamestart" type of device which lights a little fire in the manifold. 

 

That is what I initially thought until the timer relay was mentioned and looking at the Perkins ones I can't see one would draw more current than a single modern glow plug - Never measured the current though. I have seen a single inlet air heating plug and that looked as if it would draw a fair amount of current.

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