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Yes, there are internal cooling vanes.
This setup was very noisy before I stripped it, but I wasn't completely sure the noise was from a bearing rather than the belt. Running water on the belt, which I've seen suggested as a diagnostic procedure, did not affect the noise, suggesting it was a bearing.
As I said, this time around I "tuned" the belt tension with reference to the output voltage, and paid no attention to belt free play. I THINK in those terms its probably excessively tight, but I havn''t checked it
.I will later.
Went from screechy at sub-13V volt output to more or less silent at 14V with a lot of belt tension, suggesting the belt might have been the source of the noise.
It seems hot, but I dunno if its abnormally hot, because I've never given that any attention before.
I suppose a stethescope (maybe just a tube) might give a clue as to bearing status
Edited by edlithgow on 05/08/2022 at 09:52
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Went from screechy at sub-13V volt output to more or less silent at 14V with a lot of belt tension, suggesting the belt might have been the source of the noise.
If you have tightened the belt to the point where the bearing has no more wiggle-room, that may suppress the noise, but what happens in the longer term may be worth considering ?
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CB20 engine manual (as in Mk1 Charade) gives belt tension as 11-13 mm deflection with an 8kg load.
CB23 engine manual (as in Mk2 Charade, probably closer to the Skywing) variously gives it as 5-7mm deflection with either an 8 or 10 Kg load.
Borrowed GF's digital luggage scale, with a view to measuring it, but it proved to be unreliable.
If I come across a simple mechanical spring scale I'll try that, but I'm not wasting time and batteries with another electronic one.
Don't see it matters much operationally anyway, since there isn't really any choice about the 14V, so I need a belt tension that will deliver that, whether its likely to damage bearings or not.
Thunderstorms so no further test run so far.
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Don't see it matters much operationally anyway
Well it does if your alternator is fussy about how much tension it needs to operate properly, and only other worry/or not, would be if the water pump is driven off the same belt
not much point in testing apart from getting the Voltage right as no matter what you do a compromise is best you will get. ie as long as it works ok
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Does the MK2 have A/C, that the MK1 doesn't? That may make the difference in belt tension, if it 's having to drive a compressor.
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Does the MK2 have A/C, that the MK1 doesn't? That may make the difference in belt tension, if it 's having to drive a compressor.
Those are Charades, closest manuals I have. Skywing is Taiwan only and thus itself undocumented.
Skywing aircon is separately belt driven direct off the crankshaft, at least it was until the belt went AWOL.
Since I wasn't using the aircon, and don't have all the gear required to re-instate it, I havnt bothered to replace the belt.
As I said, measuring the belt tension will only tell me if its in spec.
If its too tight, I wont be able to reduce it and still get the 14V required to charge the battery, since I adjusted it to the minimum tension for 14V,
This means that the actual belt tension is of fairly limited academic interest.
If it is actually overheating,I suppose its either got a dry bearing or its shorting out somewhere. The latter explanation might mean its not generating efficiently and so needs a higher belt tension than spec to reach 14V output
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Does the MK2 have A/C, that the MK1 doesn't? That may make the difference in belt tension, if it 's having to drive a compressor.
Maybe "This means that the actual belt tension is of fairly limited diagnostic only interest". would be a better phrase
Edited by edlithgow on 07/08/2022 at 03:20
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I should have said that the belt (another variable) was replaced fairly recently.
I suppose I can't be completely sure it was the correct profile, but I'm assuming that's fairly standard for V-belts
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I should have said that the belt (another variable) was replaced fairly recently.
I suppose I can't be completely sure it was the correct profile, but I'm assuming that's fairly standard for V-belts
I seem to recall the important measure is that the V belt does not 'bottom' on rthe pulley but only engages with the sides of the groove,
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I should have said that the belt (another variable) was replaced fairly recently.
I suppose I can't be completely sure it was the correct profile, but I'm assuming that's fairly standard for V-belts
I seem to recall the important measure is that the V belt does not 'bottom' on rthe pulley but only engages with the sides of the groove,
I suppose I could test that with Tippex or chewing gum in the pulley V.
The belt does seem rather narrow (though similar to the previous one) and it might be possible to get a wider one.
Another rule of thumb is that the belt should be twistable through 90 degrees. This is easily doable with this belt, and I think you'd need a lot of tension to prevent it.
I THINK I heard it on a ASPW 4X Overlander youtube video though, so it may only apply to Landcruisers rather than being generic as I'd assumed.
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Everything you never really wanted to know about V-belts.
Its complicated.
SURPRISE!
mrosupply2-dyn-documents.s3.amazonaws.com/product_...f
This is about V-belts in industrial use, though I suppose the same principles apply.
They say (Page 5)
"Classical V-belts should ride in standard sheave grooves so that the top surface of the belt is just above the highest point of the sheave."
"Narrow belts are purposely designed so that the top of the belt will ride above the O.D. of the sheave"
I dunno what type of belt I (should) have (though "classical" is probably the way to bet) , but the top surface of the present one is way below the rim of the alternator sheave and its only about half its width, suggesting it might be too narrow. However
"In A-B combination grooves, an A section belt will ride slightly low in the groove, while a B belt will be in the normal position. In deep groove sheaves, belts will ride below the top of the sheave. "
www.apprep.com/belts-and-sheaves-v.htm
has
"the belt will sit with its outside diameter pretty close to the outside circumference of the sheave. That's when you know you've got it right. Some sheaves, however, are "dual" sized sheaves and the belt may not ride that way. The belt may ride above or below the outside circumference of the sheave."
So it depends on what type of V-belt and sheave should be fitted to the car
From a bit of Googling, the belt identification/sizing guides I could find are based on measuring the existing belt, assumed to be correct, but NOT from sheave measurements
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My daughter has a 1.0 litre 2005 Daihatsu Charade on which the V belt outer surface is flush with the pulley outer rims.
the belt looks about 1/2 inch wide, I would suppose Daihatsu would aim to standardise such things where possible?
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Thanks,
Most of the pictures I could find online of V-belt alternator pulleys of any or unknown make appeared to be like that, suggesting it might be the general nature of the beast.
This would suggest the wrong belt was supplied.
This is Taiwan, so mistakes due "lost in translation" and "chabuduo" (roughly means "close enough", the basis on which all consumer level mechanical bizniz is conducted) are likely.
OTOH, the current belt was bought from a spare part supplier who appeared to check it out on their stock control computer program, and it looks pretty similar to the old one, which had started to shed teeth.
I might try a wider belt, but I think first I'll take the (used replacement) alternator off and try and check out the sheave in case its V...er...isn't .
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Yep, alternator pulley seems wrong. Access is limited, but it looks like the belt bottoms out on the alternator sheave but is OK on water pump and crankshaft
DUH!
So much fannying around, so bleedin obvious!
I have the remains of the old alternator but seem to have lost its pulley.
Getting a replacement pulley is likely to be difficult, so I may have to try and find a workable compromise belt.
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Yep, alternator pulley seems wrong. Access is limited, but it looks like the belt bottoms out on the alternator sheave but is OK on water pump and crankshaft
DUH!
So much fannying around, so bleedin obvious!
I have the remains of the old alternator but seem to have lost its pulley.
Getting a replacement pulley is likely to be difficult, so I may have to try and find a workable compromise belt.
Any possibility of access to a lathe to turn a new pulley from wood?
Apologies if this is a daft idea, I do realise the difficulties you have in sourcing things which are readily available here.
Mind you, the way things are going and the slim prospects of improved governance and functionality of everything you may soon be in a better situation than we are here.
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Mind you, the way things are going and the slim prospects of improved governance and functionality of everything you may soon be in a better situation than we are here.
Or not...very marked increase in fighter night operations from the local airbase, with a lot of helicopter operations during the day.
Also very marked decline in lights out to sea. Rumour has it that night fishing off the coast has been suspended.
Good for the fish, I suppose.
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Pulley not so convincingly wrong with alternator off. Maybe some slight wear "shoulders" but not bad. I cut the old belt and, holding its end in the sheave V could still see daylight under it.
Fitted a slightly wider belt which should be better but still seemed to need a lot of tension to give 14.2V. This declined to 13.6V with headlight and fan load, which is a biggish drop and just out of spec for the Mk2 Charade CB-23 engine (range 13.9 to 15.1V) but this is a CB-22 so perhaps it might still be acceptable
Remains to be seen how it will hold up on a long drive.
Edited by edlithgow on 21/08/2022 at 04:19
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