240 General: New (to me) 1980 Volvo 244

[Othen]

Originally Posted by john.wigley

Alan, I salute you. That is a perfect example of what makes an already good forum great. Would that such behaviour was at times more prevalent in the lounge ... J.

You may recall I had a brief foray into the lounge about a year ago, and found it to be a rather abrasive place - somewhat like standing on the terraces at a soccer match in the 1980s (I don't follow the football, but I do recall going to the odd match and feeling very vulnerable). By comparison, the 200 series area I restrict myself to now is like meeting in the village pub or tea shop with a group of polite, helpful and like-minded friends.

Long may the serenity of the 200 series area continue :-)

Alan

[Laird Scooby]

Originally Posted by Othen

I was being a bit of a pompous arse when I wrote this last night Dave, I'm sorry about that and I apologise. My physics degree was nearly 40 years ago and has no more bearing on this than would O level chemistry.



The physics behind the maximum open circuit potential difference that a lead-acid battery can maintain is actually limited by the chemistry: a less exact science (as Ernest Rutherford said: when it comes to sciences there is physics, and the rest are stamp collecting (or words to that effect)). The voltage is determined by the molarity of the acid - and so is a bit hit and miss.

As far as I know nominal 2v cells have always actually been 2.1v since they were invented. A normal lead-acid battery (like the one on the RB) should be charged at 14.4 volts (the chemistry dictates this) and straight after charging (within seconds) will register just over 13v, but this will fall to 12.6v within an hour or so (the extra half a volt or thereabouts is due to the capacitance between the plates - which as you will know will soon leak away). It will then stay at 12.6v for weeks, maybe months. It doesn't matter how long it is charged for, it will still never maintain more than 12.6v - just limited by the molarity of the acid.

12v lead-acid batteries should be charged at 14.4v (due to the chemical process), but once charged won't maintain more than 12.6v. If fully charged they won't discharge if the voltage at the +ve terminal is above 12.6v (because the electrons will follow the potential gradient from the alternator and regulator to the car's wiring) - but if not fully charged (as it won't be after powering that great big starter motor) the chemical charging process won't get underway until the alternator and regulator are providing something approaching 14.4v (actually 12.9v, so your figure of 13.7v is about right - but the chemistry will depend on the molarity of the acid at the start and (very significantly) the temperature). So, the bit between 12.6v and about 13.7v is a grey area where the battery (if fitted in a car) won't be discharging, but the chemical process to increase the molarity of the acid may not have started - so you have a good point. Simple really, isn't it: 12v batteries are really 12.6v, but they won't start charging until the difference in potential across the posts is about 12.9v (ish) - hence float charging to maintain the battery is generally set about 13.7v.

Anyway, I'm really sorry I was a pompous arse above.

:-)

Apology accepted but not really necessary Alan as we were both saying virtually the same thing from different angles. I belive this is because we were taught by very slightly different methods, in mine the theoretical maximum voltage of 2.2V with the practical voltage of 2.1V and in yours the practical open circuit voltage of 2.1V, as i alluded to in my first long post.
Why they were teaching the same things from different viewpoints i don't know and almost certainly never will but it seems there are a growing number of things taught differently.

[Othen]

It looks like winter is sufficiently over to swap back to my Virgo wheels and summer tyres, so that is what I have done this eve. The Pholus/winter tyre combo has worked perfectly, and was a good investment:



Happiness is... my new 3 tonne jack, it really does save a great deal of time and effort:



I wouldn't really recommend these cheap Chinese impact drivers - this one was very cheap but didn't really produce enough torque to loosen the wheel nuts (well, it probably would have done given time, but it was quicker to do it the old way and give each of the nuts a nudge with the car on the ground - after that the driver did get them off and on very efficiently):



Swapping wheels twice per year is a really good opportunity to check the brakes, steering and suspension (all good) and give the outgoing wheels a good clean up before going into storage for the summer:



The Virgo wheels are back on - I still can't decide whether I prefer Virgo or Pholus wheels - but I like them both, so that is a good situation to be in :-)



... Millicent approves :-)

[Laird Scooby]

Originally Posted by Othen

... Millicent approves :-)

I'm with Millicent!

[Othen]

As I think I mentioned a while ago, I'm going to put the AW71L auto box conversion on the back-burner for a year or so, hence I've decided to make sure the BW55 3 speeder is in good order. To that end I ordered this little kit from a very helpful chap in Poland, and it showed up in the mail a few days ago:



It cost just £11.20 plus a bit of postage (paid for in Zloty via my US$ account, so the currency conversion is a bit approximate - anyway, it was cheap). It is a nice day to be outside working on the RB (19c forecast later), so cleaning the bottom of the BW55 will be todays little task... mehr später...

[Laird Scooby]

Originally Posted by Othen

As I think I mentioned a while ago, I'm going to put the AW71L auto box conversion on the back-burner for a year or so, hence I've decided to make sure the BW55 3 speeder is in good order. To that end I ordered this little kit from a very helpful chap in Poland, and it showed up in the mail a few days ago:



It cost just £11.20 plus a bit of postage (paid for in Zloty via my US$ account, so the currency conversion is a bit approximate - anyway, it was cheap). It is a nice day to be outside working on the RB (19c forecast later), so cleaning the bottom of the BW55 will be todays little task... mehr später...

Might pay to retain the extension housing gasket for the AW70/71 conversion Alan so you can swap extension housings for the speedo drive.

[Othen]

What a lovely day it was today, just right for servicing the gearbox on the RB. It is a good idea to pump out as much ATF as possible first - to save mess - I managed to get about 2 litres out that way. Next remove the dipstick tube, loosen the two brackets (bolts that hold the starter motor on (17mm I think) and then undo the plumbing fixture (15/16" open ender required) that got another litre out, plus about half a litre in the filter housing:



The pan had a layer of 40 year old emulsified oil at the bottom, but was largely free from metal particles, and the magnet was pretty clean. Here is the old filter (again, not too many metal particles for 40 years):



... the outside of the pan was pretty scabby:



... so I gave it a coat of silver Hammerite after I'd given the inside a good pressure washing and cleaned up the mating surface:



The new gauze filter and the filter gasket were soon on:



... and the pan ready to be replaced. I chose to use the spare gasket that came with the RB (a sort of neoprene looking material) rather than the cork one that came from Poland (so I still have a spare - just in case):



Once I'd measured all the ATF that came out it came to 3.5 litres, so I replaced it with the same amount of Type G (I often think it is best to use what would have been fitted back in the day).

It was a lovely afternoon, 20C and sunny, so Bob and I took the RB for a good drive to get the gearbox warm and so check the level. No leaks (which was good) and the auto box is noticeably smoother than it was previously. This could be due to the Type G ATF, changing the filter or cleaning the crappy emulsified oil out of the pan, or any combination of them. Once warm I added another 0.25L of ATF to top up.

All in all a good morning's work and well worth £30 in parts and ATF - this has been a significant improvement for the RB.

:-)

[Laird Scooby]

Sounds like you had a fun morning spanner-twirling Alan!

[Othen]

Originally Posted by Laird Scooby

Sounds like you had a fun morning spanner-twirling Alan!

Actually, I did enjoy that little job Dave. It is satisfying to know the auto box is in really good health, and to save perhaps £150 in garage fees. I'm feeling very happy with myself :-)

[Laird Scooby]

Originally Posted by Othen

Actually, I did enjoy that little job Dave. It is satisfying to know the auto box is in really good health, and to save perhaps £150 in garage fees. I'm feeling very happy with myself :-)

What's the next job going to be then Alan? Changing the diff oil perhaps?