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Posted: Wed Jun 13, 2007 12:15 pm
by minor_hickup
I wouldn't advise driving with suspect dampers. They're easy enough to remove so their condition can be assesed. A smooth resistance should be felt all the way along the operating stroke. While you're there change the oil. Hydraulic jack oil is what suppliers use, if its suspect use a thicker oil like 20w50. Often after changing the oil the damper leaks, it means it was shot.
I may have a pair of recently reconned dampers to sell, depending on whether I'll need them for my next mog. They've got about a 1,000 miles on them if youre interested?
Posted: Wed Jun 13, 2007 1:19 pm
by bmcecosse
1" of clearance is not too bad - you can afford to cut another 1" off the top of the bump stop without running into problems. If you really want to raise the car you can make up longer shackle plates for the rear spring location. 1" longer will raise the car by 1/2" at the bump stop - I wouldn't go any longer than that. Good dampers are very important - drain off the horrible old oil and refill. The heavier the grade of oil the better the damping. I have used EP90 - but for you I suggest don't go beyond straight 40 engine oil - and 20/50 works fine.
Posted: Wed Jun 13, 2007 2:10 pm
by Kevin
The heavier the grade of oil the better the damping. I have used EP90 - but for you I suggest don't go beyond straight 40 engine oil - and 20/50 works fine.
Stick with the reccommended oil for the shockers or if you cant get any locally use jack oil as its the same spec.
Posted: Wed Jun 13, 2007 2:24 pm
by bmcecosse
Kevin - we have been over and over this - it's standard practice to use heavier oil for better damping. 750MC have been doing it for many many years (even up to EP 140!!) - and there is heavier oil sold by some of the MGB parts suppliers to do the same thing! It works.
Posted: Wed Jun 13, 2007 3:20 pm
by Kevin
Kevin - we have been over and over this - it's standard practice to use heavier oil for better damping
Can you please quote a recognised source of this information for the Moggie as none of the recognised suppliers of improvements for the suspension mention doing this, they either quote a tele damper conversion or coil over conversion of one form or another and I have not seen your suggestion mentioned in any books either, if it was that simple dont you think the likes of Chris Street and Jonathon would be reccommending it along with the spares suppliers as an option for the lever arms.
Posted: Wed Jun 13, 2007 6:28 pm
by plastic_orange
Nothing wrong with doing this - it is a cheap and cheerful solution if working to a budget - the worst that can happen is that if a seal goes and the damper leaks, you then replace the damper - up until this happens you do get a slightly stiffer ride.
It really was standard practise back when lever arms were the stock fitment on a wide range of cars - and is standard practise today in the motorcycle world (front forks).
I'm sure the reason it's not recommended is because of the possibility of leaking seals, and in todays world the litigation problems.
Pete
Posted: Wed Jun 13, 2007 7:52 pm
by bmcecosse
Of course suppliers don't mention it - they want to sell equipment - which I fully understand - they are making a living from it and I only wish I could do so too!! But read any of the old motor racing books/750MC/how to tune your XXXX etc - it's there in heaps.
Posted: Wed Jun 13, 2007 8:02 pm
by jonathon
Pete is correct, at least in respect to our working policy on modifications. But one ought to remember that everyone writing on this forum is responsible for their suggestions/advice whatever so be carefull in what you say, most stuff on here is pretty harmless and should not end in a dispute or action. However some suggestions have been extreamly contentious and bad advice, which could well end in tears and litigation.
As for suppliers and sales, I can only speak for ourselves but we only suggest parts/mods which we feel the customer needs, and not what we need to sell. Advice (free) often leads to no sale but a happy customer!.

Posted: Wed Jun 13, 2007 8:04 pm
by minor_hickup
Besides I mentioned it (hoping not to get into this again) as a stop gap to help an ageing lever arm until a replacement is found. I'd rather risk damaging an aged lever arm than risk insufficient damping. Besides I've done 10,000 on front shockers filled with 20w50 and it feels a hell of a lot better than the other mogs ive driven.
Posted: Wed Jun 13, 2007 8:19 pm
by jonathon
Trouble is putting thicker oil in an ageing damper increases the risk of it failing through blown seals, just as bad as insufficient damping. As for it damping better, I have no doubt that it might improve performance, but I would require conclusive proof that it was safe to do so, before doing this. Experience is subjective, as you may have just been lucky, hard facts from the manufacturer are what's really needed.

Posted: Wed Jun 13, 2007 8:20 pm
by bmcecosse
A convert at last !! Hallelujah!!
Posted: Wed Jun 13, 2007 8:23 pm
by jonathon
Posted: Wed Jun 13, 2007 8:46 pm
by bigginger
"The original lever arm dampers... were quite an innovation in their day, but times move on, suspension systems improve, roads become better and we all drive faster. Provided they are actually working,the front lever arm units ... are really not that bad at all, however the ability to disperse heat build up during working is very poor.
...a thick casing, which has trouble dissipating the heat, not helped by the very small oil reserve in it and its position in the engine compartment with the associated extra heat input... the inability to lose the heat generated in use allows the oil temperature to rise, which then becomes frothy and full of bubbles (sic). Damping efficiency begins to fade, handling quality falls and the ride becomes bouncy and the handling unstable."
The Morris Minor modification manual, Owen Burton, 1988
I can't imagine how thicker oil helps with this, and have been told by somebody who asked a man who was on the design team that it wasn't a good idea. What can I say? Another thing we disagree over.
Posted: Wed Jun 13, 2007 9:37 pm
by jonathon
Posted: Wed Jun 13, 2007 10:38 pm
by Onne
I would presume that thicker oil would increase the heat with the added friction, thus making more problems.
Which would not play up if the car was only used in short stints, like rallying etc
Posted: Wed Jun 13, 2007 11:36 pm
by minor_hickup
Jonathon I agree that its not the ideal way to go. I think my next minor will recieve tele dampers all round. However given the inability to shed heat by the damper, I would have though multi grade oil would be more suited!? It seems to be the superior option for engines, gearboxes and even differentials.
Posted: Thu Jun 14, 2007 8:14 am
by bmcecosse
Any damper does indeed work by turning the energy into heat - and I have seen Mini dampers on rally cars very warm to the touch - but I haven't found the Minor dampers more than hand warm even after a spirited run - which just proves they don't do all that much work. However - be assured this mod improves the car's handling very considerably -although in my case I have also added teledampers on the front - and the two together really make for a smooth ride with no wallowing or crashing onto the bump/rebound stops.
WOW!
Posted: Thu Jun 14, 2007 11:49 pm
by AndrewSkinner
Well, this thread has moved on abit since I last looked!!!
I did refill all of the dampers, they all took at least 40ml of oil, which seemed like allot, and then after toping them up 3 out of 4 dampers leaked. I think it is time for an overhaul of the dampers and shocks.
The problem is that the car has done 50,000 slow careful miles on all original gear. Now the car has a bit of a shock, from quiet sunday trips to the pub, it is being used everyday for every task. I am a student and so it is driven everyday and hs the usual trips to Tesco at lunch with often 4/5 people in the car.
I would not say (or hope) that this is seen as abuse to the car, but I do feel that the morris has been used to the max!? I dont boy race it about or floor it round every corner, but i do enjoy the odd fast corner and blast down the motorway.
Do you guys feel the same about your cars?
Posted: Fri Jun 15, 2007 12:40 am
by bigginger
Yes!
Posted: Fri Jun 15, 2007 8:08 am
by bmcecosse
The reason you had to top them up was because they had already leaked! The topping up didn't make them leak.