Bell crank bushes and front damper works

cobraboy

Well-Known Member
#1
Had a little play with the bell crank bushes and turned up some made from nylon, also threaded the lower damper pin for a nut. Cut an M16 x 1.5 thread and fitted Nyloc nuts, no more skinned knuckles for me ! Made sure the nut put the same pre load on the bush as the pin and washer.
Also had AVO units re valved to get a higher damping range.
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mrtask

Well-Known Member
#2
Is the nylon you've used for the ball crank bushes as compliant as urethane bushes, or harder still? My purple poly inner bell crank bushes are saggy and the creaking noises are pretty loud! I'd like to know how you get on with them, so keep us posted please. I'd be interested in a set of stiff bushes, if they're something you could make to order?
 

cobraboy

Well-Known Member
#3
Alasdair
There is zero compliance, which is what I am after. The next stage is to make a link from the outer bell crank nut to the top ball joint nut to triangulate the top link.
I have had one drive and there is negligible difference in terms of road noise / harshness.

I do not have a lathe, I have to borrow time on a friends machine. Until I get my own I do not feel able to impose too much.
I would gladly make you a set if I had access to my own lathe.

Mark
 

mrtask

Well-Known Member
#4
Will the triangulating link be a bolt-on addition? Another item I'd be very interested in trying out on my car. Shame you don't have your own lathe.
What would triangulating the top link do then? Further stiffen the ride? Make the handling more precise? Is the beefy looking bell crank subject to deformation under hard cornering!? I saw that Mal Clark of Bygone Rovers in New Zealand had trinagulated the top links in his Targa rally P6, in addition to replacing the vertically mounted shock absorber with horizontally mounted adjustable coilovers in place of the standard road springs.
I'm by no means an auto engineer, but I did learn the hard way that replacing the compliant bushes for the lower front shock mount with white 'Delrin'/nylon bushes didn't work – the lower shock eyelet just cracked and failed. I went back to purple poly. Just throwing that cautionary word into the mix. Really looking forward to following your learning curve with these suspension mods.
 

cobraboy

Well-Known Member
#5
I have purposely left the shock bushes rubber and allowed flex for the reason you mention. I suspect that during extension and compression the mounting pins move out of alignment.

I am also on a steep learning curve. After long time trying I am in conversation with Mal, he has been so free with is knowledge. I am taking his advice on triangulating the bell crank to eliminate flex and to try to help control a handling issue I have.
It will be bolt on, slightly different to Mal's - watch this space.

Yes Mal has a horizontal coil over but I had already committed to having the vertical AVO units re valved, and also Mal has not lowered his car, whereas mine is lowered and I do not have the spring length to accommodate a coil over and mounts.

I appreciate your comments, we are all learning when we move away from what the Rover boffins did in period.
 
#6
Hi, There's a thread somewhere (I can't remember if it's on here or elsewhere and I've had a scout round) when they replaced the front spring with a coilover and they cut the 'ball' mount for the spring off and fabricated and welded a new mount onto the top link. Along with a new mount that, I think, bolted to the bulkhead spring pan. Because the forward coilover mount was effectively further forward they could adjust the ride height down.

I will have another look round for it if inspiration strikes and lets me know where I saw it.

Colin
 

cobraboy

Well-Known Member
#7
Thanks Colin.
I had a rough measure and figured I could remove the ball mount rod and install a new mount for a coilover into the arm, but by the time I allowed for that mount and the eye mount on a damper, and the same the other end I would have no room for a spring.
I am running an 8" spring at the moment and it is around 1 1/4 " off the firewall and an inch off the forward end of the ball rod.
An option to gain over 2" is to cut a hole in the forward firewall skin and make a cup to sit in the void between the two skins in order to push the mount rearward, but you would have to be a brave man to do that.
I am pleased with the spring location as is, it is working well.
 

corazon

Well-Known Member
#8
Read my mind with the nylon bushes, I’ve been thinking along those lines lately!
Looking forward to hearing more in depth results, including the hopefully fit and forget threaded shock mount which you know I’ve already done to my shell.
The horizontal coilover conversion was Simon’s second P6, was looking very promising. But he’s got an awful lot of projects..

Speaking of too many projects and on the subject of lathes, mine is almost ready to use- just waiting patiently for me to topcoat it..So I’ll be making some bushes of my own soon :D

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Jim
 

corazon

Well-Known Member
#10
Good to know about the self lubricating nylon, Oilite also do all sorts of compounds other than the standard sintered bronze.
I had wondered about Teflon from its use in high performance rod ends etc, but think it’s probably unsuitable due to wear in this application..?
Jim
 
#11
Hi all,
We used Nylatron, yet another lubricated Nylon. I remember the aftermarket 'uprated' bellcrank bushes were so deformed that I was not happy. (These were the blue, purple or red aftermarked items, i can't remember the colour or who's product they were)

The Nylatron was easy to cut on the lathe, but getting it to size was hit and miss. If you end up trying to take off too little, the cutting tool slipped over the work piece surface and cut nothing, Or it bit in and cut off to much.
After a while as written in the P6V8 Blog the bushes developed stiction, the car sounded like a Caribbean steel drum. I found that liberal Red Grease is answer. I had made lub points in the bushes, which I had tried all sorts of lubricants until I found the Red Grease worked. In the photo the little bolt is in the lub hole.



As for fitting coil overs, I sketched out a plan on the back of something around the same time. I over came the space issue, like you the car is lowered and there is not enough room, without going trick. I'll see if I can find it.

Regards,
Gavin.
 

mrtask

Well-Known Member
#13
Looks like you may have a customer lined up for bushes already....... ^^^^^^^
Hi Corazon. Just as Cobraboy suggested, I'd happily take a set of uprated bell crank bushes from you if they weren't prohibitively expensive. Do you plan on turning them up using the Nyloil or Nylatron substances mentioned above? I'd certainly like to hear back from you regarding this, either on this thread or a private message if you prefer.
 

cobraboy

Well-Known Member
#14
Thanks for the thoughts on the top link Gavin.
I also considered fitting a grease nipple into the bell crank bushes, something I will have to do if I get issues. I assembled with bush lube from Superflex I had left over.
 

corazon

Well-Known Member
#15
I messaged you privately Al.
Once I’m up and running properly and have turned out something I’m happy with, I’d definitely make up some sets if there’s interest- and if I can do it economically of course..
I’d also thought about adding grease nipples here, and to other suspension components I’m fitting poly into..

Jim
 
#16
Today got the extra bell crank braces made and fitted.
Brackets are, 6mm at the pivot end and 3mm at the ball joint end. 3mm being the thickest possible under the castle nut.

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I used M12 studding, LH and RH thread to make a turnbuckle to allow fitting without having to break apart the top ball joint. The 6mm thick bracket takes the place of the 5mm thick washer.
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Camera would not focus in the confined space.
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Have yet to drill a higher hole for the split pin.
 
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