mk1-forum.net

Realized I never look much in readers cars so I have worked out how to show what I have been up to and saving you £5 odd a month by putting some of my stuff for Mini Mag into my Flickr thing. Slightly jumbled but hey ho

https://www.flickr.com/photos/28276454@N03/albums

Nice to see Tim, i don't tend to buy the mags that often, nice to see a pic of our car in the hillclimb article

Absolutely love the Coombes Jag! My ultimate car.

Tim

Love the one of Rich looking into the engine bay - do you think he’s worked out the problem?

Just put my latest efforts up onto Flickr

One for the anoraks among us to identify what I threw away. The bonnet in the background was completely flat where it had been under the back of a lorry and the grille from my racer had its second and final blow after Oulton. the blocks are all A+ 1000's except one thin flange 1100 which I should perhaps feel guilty about , other than I have a couple more anyway

Scrap mechanical pile 2018 by tim.harber, on Flickr

Got a proper Super grille for my racer last year and fitted it as requested by one Garry Superman. Just about the last thing to finish it to totally original as you can see now....

Silverstone 2018 Paddock 4 by tim.harber, on Flickr

No racing pics in my article. Do like this though - scariest thing as the leaders would lap me every 8 laps or so . Excuse my grimace - its a bit of a pig to keep hold of

Silverstone 2018 + Osella + Seat by tim.harber, on Flickr

Rest is on here:

https://www.flickr.com/photos/28276454@ ... 270994711/

Lovely photos, thank you for sharing. Paul

Great pics

can you elaborate on the test jig for the rubber cones ? very nice

Cheers
Luis

LuisM wrote:Great pics

can you elaborate on the test jig for the rubber cones ? very nice

Cheers
Luis

Rubber cone tester 1 by tim.harber, on Flickr

Rubber Cone tester by tim.harber, on Flickr

First of all , understand that I am pretty untechnical so I have a basic approach to queries and a tightarse approach to spending money so:

There is such a huge amount written about the springs and the trumpets that , faced with stocks of used rubber cones of differing heights (having been squashed - you'll see that there is a number on some of the ones in the picture - this is the height . They start out at about 90 and go right down to 70 particularly on the front on late cars as they weigh approx 140kg more than a 1959 car despite having the same spring

I had seen some tests by someone involved with GTM's done at Cambridge University to test old cones v new which suggested that old ones don't lose their spring rate but I thought the only way of finding out for myself how hard they were was to make a test rig of sorts - bracket on wall, scaffold bar with fixture for front trumpet to push on cone , heavy weight placed on other end - measure displacement using technical pointer(dipstick) on steel ruler. This way I could at least establish some sort of scale . I was particularly interested in seeing if the squashed cones lose their stiffness/spring as when I started doing Mighty Minis several of the racers would advocate using old squashed cones on the rear, partly as they will have settled . New cones have a percentage that they will settle to (something like 15-20%) as they are made from natural rubber which will settle after a period - there are some figures in one of the learned journals from Moulton or similar (can't find where at present). I also tried some of the comp cones .

Somewhere I have the results of the tests but they seemed to show that old standard cones don't stiffen up much if at all, partly as I understand it as the rubber forms a skin on the outer layer which protects the rest of it from getting oxidized or whatever it is that degrades rubber. I have inquired from the manufacturer how they can get a natural rubber product to be consistent - the answer is that they test the cones and machine some of the outer steel ring off to compensate.

As a result I have put used old springs in the back of my historic racer and the Mini Spares semi-hard ones at the front - more out of feeling I should have something sounding a bit technical on the car and its been like that ever since! Even cheapshit GAZ shock absorbers

I've got interested in how a simple blob of rubber can do such a good job and when I cut a displacer apart it shows how the rubber spring was just adapted to fit and the S one looks the same as a standard one

Finally - WORLD EXCLUSIVE fact to followers of our little box - even more exciting than BMC tractors....

One of our Mini-owning customers also has the last Hesketh raced by James Hunt . Guess what it originally used for suspension : Yes, Rubber

It has since been converted to conventional springs but our customers mechanic has a picture of the original springs somewhere , which I look forward to seeing


Lick this for rambling rubbish Peter Laidler!

Cheers Tim,

Great post & good info!

Very interesting and love the test rig! Just shows how long established folk law can be challenged and save you money in the process!

coopertim wrote:Absolutely love the Coombes Jag! My ultimate car.

Tim

Came across this the other day, lovely Event smelt right inside.

First of all , understand that I am pretty untechnical so I have a basic approach to queries and a tightarse approach to spending money so:

There is such a huge amount written about the springs and the trumpets that , faced with stocks of used rubber cones of differing heights (having been squashed - you'll see that there is a number on some of the ones in the picture - this is the height . They start out at about 90 and go right down to 70 particularly on the front on late cars as they weigh approx 140kg more than a 1959 car despite having the same spring

I had seen some tests by someone involved with GTM's done at Cambridge University to test old cones v new which suggested that old ones don't lose their spring rate but I thought the only way of finding out for myself how hard they were was to make a test rig of sorts - bracket on wall, scaffold bar with fixture for front trumpet to push on cone , heavy weight placed on other end - measure displacement using technical pointer(dipstick) on steel ruler. This way I could at least establish some sort of scale . I was particularly interested in seeing if the squashed cones lose their stiffness/spring as when I started doing Mighty Minis several of the racers would advocate using old squashed cones on the rear, partly as they will have settled . New cones have a percentage that they will settle to (something like 15-20%) as they are made from natural rubber which will settle after a period - there are some figures in one of the learned journals from Moulton or similar (can't find where at present). I also tried some of the comp cones .

Somewhere I have the results of the tests but they seemed to show that old standard cones don't stiffen up much if at all, partly as I understand it as the rubber forms a skin on the outer layer which protects the rest of it from getting oxidized or whatever it is that degrades rubber. I have inquired from the manufacturer how they can get a natural rubber product to be consistent - the answer is that they test the cones and machine some of the outer steel ring off to compensate.

As a result I have put used old springs in the back of my historic racer and the Mini Spares semi-hard ones at the front - more out of feeling I should have something sounding a bit technical on the car and its been like that ever since! Even cheapshit GAZ shock absorbers

I've got interested in how a simple blob of rubber can do such a good job and when I cut a displacer apart it shows how the rubber spring was just adapted to fit and the S one looks the same as a standard one

Finally - WORLD EXCLUSIVE fact to followers of our little box - even more exciting than BMC tractors....

One of our Mini-owning customers also has the last Hesketh raced by James Hunt . Guess what it originally used for suspension : Yes, Rubber

It has since been converted to conventional springs but our customers mechanic has a picture of the original springs somewhere , which I look forward to seeing


Lick this for rambling rubbish Peter Laidler!

Many thanks for taking the effort & time to share all this useful info.
Funny about the squashed cones on race cars, one of the few mini tuners here in Portugal uses since very long time highly squashed cones on his customers race minis.

Thanks once again Tim.
Cheers
Luis

Tim Harber wrote: Somewhere I have the results of the tests but they seemed to show that old standard cones don't stiffen up much if at all, partly as I understand it as the rubber forms a skin on the outer layer which protects the rest of it from getting oxidized or whatever it is that degrades rubber. I have inquired from the manufacturer how they can get a natural rubber product to be consistent - the answer is that they test the cones and machine some of the outer steel ring off to compensate.

As a result I have put used old springs in the back of my historic racer and the Mini Spares semi-hard ones at the front - more out of feeling I should have something sounding a bit technical on the car and its been like that ever since! Even cheapshit GAZ shock absorbers

Interesting post Tim
I have Put unused NOS springs on the back of my race GTM and new ones on the front that have been machined.
The car should be around 600kg so slightly different dynamics at play. we shall see what happens!

Thanks Tim! I like your style!
I’ve still got 56 yr old cones. They seem fine to me

I am with Tim in shoestring racing, mine is on 59 year old cones!

Love the colour of that Jaaag, would love a Minisprint in that colour, same as the Radfords?

GTM71 wrote:

Tim Harber wrote: Somewhere I have the results of the tests but they seemed to show that old standard cones don't stiffen up much if at all, partly as I understand it as the rubber forms a skin on the outer layer which protects the rest of it from getting oxidized or whatever it is that degrades rubber. I have inquired from the manufacturer how they can get a natural rubber product to be consistent - the answer is that they test the cones and machine some of the outer steel ring off to compensate.

As a result I have put used old springs in the back of my historic racer and the Mini Spares semi-hard ones at the front - more out of feeling I should have something sounding a bit technical on the car and its been like that ever since! Even cheapshit GAZ shock absorbers

Interesting post Tim
I have Put unused NOS springs on the back of my race GTM and new ones on the front that have been machined.
The car should be around 600kg so slightly different dynamics at play. we shall see what happens!

Haven't looked at this since I posted it hence delay . Actually I had one NOS Dunlop cone that we tested at the time and I recall it was stiffer than either used or currently manufactured cones so it threw a bit of a spanner in my amateur workings anyway

However , have just posted the current issues' offerings and have to point out that our last editor has mashed what I said

1. I used to keep away from long fast tracks but now am more inclined to try them with my cleverdick crank and bits that might take the revs better . In truth if you look at my footage from Combe in 2015 where it was regularly holding 8000 rpm in top along the straight the standard crank and rods held out just fine . Maybe , as with my rubber testing stuff , all the best ideas aren't necessarily the most expensive ones
2. Car would fire up and then go onto three as soon as I showed it the track

Miserable day at Goodwood. Better day when the delightful Ranger turned up for £12.50 . I have since given it away to one of our locals

Finally one unrelated pic for those worrying about the weather. A pic of yours truly having fallen over in the road when it got blocked near to us. The Min had been abandoned as the snow drifts were huge further down the road . This was 1962

(Waits for rustle of rivet-counters googling the reg of the car)

We now have a new editor who only lives 7 miles away so I can go and thump him if he gets it wrong

Mini Mag March 2019 by tim.harber, on Flickr

Tim 62 snow fallen over by tim.harber, on Flickr

Cheers for the update Tim!

davidnutland wrote:I am with Tim in shoestring racing, mine is on 59 year old cones!

You have to turn it into something competitive don't you

Bloody Southerners

Hi Tim, I absolutely LOVED that article about testing compressionability.

It just goes to show that you don't need special test rigs or apparatus or a lab to do these small tests. Even at uni student level all these test rigs ALL started using the simple things that were handy. Like hanging paving slabs (a fairly good heavy 'constant' datum load) on springs or emptying a weight or volume of water through a funnel to test hydro pipes for flow, volume and area, the Bernoulli equation, (the backbone of hydrolastic). Or boiling waterless coolant on the stove to show.........

MORE power to your elbow and more examples of KIST please Tim. That's Keeping It Simple Tim!