Mclaren M8b replica (visual)

[Michel]

Hello
4130 used for an antiroll bar will give a very low result and "twist" effect beside the fact it is avery nice chrome moly tube ; I would advise another chrome moly family named -15 CDV6- commonly used in aeronautics applications and in modern race cars ( wishbones etc etc )
If you want to machine blades you need to use a very specific material named V300 ; this one is easy to machine once sourced and then need to be treated

Hope this helps

 

[René Jacquier]

Hello Russell, it looks that you have now an effective expert advice with Michel ...

Bonjour Michel, comment ça va ?

If I understand, I better have to investigate soon a 15CDV6 tube provider ....

I gave a kick look at ULM Technologie, but tube thickness is max 1.2 mm ; ULM oriented of course ...
Do you have an idea for an European source ?

Cheers

René

 

[Michel]

Hello René
yes 1;2mm is far not enought you need at least 1.5 to 2 mm ; have in mind too that when you increase thickness you lower speed flexibility (well known formula is Io/v !!!!)
You can for awhile do some more test with your 25CD4s but it will last only few track session and then it will be too "chewing gum " materiall !!
I will dig out some european producer data for 15CDV6 and will MP to you be aware that it is at least two times tricy ... and the only concern is to get only the material you need
Best is to try to have some from people building racing cars ( I will try to ask to previous friends working in that field !! and come back to you)
On the state there are many factories selling 15CDV6 ; again the only concern is to find who is able to sale small batch of stuff !!!

 

[René Jacquier]

Thank you for this support Michel ; meanwhile, I will keep close eyes on theses 25CD4S/Chewing gum bars .....

 

[Russell]

Michel
thanks for the info assistance there, do I take it that you feel that chrome moly tube used as a anti roll bar will `go soft` after little use. If that`s the case then, what should be used for a simple tube roll bar?
Russell

 

[Russell]

Hi all, not a lot of progress to report of late, been working on sorting out throttle pull and after 3 prototypes I feel that i have got it sorted. Tried 2 versions of single cable pull and not happy so ended up running 2 cables to pulll 2 pair of carbs. Each end has adjustment along with the adjustments on the carbs so will be able to get both pairs of carbs synchronized. Got he gauges in and started working out the wiring. Sadly progress will be slowed as Carols cancer has returned, we get the moving forward plans next Wednesday so are hoping for the best.

 

[Russell]

Left off the last photos, the back of the car is starting to get a little busy with the fuel surge tank and regulator all mounted up.

 

[Russell]

What i forgot to explain was how the pairs are synchronized, each pair is connected with a peg in groove on the arm so that when the `master carb` is pulled, its mate is also opened at the exactly same time. Each master carb is pull from the ball on the arm with the throttle cable which fits into the end of the adapter and the cable is pulled around a small alloy pull mounted below the carb.( you can just see it in the picture in the valley) This enables the motion to be pulled by the cable in the normal fashion. Very simple and effective with with all the adjustments available.
Regards
Russell

 

[Terry Oxandale]

You and your wife are in our prayers and thoughts.

 

[Randy V]

Prayers said for Carol and you Russell....
Be strong together!

 

[Graeme Stebbing]

Hi Russell, I am so sorry to hear of your news, prayers are sent for you both at this difficult time.

 

[Leon]

Chin up my friend, we are all thinking of you and your wife.

Best wishes Leon

 

[Dave P]

Hi Russell:
We will be praying for Carol.

 

[Michel]

Michel
thanks for the info assistance there, do I take it that you feel that chrome moly tube used as a anti roll bar will `go soft` after little use. If that`s the case then, what should be used for a simple tube roll bar?
Russell

If you want to use tube the requiered material is 15CD V6 ( fully machinable and weldable but just more pricy than 25CD4s)

If you want to use plain bar material you need ; V300 ( very difficult to find , to machine and always need specific treatment to become hard)

Hope this helps

 

[Russell]

Thanks for that Michael,
Working on the carbs at the moment, Jac, I do have a pressure regulator after the pump and before the carbs....but cannot remember if I need any restriction in the return line to maintain some pressure in the carbs. My setup runs a line to each carb and I will join all the returns into one return line...hence the question.
We also got Carol's results today, not good but could have been worse! Now we fight the fight again......till next time.
Cheers for your help.
Russell

 

[Jac Mac]

Russell, here is a dwg of a regulator fitted to the return line on a holley, you should be able to do similar, just imagine you have two holleys. This way while you don't really need 4 return lines, just simply a loop with a 0.25" restrictor to remove pressure in line after shut down.

 

[Russell]

Thanks Jac
I have plumbed it up with the regulator before the carb (after the fuel pump) will that still work if I put the re stricter in the return line.
Cheers

 

[Russell]

Hi there
Just been doing some small bits before we have a holiday then it will be on with the good fight.
Could not buy any fuel banjo`s for the front carbs so made up a pair, plumbed the carb`s from the surge tank and generally mucked around with small stuff.
I need to improve the throttle cable attachment at the pedal to ensure a strong accurate pull on both cables. With no fuel in the carbs its an ideal time to play with the throttles and not flood the motor with fuel.
So, no more car work for ten days...I am sure I will survive.
Cheers and thanks for the thoughts.
Russell

 

[Russell]

Back from our break and Carol will be home tomorrow from her op.
Trying to keep things normal moving forward however progress has been slow with my mind and time elsewhere.

Jac, a couple of questions thanks.
I have standard master cylinders set up the same as my last car yet these ones are not pumping / bleeding as I would like. They seem to push fluid then suck it straight back, not building any pressure? any clues before I pull them out thanks.

I have also just fitted the standard Audi clutch slave cyl and have needed to firmly push it in to bolt up. This makes me think that it is exerting pressure on the clutch fork and I need to shorten the piston pushing rod! Given that the slave has a small spring inside keeping `pressure` up on the rod, what sort of clearance should I have (allowing for that spring) I think that what ever I cut off will be taken up by the slave cyl and should back of slightly once the pedal is released.

Did the drill down the dizzy hole and got almost instant oil pressure 75psi....things worked better once I had the hoses on the remote oil filter around the right way. I am in the process of shortening a Chevy distributor and then will be in a position to fire it up for the first time. I will be nurse / chief cook and bottle washer for a while so the car takes second place.

 

[Andrew Robertson]

Back from our break and Carol will be home tomorrow from her op.

Jac, a couple of questions thanks.
I have standard master cylinders set up the same as my last car yet these ones are not pumping / bleeding as I would like. They seem to push fluid then suck it straight back, not building any pressure? any clues before I pull them out thanks.

I have also just fitted the standard Audi clutch slave cyl and have needed to firmly push it in to bolt up. This makes me think that it is exerting pressure on the clutch fork and I need to shorten the piston pushing rod! ....

Hi Russell, hope Carol's on the mend.

I usually have success bleeding masters initially from the pipe union at the master (slacken the tube nut at the master, stroke and hold pedal down, nip up the tube nut, release pedal, wipe up mess, repeat!). Once you get the master moving fluid, move to the calipers.

If you have plenty of stroke length available from your clutch slave, I would set pushrod length so that the slave is 5-10mm from being fully compressed (bottomed out) when the fork/release bearing assy is firmly pushed against the pressure plate. That will give you some capacity for clutch wear which will close up that clearance.

Cheers, Andrew