Author Topic: Straight axle to A arm engineering.  (Read 12482 times)

Offline H.G. Wells

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Straight axle to A arm engineering.
« on: February 07, 2016, 04:49:20 PM »
Working on a new build and had planned on swapping the torsion bar and straight axle from my old bent car to the new chassis. builder has talked me into not reusing any of my 40+ year old stuff on this new car. (yea he is smarter than I am) I plan on using a bel-crank and two steering arms like I did when it was a straight axle. Since the track will be much more narrow I wonder if I would be better off with a third arm from the spindle and steering off of it with the drag link instead, so I would have just one link between the spindles? Any difference in the way it will steer?
Racecar spelled backwards is racecaR

Offline Van

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Re: Straight axle to A arm engineering.
« Reply #1 on: February 07, 2016, 07:17:35 PM »
It's just as easy to mount a new tube axle solid as mounting A arms. The new axle doesn't need to be narrow and the A arms don't need to be either. I personally hate the narrow A arms on a FED. If you are paying the bills It's your opinion that counts, not the builder.

Offline rooman

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Re: Straight axle to A arm engineering.
« Reply #2 on: February 08, 2016, 07:26:47 AM »
Van,
      I think that H.G. is thinking about a rigid mount straight axle. What he is asking about is the difference between cross steer and going straight to the spindle. The main reason for cross steer with a bell crank was to negate the effect of the extreme caster that was run back in the day. With as much as 40 degrees of king pin inclination the regular drag link was trying to push the arm down relative to the spindle as much as it was trying to rotate it. On later cars with around 20 degrees caster it is a lot easier to rotate the spindle with a straight drag link.
   Either way (axle or A-arms) with less caster the bell crank is redundant to a great degree.

Roo 
Yeah, I am from the south--any further south and I would have been a bloody penguin.

Offline H.G. Wells

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Re: Straight axle to A arm engineering.
« Reply #3 on: February 08, 2016, 07:55:07 AM »
Thanks Keith, yes I was looking for info on bel-crank vs spindle mount.
I did struggle with straight axle vs A arm and see advantages to both, this one will be an A arm car with about 13 degrees caster.
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dreracecar

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Re: Straight axle to A arm engineering.
« Reply #4 on: February 08, 2016, 08:18:06 AM »
I could say something about A-arms on front engine dragsters and the builders/owners that do them that way, but Glenn would kick me off this site

Offline H.G. Wells

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Re: Straight axle to A arm engineering.
« Reply #5 on: February 08, 2016, 08:45:17 AM »
And that is why I did not ask about A arm vs Straight axle. Just about the steering system.
Thanks for the help.
Racecar spelled backwards is racecaR

Offline ricardo1967

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Re: Straight axle to A arm engineering.
« Reply #6 on: February 08, 2016, 10:18:41 AM »
And that is why I did not ask about A arm vs Straight axle. Just about the steering system.
Thanks for the help.

The day I consider replacing my wide-track SPE front axle with A-arms I'll also install power steering and A/C in my FED.

Offline George

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Re: Straight axle to A arm engineering.
« Reply #7 on: February 08, 2016, 03:13:08 PM »
The A/C would make cackling a bit more comfortable.  :)

Offline ricardo1967

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Re: Straight axle to A arm engineering.
« Reply #8 on: February 08, 2016, 04:53:29 PM »
And that is why I did not ask about A arm vs Straight axle. Just about the steering system.
Thanks for the help.

The day I consider replacing my wide-track SPE front axle with A-arms I'll also install power steering and A/C in my FED.

The A/C would make cackling a bit more comfortable.  :)

Glad you liked the idea George :). Of course I mean no disrespect to my friends that use A-arms. I just have a strong attachment to the classic FED look.

Offline Van

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Re: Straight axle to A arm engineering.
« Reply #9 on: February 08, 2016, 07:12:39 PM »
I could say something about A-arms on front engine dragsters and the builders/owners that do them that way, but Glenn would kick me off this site

 Bruce  I think FED's with the frame going way past the spindles & a big overhang are the TRANSFORMERS of FED's just like the Transformer Altereds  Just cap it off with a big fiberglass nose piece and now its XXXX
« Last Edit: February 08, 2016, 09:54:57 PM by Van »

Offline digster

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Re: Straight axle to A arm engineering.
« Reply #10 on: February 08, 2016, 09:11:55 PM »
Another straight axle  guy here too. My car had over 30 degrees of king pin inclination in it when I purchased it. Scott Parks gave me some tips on toning it down. I was able to get it to 22 degrees and the std. drag link works well there. I Love the way my old bent and chromed Anglia spindles look but they have some time on them now. I just ordered a new set of strange spindles. about the same look and a little more piece of mind at higher speeds. :)   

Offline rooman

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Re: Straight axle to A arm engineering.
« Reply #11 on: February 09, 2016, 05:28:50 AM »
Digster,
           the Strange (or any other late model) spindle is not a straight interchange for the Anglia. The king pin boss height variation can be fixed with a shim but the king pin inclination is different. Original Anglia is 9 degrees, most aftermarket (P & S, Neil and Parks, McKinney,  Boulton etc are 8 degrees and Strange are 7.

Roo
Yeah, I am from the south--any further south and I would have been a bloody penguin.

Offline digster

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Re: Straight axle to A arm engineering.
« Reply #12 on: February 09, 2016, 07:34:09 AM »
 Roo
 Frank said I'd need to shim it up. Bronze washers top and bottom should do that But I've not got to the bottom of the inclination issue yet.  Nothing is bolt and go, is it?  :)
Thanks for the Heads up

dreracecar

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Re: Straight axle to A arm engineering.
« Reply #13 on: February 09, 2016, 07:59:53 AM »
2* of change will will cause exsesive camber and look like you just came down from a 10' wheelstand.  Personally I would send the spindles out to magnaflux and if passed would just re-bush and run them. If your heart is set on the Strange spindles, then the spindle bosses on the axle will have to be machined out and replaced at the proper angle--- For peace of mind sakes

Offline digster

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Re: Straight axle to A arm engineering.
« Reply #14 on: February 09, 2016, 04:48:06 PM »
Roo
 You were talking 2 Degrees inclination  (or axle lay back ) not camber right? Do I have my alignment terminology fouled up?