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Birth of Long John

I tried using my iPad for this post so I don’t have a compressor on it I can figure out. It was late and I was tired but was excited and wanted to post. I’ll work on it after my exercise today.
 
Those with laptops or desktop with windows can just use MS Picture Editor for about anything. It comes with just about all versions of windows.
 
]When you narrow the axle 8” and stretch the frame 60” thinking Ackerman will be close with stock steering arm is a dream! Only option is build your own! I started with the 3/8” rod on the front of spindle holding spindle straight. Tied string from center line of king pins to centerline of rear end. My steering arms will be 5” center of kingpin to center of tie rod end. That is the magic spot. Plumb Bob down and your golden.
 

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Great work, ORF. And thanks for uploading the pictures. They're worth 1,000 words!!! (or more :laugh:)
 
With the help of Indycars (thank you) I think I may be able to make a little more sense of my steering geometry.

Top arrow- from center of kingpin to center of rear end.

Second arrow- Rod holding spindles straight ahead.

Vertical arrow- line from 5” from center of king pin along string on top arrow to match steering rod length from center of kingpin.

This will give me close Ackerman steering.

Does that make since or not? 3E663561-4AAF-4534-B5E5-15804F3F6F87.jpeg
 
Makes sense to me. I think you described it to be the Steering arm-to-tie rod joint is on the line from king pin-to-rear end line.
 
I’m a retired Government employee. Close enough for Gov. work is 1) measure with micrometer 2) mark it with a piece of chalk. 3) Cut it with an axe. On my car I go for 1/16.
 
Just a few numbers to muddy the water.I had a 1976 1 ton Chevy crew cab. Got to having problem eating left front wheel bearings. Usually killed the spindle surface under the inner bearing. Would go get a wrecking yard replacement. After going through two spindles I got tired of worrying about being on the road without a spare. Went down to the Local Pontiac dealers parts department and pricing a new one I realized there wasn't that much difference in price so I told him I needed it. He pulls on up but it had a 3'4 Ton part number and cheaper then the 1 ton. Looked at it and it measures exactly as the 1 ton I brought with me. Come to find out they used the exact same spindle on a 1 & 1/2 ton trucks no matter what wheel base you had. So, to answer Neshkoro's question of
1/8” or 6”?

117.5 in (2,984 mm)
131.5 in (3,340 mm)
164.5 in (4,178 mm)

I do still have a 1 Ton single cab with a long flatbed and will measure the WB next trip home. Evidently GM wasn't to concerned about it. I drove both of those trucks like sorts cars with the current one being in the mountains. I have read in several road and circle track racing that the Ackerman length was moved both forward or rearward to make the car turn better depending on what they wanted to do. Just getting it close in all probability is close enough. Take this for what it is. Just more muddy water to filter though the confusion. Have Fun!
George
 
Just a few numbers to muddy the water.I had a 1976 1 ton Chevy crew cab. Got to having problem eating left front wheel bearings. Usually killed the spindle surface under the inner bearing. Would go get a wrecking yard replacement. After going through two spindles I got tired of worrying about being on the road without a spare. Went down to the Local Pontiac dealers parts department and pricing a new one I realized there wasn't that much difference in price so I told him I needed it. He pulls on up but it had a 3'4 Ton part number and cheaper then the 1 ton. Looked at it and it measures exactly as the 1 ton I brought with me. Come to find out they used the exact same spindle on a 1 & 1/2 ton trucks no matter what wheel base you had. So, to answer Neshkoro's question of
1/8” or 6”?

117.5 in (2,984 mm)
131.5 in (3,340 mm)
164.5 in (4,178 mm)

I do still have a 1 Ton single cab with a long flatbed and will measure the WB next trip home. Evidently GM wasn't to concerned about it. I drove both of those trucks like sorts cars with the current one being in the mountains. I have read in several road and circle track racing that the Ackerman length was moved both forward or rearward to make the car turn better depending on what they wanted to do. Just getting it close in all probability is close enough. Take this for what it is. Just more muddy water to filter though the confusion. Have Fun!
George
 
Slight Correction.
had a 3'4 Ton part number and cheaper then the 1 ton. Looked at it and it measures exactly as the 1 ton I brought with me. Come to find out they used the exact same spindle on a 1 & 1/2
Should be 3/4 Ton & 3/4

No excuse for using braille on a screen. Even Ray Charles knew that!
Ray Charles
 
Makes sense to me. I think you described it to be the Steering arm-to-tie rod joint is on the line from king pin-to-rear end line.

Very nice work! Very early dragster thinking, Just a bit stiffer in the frame rails I would suspect. Continue on Sir!
George
 
That looks pretty much the way I understand things should work. Its probably worth noting that you're "close enough" tolerance is probably pretty wide since its unlikely your going to be attempting any hard cornering in this car.
 
Also, don't forget to set any desired Toe before finalizing the Ackerman. A tiny bit of Toe-in might not be a bad idea for this car.
 

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