Wax the suspension.. Or how to find a crack in the K frame.

[dvw]

Oil pan is straightrned and welded. Leak checked it with air and soapy water. Then filled it with water for 3 days. All back on the car. My wife did an awesome job repairing the daiper. New wheelie bar is on. Went to wax the K frame. Thought I saw a piece of hair on it. Nope, cracked. It's trimmed up pretty good. The left lower control arm must have loaded it pretty good at the hit. Got it ready to weld. Waiting on a new gun liner for the welder. Then hope to test Wednesday.
Doug

 

[davek]

If its not one thing its another,glad you seen it.

 

[Wookie316]

Oil pan is straightrned and welded. Leak checked it with air and soapy water. Then filled it with water for 3 days. All back on the car. My wife did an awesome job repairing the daiper. New wheelie bar is on. Went to wax the K frame. Thought I saw a piece of hair on it. Nope, cracked. It's trimmed up pretty good. The left lower control arm must have loaded it pretty good at the hit. Got it ready to weld. Waiting on a new gun liner for the welder. Then hope to test Wednesday.
Doug

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Those cracks I tell you. Great catch.

 

[fullmetaljacket]

Oh gee is that scary. So glad you found it Doug instead of it finding you.
That's why I painted my cross member for the transmission white. As hideous as it is, I can most probably see a crack easier than on a black surface. This is why a multi-point pre-race check is essential.

 

[Tex013]

i know you do an ok wheely . But . Would that be a possible result of altering factory k frame ? I know you boxed and full welded plus use a engine pkate . But must be some body twist ?

Tex

 

[j-c-c-62]

i know you do an ok wheely . But . Would that be a possible result of altering factory k frame ? I know you boxed and full welded plus use a engine pkate . But must be some body twist ?

Tex

I would be curious where the crack first started, the vertical crack near the steering box would make me suspicious if it started there and migrated away. Cracking often is not a single occurrence in steel, it takes time and or repetitious overloading of the area. Welding repair alone will not likely make the repair area any stronger then original, and it should remain under close future scrutiny.

 

[dvw]

So this car has around 1050 passes. It goes up on the hoist 3-4 times a season. Yes the K is cut up. If you look close, all of the crack is on a weld area that was metal finished. It came down pretty hard from the wheelie.

 

[stage3]

Oil pan is straightrned and welded. Leak checked it with air and soapy water. Then filled it with water for 3 days. All back on the car. My wife did an awesome job repairing the daiper. New wheelie bar is on. Went to wax the K frame. Thought I saw a piece of hair on it. Nope, cracked. It's trimmed up pretty good. The left lower control arm must have loaded it pretty good at the hit. Got it ready to weld. Waiting on a new gun liner for the welder. Then hope to test Wednesday.
Doug

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on your new wheelie bars, why is the shock spring on the bottom where it cannot compress ?
i have a set of regular bars here that also have the springs on the bottom bars...

 

[j-c-c-62]

So this car has around 1050 passes. It goes up on the hoist 3-4 times a season. Yes the K is cut up. If you look close, all of the crack is on a weld area that was metal finished. It came down pretty hard from the wheelie.

The vertical crack is near what weld area?
Finish work to a stressed weld is usually highly frowned on in any performance application.
To be clear with my contention, long cracks are normally the resuly from many cases of high stesses over time. Single case overloading resulting in a crack often is accompanied alsp by obvious bending/distortion of the item.
The vertical crack I see is near the mounting point of the steering gear pox, which imparts a load on the K frame every time the steering wheel is turned, and additionally it is a constant reverse loading stress, first one way, and then the opposite way, like how one breaks a coat hanger by hand bending.

 

[fullmetaljacket]

So this car has around 1050 passes. It goes up on the hoist 3-4 times a season. Yes the K is cut up. If you look close, all of the crack is on a weld area that was metal finished. It came down pretty hard from the wheelie.

I could be wrong, but hear me out on this one. Perhaps the pinch shelves that everyone is now deleting are the actual points of stress relief for a factory K frame? When you think about it, the shelves or edges as they are called are perpendicular to the force amounts that are introduced when the car comes down, even on a graceful landing.
I could be wrong though.
1050 runs is amazing. Keep a sharp smart eye on that bad boy Doug. You are a treasure to our sport.

 

[j-c-c-62]

You are not wrong.

 

[dvw]

I agree that metal finishing could have a bearing. However this car has been raced 12 years without issue. Cage is all tig welded chrome moly. It also has 17 extra cage bars that are not required to run 8.50. As always it will be inspected regularly.
Doug

 

[fullmetaljacket]

I agree that metal finishing could have a bearing. However this car has been raced 12 years without issue. Cage is all tig welded chrome moly. It also has 17 extra cage bars that are not required to run 8.50. As always it will be inspected regularly.
Doug

It just might have been a one time fluke at best. Glad you found it.