k frame lightening?

[Badvert65]

OK, got a 65 Belvedere post car with a slant 6, Changing it over to a V-8 (440) over this winter. I have the V-8 K member and will be notching it for oil pan clearance (Moroso deep pan). Just wondering if anyone has done anything to their K members to lighten them. Current, stock, V-8 K member weighs in at 37.8 lbs bare. This is a bracket race car that will be driven to the track (no trailer, sigh..). I just plan to shave weight where I can since it is like free horse power. I will shave and deburr it, I figure a few holes here and there. Don't want to over do it for safety's sake. What have my fellow racers done in this respect?

 

[SUPERSTOCKRACER]

My 65 dodge is notched out and braced. I didn't hack my 65 Plymouth hemi k frame because its expensive to replace.

 

[Badvert65]

I will err on the side of safety as once it is in, I do not want to pull it back out. I wouldn't hack on a Hemi K either.

 

[SUPERSTOCKRACER]

was trying to find pics of the 65 dodge notched k frame but came up short. it is very safe and the notched out part is reinforced. ill get you a picture today some time. I also reinforced the steering box area and cut off the motor mount area.

 

[Badvert65]

Are you running a motor plate?

 

[SUPERSTOCKRACER]

Are you running a motor plate?

Yes, no need for motor mounts

 

[dvw]

Here you go. Flanges trimmed off and welded. Hole saw corners and connect the dots. I run a motor plate and lopped off the mounts as well. Been 150 drives straight as an arrow.
Doug

 

[SUPERSTOCKRACER]

well he beat me to it. guess I don't need to go get any pics. mines very similar. I go in the 8.90's with mine and straight as an arrow@152 mph.

 

[coloradodave]

Doug, Your work is incredible! Every time you post a picture of something on your race car I'm totally blown away by the execution and quality of the modifications. However, in a car that is regularly driven on the street, I'm wondering if the cornering side loads would have adverse effects on a cross member that was heavily modified for weight reduction. I'm not an engineer, just posting a thought...

 

[dvw]

The only thing I would upgrade for street is the bracing for the steering box. It's hard to see in the pic but mine does have 2 pieces of tubeing at 45 degree angles from the plate. By boxing the open cuts the K itself is plenty stiff between the rails.
Doug

 

[snakeoil24]

The K member looks nice how you modified it. For the street nix the idea and leave it alone. The steering box needs more support.

 

[tallhair]

Cranky has some exertise in this area as I recall

 

[glassman]

k-members

Check with John Holt Race cars in Columbus, Ohio. They have done one for our hemi Belv, and one for the hemi Cuda. Fine looking pieces, strong and light weight. 1-614-471-1022.............Tell them that Sled City Fiberglass sent you.

 

[66Satellite47]

I did the K member in my '65 Coronet post car very similar to dvw except I didn't notch it quite as wide, only enough for the width of the oil pan we ran (deepened stock). Worked just fine, I'd guess over 2000 runs at the strip. I ran solid motor mounts, no plate.
Side load is a concern if you take metal out. We put the car sideways one time & the K member did deform and got replaced. The less you take out the stronger. Aluminum struts would be a weight saving step.

 

[coloradodave]

I did the K member in my '65 Coronet post car very similar to dvw except I didn't notch it quite as wide, only enough for the width of the oil pan we ran (deepened stock). Worked just fine, I'd guess over 2000 runs at the strip. I ran solid motor mounts, no plate.
Side load is a concern if you take metal out. We put the car sideways one time & the K member did deform and got replaced. The less you take out the stronger. Aluminum struts would be a weight saving step.

This got my attention...

 

[dvw]

This got my attention...

Mines been sideways twice, once over 100 mph, not fun. But nothing moved. Hundreds of wheel stands. The secret is to box the bottom where the factory leaves it open. Look at the difference between the 3rd and 4th picture in my earlier post. Not to mention when the flanges were cut off the upper and lower halfs are completely welded solid instead of the factory spot welds.
Doug

 

[383man]

The K member looks nice how you modified it. For the street nix the idea and leave it alone. The steering box needs more support.

Myself I agree with this as my car is a street car that spends most of its life driving on the street and I honestly could not see lighting and maybe weakening my K-frame for maybe a tenth or two on a street car. But I also am not out to set any records just have some fun. Ron

 

[66Satellite47]

Mines been sideways twice, once over 100 mph, not fun. But nothing moved. Hundreds of wheel stands. The secret is to box the bottom where the factory leaves it open. Look at the difference between the 3rd and 4th picture in my earlier post. Not to mention when the flanges were cut off the upper and lower halfs are completely welded solid instead of the factory spot welds.
Doug

dvw, your setup looks incredible! No doubt filling the lower openings dramatically improves the stiffness for the lateral stress. Outstanding design & execution. I wasn't smart enough to do that. I welded the top & bottom all around too. Your quality is light years beyond mine. Keep showing us how it should be done!

 

[hangn0ut]

Reinforce the steering box mount. Because they move around A LOT! Thinking of an aluminium bracket to the frame rail.....

 

[funnykarman]

While building my 65 Coronet AFX I changed the steering box over to 16/1 for quicker steering input . I cleaned off the motor mounts from the K-member and will use motor plates . with the Hemi in the car the steering box would flex when turing left or right . so I used a piece of cardboard and made a template to cut out a piece of 1/8 inch steel , after welding it in I plated the top of the mount . This took care of any flexing problem ...