1964 C10: Something A Little Different

[kjimmy918]

What's up Pro Touring!

My name is Jimmy, and I'm starting to build a road race/hillclimb truck from my 1964 C10. This project has been in the design stage for some time now, and I just finished building the chassis. I figured this would be a good starting point for this thread.

Background: I've been surrounded by classic trucks my whole life (my dad has been building hotrods for a LONG time), and then I developed a knack for speed (and maintaining that speed around corners specifically). I first had the idea of building a full blown race truck about 3 years ago or so. Around that same time, I found the Pro10 C10 and Smokey F1 trucks. My plans differ from those builds, but those trucks gave me more inspiration to make a brick with wheels go fast.

As for my background, I'm a mechanical engineer. I think with what I've learned in school and helping my dad with hot rod projects since I was a kid, I have a good foundation for designing something with high performance in mind. I love using theories and math, and I'm able to use those with this project! That's a rarity in my job.

For the last year or so I've been designing the chassis and suspension, reading as many design books that I can, and putting a plan in place. Now that I've been out of college for a couple years, I have some funds to use toward this project. First up is the chassis.

CHASSIS
With the idea of a dedicated race truck in mind, everything I design needs to designed with the intent of allowing me to go as fast as possible. I designed the chassis to be as stiff in torsion as possible, while keeping the weight reasonable.

I ran a number of chassis configurations in Solidworks, eventually testing them using FEA software. To confirm my predictions, I 3D printed scale models and torsion tested them. The only thing that this physical testing proved was the effect of chassis geometry on stiffness. I wasn't designing for strength here. I think given the material, it will be plenty strong based on other race car designs.



The truck

The torsion testing fixture was basic, but gathered a ton of data. I fixed one end of the chassis, allowed rotation of one corner, and let the last corner move freely. I added washers as load to moment arm. Added more weight each time, measured deflection, and plotted the data. I was able to calculate stiffness values from here.

I ended up on a design that I liked and got building!

Main structure


Fixturing and welding kick ups


Some fitups and welding. I made 3D printed pieces to help me miter cut the tubes.



Done!

If anyone has questions about anything, I'd be more than happy to go into more detail!

[Sbeck09]

Nice approach to the chassis design with modeling and testing! I'm very interested to see how you package everything under the truck with all the braces.

What are the plans for engine, trans, and rear end?

[kjimmy918]

Thanks!

I designed the chassis this way because I have pretty big plans for aero equipment. The most important piece being an undertray to seal everything from the road. The drivetrain will sit on top of the chassis. I'll cut some of the tubes and box them in to reduce height to push the engine down.

My drivetrain plan is to start with an aluminum 5.3 (doesn't really matter which one), bore it to accept LS1-sized pistons, and drop a 4.8 crank in it. I really want something that revs to 8000 RPM's or more. I think this will be a cheaper way to do it. I don't have an exact blueprint of what parts are going to be in the top end, but I'll figure it out later on.

I'll run a 4 speed trans. Not sure which one yet. I think this will mostly depend on what deals I can get at the time when I'm trying to buy. Ideally, it would be a NASCAR style (G-Force, Jerico), but Midwest Muncie builds a 4 speed that can be shifted without using the clutch. A used Jerico runs about the same price as the Muncie, so it's up in the air.

The rear end will be a quick change. The rear suspension will be independent, and Winter's has a quick change for that application. I don't know what other companies make a quick change for independent rears, so if anyone knows of any, that would be helpful.

[kjimmy918]

Also, for anyone interested, I made a video talking/showing this stuff. It’s the first time I’ve ever messed with videography. Any feedback is appreciated!

https://youtu.be/spcmw_XPLyM

[77tony]

Really like where your heading...I'm in. T

[egoman]

Watching with interest. I too am a long ways into my build and have waited to start the build thread. I don't want to run out of material for several months while the winters here shut me down. I believe I have a 1 to 1-1/2 year posting lead right now.

[kjimmy918]

Here's a few updates on what I'm designing currently.

I'm trying to figure out the positioning of the subframe relative to the engine. I anticipate the engine being about halfway across the plane of the firewall. You'll notice in the pictures that the oil pan is interfering with the chassis. I will cut and box some of the tubes at some point, but I don't know what engine placement I can get away with (I will have a dry sump pan to minimize engine height).

Otherwise, I've been running FEA simulations to minimize deflection in the subframe. In the screenshot below, the subframe deflected ~.017" with a 1500 pound load at each suspension pickup. That's WAY more that what the subframe will actually see. There some places that I have not modeled gussets in yet, so I expect that deflection value to decrease. I might play around with the subframe's envelope a little more. In the event that I don't predict engine placement correctly, it would be nice to have some wiggle room.

Also, I plan to make the subframe from 1" X 1" X .065" steel tube for anyone who is curious.

[Sbeck09]

I'm interested to see how things workout with the 4.8 crank idea. I've been tossing that around in my head for a near future project.

Also, not sure if you had it for the simulations, but the control arm acts as a lever so it does multiply the suspension loads into the towers. I doubt it exceeds 1500lbs, but it's worth noting. Plus your highest loads are in the lower arms so the top doesn't have to be built as heavy. The only other thing to consider is down force. If you plan to go down that path, which it seems you will, that really ramps up the loads on everything.

Nice job on the video btw. I really feel like a slacker for not putting out any of my own now.

[kjimmy918]

Here's a force analysis showing some realistic values that the suspension pick up points will see. The drivers behind the forces are the upright distance between ball joints (pivot points) and the distance from the contact patch to the lower pivot point. To some degree, the greater the upright length (distance between ball joints), the upper pickup will see less force. There will always be a force balance so if one pickup sees less force, the other will see more force and vice versa.

Suspension arm length comes into play with forces acting on the spring and damper. But, the forces in the suspension arms and the reaction forces on the suspension pick ups are not affected by suspension arm length directly.

Also, the first two pages are analyzing one axle (only front or only rear). The last two pages look at one corner of the vehicle.

[Z06killinSBF]

^You forgot to carry the 7....

[langleylad]

Also, for anyone interested, I made a video talking/showing this stuff. It’s the first time I’ve ever messed with videography. Any feedback is appreciated!

https://youtu.be/spcmw_XPLyM

Great job ! I'm looking forward to more of this build. Beautiful welds by the way. Subscribed to your Youtube channel.

[FLYNAVY53]

Love the build! A suggestion for your motor... if you're looking for (relatively) budget big bore/ short stroke combo in an LS, I would recommend either a 6.0L block or 6.2L block with the 4.8 crank. As far as cost goes, you can probably find an aluminum 6.0L block and be $$$s ahead of the 5.3L aluminum block after you have it bored to accept the LS1 pistons (which is still a smaller bore than the 4.0 inch bore of the 6.0L block)

Really the best way to do it is de-stroke an LS7, but that gets pricey real fast. No matter what direction you go, you'll need a dry sump oil system to spin over 7K for any extended period.

[kjimmy918]

Great job ! I'm looking forward to more of this build. Beautiful welds by the way. Subscribed to your Youtube channel.

Thanks! I appreciate it!

[kjimmy918]

Love the build! A suggestion for your motor... if you're looking for (relatively) budget big bore/ short stroke combo in an LS, I would recommend either a 6.0L block or 6.2L block with the 4.8 crank. As far as cost goes, you can probably find an aluminum 6.0L block and be $$$s ahead of the 5.3L aluminum block after you have it bored to accept the LS1 pistons (which is still a smaller bore than the 4.0 inch bore of the 6.0L block)

Really the best way to do it is de-stroke an LS7, but that gets pricey real fast. No matter what direction you go, you'll need a dry sump oil system to spin over 7K for any extended period.

Thanks for the input! You definitely have a point with the bigger bore blocks. I just need to stumble upon someone selling a block by itself. I will be going with a dry sump. ARE makes a pan that only 2 inches deep, and that's what I'll run. Keeping the CG as low as possible is a priority. Sourcing the rest of the components shouldn't be problem (I'm going to get used stuff). There are pumps and tanks all over eBay. I'll need to give extra attention to whatever pump I buy just to make sure it is in working order.

[WallaceMFG]

Awesome work so far, those welds look great!

I've been wanting to so a similar project and design my owns chassis/suspension, just haven't had the time and right project come along. And I'm a little rusty in the statics & dynamics department lol

[jlcustomz]

Cool project. It's good to have someone with a schooled engineering background build something so others can just make theirs look similar & be in the ballpark of something great.
I'd like to have a destroked LS7 myself.
https://www.youtube.com/watch?v=V_P-sZ1D9N0

[FLYNAVY53]

With regard to the big bore, short stroke LS combo....I've done a bunch of research as I have a '64 Corvette that I'm building and have delusions of a 327 (-ish) cu. in. LS based, solid lifter motor to replace the number matching motor. I dont have my notes in front of me but I believe the 6.0L block with the 4.8 crank gives you something like 329 cu. in. Going forged replacement pistons and custom rods, you'd have a pretty stout bottom end. I think the same set up with the 6.2L block and pistons gives you something like 332 cu. in. Theres a company called Cam Motion that specializes in solid roller lifter cam set ups for LS and LT motors. If you get deep into the google machine, its been done before a few different ways. Again, the most effective is to de-stroke an LS7, but that is big money. I personally really like the 6.0L block and 4.8L crank combo with a good set of off the shelf AFR heads and a properly spec'd solid roller cam. In my project, Im going for throttle response and driving characteristics over all out horse power.....think LS based DZ302. Anyway, I've rambled on enough.....looking forward to the updates!!

[langleylad]

Cool project. It's good to have someone with a schooled engineering background build something so others can just make theirs look similar & be in the ballpark of something great.
I'd like to have a destroked LS7 myself.
https://www.youtube.com/watch?v=V_P-sZ1D9N0

That thing sounds like an F1 car ! awesome !

[Sbeck09]

Actually there is 2 big reasons why the LS7 is the preferred choice for destroking. 1, is the larger bore size like everyone has pointed out. 2, is arguably more important since it's for the internal dry sump oiling. When you spin these engines up that high (7,000 or more) for very long you quickly run into issues with windage and sucking your oil pan low. Obviously you can add an aftermarket dry sump to any LS block (like the OP plans to), but that can be too expensive for some. Personally, I would probably choose the LS3 block to destroke with a good dry sump system since it's a good strong foundation and is around $1,000 less than an LS7 block.

Speaking of Cam Motion...I have a custom solid roller cam from them in my SBF for my truck. I had to do that to allow me to rev to 7k rpm. The LS7 lifters fit any LS block and have been proven to work fairly reliably up to just over 7,000 rpm and aftermarket options like Johnson will reliably go a little north of 7500 rpm. Any competent engine builder will already have a solution in mind though.

[kjimmy918]

Quick update..

I've been doing more design, and trying to lock down the suspension components. I've also been working on fixture design.

With the current geometry, I can get about 32 degrees of steering angle at full bump/droop (+/- 3 inches). It is definitely overkill because full bump/droop with full steering lock would never happen during a normal driving scenario. However, wiggle room is a good thing just incase I miss something during the design phase.

If anyone out there needs ideas for how to fixture components you want to build, check out Mitee Bite or Carr Lane. They have a ton of fixturing devices (mostly for machining), but you can find ways to make them work. I also didn't know this kind of stuff existed until not too long ago. These kinds of tools can be a huge help, and knowing they exist can yield better ideas for manufacturing.