C20

[Thomo5150]

Hi from downunder, I'm building this C20 with a few different things added.

Had to travel 7000 miles to pick it up!!! I live in Perth the C20 was in Sydney Australia...........

Loaded for the trip back across Australia.



Unloaded back at home, this is a factory RHD cab





Stripped Cab sold the motor, gearbox and diff...







The last owner had good taste in music found this CD in the glovebox...









Setting up the chassis jig, anyone guess what the drivetrain will be???











Sorry for all the pic's, but sometimes they are better than words.....

Cheers Tim

[Remon.]

Super cool project! RHD square is awesome.

Drivetrain out of a c6 corvette?

[Thomo5150]

Originally Posted by Remon.

Super cool project! RHD square is awesome.

Drivetrain out of a c6 corvette?

Close, its mainly 2004 ZO6 C5. The torque tube is legthened with a Carbon fibre drive shaft. Suspension and the Steering rack is custom Flamming river with Pfadt coilover shocks. I was looking at shorterning the wheelbase to suite a stepside or short bed fleetside. Because of the suspension and its ability to carry no weight, I've desided to shortern the chassis to a Blazer wheelbase and fit Blazer side panels to give it this kind of look. ( sorry for the poor photo shop)



To get the Body lines rite a 2 to 3 inch top chop is on the cards and 22 inch rims will be fitted with 28 and 29 inch diameter tires

I should have the chassis cleaned up and shorterned today and sitting over the Vette drivetrain.

Steering rack.

[BP87GMC]

Well, that's just gonna be all around awesome.
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[tinydb84]

Nice to see another C20. That is going to be badass

[Thomo5150]

Spent the weekend grinding the frame, its now at the Blazer wheelbase. I've split the frame from all of the crossmembers to weld the front and rear rails together. Plan for this week, finish welding and cleaning the rails then re square the frame fit it to the chassis table then fit the Cab. There is no clearance issues with the gearbox and frame crossmembers.......



Oh and a Garage clean..........

[Thomo5150]

More progress....

I turned the frame on its side an bolted the front and rear sections of frame together. By cutting the frame at the centre of the rear cab crossmember it is very easy to reassemble.

Frame joined, you can see the 3 crossmember hole in the right side of the frame



Bolting in the crossmember



First hole drilled on the rear of the frame



Because 25 inches was cut from the frame it does tapper in on the rear section, by jacking and using a straight edge the rear was squared again there is a 3mm tapper in the rear frame section added....

Passengers side



Drivers side



The frame wont be welded till its back on the chassis jig and squared and set at ride height with is 6 inches to the lowest part of the frame under the cab....

[rusty76]

Too cool.

[mooseknuckles]

cool build!

[Thomo5150]

Frames on the table, now trying to set ride height, and start to fab crossmembers. As you can see from the pic's going the Blazer wheelbase just allows the transaxle to clear the back of the cab.






Still alot of sanding and grinding to do on the frame. Trying to do a simple swap that anyone could copy. There is alot of research in this project, on the Pro Touring and Lateral G forums they say the C10 trucks are the new Camaro!!!! Now lets make em handle better than a Camaro.............

Cheers Tim

[Thomo5150]

This is where I am, need to go back to work for a week. I'm still working out the ride height, problem is my Cab is stored else where so I can't place it on and check things. The drivetrain is in, it needs to be lifted at least 2 inches but you should get the idea of how this will work. The firewall will need to be recessed I have the motor set back where a normal LS engine would sit in one of these trucks....

Ground clearance for the sump is only 4 inches atm...



Frames lowest point is set at 6 inches, this may change....( Please feel free to comment on the height, I have never owned one of these trucks its all a learning curve for me



Started adding threaded rod between the frame rails to help square and hold the frame before final welding...

[Remon.]

This simply is a super build! You are doing a great job and I'm definitely going to follow this ons.

[Thomo5150]

Thanks for your support Remon.....

Ok ride height is sorted, looks like I planned this well, everything is working out OK, heres what's happening.

Ride height will be left a 6 inches lowest point, here's a mock up pic...( Note the engine and torque tube needs to be raised 2 inches in these pics)





Best news is with the drivetrain raised, it places the torque tube level with the top of the rear cabs crossmember which means I won't have to chop any sheetmetal on the back of the cab......





Reference pic shows I'll just have enough room for the shifter rod...



You can see the shifter rod in this pic...



Looks like this part of the foor will need to be cut for the torque tube...



Another bonus is the firewall will need minimum mods for the engine, it is very close to fitting with out mods....







Sorry for all the pic's guys, but these help me alot, when you study them many problems can be sorted before the oxy or angle grinder comes out.

So it looks like a Corvette drivetrain can be fitted to a standard framed square body truck....

Next on the list is crossmembers, this is were the fun begins, please enjoy...

Cheers Tim.

[Thomo5150]

Probably best to explain suspension and crossmembers. I've kept the factory cradle on the rear for a few reasons. First its very simple to remove the trans for service or to replace a clutch (A few miss this point with custom frames and tubes every where they sometimes forget how am I gunna pull this out) Remember with the Corvette ZO6 C6 it has 325 tires and a 12 inch wide rim so fitting these under the wider C20 rear quarters is not a drama.

Front suspension is different, I've gone a narrower track than the C5 Vette, reason being I want a dish rim with a wide tire under the front hopefully a 285/25/22. Because the frame of the C20 trappers in at the top mounts, my crossmember will be designed as a 1 piece bolt on with the top and bottom A arms fitted to it. The engine is set back behind the front axle centerline so I don't have to buy $1000 custom drop steering knuckles, my steering rack stays at the C5's original position. Heres some mock up pic's of C5 suspension.







Using a 22.25" pivot point the C5 mounts are in the way so custom mounts will be fabricated



Front axle center line will be changed to even the look of the 22" rims under the front fenders

[Thomo5150]

Working out measurements for the front crossmember using Corvette C5 clip to help...





Using fixed lower arms I now have to work out how far to bring the top contol arms in to allow for camber adjustment.







Corvettes 26 inch pivot point. New crossmember brings this into 22.25 inches.





cheers
Tim

[Ziegelsteinfaust]

Sounds like a way cool project.

Hows the track width of a C20 vs the Corvette?

I put a Crown Vic front end under my 66 F100, and that was my big mistake. All said and done I couldn't out turn a Big Rig. I got a new frame last month, and I am starting again here again.

[Thomo5150]

Final track width won't be known until rim size is sorted, the lower control arms are almost 4 inches narrower than factory C5.

I'm not sure about the crown vic suspension it's stuff we don't have in Australia. Did you move the crowns crossmember to centre the rims in the front guard? I have done a 76 F100 chassis using the C5 front and rear cradles, it was a lot harder than the chev but it can be done. I've still got the chassis in storage I mite fine a non rusted dent cab to finish it one day......
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[Thomo5150]

Spent today doing final tweaks before I start on the crossmembers.... Ride height is done, everything starts to line up perfect.......

Motor and drivetrain at height and centred.




Exhaust clearance both sides....







This is the start of the center or gearbox crossmember... 2 inches will be sectioned from the center to give the torque tube clearance, then sectioned at the bottom for the cats to clear. If my planning is rite the cats will sit just above the bottom of the frame....



with the exhaust bolted up the cats will tuck into the center crossmember giving it a clean look under the chassis.....

[Thomo5150]

This is a warts and all build, happy to share mistakes and boy did I make one today.................

Started marking and cutting out the center crossmember
( Note Old Skool build basic tools )


Got the shape of the crossmember done then drilled holes and punched them out to be dimple died. In this pic the holes been punched no drama's. I then thought to myself I shouldn't dimple the hole till I have added the top and bottom plates and gussets to strengthen the crossmember......

Got a phone call, went back to the shed, for some reason I picked up the dimple die and punched the crossmember with it. Instant fail the pressure distorted the metal and just wrecked 2 hours of work....



At least with the exhaust bolted up the cats are tucked up near level with the bottom of the frame.....

[Pop's C-10]

this is great

[Thomo5150]

Cheers Pop's


Started the front crossmember today, using 2 bits of L angle bolted together

Left and right holes are for the lower control arm.




Drilling out the holes to 25mm




shaping the lower edges of the crossmember ( upside down in the pic)




Clening up ready to section the top part of the crossmember...




This is a hand built project, yes I could get in the car drive to a Lazer cutting place pay money for a design to be cut and then bend the steel up. Leaving me to tack and weld them together....

Done this before, most of the time it took 2 weeks to get something done and then most of the parts made were wrong anyhow. This time I'll save time and petrol and do it like my Grand Dad use to build things, by hand.

[Thomo5150]

More crossmember design...........



Trail fit of crossmember.



Checking the balancer clearance.



Crossmember cut out and the 2 halfs clamped together.



Trail fit.



Lower control arm fitted ( not in postion cause of the engine mounts stopping the arms from moving further back)



Hitting the engine mount, trail fit so wasn't going to unbolt the mounts



With the lower control arm in the rite position there will be enough clearance with the crossmember.



Quick mock up to showing how the top arms will look when the side plates are added to the crossmember.









Results from the days work!!! Start again. The crossmember will change from 4 inch to 5 inches in length, it has to be narrowered down from 900mm to 850mm. Also the weight, I can afford to step up from a 3mm to 5/6mm thickness, the weight will still be half of the factory crossmember. Instead of L angle steel the next crossmember will be shaped out of 150mm x 150 mm (6" x 6") box steel. This will be easier to shape....

So did I waste time doing all of this? NO!!! This is a one off design, things will need to be reworked and changed. As I said this is a real world build, I'm over seeing project with A pic B pic and everything fits and the builder pretends its all straight forward. I'm happy to show problems / rework, to help others looking or thinking I can build something like that.....

After all I'm just a simple Truck driver with a gimp hand, if I can do this anyone can or should try......

[Mike Bradbury]

Looks good so far, Im along for the ride.

[Thomo5150]

Updates.................

Picked up some steel for crossmembers today.... 6 x 6 inch for the centre crossmember and 5 x 5 inch for the front....

Precision cut at Di Candilo Steel.....





Cleaning the frame rails.



Tweaking the rails before I weld them together.





Found by standing the frame rails up right and placing a jack under the cut it was easy to line up.





Rails are square.





One welded together, full day tomorrow should get some work done.......

[Thomo5150]

More work.....

Started marking out the centre crossmember....



Next was the front crossmember.....



Drilling for the lower control arm





The old saying comes into play here, measure 10 times and drill once...

Tubes are square, only drilled with a hand drill, as I've said Old Skool build...





Welded the other frame rail together today spent 1 hour measuring both rails at different points got it exact.... Pic shows using body holes for reference points.



Called an early day my hands not working to well, this should explain why. I fell off the back of a Semi trailer a couple of years ago. Result shattered both wrists, fractured skull broken toes and shattered 2 bones in my right hand. My right hand basically doesn't work, I've got some cool Titanium parts in my body though....



Hopefully I should finish the crossmembers this week and have the Cab mounted....