Rod C's Ohio RCR40

Randy Folsom

Supporter
My spider does not fit to the cage for crap. It is not symmetrical from right to left. I was afraid the spider was way off, but took to measuring the cage to the chassis first.
(1) The two overhead front to rear bars of the cage are shifted towards the driver and are not in the center of the chassis.
(2) My front hoop has a bit of fore/aft curve along the top "straight" part, especially on the passenger side
(3) Passenger A pillar cage point is more outboard on the bracket while the drive A pillar cage point is centered in the bracket.
(4) I needed to trim the spider at the bottom of the A pillar due to cage interference.
What is really odd is the overhead bars are shifted toward the driver while the front hoop of the cage seems to be shifted toward the passenger side of the car. I do not believe any of this is the end of the world or has any functional impact. It certainly does not look right from the front of the car.
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Rod,

I decided to cut off the front hoop and move the rear hoop behind the FW. There were just too many challenges with retaining the front hoop and many advantages to moving the rear hoop. I am retaining the ability make and install a front hoop, but it will be significantly different.

If you want I can share the plans for the rear hoop I made in Fusion 360.

Cheers, Randy
 

Randy Folsom

Supporter
I started body fitment with rockers and the spider. The edge of my rockers was far from horizontal when placed on the chassis and even further from being flat.
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I tried to heat and adjust with no success. I decided to remove the edge and glass in 1 1/2 x 1/16 aluminum bar. I fixture this to be parallel with the bottom edge and straight/flat. I figured the aluminum would make for a stronger top surface for mounting, body pins, etc. I have some gaps to fill and body work to do, but overall they cam out looking pretty good.
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I will attempt to fit them to the car this evening.
Rod, I found the same issues with the rocker panels. I was planning to use fiberglass mat to correct the edge. I like the idea of using aluminum but I am concerned that the aluminum might expand differently than the fiberglass when heated by the sun and result in cracks. No idea if this is something to worry about. Cheers, Randy
 

Randy Folsom

Supporter
I put my roll cage back on, along with the rear bulkhead. When I tighten everything down, the bulkhead 'bar' between the rear window and lower bulkhead access panel would bow, quite a bit, more than an inch. I tried to slot the bulkhead between the front and rear cage connection with no success. I then noticed the trailing rod connection covers by the rear bulkhead stuck into the cabin past the bulkhead. There was no way I could have installed the lower access panel. The rear bulkhead was out of whack once all connected. If I removed the screws at the bottom of the bulkhead into the tub I could get the bow to go away and maybe get the lower access panel to fit. I have installed a 3/8 thick spacer along the edge of the tub where the rear bulkhead connects. Everything fits a better now.
I am terrible at taking pictures as I go. I will add a few pictures here to help every see what I am talking about.
Rod, I removed the trailing rod end covers. These cars have been around for a very long time and I have never heard of anyone getting speared in the back. Those covers were recently added. If you want to retain the safety aspect that those covers are supposed to provide, you could just rivet a square piece of 1/8” steel plate on to the back of the seat. I mentioned earlier that I am moving the rear hoop behind the FW. One of the advantages is that the hoop foot no longer goes below the bulkhead so the FW can sit about 1/8” lower. I slotted the six lower mounting holes to make that happen. Cheers, Randy
 

Randy V

Moderator-Admin
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I continue to plug away putting this car together. I have my fuel tanks installed and bolted down. Nothing real exciting there.
I have installed the suspension, front and rear, set everything back on the ground and dialed in the alignment fairly close. I do not have a steering rack yet, so setting front toe is not possible, which makes a wheelbase measurement not quit accurate. Currently I am setting around 95 3/8 on both sides. I could bring the rear in a bit since my lower trailing arms are threaded out a little (few turns). See my first concern below as another potential to shorten wheelbase.
I have few areas of concern I hope others may be able to help me with.
1.) My fronts are not set with bottom A-arm to the front and top A-arm to the rear. My tops are toward the front and bottom are towards the rear. This has given me 5deg of caster. I would have to figure something else out to reduce the caster. This is opposite of most of what I have read.
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Rod - If I read you correctly, you have the shims reversed on your front control arms.
The lower control arm should be shimmed all the way forward (toward front of chassis)
The Upper control arm should be shifted toward the rear of the chassis.
ultimately, you’ll want +5° to +6° (positive) caster.

Setting toe without the rack is possible, but you’ll need to fabricate something to connect the steering arms to.

Remember that your alignment should be done at finished ride height - that’s generally when the lower control arms are level to the ground. This is true for the rear also..
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
My spider does not fit to the cage for crap. It is not symmetrical from right to left. I was afraid the spider was way off, but took to measuring the cage to the chassis first.
(1) The two overhead front to rear bars of the cage are shifted towards the driver and are not in the center of the chassis.
(2) My front hoop has a bit of fore/aft curve along the top "straight" part, especially on the passenger side
(3) Passenger A pillar cage point is more outboard on the bracket while the drive A pillar cage point is centered in the bracket.
(4) I needed to trim the spider at the bottom of the A pillar due to cage interference.
What is really odd is the overhead bars are shifted toward the driver while the front hoop of the cage seems to be shifted toward the passenger side of the car. I do not believe any of this is the end of the world or has any functional impact. It certainly does not look right from the front of the car.
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Rod -
You’re in the process of realizing that you’re trying to attach a non-symmetrical body to a perfectly symmetrical (CNC) chassis. Most of us that have built these cars struggled in the same way.
I would advise that you remove the windshield and store it in a safe place.
Take the bolts out of the roll cage and just let gravity keep track of it for now.
Get your alignment done and wheelbase set to ~95”
Wheels on and set to ride height (lower control arms parallel to ground)
Put the spider in place (no screws)
Put the sills in place - held with tape
Put front and rear clams on the chassis
Adjust the rear clam to have the wheels centered in the arches.
Adjust the front clam to have the wheels centered in the arches.
Note - clams should be spaced up 1/8” from sills
Slide the sills fore/aft to align with the clams
Move the spider fore/aft to get a tolerable fit with the clams.
Set doors in place with tape.
You should be able to get a good read on cage fitment at this point. Noting that the factory holes are not necessarily perfect or permanent.

Reassess the fitment.
Note that you should have weather stripping in place when final fitting of the doors and rear clam.
Note also that sometimes it takes a bit of sanding on the edges and corners of 5he windshields to make them fit properly. Don’t do this right away - wait until the fitting of the doors is nearing completion..
 
Randy V - Thank you for the replies and information provided. I am going to go back to the alignment and verify everything, then move along with body placement again, primarily just to triple check everything to make sure I am headed in the right direction.
 
Randy F - I am fairly jealous at the speed you are moving along with your RCR. I am not even going to attempt your pace. Thanks for the input and advice. I am going to take a few steps backward in hopes it will improve my steps forward in the future.
 

Randy Folsom

Supporter
Randy F - I am fairly jealous at the speed you are moving along with your RCR. I am not even going to attempt your pace. Thanks for the input and advice. I am going to take a few steps backward in hopes it will improve my steps forward in the future.
It getting hot here in Austin. I will be slowing down for sure.
I continue to plug away putting this car together. I have my fuel tanks installed and bolted down. Nothing real exciting there.
I have installed the suspension, front and rear, set everything back on the ground and dialed in the alignment fairly close. I do not have a steering rack yet, so setting front toe is not possible, which makes a wheelbase measurement not quit accurate. Currently I am setting around 95 3/8 on both sides. I could bring the rear in a bit since my lower trailing arms are threaded out a little (few turns). See my first concern below as another potential to shorten wheelbase.
I have few areas of concern I hope others may be able to help me with.
1.) My fronts are not set with bottom A-arm to the front and top A-arm to the rear. My tops are toward the front and bottom are towards the rear. This has given me 5deg of caster. I would have to figure something else out to reduce the caster. This is opposite of most of what I have read.
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2.) My front driver side suspension is noisy. It squeaks with up and down movement. I did get in the tub and grind away some weld ends and interference to improve the connection for the top A-arm brackets. They were not sitting flush due to interference inside the tub with welds and such. Improving these mounting surfaces did not help. Could this be because everything is not torqued to spec yet? Specifically the lower A-arm bolts inside the tub?
3.) The lower trailing rod connection is really close to the rear wheel. I am concerned with any in/out movement causing this connection to cut a rear tire. I do not want to cut a rear tire. Should I worry about clearance here? How much clearance should I have?
Picture here shows the area I am describing. I will post a picture of the actual gap later today.
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4.) I tried to keep the trailing rod connecting brackets at the rear tire 'vertical'. This made it difficult to connect everything, so I let the rotate a bit. Should I worry about these being vertical, or just let them rotate as long as they do not bind? Again, picture to show the area I am describing.
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I am beginning to set on the body & will post about how that process is going.
Rod,
My car’s wheel base is 94.75”. If my limited research is correct, original car’s wheel base is 94.5”. So my wheel base is just a bit too long. I still have one washer on the back side of the aft LCA so I can move the front back 1/16” but the turning radius is already quite limited because the tire hits the fuel tank cover. The lower Hiem joints are inserted 9/16”. The minimum is generally considered to be the diameter of the bolt (5/8”). I have about 1/16” of thread left at the UCA so I might turn both top and bottom in another 1/16”. That will also shorten the wheel base, but not very much.
At the back, I don’t have much thread left on the trailing arms, they are just about fully inserted. I might have enough to bring the rear wheel forward 1/8”. I have the longer control arms that go with the +2 flares so your situation might not be the same.

The lower link bar mount is indeed very close to the tire. I rotated the mount for a bit more clearance. I removed the shock and moved the suspension full travel to ensure no binding of the Hiem joint and then tightened the bolt.

Hope that is helpful. Cheers, Randy
 

Paul Proefrock

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Randy,
The SAE papers submitted by Ford and the FIA papers from F.A.V. both show the wheelbase to be 95" (2413mm) - You're just a bit short. If you need copies of the documents, let me know

Paul
 

Neil

Supporter
It getting hot here in Austin. I will be slowing down for sure.

Rod,
My car’s wheel base is 94.75”. If my limited research is correct, original car’s wheel base is 94.5”. So my wheel base is just a bit too long. I still have one washer on the back side of the aft LCA so I can move the front back 1/16” but the turning radius is already quite limited because the tire hits the fuel tank cover. The lower Hiem joints are inserted 9/16”. The minimum is generally considered to be the diameter of the bolt (5/8”). I have about 1/16” of thread left at the UCA so I might turn both top and bottom in another 1/16”. That will also shorten the wheel base, but not very much.
At the back, I don’t have much thread left on the trailing arms, they are just about fully inserted. I might have enough to bring the rear wheel forward 1/8”. I have the longer control arms that go with the +2 flares so your situation might not be the same.

The lower link bar mount is indeed very close to the tire. I rotated the mount for a bit more clearance. I removed the shock and moved the suspension full travel to ensure no binding of the Hiem joint and then tightened the bolt.

Hope that is helpful. Cheers, Randy
Does that 1/4" wheelbase difference really matter?
 
Does that 1/4" wheelbase difference really matter?
My “original” skin sill covers were about 1/4” different in length from side to side as well as the non symmetrical dimensions of the front and rear clamshells. I would make the alignment and thrust angle correct to the recommended specifications and be less concerned with the original wheelbase possibly being slightly different which can be made unnoticeable when adjusting the body and gaps.
 

Randy Folsom

Supporter
Randy,
The SAE papers submitted by Ford and the FIA papers from F.A.V. both show the wheelbase to be 95" (2413mm) - You're just a bit short. If you need copies of the documents, let me know

Paul
Paul, Thx much. My very limited research was Tom’s build log. I agree with what others have mentioned about prioritizing making it fit and not fretting over a 1/4”. I am actually hoping I will need to move the front forward so as to provide a bit more clearance to turn the front wheels. Just 1/8” could make a difference. Cheers, Randy
 

Randy Folsom

Supporter
My “original” skin sill covers were about 1/4” different in length from side to side as well as the non symmetrical dimensions of the front and rear clamshells. I would make the alignment and thrust angle correct to the recommended specifications and be less concerned with the original wheelbase possibly being slightly different which can be made unnoticeable when adjusting the body and gaps.
Agreed. Thx much.
 
An update on how this is going, it has been a while & I have done a few things.
The plan to use aluminum bar in the rockers did not work out. I rebuilt them with fiberglass and filler, which took some time. But I now have flat rockers to work with.
I have begun hanging the body. My alignment is pretty good, checked over and over. Ride height is pretty good, checked over and over. I do not have a steering rack yet, so toe is not right, but not too far out of wack.
I started with the front clip, fairly well centered on the wheels and side to side, then rockers, fore and aft, side to side, then rear clip.
I then moved these three parts around until I hade pretty good fit all around. One has to be able to live with a little give and take here. As many have found and shared, the body is not square or symmetrical.
Once I got things where I liked them, I hinged the rear and built hinges for the front.
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I fiber glassed and bolted aluminum plates in the front clip. I built some adjustable mounts with heim joints in the front to attached the front clip.
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I started with aluminum angle mounts, but have changed them out to steel for the extra strength. It pivots well and returns to the right location when laid down, so all is pretty good. I installed the locater pins and need to think about the clasps behind the front wheels. I am planning on installing hood pins up top for additional support and location of the front clip.
Next up, getting the doors on. I am going to remove the roll bar and rear bulkhead while I work on the doors.
 

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Before I took the cage off, I took some more measurements.
The overhead bars are certainly not centered. The passenger bar is 2.5 inches closer to the centerline of the car and the centerline of cage than the driver bar.
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The driver side front hoop top corner is 3/4" further inboard to the centerline of the car than the passenger side front hoop top corner.
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The driver side front hoop top corner angle measured 124 deg and the passenger side measured 119.3 deg.
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This shifts the front hoop toward the passenger a bit, causing the 3/4" measured shift toward the passenger in the front hoop. The lack of symmetry in the front hoop is not large enough to explain why the two top bars are so far off center.
The rear hoop is much more symmetrical, square and flat.
There is not much I can do to square the bends of the front hoop, so they will likely stay as they are. I will likely cut out the driver side top bar, shift in inboard and reweld. This way to two overhead bars are centered in the car, fit within the spider overhead & give good clearance for my noggin'.
I am putting this aside for now. If someone thinks I am missing something or not understanding why the cage is as it is, please chime in.
 
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I attacked the door hinges in several ways.
I went with one long bolt instead of two short ones. I installed brass bushings in the hinge brackets that attach to the car, pressed in from the inside to tighten the space to the door.
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I installed a tube between the top of the door to the bottom of the door for a complete inner lining.
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I slotted the attachment on the car for for and aft adjustment. This along with the slots in the hinge bracket provide hinge movement to get the doors aligned. I am using doublers in the car to strengthen the hinge attachment, especially with all of the slots. I did have to create some spacers to move the hinge brackets outward for better alignment.
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Next I dug through all of the boxes RCR sent me 5 or 6 times until I found the bear claw latches. I was expecting a bigger box!
I cut a slot in the door and slid the bracket through the slot and mounted the bracket outside the door. I really like the way they turned out. I may add some fiberglass in the door to the bracket for added strength, but it may not be necessary. I may just calk the gap shut or use body filler to clean it up a little.
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Like many others, there was no way I was going to attempt to mount the door handles via a drilled hole in the fiberglass. I have no idea how I would have even drilled the hole with such little space! So I cut out the handle opening and fabricated adjustable mounts that I will epoxy and fiber glass into the door. Slots are our friend when it comes to adjustability! These will allow me to adjust fore and aft to center the handle in the opening, as well as in and out to get the handle flush with the door. At least, that is the plan!
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Also like several others, my RCR passenger door is a wreck! the inner front corner is way deep while the rear is way high. I will be applying weight, heat and shims in an attempt to square this door up. The driver side door is pretty good. It has a little warpage, but my heatweightshim tool seems to have gotten it corrected.
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