Mounting an Early Chassis on a Rotisserie

Britain Smith · 01-16-2004, 03:34 PM

I have a '69 chassis that I want to mount on a rotisserie this weekend. All the cars that I have seen up on rotisseries are late '70s and 80's 911 and are mounted using the bumber shock mounts. The only problem is that my early car did not have bumber shocks and was not as heavy reinforced in these areas. Am I going to have any issues mounts it in these locations? Does any else have any better ideas?

-Britain

Britain Smith · 01-16-2004, 05:57 PM

Does anyone have any thoughts on this one?

-Britain

boston95 · 01-16-2004, 06:04 PM

I was ask Damon (Series9000) or Jamie (jpnovak). These guys rock...

unimog · 01-17-2004, 10:20 AM

I can't say for sure for 911s but us 356 guys pick-up on the swaybar mounts in the front, and the transmission hoop mount or torsion bar mounts in the rear.

Zeke · 01-17-2004, 11:45 AM

The rear bumper bracket mounts are part of the sub frame. Should be strong enough. In the front, I'd pick up the front a-arm mount plus on other point on each side. The front panel alone looks too weak, but the front arm mount is not enough by itself, IMHO. One way or another, youre going to need some custom mounting brackets.

The whole length mount under that 356 looks great! Can't go wrong with that.

Britain Smith · 01-17-2004, 12:14 PM

Yea, I agree with you on the front not being strong enough...that is the main reason why I asked about it.

Do you think that the front a-arm mount is not strong enough either? I was thinking that I could take a set of used a-arms, cut-off the traiangle part that goes to the wheel, and weld a support to it from the rotissere. That would pick-up both front suspension mounts.

My early car has the weight advantage of not having all the crash protection but is not as strong.

-Britain

Chuck Moreland · 01-17-2004, 12:39 PM

Except you'll probably be pulling off the suspension crossmember, and losing your rear mounts in the process.

Make a bar that bolts to the front suspension mount, and the crossmember mount. It will be plenty strong and easy to make. Just a straight chunk of box-section with two bolts through it.

The front of the car is very light once it is all stripped.

rcm · 01-17-2004, 12:48 PM

I'll try to get series 900 to chime in. I believe he built his own. He has any early car on it right now.

Britain Smith · 01-17-2004, 03:36 PM

Thanks for all you help.

I will be getting a rotissere for a 914 on Monday. I just need to make new mounts for a 911 body to fit into it. I will take some pictures of the different areas I am thinking of mounting it to today and put them up here for everyone to look over.

-Britain

Zeke · 01-17-2004, 04:34 PM

Quote:

Originally posted by Schmuck69
Yea, I agree with you on the front not being strong enough...that is the main reason why I asked about it.

Do you think that the front a-arm mount is not strong enough either? I was thinking that I could take a set of used a-arms, cut-off the traiangle part that goes to the wheel, and weld a support to it from the rotissere. That would pick-up both front suspension mounts.

-Britain

I think we are all talking about the same thing using different terms. Yes, by bolting to both front suspension points on each side, you should have enough. And Chuck's way of going about it will save a set of a-arms. I was referring to a different style of bracket that might pick up the front bumper mount and the first a-arm mount in an 'L' type of fashion. But I didn't say it. Lots of ways to do it, just need at least two bolting points for each corner.

Axis11 · 01-18-2004, 07:59 PM

Just movin this to the top, as i'm looking to do the same and am
curious as to what mount points to use for an early car.

Britain Smith · 01-19-2004, 09:07 AM

Alrighty...its a new week, can we get some more info on this?

-Britain

Series900 · 01-19-2004, 02:19 PM

69-73 front bumper mount holes on the body are plenty sufficient. the rear bumper mounts pose a problem in that the front bumper hole is very tight to the pinchweld, therefore a beefy bracket is hard to fabricate and drill for mounting purposes. I made up mounts from plate and 2" tubing that bolt into the rear engine mounts, they drop the roll center below the rear body panel, and then bolt to the arms of the rotiss. 65-68 front bumper mounts are spot welded on, made brackets to fit these also. these can be weak and deflect with body weight when rusty, Just add a piece of metal from the front of the bulkhead to the arm, and cutoff when done. Utilizing any of the front suspension mounting will require additional welding of the brakets to come out and up, unless you want a very top heavy car. Think about roll center... I will take some pics of my brackets, email me at series900@nhvt.net

Series900 · 01-21-2004, 07:51 AM

front mount on a 69-73 chassis

early car on rotiss with large angle brackets bolted to bumper mounts which then bolt to the 69-73 brackets, thus versatility of years. if the bumper brackets are weak, a temporary plate can be welded from the bulkhead to the angle iron or just blow 4 holes into the wheelhouse and utilize the 69-73 brackets

rear bracket and jig, fits all years

I built this rotisserie for 356's years ago...

collier · 01-22-2004, 07:18 AM

I have a question regarding these Rotiss mounts.

I think that once you have mounted the front, and mounted the rear to your rotis stands, the "plane" or line of rotation will not be in the same line...so does this mean that you must make a 'step' mount for the front, so that you can lower it down to match the mount in the rear?

I would think that this would be necessary in order to get a smooth axis of rotation???

Am I way off?

chris

Series900 · 01-22-2004, 08:23 AM

No, you are not way off, nor are the brackets from roll center. I never measured for perfect center, yet I have no major bind. Now that I think about it, both the front and rear mounts are in a center, think about where the bumper mounts are, then translate that to the deco strip. This is a datum line for roll. It may not be the perfect center for even weight distribution allowing one finger rotation, it still is top heavy, but not unruly. If one was to build off of the front A-arm mounts, then yes, the bracketry would have to come out, then up , to a center polar axis. And the A-arm area is a common area to be bad and needing work, which the rotiserie is to be helping , not in the way. The mounts pictured work perfectly.
Another noteworthy part of rotiseriee building is , if you do not have a lift, you need to walk the car up to hieght for complete 180 rotation. If your brackets are straight out and mount to the center pivot, you will bind/bend as you jack front or rear up. If you look carefully at the yellow arms, you will see a big bolt at either end, this bolt tightens into a a large nut welded into a tube to which the straight out arms are welded. By loosening the bolt on either end the outer brackets are allowed 20-30 degrees of angle, thus permiting jacking of either end of the car, up or down. This was built way before I had a lift, and solved the problem of getting the car up and down for complete rotation. 356 bumper mounts are very low, and the car has to go up quite a bit before the roof does not hit the ground at 180. The 911 does not need as much hieght when mounted to its bumper mounts, 42" from front bumper center to ground gives me complete rotation. the center roll tubes are a slide fit with a pinch bolt for locking and I can grab the rocker and roll the car over myself. Is it perfect center? no. does it mount easily, roll easily? yes.

collier · 01-22-2004, 08:40 AM

That is EXACTLY what I needed to know....and it has been very helpful. Now I just need to source all my tubing, start welding

Thank so much for your insight....

One more thing: it has been discussed the pros and cons of having a Rotisserie that will spin 306 degrees; some say 180 is all it should do, others (like myself) would want to have the flexibility to spin 360.

Any thoughts on this???

thanks,

chris

Matt_'77_2.7 · 01-22-2004, 08:46 AM

Why wouldn't you. The extra tubing necessary to make it spin 360 is trivial to the total cost of the project that you are building the rotisserie on in the first place. If you get salvage steel, which is all that is necessary, it will be even more of a trivial cost.

Series900 · 01-22-2004, 09:00 AM

I use my rotiss for other projects too! I made a complete outer body mold for a customers needs, sort of a 7/8 pro stock thang. Rolled to 90, I can spray in the gel coat on the door/fender area, roll to 180 spray the roof/bumper, roll the other 90 and spray out the other side of the body. Let dry, and start the glassing, roll the mold and continue. Once it is ready to release, roll it right side up and the body shell drops out. I would have to scan some pics of that project, no digi's in the puter. I made another type of rotisserie for boats, all mounted on a trailer, 2 large rings that cradle the boat, the rings are on rollers, and I roll the boat to 90, easy bottom repairs! Better than fighting gravity with resin and glass!!

Britain Smith · 06-22-2004, 02:03 PM

Well, I have finally gotten my car on the rotesserie and starting stripping off all the layers of dirt, grim, and undercoating. I ended up building the rotesserie myself and coming up with some creative solutions to mount the early 912 chassis to it. I had to replace the front suspension pan before I could get the car on it, so I was delayed a couple of weeks.

Check it out: