Author Topic: TC Chassis Dims  (Read 847 times)

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Offline Squeek

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TC Chassis Dims
« on: Monday,January 13, 2020, 07:25:36 PM »
 :newhere:  Hello everyone!
 My first post here after registering 2.5 years ago.  Here goes;
I have a 1972 TC that has had some frame damage.  The PO had taken the car to a RX7 engine tuning establishment, because obviously, it has a 13B engine.  Upon completion of work, a test drive was in order.  The PO accelerated, only to have the throttle stick open- no throttle return spring was fitted.  As he was approaching a T intersection, he pitched the car into a left slide, hitting a curb on the right side.  No one was hurt.  However unscathed the body was, the chassis was bent at the front "T", which was bent down and back, and the right rear outrigger and trans-axle support hoop. 
I have hatched a plan (actually borrowed, stolen, usurped) to straighten the front, and carried it out with good results so far.  I will weld a 16ga panel under the T to keep it square, and a panel on the front with all the holes cut out for steering, cooling, brake lines and suspension points, etc..
HOWEVER, what I really need now are the dimensions for the rear part of the chassis.  I have not been able to find anything from Google and Bing searches except for Series 1 dimensions.   I have the 352 transaxle and want to bend a new hoop to the stock dimensions and re-weld it to the outriggers with small closing plates on the chassis. 
Does anyone have any specs. as they pertain to this area of the car?  Or where I might find them?
Thank you.

Offline BDA

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Re: TC Chassis Dims
« Reply #1 on: Monday,January 13, 2020, 07:57:52 PM »
 :Welcome: Squeek!!

Sorry I don't have any specs for you. Since you have one side that is unbent, you could measure from some point on the frame toward the front to the unbent rear corner. Then the other side should have the same measurement from the corresponding place in the front to the other rear corner.

If you are confident your 'T' section is right, you could use a place on the 'T' (which has the advantage that larger measurements would be more accurate - i.e. a 1/4" wrong out of 6' is closer than a 1/4" wrong out of 4' if you catch my drift) but it would be safer to keep your control measurements on unmolested frame points. Maybe the best idea is to measure from the furthest up the backbone that is known to be straight.

Good luck!

Offline jbcollier

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Re: TC Chassis Dims
« Reply #2 on: Monday,January 13, 2020, 09:49:35 PM »
New frames are expensive, yes, but used ones aren't too bad.  Personally, that's the way I'd go.

However, if the front is now straight, then you can measure off it to square the bent right rear.

I fabricated a new rear hoop for mine.  Pretty easy.   Install the engine and tranny.  Line them up and build the hoop to suit.  Remember, the transmission is the rear suspension mounting point so it has to be exactly in the middle.

Offline lotusfanatic

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Re: TC Chassis Dims
« Reply #3 on: Monday,January 13, 2020, 10:29:10 PM »
Hello Squeek!

 :Welcome:

I would look for a good, straight replacement chassis if possible?
If that isn't possible, then follow JB's advice and fire up the welder!

:welder:

Mark 

Offline Bainford

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Re: TC Chassis Dims
« Reply #4 on: Tuesday,January 14, 2020, 09:01:08 AM »
Welcome to the forum, Squeek. Good luck with your project.

I seem to recall a forum member here a few years ago that had rotary engine in his Europa.
The Twin Cam plays the symphony whilst my right foot conducts the orchestra. At 3800 rpm the Mad Pipe Organ joins in.

Trevor

Offline dakazman

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Re: TC Chassis Dims
« Reply #5 on: Tuesday,January 14, 2020, 02:58:32 PM »
  :Welcome:

   Way Back in 1985 I was also going to install a rotary 13b then add the twin turbos.
That was the plan! I still have a huge folder with lots of information. I just sold my 13b this week after 20+years in my garage. With my entire harness an A/C system.🙁
    I guess then you went with the Kennedy bell housing instead of the Porsche bolt in gearbox . I was reading the manual and noticed there are 4 part numbers for the 352 gearbox. Some dimensions are in the workshop manual, under chassis unit page 4 of the s2.
Dakazman
Ps  we would love to see some pics

Offline dakazman

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Re: TC Chassis Dims
« Reply #6 on: Tuesday,January 14, 2020, 04:28:23 PM »
 :BBQ:  I went through some prints and now see the gearbox hanger is not on my prints to my surprise .
I just downloaded and printed.. they are very detailed.  Thanks for pointing out this missing information.
  I don’t know if this will help but some of the dimensions should be the same. You’ll need a o check the parts manual.
Dakazman

Added that link , but still nothing: http://lotus-europa.com/manuals/s2work/diagrams/index.htm#dimfig1
« Last Edit: Tuesday,January 14, 2020, 04:43:32 PM by dakazman »

Offline Squeek

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Re: TC Chassis Dims
« Reply #7 on: Wednesday,January 15, 2020, 06:00:49 PM »
Well thanks everyone for the great responses.
I will attempt to respond to all of you at the same time.
Yes, replacement frames are pricey, good used ones are less pricey but still a lot, and I'm on a budget with another Lotus and other fun activities to spend on.  The car came with a spare 365 frame, which is also bent and rusty.  My partner in this project (who was the passenger in the bending incident) found a chassis, body, roll bar and other stuff on eBay in NJ.  By the time the stuff arrived here with the winning bid and shipping, the cost  was 2/3 the way to a new frame.  Turned out, that one was rusty AND also bent.  Not my bad. The one on the car, though bent, was nicely fresh and corrosion-wise.  I have been making progress with clamps and thick steel bars to straighten the right outrigger, WITHOUT using heat. 
All your suggestions are good ones relating to measuring the good side vs. the bad.  I have purchased a 1.25" steel tube of the same thickness as the original, and borrowed a pipe bender, filled the tube with sand and started bending the thing but stopped short of what looks like the correct  angle and radius. 
NOW, what I need from any of you nice folks, is a favor to measure the transaxle hoop distance from the top of the outriggers to the top of the "V" in the center on a 352 4 speed frame. AND the distance between the outriggers.  These dimension are crucial to keep the original geometry and the "magical" Lotus handling.  Once I have this, I can proceed with the rest of the repairs.  I plan on using small gussets and plates in 16ga. sheet to reinforce the area without going crazy overkill. 
I much all your responses.