Is this chassis bent? Forum wisdom required!

[alan.barker]

The two horizontal bolts into the tapped holes in Rear Turrets should pull Body tight against them. Then with Engine in place Body height at front adjusted with Shims for Camcover clearance.
Lastly all the hole positions marked along Chassis Backbone Flanges, two vertical bottom of Dashboard then Front Turret holes, last Pads infront of Steering Rack.
Alan

[berni29]

Hi Alan

Thank you, very helpful. I shall have a look at the mounting bolts tomorrow and see whats what. I will undo as many as possible and see what movement there is. Does the body sits on the fibre matting that lays across the chassis backbone or is it actually suspended from the turret mounting points and rests on the shimmed body mounting points. I guess in order to shim the dashboard ones on the upper surface of the chassis the body would need to be raised to clear the cassis backbone completely.

Thanks again......

Berni

[berni29]

Hi There

Well, the plot thickens somewhat. I removed some body mounting bolts. There were the four turret bolts (14mm head) and also 6 under the car. I ran out of time on the two behind the dash.

I also investigated a bit further generally. It seems the nose is long (as suspected), but also twisted horizontally to the right slightly. Please see attached pictures.

The bonnet aperture seems as square as one would expect (which given the other measurements I wasn't expecting).

At the rear the drivers side (right in the UK) turret seems to intrude into the car more than the passenger (left). This along with the left hand intrusion at the front suggests a banana type of twist across a diagonal. Correct me if I am wrong, but a car being low across a diagonal, and high across the other diagonal cannot be shimmed out at the body right? Please see attached pictures.

There is a fair bit of extra welded gusseting at the turrets both front and rear on the car.

Edit: I have one of these magnetic digital inclinometers coming tomorrow, and using that and my lazer level I can hopefully ascertain if it is the chassis that is the issue or not. I'm thinking more and more that it must be.

By the way, the PO is happy to take the car back, but I really do not want to do that. I'm a problem solver by nature, and in may ways it brings me closer to the car. I bought the car believing that the chassis must be bent, and I have no problem swapping that out. A bent body is another matter, but I do not think it could possibly be so bent that it is casing the symptoms I am seeing.

On another note, the jacking points have been glassed over. Apparently before it was painted as when I look at racing photos back to before it was painted it does not seem to have them either. I can see the metal sills from inside the car and they look new.

Thoughts please!

All the best

Berni

[NTG999]

It looks like the rear of the body is in approx the right place judging by the strut tops in the openings, the front looks approx 3/4" too far forward, so as it has had a new nose it looks like it hasn't been attached in the correct place. Trying to improve this on a repaired chassis is a recipe for it never being right - sorry.
Body off, new chassis or rebuilt/checked by someone Lotus competent then tackle the nose if your enthusiasm continues. Nick

[berni29]

Hi There

I have done some more measuring, but will repeat tomorrow for three reasons. Firstly I still had one bolt in the RHS front turret (although when I pulled it there was little resistance and the body seemed not to move. Secondly the screen on my newly acquired Chinese made digital inclinometer was unreadable due to the lighting on the upright readings. Thirdly I made the mistake of jacking against the sill of the car to get it completely level (as measured at the rear turrets) with the body bolts out thereby potentially changing the relationship between the body and the chassis and thereby invalidating comparative measurements.

You would think that the following (seemingly valid) measurements would illuminate and provide some clarity. Instead they have only added to my confusion.

Firstly I jacked the front of the car with a single jack in the middle of the crossmember. Then I jacked under the low sill to level it up. Level was measured as below with two head bolts resting against the turrets where the top is closed off and the suspension leg protrudes through. I put a spirit level on the bolts and bubbled till level. I then confirmed zero degrees with the inclinometer. Please see pictures below.

For comparison I also measured the rear parcel tray of the car even though its not necessarily a valid comparison. I recorded a downwards slope left to right of 0.65 degrees, which corresponds with what I see at the rear turrets in direction if not size. Please see picture.

I then went to the front of the car and measured the front crossmember in the same plane. The bottom of the crossmember has been jacked on frequently and is somewhat uneven so I measured on the top. I was expecting (and hoping for) a reasonably large torsional twist in order to explain the way the body was sitting. However it looks like it is only slightly askew. Like almost nothing. Please see pictures. I will get a bubble level on it tomorrow if possible. I don't really trust the digital gauge. This result both surprised and worried me.

As far as the nose goes, I got a straight piece of long wood and gently jacked it against the flat floor area of the car where the drivers seat sits. The wood passed under the outside edge of the front crossmember (I removed the roll bar to get clearance) and past the nose. I set up both sides similarly using the same bit of wood, and I fount that the distance between the lower edge of the nose and the wood was the same both sides. So the nose is in all likelihood straight.

I also did a rough and ready measurement across the front of the engine bay and found that was level. Please see picture.

Now that the body has been released the front suspension turret no longer protrudes through the hole, which is good news. It is still about 1/4" closer than the other side though.

The rear RHS one does though. The next thing is to get the rear wheels off and see if I can see anything amiss, as the suspension is not actually fully done up.

Any comments welcome.

Berni

[berni29]

Hello again

Popped outside in the dark to retake the front turret angles and try the laser level out on the car.

Results below. I levelled the chassis then used the laser to see if I could see any obvious discrepancies. By chance the body seems to be sitting level also even though it has no bolts in. The front also seems to be fairly straight looking at the laser lines.

I do not know if the 0.6 of a degree difference in the turret arm leans is significant.

Even though there is no longitudinal twist in the chassis (from my measurements) there is clearly some strangeness going on. I will investigate further this week before taking the body off when I get set up to do so.

In the meantime if I see a well priced secondhand Spyder chassis for sale I will go for it.

All the best

Berni

[nmauduit]

I'm not sure exactly what you're trying to achieve with these preliminary measurements, if indeed you are already set to take the body off and swap chassis...

- my first concern (chronologically along your thread) woudl be the repair of the current chassis : slapping plates here and there alter the stiffness of the various parts of a chassis which should otherwise flex, and this create stress risers which are likely to start some cracks (even if the welding has been perfect on suitable prepared material, which remains to be ascertained) : if the cracks displayed above in photo are still there, I would not go further... properly repairing this chassis, if somehow that was the route to follow, would require removing some or all of there previous repairs in my book (which makes changing the chassis all the more justified by this extra work). The difference in turret angle is not negligible, and would likely require care (adjustable suspension arms to compensate as much as possible) if the chassis were to be kept...

- my second concern, which emerged later but fits this story, is that of a poorly repaired bodywork (e.g. nose section grafted at a wrong angle and/or location) : this may be assessed by looking at the reverse side to guess where the parting line are (trying to follow them completely, with the help of a suitable lighting). This is made more difficult with a lot paint applied, so may or may not be conclusive. This concern is more severe than a bent chassis, as the amount of work to rectify a poor repair is the most time consuming. You may also try to measure the body itself (overall straight and across, fender to front, door to fender etc etc), with the help of fellow forum members with an undamaged reference at hand if need be.

good luck !

[rgh0]

Both body and chassis so far look within the normal sorts of variation tolerances in good condition older units as far as I can judge by your measurements so far. The laser line measurements of the body are very revealing and a great novel approach and showing good consistency in body dimensions with no significant repair distortion.

Even "like new unmolested" old bodies and chassis show significant dimensional variation. New bodies and new chassis are not much better.

If you can get good alignment on the chassis and suspension and the chassis repairs look good then no need to replace the chassis until you get significant cracking problems, if ever these occur in the future.

If the body can be shimmed onto the chassis to get acceptable alignment and clearances then no problem there either unless you experience cracking from the previous repairs.

I would not spend a significant amount of money on the chassis or body assuming you can set it up ok. I would do that and then drive it and see if any future issues emerge that need action. Just my approach to not over think future problems that may not really exist

cheers
Rohan

[berni29]

Hi Guys

Thank you for your well considered responses. I agree that any more mucking about is pointless, and the next thing is to get the body of and see what is what. Actually for me personally I am with Rohan on not needing the car to be perfect, so things like a sub optimally repaired nose does not worry me. Its hard to spot it, and I much prefer it slightly longer to slightly shorter. I have seen quite a few plus 2's with tight gaps between the nose and the tyre, and it looks really uncomfortable.

The chassis and mechanicals have to be spot on me though so I will be getting a Spyder spaceframe one (stronger than standard Lotus), secondhand preferably, but new if I have to. I intend to drive the car without restrictions, so speed humps and the like will not be avoided by me out of sympathy to the car.

I had a yellow plus 2 once that I used to drive everywhere all year round including hard winters. I want to get back to being able to do that. The advantage of a less than perfect non-original car is that I feel much freeer. I hate babying cars and feeling that I have to leave the car original.

Thanks again

Berni

[RichardHawkins]

Bernie,

My body distorted during the painting and cosmetic repair process. Your body looks like it has been recently painted. I don’t pretend to understand how this happens to a fibreglass structure that is 50 years old, in fact I would have thought that something this old would now be stable.

One of the mistakes I keep making is to judge a 50 year old hand built fibreglass car by current standards

Hope this helps,

Richard Hawkins

[nmauduit]

I don’t pretend to understand how this happens to a fibreglass structure that is 50 years old, in fact I would have thought that something this old would now be stable.

a common mistake by bodyshops which usually deal with metal bodywork is to cure the paint at higher temperature than the fiberglass can take...

[h20hamelan]

I was able to see more than 1/2” flex when body was off frame on a +2, DHC would be similar I would guess.

[berni29]

Hi

How interesting. Yes I bet a few fiberglass have been baked at the wrong temperature! I hadn't thought of that.

Richard, in what way did your car distort exactly, and what did you do to resolve the situation? (If anything, acceptance works well).

All the best

Berni

[RichardHawkins]

Bernie,

I had gone to some considerable trouble fitting the new chassis to the body, and everything fitted. I sent chassis and body to different places for painting. In the meantime I set about overhauling everything else confident that I would have finished before the body was ready. Well this all went wrong, I have spent years overhauling all the other bits. The chassis came back promptly, but the body was away for about 9 months. After the body returned I parked it on a large timber and plywood frame looking rather like a trailer from an articulated truck. I took care to ensure that the body was evenly supported.

When I came to fit the body only two holes where the body fits to the chassis flange either side of the gearbox were still aligned. Most holes were about half a hole diameter out of alignment. I made and fitted screwed aluminium plugs into the bobbins, secured with an epoxy recommended by Loctite. I re-drilled and tapped the bobbins to align with the chassis. The two bolts that pass into the chassis just behind the dash I managed to force into place by deflecting the body. The two bolts that pass through the body into the chassis at the top of the rear struts, we’re so far out that the bobbins had to be cut out and relocated. I don’t do fibreglass repairs and was helped by a good friend.

Hope this helps,

Richard Hawkins

[Donels]

Just a couple of observations. It appears that the body has been fitted, I use the term loosely, to the chassis with no felt padding saddle on the transmission tunnel. This has allowed the rear suspension struts to sit too high hence the holes in the body.

The body was bolted to the chassis but since releasing the bolts something has untwisted. Is this the body or the chassis. They both compliment each other to give stiffness but something is twisted. If it’s the body it looks to be twisted more than the 1/2 inch discussed above. So do the doors fit? If not it could be a big job to make it acceptable. Are there any body cracks from the twist? If it’s the chassis then handling may always be weird unless you replace the chassis.

The body appears to be too long since the nose was replaced. The back needs to be up against the rear turrets the get the front bulkhead in the correct place so where is the additional length. Does it look right or will ii always be weird?
Do the front wheel arches look correctly spaced to the wheels when it’s shimmed?

It seems to have a lot of problems that need solving!

You seem to be a very practical person and keen to get on with the project, but before that keenness overtakes take a step back and look at what you want to achieve and will this do that. There are a lot of good +2 projects out there that may be a better starting point and if the seller is willing to have it back………