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Is this chassis bent? Forum wisdom required!

PostPosted: Tue Oct 26, 2021 5:51 pm
by berni29
I have reposted this here from the Plus 2 forum because on reflection this is the correct forum for it. Apologies, mods please remove the original.......

Hi There

I am soon to take delivery of my early +2. It used to be raced a fair bit by the PO and has had a new nose section before being painted about 5 years ago. The repair was done by someone who used to do fibreglassing on the original production lines. So the PO says. I don't see any reason to doubt him.

While the body was off the car the PO welded the chassis and added strengthening plates etc. He also made some other modifications such as uprated suspension mountings at the front.

However....... If you look in the engine bay, you can see there is a hole (made by the PO) where the top of the front damper can be seen peeping through. This must mean that the chassis in that corner is bent yes? All of the other mounting holes line up and everything else looks great.

What do we think? I have bought the car and have allowed for a chassis change (well, the cost of a good secondhand replacement chassis), I don't count the labour as it will be fun.

Opinions as to the state of play here invited. The welding to the front turrets was pretty extensive and could have caused movement, as could the previous damage if it was not straight when welded.

Unfortunately I do not have a photo of the chassis on the side that has the problem.

Thank you in advance..... Berni

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Tue Oct 26, 2021 6:39 pm
by nmauduit
berni29 wrote:uprated suspension mountings at the front.
However....... If you look in the engine bay, you can see there is a hole (made by the PO) where the top of the front damper can be seen peeping through. This must mean that the chassis in that corner is bent yes? All of the other mounting holes line up and everything else looks great.


the car having been raced implies you should be prepared for a number of modifications made, for various reasons (you've already noted the chassis being reinforced). As for the issue you point out, I would deem equally probable that in a rush (you know, racers...) there may have been a need to a quick access to the top nut of the shock, and here we go lets pop a hole...

Regarding the chassis straigtness, I would take some time, rulers, strings and squares, to make carefull measurements : if indeed there is a noticeable discrepancy between sides, you should be able to measure it. Then if apparently ok and you are still unsure because of the tolerances of your checks, for good measure you may get the geometry confirmed by a shop with a modern setup (laser and all), which will give you a reasonable appreciation of the ability of the car to drive straight.

Then if a moderate twist has occured, you can contemplate the option of installing rose joints here or there as a way to compensate for it - or to swap the chassis (understanding that they are not all perfectly that straight to begin with)...

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Tue Oct 26, 2021 7:29 pm
by berni29
Hi

Thank you for the reply, the car does indeed have some modifications such as electric pop up headlamps, dual circuit brakes, type 9 gearbox and various bits and bobs. I prefer not to have an original car because I feel I have to keep it that way. With this car I can do as I please with no guilt.

I was thinking of buying a replacement chassis before I actually have taken receipt of the car, then got to thinking that maybe there might be another reason for the suspension intrusion.

As far as measuring a chassis, I have read how to take the measurements with a tape, but also I have a laser level that I could use to give some indication also. I have heard stories about Lotus hammering galvanised replacement chassis straight that had twisted during the galvanising process. i don't know how true they are.

I personally would straighten the existing chassis rather than dial out any misalignment. It would really bug me. It bugs me already and I don't even have the car yet.

By the way, here are the original cracks......

Thanks again

Berni

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 7:41 am
by nmauduit
berni29 wrote:By the way, here are the original cracks......


now that is something else : as the chassis has some cracks (have they been welded? do you know who did the repair and can he be 100% trusted? ...), removing the body for a full inspection (removing paint to expose the repair etc.) is a lot more justified, then I would also consider swapping the chassis to remain confident of the condition of the chassis. As strong blow on the wheel (cf. previous nose repair) is likely to push back on the turret, which may crack (could be weakened by previous racing use with slick tires of repetitive curb push, or even underneath corrosion). This turret getting pushed in may cause the hole you're observing.
Starting over with a non damaged chassis would also lightened the car from all the steel that has been slapped on to take the racing abuse or repair them, and there is little point saving the original chassis in your case I understand.

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 10:10 am
by rgh0
Hard to tell if the lack of symmetry is due to the chassis repairs or body repairs or both ( or maybe the original body moulding was also non symmetrical :shock: ) It will be hard to tell without a lot of careful measurement and may need the body off to be certain.

Whether its a problem or not when driving the car depends on how its affected the actual suspension and wheel alignment.

From an aesthetic view point or reliability view point whether its a problem or not depends on how well the repairs have been done.

cheers
Rohan

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 1:02 pm
by berni29
Hi

Thank you again for the replies.

I am not so worried about the extra weight from the steel gusseting, that is minimal for sure.

I really hope the body is straight. The body will be coming off whatever happens I think.

Thanks again

Berni

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 10:19 pm
by Bigbaldybloke
Years ago I had a Spyder refurbished stressed skin chassis where they basically cut off the front cross member and uprights and replace with new and do a few other mods to reinforce known weak areas. Not sure if they still do this but it looks like something like that would sort out most of your problem areas. It’s still on the car now and with a bit of work to finish the outstanding items after a complete rebuild it will soon venture out on the road again after over 30 years!
The reason I replaced the chassis was for corrosion and cracks in the areas that look to have been weld repaired on your chassis. The “normal” front chassis failure has the front uprights leaning in and cracking the side panels at the front of the engine compartment not holes above the damper, so the theory put forward in one of the earlier replies about a racer need rapid access to the top bolt on the damper is quite possible.
Personally the first thing I would do is take the car to a garage with good laser alignment equipment and find out for sure if the chassis / suspension is straight or not. Good luck.

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 10:54 pm
by berni29
Hello

Best of luck with the car! Will be great having it back on the road after so long!

Over the years I have had 2 original chassis that were beyond repair (In my opinion). One was very badly cracked and torn, the other was off a 33k mile very early car and came back from shot blasting looking like Swiss cheese.

I would not trust a steering alignment guy to tell me anything about the chassis alignment even with 4 wheel lazer equipment. There are too many variables with the suspension. There must be loads of misaligned cars driving round with bent rear A frames due to incorrect jacking. Quite apart from those with bent chassis.

Measuring the body and chassis independently is the way to go. I did see a picture of a plus2, I think on this forum, that has strut braces fitted to the towers. I will investigate that possibility for sure.

By the way, the theory that the hole is there for suspension adjustment would be reasonable if there were one on the other side. But there is not. Plus the PO told me he made it for clearance.

All the best

Berni

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Wed Oct 27, 2021 11:23 pm
by Foxie
berni29 wrote:Hello

Best of luck with the car! Will be great having it back on the road after so long!

<Snip>
Measuring the body and chassis independently is the way to go. I did see a picture of a plus2, I think on this forum, that has strut braces fitted to the towers. I will investigate that possibility for sure.

<Snip>



Attached pic of my Mark III tower brace. It is fabricated from 1" SS box section.

It is bolted to a pair of brackets inside the front tower bolts, and is easily removed for engine/rad removal.

:)

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Thu Oct 28, 2021 6:12 pm
by berni29
Hi

That looks really cool. The one I saw was done with a criss cross pattern, bottom of one tower to the top of the other, using two tubular adjustable bars.

Berni

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Thu Oct 28, 2021 11:15 pm
by Foxie
berni29 wrote:Hi

That looks really cool. The one I saw was done with a criss cross pattern, bottom of one tower to the top of the other, using two tubular adjustable bars.

Berni


Thanks.

I'm wondering how the criss-cross was fitted, the water pump pulley and belt is very much in the way.

Also how it was attached to the lower angle of the towers.

:)

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Fri Oct 29, 2021 3:30 am
by rgh0
I have looked at a front brace for my Elan suspension towers given the racing loads with sticky tyres and stiffer springs and roll bar but in the end concluded it was not needed as the movement in the front towers is very small even with just the standard Lotus frame I use. It would be even less with a reinforced 26R style frame. The movements in the rest of the chassis and body are greater than the small relative movement of the front towers versus each other and the front cross member when loads equivalent to those seen on the track are applied and movement measured.

I have never checked the tower movement in my Plus 2 but I would suspect it may be a little more but in a road car and especially in my Plus 2 with its Spyder chassis it again is not something I believe you really need to worry about.

I also dont think a cross brace would do much to solve any issue with cracking where the front U section of uprights and cross member joins the Z shaped arm sections each side of the engine.

cheers
Rohan

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Fri Oct 29, 2021 11:58 am
by Donels
The chassis may be bent, it rather depends upon whether it was straightened before the strengthening was added. On the other hand the body to chassis may be just badly shimmed or the new front may not be correctly aligned. I don’t think you’re going to know until you remove the body. My concern would be what caused the cracking and the need for a new front, it certainly sounds like a 'racing incident'.

It then depends on what you want from the car. A racing car is a tool, a road car is a passion.

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Fri Oct 29, 2021 12:45 pm
by Foxie
Shortly after I bought my wrecked 1970 +2S in 1987 and got it driving I found one of a front wheels at a funny angle.

The front rhs tower was cracked 2/3rds round.

When I did a body lift to repair it, I also found that both rear suspension ears were cracked and bent upwards.

I welded and reinforced the front tower, and straightened and reinforced the ears.

When I fitted a Spyder chassis in 1998, the repairs on the original chassis were still good.

The old chassis is still hanging on the wall... :)

Re: Is this chassis bent? Forum wisdom required!

PostPosted: Fri Oct 29, 2021 1:33 pm
by Donels
Wow, that was a lucky save. I stripped my body back to the gelcoat on my 1972 +2 and found that the drivers side front corner had been replaced (badly) and there were extensive tyre scuff marks in the wheel well under where the pedals are. The chassis was replaced in 1983 so it looks like it had a front suspension tower failure allowing the wheel to fold back. Not a pleasant experience I would imagine.