Why are cut and shuts illegal ?

Caporegime
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simple you say, because they're unsafe

chopping out major parts of the crash structure and welding them back together is dangerous, it compromises the integrity of the chassis and means the car can easily split in two

that part i do understand

but what i dont understand, is how projects like the VW campervan restoration on here, and that Juha Kankunnen Celica Rally car that got posted a couple of weeks ago, can have huge swathes of the chassis cut out and welded back in

why is this safe, but cut and shutting something back together not ?
 
I always thought a cut and shut was cutting certain parts in half and welding back on... however you can replace various parts of the car (roof) etc if done correctly...
 
I thought the legality issue behind what was commonly known as a cut and shut is due to vehicle identity and stolen parts issues.
 
its not what you cutting a shutting its who is doing it, all cut and shuts are normally stolen and done by dodgy Dave down the scrap yard, a rally car or limo will be done by a proper welder who has the ability to do a proper job.
 
to the best of my knowledge cut and shuts are not illegal, just heavily frowned upon. I could be totally wrong though. If the welding is good then it is perfectly strong. Hardly scientific I know, but they cut chassis's all the time on american hotrod and boyd is a real stickler for safety, if it wasn't safe they wouldn't be doing it.
 
What Fox said. It's all about the stolen vehicle/parts and identity issues. These issues will stem from people who not only break the law by doing this but most likely do it very poorly and in an unsafe manner. The two go hand in hand I suppose.

At the end of the day, a chassis is usually welded together from various cast pieces. So long as you weld the chassis to the same standard if not better and it passes and MOT then you're road legal and not illegal.

I think one of the main issues is people being sold a cut n shut without knowing it was. Hence we have HPI and car data checks.
 
I think another main issue is that if "dodgy Dave from the scrapyard" is chopping two cars together to make a few quid, he's not going to be spending the same time, money, and effort as say Simon Norris reducing the wheelbase of his evo.

Hence the slight differences and safety/structural integrity.
 
so in essence cut and shuts arent dangerous then ?

its just the implication that if somebody has done to this to pull the wool over your eyes and make a quick penny, it wont have been done properly ?

id allways though it was because doing so is unsafe,

because as somebody has alread said, id see them chopping the chassis in half on telly and welding it back together during restoration of old cars and wondered is that even legal here ?
 
so how do people restore cars by cutting out huge ammounts of rotted chassis then ? if its structural

its no different.
 
Well the welds are never as strong as an original solid chassis are they, but theres not a weld across the whole car which makes it better i guess, more of the original structure intact.
 
The original "cut and shut" is quite literaly mating the rear half of one car with the front of the other. Ignoring possible legal implications, doing this properly is not easy, many sections like the sills and pillars are not simple box sections, but have an extra member inside so the joint has to be staggered. You would also have to perform the welding on a body jig to ensure both halves are properly aligned. Then you have the issue of the quality of welding, some of the stuff I have seen is frightening with virtualy no penetration at all.

Yes it can be done safely, but the big worry is that you will probably never know until another car hits you.
 
Yes it can be done safely, but the big worry is that you will probably never know until another car hits you.

so thats the real issue with cut and shuts

it can be done properly, but baring in mind its illegal to mix the identities of two cars, you'll never see a quality tradesman doing a cut and shut to perfection. It will be done by cowboys so will allmost certainly be done poorly and not properly balanced etc..

the enthusiasts we see restoring old cars are doing them to perfection, and doing it properly. And if people were willing to do this, you could put 2 halves of a car together properly if you were suitably mad ?
 
A typical "cut n shut" would be something like taking the front end of a rear-ended car, and the rear end of a front-ended car, and putting the two together, to make one complete car, usually to make as much money as possible. This could cause issues by weakening particular chassis parts by the process of cutting them in key places.

An enthusiast restoring a car might still cut out panels/bits of the chassis - but the overall strength and integrity of the resulting car isn't compromised. Additionally, it is done in stages, ensuring that the alignment and overall strength is not reduced - if anything, it could be improved. Often restoration jobs are done by removing panels at factory-welded positions, and replacing with OEM, or aftermarket pattern parts, which would be all but identical to those used during the original building of the car.


Of course the first type could be done very well, causing no long-lasting effects, and the 2nd could also be done very badly, leaving a car which is unsafe - but typically a restoration would be done to a higher quality than a bodged cut'n'shut.
 
so how do people restore cars by cutting out huge ammounts of rotted chassis then ? if its structural

its no different.

Typical panels/members are spot welded in place during manufacture. Seam welding in a new part is much stronger than the original, far stiffer (also the weld itself is tougher than the panel material). In fact too stiff for normal use, the technique typically used is a stitch weld. One thing to consider is crumple zones are cunningly designed to absorb energy by controlled deformation and involves spot weld failure. The 'cut n shuts' you hear about are little more than a few tacks holding butted chassis' together, often mid panel and therefore very dangerous.
 
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Didn't top gear do it on that episode when they chauffered people around, must have been legal to have the cars on the road.

Although they welded 2 front ends together :p
 
Didn't top gear do it on that episode when they chauffered people around, must have been legal to have the cars on the road.

Although they welded 2 front ends together :p

It's legal as long as neither car is stolen or a Cat A/B write off. I remember the episode, but can't remember if they had to get the cars SVA tested? If you modify a cars structure extensively then you are generaly obliged to have an SVA test, e.g. Z Cars Minis should be SVA'd.
 
SVA is tricky...Cars *should* be SVA'd if they score more than a certain amount of points...

From memory, if the chassis is heavily modified from standard, you get 5 points and two points each for changing the engine and drivetrain...

But nobody at SVA or VOSA knows Harris from elbow.

A friend pretented to be building a stock bodied beetle with Impreza running gear. he rang VOSA and was told as it had a reg doc no SVA required. He rang again and was told that as the car is pre 1990 something its pre type approval, no SVA. He rang the SVA and spoke to them and they said nothing to do with us as it has a reg doc, plus a stock Beetle or any old car would fail the SVA.

*n
 
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