49 replies to this topic

[tadleysimon]

hi all,

now i know this is a sore subject but hear me out

a friend of mine has come across a project he would like to start. its a mini pickup.

however he has been told its a cut and shut. neither of us have seen it so i cant comment on its condition ect but apparently the load bed and roof ect is a pickup and the floor, windscreen surround and front end ect is from a saloon.

im fully aware that cut and shuts are bad news but surley if the work is done correctly it could be ok?

i mean, modern cars are laser welded ect so yes a cut and shut would make it much weaker but in the case of a mini, it was spot welded at the factory so surley some good quality seam welds or mig spot welds would be just as strong. after all, loads pf people change floorpans, roofs, side panels sills, or front ends ect with migs and no strength is lost.
i cant see the difference between this 'cut and shut' and say a mini shortie or a limo. surley they are just as bad?

ive been thinking and depending on how it looks i think it could be a viable project.

any thoughts?

[Shifty]

I'd run a mile, its cheap for a reason.

If its a "Proper" cut and shut then the car will have been cut at the windscreen pillars and then along the floor by the crossmember. This is usually the easiest way of doing it.

In the event of an accident all that's keeping the front end on the car is the welding at these 2 points.

Stuff like this simply can't be trusted to give any protection in the event of an accident.

EDIT

Also chances are the car will never steer straight either as aligning the 2 halves properly is very tricky and well beyond the capabilites of most cut and shut monkeys!!

[tadleysimon]

thats probaly how its been done, what i dont understand though is, you said the only thing holding the front on is the welding at the 2 points, but isnt that the case anyway? from the factory?

and what if the full floorpan was to be changed anyway?

im not dismissing your advice, im just asking..

[Dan]

When a car is cut and shut, all the seams are butt joints and line up in one plane. An accident (or even spirited driving) is likely to generate extreme shearing forces on this joint and split the welds. As standard all the panel joins are off set from one another by a good distance and overlap quite well. This serves to spread the loads. Is this a real cut and shut or has it had the front end of another vehicle properly joined to it at the original panel joins? The other question raised by this kind of work is how legal it is.

i mean, modern cars are laser welded ect

Err, not normally no! They tend to be spot welded.

[tadleysimon]

Is this a real cut and shut or has it had the front end of another vehicle properly joined to it at the original panel joins?

so what is a real cut and shut then? if the front of another car has been joined at the orignal seams with spot welds (around the doorpillars for example), why is it weaker?

lets assume it has a fresh mini pickup floorpan from heratage (i dunno if they actually do one) or m-machine, would this put the strength back into the shell at the floor?

[Shifty]

thats probaly how its been done, what i dont understand though is, you said the only thing holding the front on is the welding at the 2 points, but isnt that the case anyway? from the factory?

and what if the full floorpan was to be changed anyway?

im not dismissing your advice, im just asking..

Nope!!

Think about it....

When you replace a pair of sills or a floor pan, do you replace 1/2 of them. A cut and shut would. The front 1/2 of the sill is car A and the rear car B(along with the door steps)

You've now added another 3 fractures point(which is entirely dependant on the quality of the welding).

The welding at the pillars will have been ground back to nothing to disguise the repair(as will the floor)

All this is a recipe for disaster, as I said before chances are it will never steer straight again.

[tadleysimon]

so if you where restoring a complete rot box and you replaced the doorsteps, sills and full floorpan, could this make the whole shell weak?

also, how do shorties and limos get round all this, they are basically cut and shuts after all

[Dan]

if the front of another car has been joined at the orignal seams with spot welds why is it weaker?

Err, it isn't. That's what I said. A cut and shut is two cars literally gas axed or otherwise chopped in half along a chalk line and seam welded along that line. Usually without bothering to remove any carpets, brake lines etc. that get in the way first and just joining all of that together afterwards. Cutting the front off a car at the original joins takes a lot of time and patience and means chopping a lot of other panels (that you still need) carefully out of the way bit by bit. The two parts would then have to be joined using some kind of jig and accurate measuring to align them and then have the carefully removed panels replaced. This is because you cannot access all the joins at the same time, the panels overlap and cover the joins which is where the strength comes from. Doing this properly takes skill and time, a cut and shut is a very different story.

Strength in the floor makes the floor strong, not the rest of it. The car is a box, not a panel and it doesn't have a chassis to sit on as you know. If you make a car into a convertible you have to add reinforcing, taking a cut and shut and just replacing the floor would be more danerous than failing to fit the extra parts to a convertible. If it even survived having the floor chopped out without braking in half that is.

[Shifty]

When you replace the panels in the manner in which they were intended then theres no problem.

Stuff like the structural integrity of the roof and pillars isn't touched.

Also as Dans said the welding isn't just in the one plane, its done to the standard and in the manner that it was intended.

How many times have you seen pictures of the mini assembly line at longbridge where they are welding the two halves of the cars together???

[Dan]

also, how do shorties and limos get round all this, they are basically cut and shuts after all

Lots of careful design, welding and reinforcing. Most cars that are made into limos are not monocoques for this very reason. They have a chassis to sit on and extending a chassis is fairly simple.

[Shifty]

also, how do shorties and limos get round all this, they are basically cut and shuts after all

Lots of careful design, welding and reinforcing. Most cars that are made into limos are not monocoques for this very reason. They have a chassis to sit on and extending a chassis is fairly simple.

Not some of the ones I've seen!!

True story!!

I saw a pick up for sale on fleabay a few years ago, bit rotten but cheap.

Anyway went to look at it and it was rough, but there was something else about that I couldn't put my finger on it straight away.

Bit more looking at I discovered the roof had been cut off and replaced!!

Thats not all....

At a recent mini meeting we got talking about pickups and I metioned this one, turns out a bloke from my club had done the repair after he'd rolled it!!

Thats not all...

After a bit more chatting it turned out that I'd sold him the roof that was used to repair his pick-up!!! I'd had an utterly rotten pick-up that I'd sold him!!

Small world!!

[tadleysimon]

right o guys, cheers, i didnt know the limos used a chassis, i just assumed the used an extended monocoque.

shame as pickups are so cool, guess it would be alright for banger racing or something lol

[tadleysimon]

there was a project on this site where someone had cut the roof off of thier saloon and replaced it with a roof from another shell (cut off halfway down the pillars). if i remeber rightly tho no one really said anything bad about it...

[Shifty]

there was a project on this site where someone had cut the roof off of thier saloon and replaced it with a roof from another shell (cut off halfway down the pillars). if i remeber rightly tho no one really said anything bad about it...

For very good reason, thats ok as long as its done correctly.

How do you think roof chops are done?

These have been done for many many years.

Usually by an enthusiast or someone competent, not a bodge monkey with a hobby mig.

This is completely different to the cut and shut situation, the car HASN'T been cut totally in 1/2 with the floor structure severely weakened and in all probabillity done to a poor standard for a quick buck.

[Mini-Mad-Craig]

What does "cut and shut" mean then?