Easy Way To Smash A CAT ?

[redgriff500]

My CAT is blocked and damaged so I want to smash it out.

Problem is there are bends both sides of it.

I can touch it as its a V big bore but can't get any leverage.

I've tried dropping it, hitting it reasonably hard with a hammer (I don't want to dent it if possible) throwing a couple of big sockets in and rattling them around, even tried rapid heat (petrol) and cooling.

Just thought I'd ask before I cut a flap in the bend and smash a bar through it in case there is a simpler option.

[Disco You]

err... weigh it in? Then replace with a straight piece of pipe.

[Crafty_]

^ what he said.

If the car is '93 on you wont pass an MOT without it though..

[tommobot]

I recently removed the pre-cat from my car. Took about an hour and half, multiple drill bits ruined, attacked with chizzle, hammer, every single implement you could get in a toolbox and none of them shifted it. Think in the end it was just sheer persistance. It was seriously, seriously thick / dense.

And this was on the pre-cat, which was much smaller than the CAT!

[busta]

Can you bend a metal bar to fit the bend and then hammer on that? I've never dealt with one with bends in it, but had no problem smashing the guts out of one with a hammer and a 3/4" bar.

[Strawman]

They are made from ceramics (like a toilet bowl or sink) so are seriously strong, then coated in a platinum mixture. Hard to break without removing from the exhaust casing first. Also the reason they kill drill bits.

[EDLT]

Weigh it in and get a straight pipe or just get a straight pipe and keep the cat for MOT time.

[clarkey328is]

EDLT said:

Weigh it in and get a straight pipe or just get a straight pipe and keep the cat for MOT time.

This. You can get about 30 quid a cat, at least where I live. That should easily pay for a bent bit of pipe. If you're not up to it, get an exhaust shop to make one to spec. You could also cut out the cat itself and weld ina small straight piece of pipe in it's place. Shouldn't cost more than 20 quid if you take it off and reinstall it yourself. Then you can save up and buy some second hand cats to put in for MOT tests.

[redgriff500]

It's for a TVR - a decat is £300ish.

I'd guess it's 9" across so not a tube size anywhere I know would have in stock and they can't buy in a foot of it.

[McSam]

Am I missing something? If you're taking the cat off, why would your replacement pipe need to be the same diameter as the cat, rather than just.. the same as the rest of the pipe fore and aft of it?

[Snowboy]

I wonder if by smashing the insides of the cat it still looks like it’s a cat for MOT purposes.

Although I’ve no idea what would happen on the emissions test.

[ExPat2B]

redgriff500 said:

It's for a TVR - a decat is £300ish.

I'd guess it's 9" across so not a tube size anywhere I know would have in stock and they can't buy in a foot of it.

Are you sure about £300 ? What TVR is it ? Its just that I have seen them advertised at around 125-175 £ mark for a pair for the cerbera 4.5 so 300 seems very steep !

[900T-R]

McSam said:

Am I missing something? If you're taking the cat off, why would your replacement pipe need to be the same diameter as the cat, rather than just.. the same as the rest of the pipe fore and aft of it?

On the TVR, things are a bit more complicated than that as the main catalyst assembly doubles as a Y-pipe ehere the exhaust manifolds for both cylinder banks join.

[McSam]

900T-R said:

McSam said:

Am I missing something? If you're taking the cat off, why would your replacement pipe need to be the same diameter as the cat, rather than just.. the same as the rest of the pipe fore and aft of it?

On the TVR, things are a bit more complicated than that as the main catalyst assembly doubles as a Y-pipe ehere the exhaust manifolds for both cylinder banks join.

Outstanding.

Obviously this makes it a little more awkward. I would definitely still look at just redesigning a longer, narrower Y-pipe so you can use a reasonable bore, though!

[funkyrobot]

Has the OP managed to steal that CAT yet?

[Magictrousers]

Snowboy said:

I wonder if by smashing the insides of the cat it still looks like it’s a cat for MOT purposes.

Although I’ve no idea what would happen on the emissions test.

I did just this for the MOT and it flew through. No mention of emissions at all.

[900T-R]

McSam said:

Outstanding.

Obviously this makes it a little more awkward. I would definitely still look at just redesigning a longer, narrower Y-pipe so you can use a reasonable bore, though!

Already available from ACT and Clive Ford.

2 issues:

They cost money which the OP isn't prepared to spend.
They make it rather obvious that the catalyst has been removed when looking in the engine bay.

[redgriff500]

900T-R said:

Already available from ACT and Clive Ford.

2 issues:

They cost money which the OP isn't prepared to spend.
They make it rather obvious that the catalyst has been removed when looking in the engine bay.

Exactly !

I'd rather it looks std.

I was intending to buy a Clive F version and swap mine back on for MOT's but as it seems mine is buggered - plan B is just to knock it out which it seems is harder than I thought.

I wonder if a shotgun blank might shatter it - probably not.

[billzeebub]

hit it over the head with a baseball bat

[redgriff500]

billzeebub said:

hit it over the head with a baseball bat

Unfortunately if you google those are the types of suggestions you find.