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Will a carb kill a cat?
Mr Whippy - 15/10/08 at 08:27 AM

I have a new cat in the garage which wasn’t cheap, it was meant to be fitted to the vectra but since that’s a pile of scrap the cats now excess to requirements...it taunts me every time I walk into the garage, "I was expensive and you never even used me..." it says

But I was thinking, I could fit it to the Bluebird? It’s in the middle of being converted to LPG the system uses a lambda sensor so the exhaust is optimised for the cat to convert.

The issue is that the car is started on petrol and is only switched over after a few minutes once the engine has had a bit of heat into it. Since the petrol side of things is handled by a carb will this over-rich mixture damage the cat or will it have no effect? It runs on unleaded btw.

nick205 - 15/10/08 at 08:39 AM

My cat prefers Whiskas pouched food (steam cooked no less) rather than petrol. We tried Sheba tinned food, but TBH she did find that a little too rich and tended to bring it back up again (no long term damage though).

As to petrol and carbs, she does sleep in the Indy from time to time, but has never really shown any interest in the fuelin and emissions of the vehicle.

Sorry - couldn't resist it

coozer - 15/10/08 at 08:40 AM

To answer your question the is yes, maybe. If the carb is big and heavy, you then drop it from a sufficiant height, and, presuming the cat is a) slow or b) asleep there is a good chance the carb will kill the cat.

Only them it will be the RSPCA on your back instead of Friends of the Earth.

Mr Whippy - 15/10/08 at 08:44 AM

yes I forgot to mention the cat does have a rather unpleasant exhaust note as the gas exits the rear outlet

nick205 - 15/10/08 at 08:59 AM

quote:
Originally posted by Mr Whippy
yes I forgot to mention the cat does have a rather unpleasant exhaust note as the gas exits the rear outlet



You want to be well away from that end and paying more attention to the inlet end if you ask me

smart51 - 15/10/08 at 09:02 AM

Cats are damaged by overly lean or rich mixtured for prolonged times. Even EFI cars vary the fueling mixture from time to time.

Carbs are relatively poor at regulating air fuel ratio at all revs / loads. You generally adjust them to be good enough. Set your mixture to be stoichiometric and for the short time it runs on petrol, it might last long enough.

tomgregory2000 - 15/10/08 at 09:04 AM

why would u want to fit it to a car that never had one in the first place?

AndyGT - 15/10/08 at 09:10 AM

Will a crab kill a cat?

Only if you swing it hard enough!!

Mr Whippy - 15/10/08 at 09:12 AM

quote:
Originally posted by smart51
Cats are damaged by overly lean or rich mixtured for prolonged times. Even EFI cars vary the fueling mixture from time to time.

Carbs are relatively poor at regulating air fuel ratio at all revs / loads. You generally adjust them to be good enough. Set your mixture to be stoichiometric and for the short time it runs on petrol, it might last long enough.


cheers, the carbs quite an advanced model though it doesn't have any automated mixture control, only an idle up for increased electrical load so it will be quite rich on choke (electric bi-metal type). I read that the unheated Lambda sensors which I have take a short time to heat up and work properly so really it’s a few minutes then switched to very clean exhaust gasses, with practically no particulates, perhaps this will compensated for the start up mixture?

quote:
Originally posted by tomgregory2000
why would u want to fit it to a car that never had one in the first place?


My idea was that I could get the emissions so clean (after all the engine is tested at running temperature so is on LPG) the road tax would be practically nil...

[Edited on 15/10/08 by Mr Whippy]

Peteff - 15/10/08 at 09:30 AM

If the car is registered before 2000 it will be in the old taxation system and not eligible for reduced emissions banding, save it for something that needs it.

Mr Whippy - 15/10/08 at 09:36 AM

quote:
Originally posted by Peteff
If the car is registered before 2000 it will be in the old taxation system and not eligible for reduced emissions banding, save it for something that needs it.


hmm?! it's registered in 1990 never heard of this tbh, I'll have to check it out, ta

It's my newest car!

BenB - 15/10/08 at 10:32 AM

Yup. There's no point. If the engine is old you won't get a reduction you'll just loose power and add weight....

Talking of old engines / cars I was concerned to hear that Dubai has announced that it will be illegal to drive cars older than 20 years old on their roads (or rather they'll be refusing road tax) which will reduce to 15 years in 5 years time!!

Which is a shame really because it'll just restrict the use of old cars to tracks. Which is quite silly really because it means you'll have to put the car on a trailer and attach that to something environmentally unfriendly to get it to the track!!!

No doubt it will appear here soon (I think it's already happening in Edinburgh)...

One of these days the governments will realise that re-using old cars is actually quite a green thing to do!!!!

Mr Whippy - 15/10/08 at 10:38 AM

no doubt it was pushed by a car manufacturer...

I like this quote by Egon Möhler, spokesman for the Stuttgart city authorities who is looking into the Edinburgh ban -

"some exceptions would apply, such as for older fire engines, ambulances and police cars, and for specially licensed historic cars. But he explained that drivers would be unable to claim that highly polluting "rust-buckets" from the 1980s or early 1990s should be granted special status as antique vehicles."

so now some one is going to decide if your car is worthy of classic car status?

and check this out at how draconian the councils can be...

linky

[Edited on 15/10/08 by Mr Whippy]

dinosaurjuice - 15/10/08 at 11:43 AM

quote:
Originally posted by BenB
One of these days the governments will realise that re-using old cars is actually quite a green thing to do!!!!


keeping an old car on the road is far better for environment, relatively speaking. the reduced MPG and higher emissions is EASILY offset by the masses of energy that goes into manufacturing a new car with slightly higher MPG and lesser emissions. Some clever researcher calculated that over vehicle life (the most important green issue) a new discovery 3 is better for environment than a prius!

kit cars are 'fairly' green IMO:
chassis steel is usually sourced from UK.
donor parts are reused with little re-manufacture.
in the event of an accident/breakdown the car can easily be repaired to a working standard fairly cheaply.

i dread to think how easily a prius or other hybrid could be written off by a minor accident, it only needs to damage some clever eletcronics and/or battery and its 'uneconomical' to repair.

rant over.

btw, im glad the hybrid was made, but its FAR from a sustainable answer.

smart51 - 15/10/08 at 03:08 PM

quote:
Originally posted by dinosaurjuice
quote:
Originally posted by BenB
One of these days the governments will realise that re-using old cars is actually quite a green thing to do!!!!


keeping an old car on the road is far better for environment, relatively speaking. the reduced MPG and higher emissions is EASILY offset by the masses of energy that goes into manufacturing a new car with slightly higher MPG and lesser emissions. Some clever researcher calculated that over vehicle life (the most important green issue) a new discovery 3 is better for environment than a prius!


The "embedded energy" of a typical car is about 10% of the total of its lifetime's use, which is often taken to be about 10 years, which is not that much. Scrapping your 1.6 focus, for example, and buying the diesel version means you save the embedded energy back from fuel consumption in under 5 years. Keeping your 10 year old focus running for another 10 years is worse than scrapping it and buying a new diesel to replace it. Of course, keeping the old 1.6 running is better than buying a new 1.6, obviously.

It would be worse still if you were still driving a 1988 Ford Escort. The 1.6 Focus is would pay for itself in 6 years over the escort and the diesel would pay for itself in 3 years.

If your car is a classic with historical value or is likely to be a classic, keep it running for the sake of history. If it is an old shed that will never be a classic or is too ruined to be restored, scrap it and buy an eco car instead.

smart51 - 15/10/08 at 03:32 PM

quote:
Originally posted by Mr Whippy
"some exceptions would apply ... But he explained that drivers would be unable to claim that highly polluting "rust-buckets" from the 1980s or early 1990s should be granted special status as antique vehicles."

so now some one is going to decide if your car is worthy of classic car status?

[Edited on 15/10/08 by Mr Whippy]


That's the problem isnt' it. A knackered old Austin Maestro obviously isn't a classic but who is to decide whether your Alfa of the same age is classic or not?

There's no good environmental reason for keeping a plain old car on the road, the best thing is to scrap it. We shouldn't crush genuinely classic cars though.

Perhaps old cars should only be allowed on the road for, say, 2000 miles per year. Genuine classics are cars that owners want to keep for decades and who wouldn't drive them for 10,000 miles per year in any case.

MikeRJ - 15/10/08 at 05:58 PM

quote:
Originally posted by smart51
There's no good environmental reason for keeping a plain old car on the road, the best thing is to scrap it.


That is way too broad a statement to be universally true. The difference between similar vehicles that are say, 15 years apart are simply not that great.

Take for example my old Astra GTE which used to return 40mpg on a run and 35-37mpg on my daily commute. Lets look at the modern equivalent in terms of performance, which would probably be the Astra 2.0T. Hmm, it weights over 300kg more, is slightly slower even though it has an extra 17bhp, and only manages 31mpg. How long will that take to pay back the energy taken to make it?

AndyGT - 16/10/08 at 08:14 AM

here in france a car that is more than 30 years old is registered to a government body and the car automatically can have classic status. At this point you have one MOT and then thats it for the rest of the cars life, no more MOTs.

You have several coupons and have them stamped if you need to go out of the region whilst driving it. If not the insurance is nil and void!!! Simple and easy and no need to go crushing old cars for the sake of it.

smart51 - 16/10/08 at 09:24 AM

quote:
Originally posted by MikeRJ
quote:
Originally posted by smart51
There's no good environmental reason for keeping a plain old car on the road, the best thing is to scrap it.


That is way too broad a statement to be universally true. The difference between similar vehicles that are say, 15 years apart are simply not that great.

That would be true in isolation, look at the context of my posts where I talk about scrapping more polluting cars and replacing them with less polluting cars.

Take for example my old Astra GTE which used to return 40mpg on a run and 35-37mpg on my daily commute. Lets look at the modern equivalent in terms of performance, which would probably be the Astra 2.0T. Hmm, it weights over 300kg more, is slightly slower even though it has an extra 17bhp, and only manages 31mpg. How long will that take to pay back the energy taken to make it?

Here's what I said "Of course, keeping the old 1.6 running is better than buying a new 1.6, obviously" I did use fords as an example, but it would also apply to your Vauxhall.


[Edited on 16-10-2008 by smart51]

MikeRJ - 17/10/08 at 02:36 PM

quote:
Originally posted by smart51

That would be true in isolation, look at the context of my posts where I talk about scrapping more polluting cars and replacing them with less polluting cars.


Actually you simply said "plain old cars". My point is that not all plain old cars are the filthy, smoke belching monsters that they are made out to be.

quote:
Originally posted by smart51
Here's what I said "Of course, keeping the old 1.6 running is better than buying a new 1.6, obviously" I did use fords as an example, but it would also apply to your Vauxhall.


And I agree with this. My reply was in response to the post you made after this where you stated:

"There's no good environmental reason for keeping a plain old car on the road, the best thing is to scrap it."