If you've got no......

[raceboy]

....cats is there any reason you couldn't use Lead Replacement petrol?
Would there be any point? Would it do any damage?
Just curious

[apache]

Nope, the only problem is with leaded fuel and cats, the cats dont like it.
Unleaded can screw up valve seats on older engines but not really an issue these days as most forecourts have lead replacement fuel.
If you have an older car with no cats bung what you want in it....except diesel, that would be silly

>> Edited by apache on Wednesday 23 April 11:39

[raceboy]

So if your Rover V8 is completly pussy free you can bung anything down it's neck
But would you see any difference on different fuels?

[pdV6]

AS long as the management system has a knock sensor to enable it to adjust the timing slightly for different RON fuels, you should be ok.

[raceboy]

Now I didn't think the trusty old Rover V8 had a knock sensor
So what RON is LRP compared to 'normal' Unleaded

[apache]

apache said:

raceboy said: So if your Rover V8 is completly pussy free you can bung anything down it's neck
But would you see any difference on different fuels?

the higher the octane rating the more efficient is generally the rule. I had an old Kawasaki 400 which I ran on aviation fuel (no knock sensors or timing adjustments) bloody thing went like a rocket, ran smoother and the tailpipe was a nice pale grey.
I would use Optimax if poss cos it's rated at 98 which is the highest available on the forecourts

edited to add, knocking (or pinking) is only an issue if you are using low octane fuels

[raceboy]

The reason I'm asking is my 4.0 Chimaera is now De-Cated, previously when it had cats I tried it on Optimax and it ran like a dog, Super made no real difference, and it was quite happy on regular low fat unleaded, now it appears I also have the option of LRP.
Think I might just have to try a few tankfulls of each and see what happens

[pistol pete]

raceboy said: Now I didn't think the trusty old Rover V8 had a knock sensor
So what RON is LRP compared to 'normal' Unleaded

Depends how old it is -if it ain't fuel injection/got a box if electronics then wouldn't this involve a couple of spanners on the distributor mounts and rotating it a bit till the engine sounds about right (or you could use a strobe gun an do it by the book). -the old fassioned way of adjusting timing...

Pete

edited to say u just said what car it's for, so i dont think any of that will apply somehow....

>> Edited by pistol pete on Wednesday 23 April 13:05

[apache]

raceboy said: The reason I'm asking is my 4.0 Chimaera is now De-Cated, previously when it had cats I tried it on Optimax and it ran like a dog, Super made no real difference, and it was quite happy on regular low fat unleaded, now it appears I also have the option of LRP.
Think I might just have to try a few tankfulls of each and see what happens

mmmmn, sounds like you need to back the timing off a little, no big deal and worth doing to enable you to benefit from using a higher octane fuel

[shpub]

....cats is there any reason you couldn't use Lead Replacement petrol?
Would there be any point? Would it do any damage?
Just curious

I wouldn't use LRP. Not standardised with different companies using different chemistries which may interact and not do your engine any good. All the engine builders I know say avoid like the plague!

I trust you have rechipped the ECU when the cats were removed...

More details on the bible and in the unleaded FAQ on my website.

Steve
www.tvrbooks.co.uk

[raceboy]

Well it's got to go back to the garage to have a few bits sorted when the replacements are in stock so may well get that done at the same time

[shpub]

raceboy said: Well it's got to go back to the garage to have a few bits sorted when the replacements are in stock so may well get that done at the same time

If you are going to refit the cats then don't use LRP. You don't want traces of that stuff in the engine as it may poison the new cats.

[raceboy]

Oh there not going back in it's going back for new dampers and a few other bits.
This ECU re-map bit, thats not been done, my greasy monkey said it wasn't nesaccery as the Lambda sensors are still in, well new Lambda sensors as the old ones had there heads knocked off as the pre cats shot past them

[shpub]

So have you just removed the pre-cats or the precats and the main cat?

If the car has been truly decatted it needs to be rechipped as the sensors don't like operating without a cat. You also need to inform your insurers as the engine is now modified.

Steve
www.tvrbooks.co.uk

[JonRB]

You're also going to need an extremely friendly and understanding MoT Testing Station if you are to have any hope of passing your emissions test on your next MoT.

[raceboy]

The whole lot are on the garage floor, I'll have another word with my greasy monkey as he didn't seem to think it was worth while re-chipping it
I know what you mean about the insurance bit, but I'd be impressed if you could tell they've been removed

[gazzab]

Not sure I am convinced that you do need to inform insurance company.

[raceboy]

JonRB said: You're also going to need an extremely friendly and understanding MoT Testing Station if you are to have any hope of passing your emissions test on your next MoT.

You're not wrong but it was actually MOTed after the removal and got a nice clean pass

[shpub]

gazzab said: Not sure I am convinced that you do need to inform insurance company.

The engine has been modified. Your are obliged to inform them. If you don't, you run the risk of having a future claim turned down.

As for telling... all you need to do is tap the exhaust manifold. The empty ting is a bit of a giveaway. As for checking... been done many a time.

If you don't think it is necessary then fine but it is your insurance that is at risk.

[raceboy]

So question for the de-cat Cerbera boys, do you inform your insurance bods or not, wonder how pleading ignorance would fair?