Classic cars forum & vehicle restoration.

Pat Russell · Joined: 29 Jul 2009 Posts: 131

On ebay today there is a device that looks like chicken wire enclosing large white tablets that can be used to change non leaded petrol so it can be used in cars that need leaded petrol

It may be of interest ...can it really work?

pryantcc · Joined: 07 Sep 2009 Posts: 88

Nope!

...but if it makes you feel better, go for it!

Kelsham · Posted: Thu Sep 10, 2009 4:55 pm Post subject: magic pills

Hi, Just send me the money, the effect will be the same. These devices do not work. I use Castrol Valve master in my old cars and that does work. I dont think it compares with true unleaded but is ab acceptable substitute.
regards Kels.

Richard H · Joined: 03 Apr 2009 Posts: 2148 Location: Lincolnshire, UK

I've got one of these 'catalysts' in the fuel tank of my A35. The previous owner (who had it fitted) said it cost £80 and should under no circumstances be mixed with additives. He said he was sure the car ran better with it fitted. Well I've been driving it with no problems, it hardly ever runs on, although my previous A35 ran on nearly every time I switched it off. I ran that on Valvemaster. I find it hard to believe that the pellets in the tank are actually doing anything to protect the valve seats though! Shocked

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Richard Hughes

Pat Russell · Joined: 29 Jul 2009 Posts: 131

No, I had no intention of using it (I don't have the car for it yet!)I was just interested..
Thanks for all the replies..

Pat

Penman · Joined: 23 Nov 2007 Posts: 4756 Location: Swindon, Wilts.

Hi
I wonder what would happen if you ran the fuel through a lead pipe or suspended a lump of lead in the fuel tank.
Would it have the affect of "leading" the petrol?
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Any 2 from:-
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V8 V10

baconsdozen · Joined: 03 Dec 2007 Posts: 1119 Location: Under the car.

These devices along with the magnets to stick on fuel lines and the spark boosters are total junk.
Ebay is pretty much their last refuge.

Pat Russell · Joined: 29 Jul 2009 Posts: 131

mikeC · Posted: Sat Sep 12, 2009 10:33 pm Post subject:

Pat, when you get your bullnose, you won't need to worry about running on unleaded anyway. Lead was only introduced into petrol in the late twenties, and running unleaded petrol is not an issue if the revs under load don't exceed 3,500 -4,000 (which the bullnose won't!).

Pat Russell · Joined: 29 Jul 2009 Posts: 131

Nic Jarman · Posted: Sun Sep 13, 2009 11:33 am Post subject:

I tried valve master in the Talbot although the engine was made to run on unleaded. It ran better as the octane value seems to be lower now. Next time I fill up I will try super unleaded. It is a case of trial and error. You will not damage your engine by trying these different combinations. These engines can run on ethanol but I have not tried it.
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Pat Russell · Joined: 29 Jul 2009 Posts: 131

Jim.Walker · Joined: 27 Dec 2008 Posts: 1229 Location: Chesterfield

Why all this fear about unleaded petrol???

The worst that can happen over many more miles than classic cars are ever likely to cover in the future is the 'pocketing' of the exhaust valves in their seats. We used to run a fleet of taxis on propane gas (which is unleaded fuel) back in the 1970s/80s. We never had trouble within the normal mileage of most engines except that Austin/Morris B type engines did show signs of pocketing after around 100,000 miles, but with no perceptible effect on performance.
My current car (pictured above left) with a 1968 Triumph 2000 engine has covered almost 150,000 miles, about the last half of that on unleaded petrol and I have never had to increase the rocker clearance (the first sign of 'pocketing) in all that time. By the time 'pocketing' might become a problem the money saved by running on unleaded will undoubtedly have saved enough money to have valve seatinserts fitted!
Much more important is that the petrol you use is of a high enough Octane Rating (RON) for your engine, bearing in mind that engines requiring up to 100 RON were produced in the late 1960s. My engine falls into that category and years ago I reduced the Compression Ratio by fitting short reach sparking plugs instead of long reach. That stopped detonation on the (only unleaded available then) 95 RON unleaded with no detectable deterioration in performance.
Just imgine how much money I have saved in about 70,000 miles! Probably enough to buy a replacement engine!
By the way. I did initially try octane boost additives to stop the detonation. They were expensive and did no good.
Now 97 RON is available, I could possibly go back to long reach plugs, but why bother? The car still goes like excrement off a digging tool!
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Pat Russell · Joined: 29 Jul 2009 Posts: 131

Castellated nut · Joined: 08 Dec 2007 Posts: 91 Location: Shropshire, UK

There's a bit more to unleaded petrol than just the removal of the lead. In order to achieve the 95RON octane all sorts of noxious compounds are added, some of them very volatile. Today's unleaded fuel is a totally different proposition to the fuel of the 1920s. Super-unleaded has more, and even nastier stuff in it and is definitely to be avoided!

As far as valve-seat recession is concerned, I'm sure it's true that it is not really an issue for older low-revving engines, certainly over the mileages most of them are likely to be used. It might be a problem for heavily used later cars; the B-series BMC engines are said to be prone to it.

Jim, changing to short-reach plugs will have had no noticeable effect on the compression ration of your engine. According to my reckoning, the combustion volume (at TDC) of a standard 9.1:1 CR 1998cc Triumph 2000 Mk1 engine cylinder is 41cc (40cc for the 9.25:1 Mk2). The difference between long-reach and short-reach plugs won't be more than about 0.5cc. Any reduction in detonation will have been caused by the change of plugs, or perhaps by the effect of 'pocketing' the plug points. Quite a lot of engines have their plugs set into a small chamber set back a little from the main combustion volume. I think the idea was that it gave the flame-front a little time to get going before it hit the main volume, so that when it did, it went with a bigger bang! I might try your method on my own 2000; at the moment I use Miller's VSP Plus, which works out at 50p or more extra per gallon.

Of course now we have to contend with the ludicrous eurocrap biofuels directive, which, as far as I can understand it, rots out your fuel tank and destroys fuel-lines, pump, and carburettor.