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MG MGB Technical - Fuel Cat conversion

I curently have a 1970 BL that is running on LRP. I would like to run it on ULP as I have read a lot of articles on the bad points of Lead Replacement Petrol (LRP). The motor is in excellent condition and I do not want to pull it apart to change the valve seats, and was reading about a product called Fuel Cat. Speaking to the supplier here in Aus they assured it is exactly what it was made for (used since the WW2) and is a tin based catalyst that will boost the octane rating of ULP and lower the burn temperature. These units fit into the fuel line. Has anyone out there had any experiences with this or similar cataylst's before?
Steve Dellaca

Hi

I ran my old 'leaded only' Land Rover for about 20000 miles on unleaded with a Broquet fuel catalyst in the tank without any problems. The tappet gaps didn't change significantly during that time.

I kept an accurate fuel consumption log but didn't see any fuel economy improvement.

At a CR of only 8.0:1 octane boost wasn't a factor.

Don
Don

The 'Fuel Cat' advertising was withdrawn in the UK by tranding standards after it was proved that it didn't work (or rather, it wasn't proved that it did work, I can't remember).

I believe the castrol additive is very good, and doesn't work out too expensive.

fwiw.
--
Olly
Oliver Stephenson

Don and Olly, thanks for your comments so far. The Fuel Cat supplier here did make comment that as far as he was concerned, the previous claims from their advertising about improved fuel economy and improved emmission was not to be expected, but the fact that the tin cataylst actually allows running on ULP is true, so he says. This previous claim on increased fuel economy and improved emmissions not being substanciated may be why the advertising was removed.
My interest is not fuel economy or emmission improvement, but will the engine run well without damage on this system. The additives that is put into the fuel tank when refueled is a tried and proven method as you have stated Olly, but surely not having to carry a separate bottle of additive. worrying how much to put in etc, can be overcome with this system if it works.
Don , your comments seem to tally up with other articles I have read, and this maybe seems to be what I am after
Thanks for the reply's so far

Steve
Steve Dellaca

I have a '69 B that has been running on unleaded fuel for about 20 to 30,000 miles or so without additives or catalysts and haven't had any problems so far. No noticed changes in tappet gaps or anything else. The engine is stock. I don't know if there is any difference between unleaded fuel in the US and Australia though.
Robert

Steve
The LRP may have a higher octane so switching to unleaded means two issues:
What will happen to the timing?
What about valve seat recession.

On the first point, you will need to retard timing slighlty although a number of people in the UK use Shell Optimax which has been independently verified as having a 98 Octane, and with an additive boost such as Millars can reach 100 Octane. Using a super unleaded like Optimax will eliminate the need to re-adjust timing and hence maintain current performance.

On valve seat recession, several specialists I have spoken to report no noticeable or immediate deterioration in the seats, as Rob mentions, too. The seats build up a memory effect from years of leaded fuel. On mine, as it was at 120k miles and getting close to rebuild, I didn't bother and opted to wait until the rebuild when an unleaded head will go on. A replacement u/l head is about £200.
Martin
Martin

Anyone with an interest in both Fuelcat and other similar devices should look at the Advertising Standards Authority website ie www.asa.org.uk and look for Fuelcat under adjudications. The Office of Fair Trading also issued a press release about this device in October 2000 indicating that claims made for it could not be substantiated including that for replacing lead in fuel.

If it seems too good to be true, then it probably is!
Alex Taylor

I had a Broquet for a couple of years on my old A+ engined Metro, no recession on that. However, it's generally accepted that the memory effect mentioned by Martin will protect the seats for some time, and in any case seat recession is pretty minimal unless you regularly rev the engine over 3000rpm (not much need on a B!). With regards to the claims of fuel cat devices, the CSMA is still pushing them and claiming they work - I find it hard to believe that they would do so if it really didn't do anything.

If I were you, I'd run on unleaded and see how you go. If you start to suffer from VSR then change the head (I paid £200 for mine from MGB Hive about 3 years ago). I know you say you don't want to pull the engine apart, but a head swap really isn't a big deal.

Tim.
Tim Jenner

Tin is not a catalyst. A catalyst must be a transition metal as nickel, rohdium ... Tin is just a simple metal and has not the ability to enter in a chemical reaction.

To protect your valve seats the material needs to be carried by the fuel, but tin as a metal is not soluble in the fuel.

Apart the allegation of the vendors, there are no tests carried out in scientific and controlled conditions which shows the efficacity of tin to prevent valve seat recession. If a car is able to run with a tin "catalyst", so it is able to do so with nothing as Robert's car.

Tetraethyl tin was used during WW2 by Russians as an octane booster, not for valve seats.
Jean-Marc Thély

This thread was discussed between 27/03/2003 and 28/03/2003

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