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Fuel Catalysts

Posted: Fri Sep 26, 2008 6:43 am
by ferret76
G'day all,

Has anyone had any experience with in-line fuel catalysts? I'm considering installing one but just wondered if anyone has had any catastrophes. Basically, I'm sick of spending a fortune on fuel additives every time I fill up. Cheers.

Posted: Fri Sep 26, 2008 8:11 am
by RogerRust
I don't believe in magic.

I don't believe that magnets improve your mpg or that you can run your car on water.

A bottle of valvemaster goes a log way.

Sorry.

Posted: Fri Sep 26, 2008 8:52 am
by rayofleamington
If fuel catalysts , scrap tin or magnets actually did anything useful at all, they would be fitted in all new cars. They aren't, so that's the end of a story.
Valvemaster and many other products were proven on independant testing using an A-series. Some products failed badly but are still on sale!

If you plan to do more than ~50,000 miles in the same Minor then it's cheaper to have the head changed for unleaded than use an additive.
I have lots of different classics, none of which do high mileage, so a good additive suits me fine.
If you're going to exchange the head anyway, you can avoid using additive and keep using the car until the head NEEDS replacing - this is probably delaying the inevitable but some cars can go on for a long time before getting head trouble.

Posted: Fri Sep 26, 2008 12:14 pm
by simmitc
I endorse fully the comments above. Independent research and my own experience says forget the catalysts and stick with additives. Even with "unleaded" heads, many suppliers still recommend using an additive from time to time. My personal recommendation: Castrol Valvemaster.

Posted: Fri Sep 26, 2008 3:05 pm
by dalebrignall
i had one and was not impressed.you will use a lot of valvemaster to recoup the cost of a catalist

Posted: Fri Sep 26, 2008 6:46 pm
by bmcecosse
Fuel catalyst - smoke and mirrors may work better! Unless doing high/hard mileage just run the car on unleaded without any additives - it will be fine ! I've never used any in 8 years of Minor ownership. It's low mileage - but when it's running, it runs hard!

Posted: Fri Sep 26, 2008 8:00 pm
by Gareth
I used one of those for about three years. Engine was smooth and (relatively powerful).

Until it dropped a valve.

In my defence, it came with the car and, since it was in the tank (and may well still be in there, taking up space) I said I'd keep it in there until the worst happened. Which, of course, it did; on the Hagley Road. Joy of joys.

An unleaded head is by far the best way to go, if you're converting to unleaded. As for smoothness, I usually use super unleaded.

Posted: Fri Sep 26, 2008 10:22 pm
by bmcecosse
I doubt the dropped valve was anything to do with your catalyst! Only result of running without leaded petrol is a possible settling of the exhaust valves into their seats. provided the exhausts are set at 15 thou, and you keep an eye on the gaps - all will be well for many many thousands of miles.

Posted: Sat Sep 27, 2008 1:45 am
by rayofleamington
Only result of running without leaded petrol is a possible settling of the exhaust valves into their seats.
The valve seat does not always wear evenly - if it gets a pocket of erosion, the end result will be a damaged valve.
I've replaced a head on an 1100 engine (not Minor) where the seat was so burnt that it did not exist - you could push the valve right into the port! This engine had been run for 3 years on unleaded as the owner wanted to save money and 4 star was more expensive...

Posted: Sat Sep 27, 2008 9:07 am
by Gareth
Sorry, just remembered - it wasn't a dropped valve, the seat had chipped away at the edge which caused a loss of compression...

Sorry, I'm not very technical!

Posted: Sat Sep 27, 2008 9:48 am
by moggiemadman
Ive been running dolly on unleaded for a while now and clocked up over 2000 miles,Still going Strong.FINGERS CROSSED!.

Many Thanks
John

Posted: Sat Sep 27, 2008 5:08 pm
by Kevin
It also depends on the speeds you drive at as I thought the tests proved that valve recession isnt really a problem untill driving at over 55mph constantly, many owners only poodle around locally so it shouldnt be an issue, but obviously the amount of lead memory affects things and it cant be measured so varies from engine to engine.

Posted: Sat Sep 27, 2008 7:07 pm
by bmcecosse
Well - valve seats were always liable to 'pitting' etc - nothing new there - but my experience of unleaded valve seat recession is that it simply sinks the valve evenly into the head. This of course closes up the valve gap - and if that's not caught/corrected quickly enough, that's when localised 'chip or hole' develops. So - set them at 15 thou - and check them from time to time, resetting as necessary. I have picked up heads (very cheaply!!) where the valves are quite deep into the head - but the seats are still perfectly viable. Ideal for fitting larger valves - and starting all over again!
And yes - pootling about at lowish speeds is unlikely to EVER wear the seats. I hammer mine pretty much relentlessly - and so far no seat damage either!

Posted: Sat Sep 27, 2008 7:44 pm
by linearaudio
I was toying with the mearest inkling of an idea of trying one of those catalysts, and looked into it a bit. I think it was the AA who did a "scientific" test on 3 cars with and without the catalyst. They showed approx 10 percent improvement in fuel economy using the catalyst, then dismissed that as probably frictional reduction due to the engines being comparatively new. I felt they were determined not to believe! However, testimonies such as given by Gareth don't do much for me-if the device was already in the car when you bought it, how do you know how good it is? The old one about all the car manufacturers using it if it worked doesn't necessarily hold, as tin is expensive and not particularly healthy, also there are other metals in there which could be even worse. And its quite possible that something nasty may appear in the emissions due to altering the fuel makeup. I'm by no means a convert, but the design history (WW2 Rolls-Royce) lends some credance, though I've seen that dismissed as "those Merlin engines were understressed compared with modern engines"! I imagine they were at the leading edge of material/fuel technology at the time, and if one of those dropped a valve....
The whole valve recession/burning bit varies with differing quality of iron used in the head casting (earlier/pre a+ better?) Different valve steels, and probably compression ratio etc would play a part. I had some atrocious valve seat burning problems with Metro engines before we had unleaded!

Posted: Sat Sep 27, 2008 8:05 pm
by Kevin
I think it was the AA who did a "scientific" test on 3 cars with and without the catalyst. They showed approx 10 percent improvement in fuel economy using the catalyst,

Hmm don't remember that one but all the tests I remember including the FBHVC ones proved that they made no difference whatsoever and also showed that some of the additives didn't work either, also if I remember correctly not one of the catalyst makers would allow their products to be tested by the FBHVC, and if they really did make a 10% improvement to fuel consumption I think all new cars would be fitted with them as standard as the amount of tin involved is tiny.
Sorry but I cannot believe the claims made by them one little bit if they wouldn't allow them to be tested by an independent body.

Posted: Sun Sep 28, 2008 9:22 am
by Gareth
The dealer I bought Phyllis from (long since closed) showed me the 'magic beans' when he put them in.

Maybe they did something. Maybe they didn't. All I know is that the nay-sayers on here warned me that they wouldn't work, but if I was happy to use them until the head went, then that was fine. So when the head went, I got it changed. Most of my driving is fast A-road stuff and twisty B-roads, so very little town-bound running.

Posted: Mon Sep 29, 2008 12:18 am
by ferret76
Thanks all for your replies. I reckon I'll stick with what I know and keep using the additives.

Posted: Mon Sep 29, 2008 7:05 am
by bmcecosse
For hard driving I agree - provided the additive has genuine tetra-ethyl lead in the mix!