The use of Fuel Additives

[Rouseyboy]

I've only had the stag for a year, and have been adding a generous slug of Redex additive at each petroltank refill.

Which one is best? There are so many - and I wondered if I should be using Redex for unleaded or some other type.

I am not a technical bod -my butler handles such matters (Lenthe Triumph man) so please keepany reply in laymans terms!

..... Dave

[DJT]

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Rouseyboy wrote:

so please keepany reply in laymans terms!

Easy. Don't bother. Stag is already set up for unleaded.

Dave

[Guest]

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Hiya Dave,whils Stags are fitted with hardened valve seats, there is an issue with the exhaust valves, most cars will run with "lead memory" but nobody knows for how long.

Keep using the additive, but pick one and stick with it, some are based on different compounds and they don't all mix. The F.B.H.V.C. the gugu's in such matters, did exhaustive testing, and all the good ones carry their reccomendation on the label, you don't need the ones with an octane booster, just knock the ignition timing back to 12 degrees advanced.

A small point to be made here, the makers of thosecylinders of tin / whatever, that go in the fuel line, refused to submit them for the tests,they don't work, I'm amazedthey're still allowed to sell them. Martin.

[mad cyclist]

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unless your banging away at 80mph everywhere an engine never run on leaded would do many miles, the engine was built for the americans that have had unleaded since the 70's and engines had to be compliant before that.

it got my rag up in the classic ads article that said an additive was needed. i never have, and know of other engines thatn have done 100k on unleaded with original spec exhaust valves.

[NickA]

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I normally bung one of these in every other fill

http://www.millersoils.net/M3_cgi/mi...rt&cart_id=

[DJT]

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Martin Stevenson wrote:

Hiya Dave,whils Stags are fitted with hardened valve seats, there is an issue with the exhaust valves, most cars will run with "lead memory" but nobody knows for how long.

I agree that there were some exhaust valves used in the '80s and early '90s that were suspect (I got caught that way thanks to a well-known supplier :X) but all OE exhaust valves were unleaded compliant and all replacement valves since the mid '90s should be.

I would guess that most of the dodgy ones would have been eliminated by now. Mine lasted 25,000 miles on unleaded only and two burnt outtowards the end ofa long, frequently 80mph+, run from Devon to Durham and back.

I agree with your philosophy if you drive the car hard and require peace of mind, but the half-used bottle of Millersadditive thatthe previous ownergave me with my Stag hasn't been touched since I got it.

Dave

[Guest]

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How long an engine will run on lead memory, depends on a large number of variables, average speeds, sustained speeds, how long was it allowed to warm up, how long between runs and so on, there are still cars with "soft" valves running about, and I think it's too great a risk, it's no good saying, mines OK, the differing lives of different cars render that unhelpful.

It's a sensibleprecaution, like 3.000 mile oil changes, why NOT do it ? Martin.

[Ian B]

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had my engine back now for 7 years since rebuild, approx 3000 miles per year, never used anything other than unleaded - IMO additives are a waste of money, with petrol at £5.50 gallon why bump it up to £6.00 with an additive, Darling will do that for you.

[Guest]

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Ian B wrote:

had my engine back now for 7 years since rebuild, approx 3000 miles per year, never used anything other than unleaded - IMO additives are a waste of money, with petrol at £5.50 gallon why bump it up to £6.00 with an additive, Darling will do that for you.

In that case you almost certainly have the right valves, it's not knowing that would trouble me. Martin.

[V Mad]

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Its not a problem until the valve clearances drop to zero, then the valve seats start to burn out. Its easy to check valve clearances too so no need for burnt valves either way.

[Peter Hills]

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As VMad has just said,

'it's no problem until the valve clearances drop to zero, then the valve seats start to burn out. Its easy to check valve clearances too so no need for burnt valves either way.'

The action you need to take for fitting 'extra-hard' seats and valves on an unleaded conversion is exactly the same as you would take if you needed to have your heads refurbished.

FWIW

Peter

[Guest]

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Peter Hills wrote:

As VMad has just said,

'it's no problem until the valve clearances drop to zero, then the valve seats start to burn out. Its easy to check valve clearances too so no need for burnt valves either way.'

The action you need to take for fitting 'extra-hard' seats and valves on an unleaded conversion is exactly the same as you would take if you needed to have your heads refurbished.

FWIW

Peter

Wrong, new seats are not needed. Martin.

[Moraystag]

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Gent's at every tank fill I normally pour in a bottle of additive. I was told that it would do no harm, by mechanic. Hope he was right. If not I'll stop now??

Mike

[V Mad]

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I cant understand the logic of using additives. If you buy decent oil, and change it every 12 months/3000 miles that's all you need.

If you factor in the cost of the additives how much moreis your petrol costing per gallon?

And when fuel prices go up we get angry!

JMTP

[NickA]

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V Mad wrote:

I cant understand the logic of using additives. If you buy decent oil, and change it every 12 months/3000 miles that's all you need.

If you factor in the cost of the additives how much moreis your petrol costing per gallon?

And when fuel prices go up we get angry!

JMTP

I guess it depends on your mileage and usage. My Stag's a hobby I really don't give a monkeys about what it cost to fill. If I worried about the ppm I'd use the small eurobox we've got instead.

I like the octane booster so I have the ignition set as per the ROM.I'vealso got a brand new from the factory head on the right handbank. Installedfour yearsgo.Don't think that'll have much of a "Lead memory"