10 replies to this topic

[nestoreims]

Hi there,

I have a Mini from 1976 (Leyland if I'm correct), and I used to put LRP in it. Unfortunately, the provider (enemalta) is stopping to sell LRP in Malta.

Does someone knows if I can put unleaded or if I need to put an additive (which one?) everytime I need to fill the pump?

Thanks a lot!


Some references:

http://www.timesofma...ad-for-lrp-fuel

http://www.enemalta......OKLET ENG.pdf

Model:Austin Mini
Year:1976
Description of problem (please be as in depth as possible): End of the road for LRP fuel in Malta



Any non-standard parts that might be involved with the problem?

Edited by nestoreims, 26 January 2011 - 12:47 PM.

[Ethel]

It will run on unleaded, but the exhaust valve seats will eventually erode. It might take a fair while if it's had 30 odd years of lead tetrajobbystuff through it.


You could use an additive, or save the cash for having unleaded valve seats fitted when it gets bad enough.

[Mini Mad Drakeley]

you can run un leaded if it has a lead additive but whats LRP?

[nestoreims]

It will run on unleaded, but the exhaust valve seats will eventually erode. It might take a fair while if it's had 30 odd years of lead tetrajobbystuff through it.


You could use an additive, or save the cash for having unleaded valve seats fitted when it gets bad enough.

Hi Ethel,

Thanks for the quick reply! So you are saying that as the car has 30 years of LRP, it contains residual lead that will mix with unleaded?

After how many miles do you think the engine will figure out the trick and have issues?

[nestoreims]

you can run un leaded if it has a lead additive but whats LRP?

http://en.wikipedia....lacement_Petrol

LRP - or Lead Replacement Petrol is a fuel developed to provide an alternative to petrol (gasoline) containing a substance know as Tetra-ethyl lead (TEL), a compound of lead in liquid form originally added to petrol to increase its octane rating. A side effect of adding TEL is that a layer of lead compounds forms on the valve faces of the engine, retarding wear.
Lead is very toxic and lead compounds in exhaust gases escape into the atmosphere causing pollution. Impacts on human health are widely documented. This led to the introduction of lead-free petrol.
With normal lead-free petrol an adjustment to the engine's ignition timing solved pre-detonation problems (pinking or pinging) caused by the lower octane rating, but this did nothing to prevent accelerated valve wear. The use of lead in petrol had allowed the machining of valve seats directly in the cast iron or aluminium cylinder heads (or block of side-valve engines). Over time these seats would heat up, erode and even micro-weld the valve to the seat causing rapid damage.
LRP (Lead Replacement Petrol) was introduced containing other metal salts (such as potassium or manganese) to address the issue of valve wear.

[Ethel]

It's hard to say, but it will be gradual rather than catastrophic, I certainly wouldn't worry about missing the odd dose of additive if you go that route. Good excuse to fit a modified head if you wanted one - unleaded seats wouldn't add too much cost while the work is being done.

[Guess-Works.com]

LRP will have been washing your valves anyway... mainly because it does not contain the all important TEL, otherwise it'd be 4 star... here in the UK LRP was unregulated (no BS number or Kite mark ) so you could be putting pig sh*t in your tank and you'd be none the wiser...

Best thing to do is run unleaded with an additive, and if you can get hold of one with TEL in all the better....

Regarding seat recession, this can take years, but like wise it can also take minutes.... your car, your choice....

[two_spanners]

Another question on unleaded heads

I've got a 1979 Mini 1000 with the original engine. I've seen a good condition 998 unleaded head for sale at a very reasonable price. Rather than converting my original head to unleaded , can I just bolt on a replacement head or are there issues? Would I have to get the head skimmed or something?

[Guess-Works.com]

Straight swap, but you may need to tweak your timing a little if you've been using an additive with an octane booster.

[two_spanners]

Thanks for that. I'll give it a go.

[thehelstonian]

let us know how you get on