Lead-Free Petrol Additives

[JLR]

I have nothing to suggest that my 1970 Herald 13/60 has been modified for lead-free petrol, so is there anything (other than price) to choose between the products offered by Castrol, Winn's and many others? Any recommendations? Would an additive do any harm if the engine has been converted? Also, is it necessary to substitute a ethanol-proof filter and associated hoses? Or is that only advisable using unleaded petrol without an additive? With thanks.

[Amy Wade]

A lot would depend on how you're using your car & how many miles you'll be doing every year. The lead in leaded petrol acted as a lubricant, especially for between exhaust valves and seats. Over the years the valves would have gained a certain amount of ongoing protection from the lead and will continue to provide some protection going forward, any damage caused by not running a lead substitute will be seen by the need to adjust the valve clearances more than expected. As the engine will probably need a full rebuild before it gets to 100K, my personal opinion is to not bother with the lead substitute, you'll get hardened seats & all the valves done when you rebuild.  If the engine has been rebuilt in the last decade or so, I would be surprised if the previous builder hadn't had the seats done as the cost is negligible when paying for the whole engine being done. 

With regard to the ethanol in modern petrol, you should be looking to replace all your hoses with R9 hoses & replacing things like your petrol pump diaphragm with a suitable replacement. Don't swap out your working old pump for a brand new one, most of the modern ones are not fit for purpose. I done away with my mechanical pump & have a Hucco electric pump instead. 

These are my personal opinions, others may advise differently, your best bet is to go with what you're comfortable with. 

[JohnD]

JLR,

When lead-free petrol was introduced here, the alarm in the UK's Classic Car community was extreme!    In fact, experience has shown that after many years of leaded petrol, the valves, in particular the exhaust valves, has inherited a "lead memory"     There is enough lead in the metal of the valve and the valve sea to prevent micro-welding, damage and wear when they get hot.   This opinion is echoed by that in the USA.  They had lead free petrol ten years before we did, and just carried on using the new stuff, with absolutely no ill effects.

Many feel that expensive lead substitutes are unnecessary, in normal use.   Driving at motorway speed for long periods, pass storming in low gear and stressing the engine or competition use may exceed the protection of the 'lead memory'.    If you are going to do those, or just to know you are completely safe, then steel inserts in the exhaust valve seats will remove any risk of seat recession.

John

PS Ah! I see that I echo Amy!  No doubt some naysayer  will be along shortly to cast doom and gloom on our opinions!

Edited November 14, 2023 by JohnD

[Clive]

Unless driving the car hard, you should be fine without additives. If worried, the club sells Castrol at about the best price anywhere.

As to hoses, yes, you need to check yours ASAP for signs of damage/splitting etc, and replace with GOOD QUALITY R9 or 14 hoses. Gates Barricade, Cohline are 2 decent ones. Do not even condsider the ebay own brand stuff, it seems to have an incerdibly short life. 

[thescrapman]

JLR, the only Triumph engines I have heard having issues (and experienced) with VSR is the MK1 2 litre engines.

not sure why.

[glang]

They have slighter higher compression and different valves?

[thescrapman]

20 hours ago, glang said:

They have slighter higher compression and different valves?

Got to be something like that.

Had wondered if it was the cast iron at the time, but Herald engines from same period don’t seem to suffer.

[JLR]

I am most grateful for all that helpful advice. Thank you all again.

[Amy Wade]

On 15/11/2023 at 07:56, thescrapman said:

JLR, the only Triumph engines I have heard having issues (and experienced) with VSR is the MK1 2 litre engines.

not sure why.

That's good to know, I'm eying up a Mk1 2000 that's been parked up in a barn for a considerable amount of time, I guess it's something I will need to cost into it.

[thescrapman]

9 minutes ago, Amy Wade said:

That's good to know, I'm eying up a Mk1 2000 that's been parked up in a barn for a considerable amount of time, I guess it's something I will need to cost into it.

Only worry when it goes wrong, mine had had the seats recut after a rebuild in the early nineties, and new valves fitted, so I suspect lead memory had less time to build up.

A few of the others I know of were driven very hard at times.