petrol - unleaded vs leaded

[rfullarton]

hello all

out of interest how many of your cars have been converted to run on unleaded .. and how many need to put in some lead replacement into the tank ..

if so how often do you put the lead replacement in ? do you use something like redex ?

thanks

[XenonJohn]

I use Tetraboost which is basically tetra ethyl lead. Low mileage per year so although expensive I don't use much of it.
Seems to be available now via some website run by Fuzz Townsend from Car SOS - and the price has gone up a lot too.

I spoke the the original seller years ago who seemed like a really decent guy and his take on things was to keep low profile, not advertise in magazines, just sit under the radar selling to vintage car enthusiasts, classic racing car enthusiasts and so on.

[MattH]

Ive never worried about the unleaded issue, and always used it. Never used additives either in my cars. We do put a bit of something in the Green Goddess but the Challenger runs on normal unleaded.
I think our Mopars had hardened valves and seats a long time before British cars did.

I did an experiment years ago on a Herald which was a daily driver, I just started using unleaded only and didn't do anything to the head at all, just drove it (quite hard). I had no issues at all and never lost compression or burnt anything out.

For our Mopars timing might need adjustment for unleaded compared to leaded but I wouldn't worry about valve seat inserts or engine strip. The mileage the cars do would mean years before any valve seat recession started to show.

[Blue]

Have used unleaded for years without hardened seats or any other additive, zero problems. I have long since held the opinion that we just don't do the sort of mileages that cause problems with valve seat recession, if indeed that is a thing, not entirely convinced there really is an issue.

[graham fury]

I've used super unleaded in my fury since I got it 2 years ago and have done 15,000 miles with no problems and no additives

[rfullarton]

interesting .. thanks guys

[Dave999]

I spent money on hardened seats on the head i am currently using. I know believe it was probably a waste of cash

personally i wouldn't bother next time...

you would only really need to do the exhausts and if you use stainless valves its not worth it anyway. they do not micro weld to the seat like standard valves did.

Dave

[morgan]

Unleaded. It burns. It goes bang. Dont do the miles to worry...i too think its not worth worrying

[YOS79]

There has always been pros and cons re hardened valve seat inserts that go back to the '80's/90's. (whether associated to ULP or not)

When in OZ and NZ I rebuilt hundreds of Holdens / Fords / Valiants. (6's and V8's) Daily drivers, taxis and competition engines. A lot of the time there was not one specific golden rule to determine if it is necessary. The quality and grade of cast iron for certain models seemed to create issues including cylinder head design. Variations in valve spring rates ... camshaft lift and duration ... valve stem seals ... all change wear caracteristics. A lot seems to go against the rules ... eg; 330Hp 265 I built in NZ ran on 95 octane ULP and never had an issue. (maybe due to the valve train mods this engine had) (no inserts)
A few bad examples that come to mind .... the first Falcon iron X-flow heads eat the seats and valve guides as do Ford 2.0L pinto heads which also destroy their seats and valves. Jag 4.2 XJ engines destroy their exhuast seats and guides yet they have inserts in an alloy head. Equivalent engines in both NZ and OZ wear differently .... whether that be due to slightly diffrerent refinement of fuels and or octane ratings ,,, and/or climate temperatures. The only common factor that more than less created problems was the use of LPG or CNG (commonly used in OZ). Yet again ... in Oz I rebuilt a 6 cyl engine that had done over 450k kilometres on LPG which only needed a normal amount of seat cutting and original valves refaced.

It seems to be a preventative measure more than a necessity according to engine type, but someone will always debate the issue either way. If installing 12 inserts safe-gaurded an engine that does lot of miles or got hammered on track on a regular basis it might be worth it. Therefore it comes down to cost. I will more than likely do my cyl head when rebuilding my engine next year as I can do it myself, but if I had to pay for it ... probably not.
Hopefully you can decide for yourselves or check confused.com

CHEERS

[Blue]

Interesting bit of insight there, thanks for that.

[Steve]

I was talking to a guy recently who rebuilds engines and does valve seats etc and he said that he stopped doing Mopars because the castings were so tough that he was always wearing the bits when drilling them. He said they are tough as old boots from the factory and not worth doing in most cases. I did what Matt suggests (and think most of us do) and advanced my initial timing and limited total timing. I use Shell higher octane petrol when I can and that's it.

Cheers Steve

[Adam]

The SBC that was in my 55 when I bought it had the worst valve seat recession, and valve guide wear, that I've ever seen, presumably from running unleaded for years in the USA. I replaced the motor anyway, so it didn't matter, but it made me cautious. Course it was a Chevy...

So I empty a bottle of Millers VSP into the Dodge before hammering the valves on a long motorway trip, but I don't bother for bimbling about locally. Haven't had the heads off yet to check. I've left the timing at 34 all in, and it will pink a bit on supermarket fuel, so I try to use Shell V-Power where possible. Seems to be OK on Tesco 99 too, which is a lot cheaper.

[Derek]

I put an inline lead thing on the Charger years ago, never had a problem, but then again I don't know if I would have had a problem without it, inside the casing there is lead which the petrol passes over, I took it off recently to blow it out, I put it back on after the fuel filter this time where as before it was before the fuel filter.

[Steve]

just a follow on from this....the increase in ethanol in fuel and its destructive properties were discussed at great length at the NEC this weekend. Ive ordered some of this....

https://www.frost.co.uk/ethomix-corrosi ... ction.html

The Frosts stand was sold out of it and seems to be posing a real problem for the fuel systems in our old cars

Cheers Steve