Lead substitute

[Forumadmin]

Heinz Kuntze just phoned me with an end to the long saga of three bent pushrods, head changes ....

Anyway it appears that flush out of the petrol tank and new petrol was the cure. The petrol in there was over a yera old and had lead substitute in it. The valve guides and throats were coated with a thick black goo. Could it have been sugar? Heinz was telling me his garage related a tale of a farmer who used mollasess instead of oil on a tractor. It had a similar affect of the whole engine seizing solid, twice, the garage went to investigate on the farm and found the problem.

[paul wilks]

So I guess this is a warning not to use lead substitutes! Has anyone experienced problems with using lead free petrol with their Jowetts?

Paul

[Keith Andrews]

Lead in petrol was one of the greatest multi billion dollar rip ofs of the 20th century with 1 huge multinational company having the monoploly/
Lead wasnt used pre war, except for supercharged engines.
Post war was a cheap way to increase octane when added...then came all the marketing proganda abut lubricating valves and preventing valves burning....which happens if an engine timing is tunesd to the higher'octane' then filled with non lead without changing timing.
You say "what about modern cars ment to run on 96 but run ok on 9?" ...the old cars where not computor controled and could not adjust timing accordingly
Then valve resession and needing hardened valve seats...its going to happen with leaded and unleaded with bad timing...and yes if the timing is incorrect with hardened seats they do not ressess as quick when the timing is not adjusted

Its not just timing but also mixture....higher the octane of non leaded fuels the less BTU per volume which requires bigger jets and more advanve for the lower burn speed.
Note higher octane has more BTU per weight...sounds screwed up? no... higher octane has a lower spefic gravity.
Increase octane increase advance
Increase DCR dynamic compression ratio decrease advance
With older cars which have low dcr or more accruately peek pressure, and running modern 91 octanes on compressions designed for 65 to 75 octane, the advance and re jetting is very much a balancing act.

[Tony Fearn]

The valve guides and throats were coated with a thick black goo.

I spoke to Geoff McCauley at the Ex-employees' get together and he's also had the same problem with an engine including a bent push rod!

Might be Heinz and Geoff should get together and swap stories and then let the membership know by a little letter in the Jowetteer mag.

Tony.

[Chris Spencer]

I have just covered a hundred miles or so this weekend in my Rover which had been stood for 2 years while undergoing a major mechanical rebuild - the fuel in the tank had been treated with Castrol Valve Master lead replacement and also stood in the tank for the last 2 years - the car started without issues and runs very well - I would always reccomend using a well known branded product when comes to such things as additives / oils etc - maybe not the cheapest route but probably the best policy.

[Keith Andrews]

I would not recommend any except for the occassional fuel additive for injectors, and additive for limited slip diffs..which lock up if dont use it.
Its all marketting propaganda BS.
Yes unleaded fuel does go off over time

I run a dedicated LPG engine, daily..meant to have special oils, additivesc...I change oil filter 2 x a yr, flush radiator once a yr, LPG is so called "known" to burn valves, rescession, hard on bores etc...dry fuel
did way over 100K miles we had to srip the engine after it was stolen...The machinist who does the heads "there is less rescention than what I would have expected from an old petrol engine" Bores hardly worn, bearing like just done 1000 miles.

The oil I used was what was on special, but not re refined....and this has been the same for all our cars.

OH once I get around 10K miles up I add slick 50 to an oil change, and repeat about 80K miles later (about 8 or 9 yrs later)
This is also used in my 1950s briggs and stratton 1950s vintage reel lawn mower, the chain saw, line trimmer, wifes car etc.
I add 2 stroke oil to my 2 stroke engines...only because cant buy 2 stroke pre mixed at the pump.

oil aready has additives, add more additives dilutes the oil lubriaction even more.....and do yopu really think castrol . valvoline keep on their chemists with high salaries, spend millions on research....just to stop the shareholders getting bigger dividends?...and the same for the major fuel companies?
Or that spending so much on research they have got it so horribly wrong?
Does the car manufactor recommend additives? No ..they can get out of warrenttees if you do use them thu.
Will fuel companies come to the party if a bad batch of fuel gets thru QC..yes...will they if you add additives, no.

And notice how the additive companys claim great improvements...improvements on which brand of oil??? or is it an improvement on the raw oil, no brand...which we cant buy and the oil companiies add to anyway.

I have never blown a engine, on the road or track, never had fuel issues or oil issues, never had valve ressession or thrown bearring or had to do a rebuild because of bearings....because of valve guides, but 150K + miles what would one expect?
I have run a cam, because used a non zinc oil on the run in...didnt read the instructions on that one.