What fuel to use????

[Tom Bishop]

F*&k the environment....

Use LRP and you are safe.

Lead free fuel was made for Catalytic converters. They look after the enviroment, not the fuel.

[stew 89]

ok so just to be clear on this if the head was rebuit localy. with un-hardend seats than the unleaded would do some real damage. but if the head is stock its fine to run un leaded. so my 77 2l kombi can run on the green stuff and not the red? but i think the moter was rebuilt befor i got it about a year back by the previoce owner. so should i stick to LRP? just to be safe?

[bugspray]

Stew! Dude you make it soo complicated..
Non rebuilt head/engine - unleaded or leaded.
Rebuilt with unhardend seats- leaded only.
Maybe try and ask the PO what seats were used. Where in durbs you at?

[stew 89]

bug spry my good man. thank you for clearing the fog

i think i will check with the PO about that.

im curently based in glenwood. your self?

[bugspray]

Schweet man. im from the North side. ballito. Keep it cool. Enjoy the bug.

[Cyberbeast]

Is there anyone that runs their air cooled vehicle on Unleaded Fuel? I'd like to know, please!
Let us all know... post your situation here... it would certainly clear up the "uncertainty", and then we can all relax

[bugspray]

I have used unleaded in my bug once.. About 10litres of it. I ran the tank dry before and then with it, didnt seem to have any prob with it. But yeah a long term user would really help... Anybody?

[bugspray]

I have used unleaded in my bug once.. About 10litres of it. I ran the tank dry before and then with it, didnt seem to have any prob with it. But yeah a long term user would really help... Anybody?

[Ron&Gill]

Deleted... I was talking kak

[Tony Z]

Something that doesnt sound right to me is the part where unleaded burns faster.... what you are basically saying is that unleaded has a lower octane rating. If a fuel is rated with a 93 octane, surely whether its unleaded or LRP the octane is still 93.
Another way to look at octane is to think of it as a resistance to ignition. A low octane burns very rapidly and easily. A high octane resists the burn which is why you can run higher CR ratios. Also, if you are going to be driving at part throttle for long periods and have a choice of fuels, for max economy, run the lower octane fuel cause it burns faster, causing higher cylinder pressures and thus better fuel economy. However, if you open up the throttle completely, the pressure in the cylinder (from the cylinder ebing completely fulled with air and fuel) might cause detonation. Catch 22 situation.

[Ron&Gill]

Deleted... not applicable...

[Tony Z]

OK, upon re-read, I may be a little incorrect . However, a lower octane rating generally does burn faster than a higher octane rating, simply because the higher octane resists the flame front more and requires more energy to ignite.
Diesel doesnt explode either, it is also a controlled burn, just much easier to control than petrol combustion.

[Ron&Gill]

Well, Tony, and everyone else, I was only half right, if that... I apologise . As a penance, I said 5 Hail Mary's, and read umpteen boring articles from about octane ratings, additives, stoichiometric combustion, Kettering and Ricardo's stuff, ...yawn...

Anyway, my following post is the result of my browsing...

[Ron&Gill]

What fuel to use? The short version is UNLEADED.

Why? Because where other auto manufacturers only changed valve seats in the mid-80s onwards, VW already did so in 66. Same for valve guides. As always, well ahead of its competitors. Valve Seat Recession (VSR) is therefore not a problem. On older cars than 1966, if the heads were redone, or replaced, you’ll have hard valve seats, or should have. (If not, run unleaded, and you’ll need them soon enough anyway. That’s a bit facetious, I know, hehe!) Octane rating is also not a problem on standard VW engines as the compression ratios are not high enough to warrant high Octane rated fuels to prevent knocking.

Why not LRP? The least of the problem is because the additives in LRP cause spark plug fouling. More importantly, because the additives in LRP (oxygenates) can cause your engine to run lean, causing overheating. And because the oxygenates in LRP are an Octane booster which you don’t need.

The advice I was given now also makes more sense. The oxygenates in LRP vary widely, although I have been utterly unable to find any percentages of e.g. MTBE, MMT, ETBM, ethanol or other additives for SA. On overseas sites I have found from 2% and 3% to 7% and 11%. All these make engines run leaner (simply because there is oxygen already in the fuel additive and then it is mixed with air as your engine breaths) and thus hotter. It is not so much the oxygenates in the fuel, as you can set your car up for that, by rejetting, but the variation in percentage oxygenates that various fuel providers add. The VW pages I looked at said “beware of anything over 6%”. Now I know Sasol, for example, love chucking ethanol into their fuel, although again, I can’t find percentages. E10, in the US, is 10% ethanol. This stuff is particularly nasty to ACVW engines as 10% ethanol makes your engine run 4% leaner, and additions of up to 20% ethanol have been recorded!

All the additional stuff like timing adjustment, flame front speeds, throttle position, turbos, vacuum advance, altitude above sea level, etc. are a moot point. While making the discussion very interesting, they have little to do with the question at hand. One interesting point though: your required Octane rating drops by one point for every 300m elevation, cool, huh?

John Muir’s The Compleat Idiot lives up to its name by insisting that you MUST ONLY use LRP. If you feel you belong to that category, go for it.

My references: Engen, Shell, NAAMSA, Sasol, Wikipedia, Dave and Rob’s ACVW pages.

Oh yes, and how to check for knocking, go to 45 or 50 km/h, shift into 4th, put the hammer down and listen for the pinging.

[RONALDO NO 9]

what if your exaust is to loud to here the vehicle ping
what is a other way to check if vehicle is pinging