EA 81 / Timing/ Premium unleaded 98

Rabbitoh · Post by **Rabbitoh** » Mon Oct 26, 2009 4:48 pm

Hi all,
Wondering what EA 81 owners have their timing set at if using Premium unleaded petrol. I use premium RON 98 mostly and have the timing set at 9 degrees. Just read on thread about Ethanol fuel about timing set at 10 degress for RON 95 any other ideas on timing to get the car to run better without pinging.

Cliff R · Post by **Cliff R** » Mon Oct 26, 2009 6:23 pm

1982, ea81 touring wagon timing set at 12 degrees BTDC only use shell V-power No pinking. Use any other fuel, result, pinking.

Post by **TOONGA** » Mon Oct 26, 2009 7:09 pm

10 degrees and above for all unleaded petrols in Ea81 motors

TOONGA

phillatdarwin · Post by **phillatdarwin** » Mon Oct 26, 2009 7:51 pm

i are running ea82 at 9dec btdc and i are getting no ping at all and gos very good had it at 10 dbtc last week and did not have that much go .
if u have got some hi km on it u mite find like i did that back a bit is a bit better like i did .
as things wear a bit and u have to compensate for it i have 250,000+km

steptoe · Post by **steptoe** » Tue Oct 27, 2009 3:10 am

phil is correct in adding that it depends on the individual state of your engine.

someone else in here warns that ethanol is not suitable for cars with metal petrol tanks due to the make up of the fuel causing tank to rust out internally. I have seen some incredible crud inside a metal fuel tank. aging ethanol blend suspected cause.

discopotato03 · Post by **discopotato03** » Tue Oct 27, 2009 7:06 am

I spoke to Gee (BratGeebra) a while ago and he said that he used to run slightly lower temp water thermostats to reduce the inlet temps and then advance the dizzy .

Ethanol has some very good qualities but issues particularly in older pre unlead era cars . Rubber fuel hose material changed at that point and in theory so did fuel tanks .

The immediate drama with ethanol is that its air fuel ratio is not the same as petrol so when run in an engine calibrated for petrol the engine runs lean , how lean depends on the percentage of ethanol in the fuel .
Also carburettors are generally made of aluminium and ethanol is corrosive to ally .

A thing that becomes a problem for older engines in the piston ring blow by which wants to carry oil mist with it into the crank case breather system which means into your inlet manifold and combustion chambers .
Burning engine oil has a tendency to drop the effective octane of the fuel you use so you engine will detonate sooner all else being equal if you're burning oil .
You can have oil separators made to get the oil from the breather system and drain it back to the sump . Best situation is a fresh engine but thats more money .

It sounds weird but with fuel consumption the economics lie with dollars per km rather than MPG or L/100km . This takes into account what you pay for fuel because costs vary greatly .

Other things such exhausts affect detonation and engines don't like restrictions or size to be too large .

how much do you want to spend ?

A .