Page 1 of 1

timing

Posted: Mon Oct 18, 2004 7:25 am
by Thonger
Just a quick one, have the workshop manual, but should I adjust the timing on the ignition to suit the fact that I'm running unleaded and not leaded.

Posted: Mon Oct 18, 2004 7:56 pm
by Loanrangie
I've only ever run unleaded and only set the timing as per factory specs, although with lpg i have set it at 12btdc and it seems fine there even when on ulp.

nick.

Posted: Mon Oct 18, 2004 10:50 pm
by Ralf the RR
Loanrangie wrote:I've only ever run unleaded and only set the timing as per factory specs, although with lpg i have set it at 12btdc and it seems fine there even when on ulp.

nick.


I have my 79 dual fuel set to 12 degrees also.
I found that it pings using normal unleaded, so I use premium.
LRP is rated to 95, and still pings a little, but is hard to find these days.

Posted: Mon Oct 18, 2004 10:55 pm
by Dave J
12°btdc !

Manual for my '86 says 0°btdc, and I have an 8:1 motor.

Running unleaded I am worried at 2°btdc. Why the huge difference? or does efi advance kick in way quicker.

DJ

Posted: Tue Oct 19, 2004 6:50 am
by Thonger
Loanrangie wrote:I've only ever run unleaded and only set the timing as per factory specs, although with lpg i have set it at 12btdc and it seems fine there even when on ulp.

nick.


Cheers Loanrangie I've also changed the holley according to your advice, seems to have helped.

Posted: Tue Oct 19, 2004 7:18 pm
by Ralf the RR
Dave J wrote:12°btdc !

Manual for my '86 says 0°btdc, and I have an 8:1 motor.

Running unleaded I am worried at 2°btdc. Why the huge difference? or does efi advance kick in way quicker.

DJ


Dual fuel is a compromise.
Gas requires a lot of advance.
I run mine mainly on gas, so set the advance for it.
I only put about 30L of petrol through every 6-8 weeks.
With 12 degrees, unleaded pings, so I use premium, and it doesn't.

But back to the original thread.
We also have an 80RR on petrol only.
The workshop manual specifies 4 degress AFTER TDC.
Never heard of this before, on any vehicle.
So it's set for 4 degress BTDC.
Used to run it on LRP, but now run it on normal unleaded (even Woolies).
Seems to go OK, and doesn't ping.

Posted: Tue Oct 19, 2004 8:19 pm
by Loanrangie
My 81' i think was atdc in the timing but i have put in a bosch dizzy which has a recomended timing of 10 btdc, but 12 suits the lpg better and doesnt ping on ulp. Once holleys are setup, they go alright.

Posted: Tue Oct 19, 2004 8:42 pm
by big bundy
sorry but what is a ping?

Posted: Tue Oct 19, 2004 9:58 pm
by Loanrangie
Fishman., ping is that horrible noise when either the engine is under load in the wrong gear or when the timing is out causing a rattling type noise.
Any luck with getting a rangie ?

Posted: Tue Oct 19, 2004 10:15 pm
by big bundy
gees man i just saw u are from sthelena, thats like beside greensborough!!! where i live, kool, umm na not yet hopefully we are going down on sat or sunday, should be good, havn't seen the interior in pics so maybe thats fucked up but if it is mechanically good i will give hima bit of a barter

Posted: Tue Oct 19, 2004 10:36 pm
by RaginRover
so you blokes set her for 12 degrees before at idle for gas. I am assuming that is on 3.5L engines.

3.9 be the same ? or should I do the ultra technical - trial and error :)
I should really buy a vacuum gauge

TIA
Tom