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glbft1
02-09-2010, 09:26 PM
greetings,
Want to set the timing to run super premium gas, what is the best for this 6 degrees or more for this or less just want the best performance
Thanks
Greg

Nium
02-09-2010, 09:55 PM
For the best performance don't run super premium gas. The higher octane gas is less detonation resistant. Therefore the lower octane gas is more explosive. Super premium is really only necessary on higher compression (ie 9:1 or greater) engines and the Landy's 8:1 or 7:1 on a 2.25L should do better on an octane rating of 87 PON or even lower if you can find it. So unless you're trying to prevent pinging, from preignition, stick with the lowest octane to get more bang for your buck. IMHO

If you do use Super Premium you'll need to set the timing at 6 BTDC or more advanced (ex 8 BTDC) to get the fuel to have burnt up correctly to drive the piston.

Octane ratings explained...
http://www.btinternet.com/~madmole/Reference/RONMONPON.html

Cheers

Wander
02-10-2010, 07:14 AM
What setting do you like for 87? Is 3 over good?

Jeff Aronson
02-10-2010, 07:20 AM
Oddly, high octane gas and the requisite changes in timing actually makes the car harder to start :).

As Walker says "super premium fuel" will not really enhance performance in your 109". Given the age of your Rover, you probably have an 8:1 compression ratio head on your car. That's not high compression and the octane level of gas will not affect the power of your car. Land Rovers were designed with the expectation that they would run on lower octane fuels; there's no reason to spend extra money like this on fill-ups.

I have found that my nearly 350,000 mile + engine will diesel, regardless of timing, on the regular gas [our only choice] we have on the island. When I get middle grade fuel on the mainland, it all goes away. Running premium has nor made any difference on the perceived power of the car.

Jeff

glbft1
02-10-2010, 08:20 AM
when I ran mid uleaded in the rig it would diesel sometimes, a little harder to start,
Switched to super ran better alot less diesel ( still happens once and a while)so if I want to start running a lower octane what should my timing be at 3 btdc??? or in that range? just want to run the engine at optimum level for fuel effeciency and the best power( not looking to have more power just want the all the power I can get) so to speak!:D
Regards

Tim Smith
02-10-2010, 07:17 PM
No idea about the proper advance setting as I just time it by ear. :)

Dieseling can also be caused by carbon build up. I am pretty sure this was a problem for me until recently.

I would try cleaning the top end with a little Marvel Mystery Oil or Seafoam or just a drink of cold water. Make sure you know what you are doing before you hydraulic it. Use the vacuum advance line if you don't have a steady hand. ;)