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MG Midget and Sprite Technical - 1275 Pre Ignition - Solved
You may remember that I've been trying to stop my 1275 running on (carbs rebushed), mixture fiddled with, timing adjustment etc. My mate Ed (Frogeye, NSW posts on here) suggested ages ago that it might simply that I need to run super unleaded as the CR is fairly high (MG Metro pistons, head skimmed and a hot cam). I took his advise today....sorted!! I can almost hear the 'I told you so' from down under.
I don't really understand why it's cured it but assume that it's do with mild 'pinking' at tickover creating hot spots? Anyway, seems the old girl just has expensive taste..Super Unleaded from now on.
|My old girl has expensive taste too. Also my sprite prefers the super unleaded too.|
|My daily ride (not a midget just yet) goes better and further on V Power diesel. More detergeant as well as higher rated fuel. Economy gain is more than the extra paid and I gain the odd bit in acceleration. So not so expensive anyways maybe.|
|Dave Squire - Notts|
|thanks for letting us know you got it sorted|
higher compression ratio needs higher octane and the standard cars were supposed to run on 97 octane
if you've not already done so try Tesco Momentum99 as you can guess it's 99 octane which may be more suited still to your engine
see this for octane, 'knocking' and higher octane fuels - http://www.petrolprices.com/about-fuel.html
|It makes a differance...it really does|
Something else ive noticed....the fuel super unleaded W/O the ethinol additive is definatly the way to go for our older cars...its hard to find but worth it...just alot more power gas milage and umph over super unleaded with the ethinol 10% additive
|Prop and the Blackhole Midget|
Only just noticed this so only one thing to say , told you so ;-)
That said it could have been that home made plug lead set you did .......... but thats another story !!!!!
This thread was discussed between 01/12/2012 and 08/12/2012
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.