Jez @ H-Dev Posted February 16, 2012 Share Posted February 16, 2012 Would be interesting to know what engine this came out of, I would imagine the high rev 06 and onwards engines would be more likely to have this problem. I'd also like to point out there are more things that can blow a hole in a piston than duff fuel The newer ECU maps actually pull out more ignition timing when using the low octane maps, so should be a bit safer, assuming the ECU does actually switch over. Most knackered pistons are due to knock or something going through the engine. That pic definately looks like knock damage. Quote Link to comment Share on other sites More sharing options...
JetSet Posted February 16, 2012 Share Posted February 16, 2012 what happens if you put 97+ ron in a shed though - obviously built and designed around 95 Ron (mods - move this if you like) Nothing, depending on when said shed was built. The extra resistance to detonation of 97RON over 95RON would be wasted as the car would not run as high a compression. So the car would always fire the spark before the fuel to reach det prematurely. So unless it has higher compression and can alter ignition timing then its pointless. If it can use it then you'll get slightly higher MPG as the fuel is burnt more efficiently than 95RON. With todays technology it should be possible to get a car running efficiently and safely on a fuel that it wasn't designed to run on, well in theory at least I remember when they switched over from leaded to unleaded, the number of garages selling leaded diminished each week until there were none. I think there was a fairly simple fix to convert leaded cars to run on unleaded. BTW, When they were selling leaded and unleaded at the same time they changed the size of the petrol filler so you couldn't put the wrong fuel in. The leaded nozzles were massive....its a shame they didn't do that with diesel too, would have saved a few heartaches. Pete Quote Link to comment Share on other sites More sharing options...
Chris`I Posted February 17, 2012 Share Posted February 17, 2012 Would be interesting to know what engine this came out of, I would imagine the high rev 06 and onwards engines would be more likely to have this problem. I'd also like to point out there are more things that can blow a hole in a piston than duff fuel The newer ECU maps actually pull out more ignition timing when using the low octane maps, so should be a bit safer, assuming the ECU does actually switch over. Most knackered pistons are due to knock or something going through the engine. That pic definately looks like knock damage. Going by what Mark has posted before, even the high det/low octane map doesnt pull enough timing for 95RON fuel above ~5kRPM. I'm sure there have been posts where he said he's had a car on the dyno not realising it had 95RON in until he heard all the det that was happening, and the car was in the high det map at the time. Nissan categorically state not to rev the car highly when you have 95RON in it. It is designed to get you to the next garage with Super at it. So can be safely driven slowly (low revs) but as soon as you rev it the high det map still wont save you. Thats what I've gleamed over the years from what people have posted from their observations Quote Link to comment Share on other sites More sharing options...
daveparkin Posted February 17, 2012 Share Posted February 17, 2012 If higher octane fuel is not so easy to come by in the US, are US cars not just mapped differently to run on lower octane fuel? Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted February 17, 2012 Share Posted February 17, 2012 These motors do knock (detonate) pretty easily for a N/A car The damaged pistons is from a 06 Rev Up motor. Quote Link to comment Share on other sites More sharing options...
Mark@Abbey m/s Posted February 17, 2012 Share Posted February 17, 2012 If higher octane fuel is not so easy to come by in the US, are US cars not just mapped differently to run on lower octane fuel? Yep these are a huge amount of different maps for the VQ motors; The US maps do run a little less ignition timing. Quote Link to comment Share on other sites More sharing options...
jables Posted February 17, 2012 Share Posted February 17, 2012 Any thoughts on how quickly the premium fuels like Tesco 99 and V-Power start to lose their octane over time sat in the tank? I didn't even realise fuel detiorated at all until recently! Are you possibly talking as much as 1-2 octane over a few weeks? Quote Link to comment Share on other sites More sharing options...
Ekona Posted February 17, 2012 Share Posted February 17, 2012 Nah. You'd be lucky to lose that in a year. Put it this way, my car has sat now for about 4 weeks and I'd have no hesitation in jumping in and driving the arse off it without any regards to the fuel. Quote Link to comment Share on other sites More sharing options...
Gudzy Posted February 17, 2012 Share Posted February 17, 2012 BTW, When they were selling leaded and unleaded at the same time they changed the size of the petrol filler so you couldn't put the wrong fuel in. The leaded nozzles were massive....its a shame they didn't do that with diesel too, would have saved a few heartaches. They have done that, a diesel nozzle is larger than a petrol one and doesn't normally fit in a petrol car. Quote Link to comment Share on other sites More sharing options...
Ricey Posted February 17, 2012 Share Posted February 17, 2012 BTW, When they were selling leaded and unleaded at the same time they changed the size of the petrol filler so you couldn't put the wrong fuel in. The leaded nozzles were massive....its a shame they didn't do that with diesel too, would have saved a few heartaches. They have done that, a diesel nozzle is larger than a petrol one and doesn't normally fit in a petrol car. Yes but the b*****d petrol can fit in a diesel........which I found out much to my horror. Quote Link to comment Share on other sites More sharing options...
brumjohn Posted February 17, 2012 Share Posted February 17, 2012 BTW, When they were selling leaded and unleaded at the same time they changed the size of the petrol filler so you couldn't put the wrong fuel in. The leaded nozzles were massive....its a shame they didn't do that with diesel too, would have saved a few heartaches. They have done that, a diesel nozzle is larger than a petrol one and doesn't normally fit in a petrol car. Yes but the b*****d petrol can fit in a diesel........which I found out much to my horror. Yep, with you on that one, blew £300 in an hour, put £40 petrol in the wifes Jeep , drove 2 miles, started to notice a "judder" , wife realised what i'd done , £180 quid with the AA to pump petrol out, £20 with AA for some protection additive, £90 diesel to fill up completely to dilute the effects. fortunately no long term damage to engine as we spotted it early.... hopefully one of lifes lessons you only do once! Just relieved it wasn't diesel in the zed Scary seeing the results of 95 RON though, will def only put 97/98 in now Quote Link to comment Share on other sites More sharing options...
Ekona Posted February 17, 2012 Share Posted February 17, 2012 Genuine question as I honestly can't remember, but do all 350Zs not have '98 RON ONLY' or the equivalent written in large text inside the filler cap? Quote Link to comment Share on other sites More sharing options...
Chris`I Posted February 17, 2012 Share Posted February 17, 2012 Genuine question as I honestly can't remember, but do all 350Zs not have '98 RON ONLY' or the equivalent written in large text inside the filler cap? From what I remember they do But remember when they were new Super wasnt widely used by most, so I guess a lot of people assumed they just wanted you to use fancy petrol to get best performance, no one knew that the base map wouldnt handle 95RON very well Quote Link to comment Share on other sites More sharing options...
lrh Posted February 17, 2012 Share Posted February 17, 2012 Yes but the b*****d petrol can fit in a diesel........which I found out much to my horror. A diesel will run with as much as a third of a tank being petrol. People used to mix some petrol into diesel in winter to stop it turning into treacle. Quote Link to comment Share on other sites More sharing options...
JetSet Posted February 17, 2012 Share Posted February 17, 2012 BTW, When they were selling leaded and unleaded at the same time they changed the size of the petrol filler so you couldn't put the wrong fuel in. The leaded nozzles were massive....its a shame they didn't do that with diesel too, would have saved a few heartaches. They have done that, a diesel nozzle is larger than a petrol one and doesn't normally fit in a petrol car. Have they changed the nozzle sizes in the past few years? If not, I wonder how Caroline managed to fill her old Citroen up with Diesel, circa 2000 . She was in Green Flag who brought it home for us, but it took me a couple of days to clean out the tank and all the fuel lines, it didn't go to waste though, just threw it into my central heating oil tank. Pete Quote Link to comment Share on other sites More sharing options...
JetSet Posted February 17, 2012 Share Posted February 17, 2012 These motors do knock (detonate) pretty easily for a N/A car The damaged pistons is from a 06 Rev Up motor. What sort of mileage had it done? Thanks, Pete Quote Link to comment Share on other sites More sharing options...
Ricey Posted February 17, 2012 Share Posted February 17, 2012 Yes but the b*****d petrol can fit in a diesel........which I found out much to my horror. A diesel will run with as much as a third of a tank being petrol. People used to mix some petrol into diesel in winter to stop it turning into treacle. I think thats a bit of a tactic of a previous era mate - with all the electronic gizmos in cars these days I think you can do a good old amount of damage with almost any amount........certainly throws the ECU all over the place. Incidentially mine was a dry tank filled with diesel, in a car I had just paid 15k for.........and I tried to drive it Luckily it was a pumpe duse unit.....r.eckon if it was commonrail it would have written the engine off. Quote Link to comment Share on other sites More sharing options...
desertfox Posted February 19, 2012 Share Posted February 19, 2012 Well thats my piston ! Centre pot on LH bank. had been using oil steadily worse from when I bought it 34 on the clock, ran it on 99 almost from the day I got it but the damage had been done in its past life. It was made worse but fitting the wrong grade of plug by my local dealer which has effectivly spark erroded the piston. Im not happy, most of all because I should have identified it sooner . It wouldnt have stopped the engine strip and I was always going to have it rebuilt and set up. Lesson learned , they dont like it ! The bill is going to be comedy numbers..... but its worth every penny. Nobby. Quote Link to comment Share on other sites More sharing options...
JetSet Posted February 19, 2012 Share Posted February 19, 2012 I think thats a bit of a tactic of a previous era mate - with all the electronic gizmos in cars these days I think you can do a good old amount of damage with almost any amount........certainly throws the ECU all over the place. You're right, there's a very real risk of major damage using petrol . Half a pint of Kerosine to a tankful of diesel when the temperature drops to -10 is what you need, or a commercial pour point depressant which is mainly kerosine anyway. This works with heating oil as well Pete Quote Link to comment Share on other sites More sharing options...
desertfox Posted February 20, 2012 Share Posted February 20, 2012 This was an 06 Car that had done just 40.000 when it decided it wanted to be a five cylinder, I had had a spurious misfire at 38.OOO and thats when it got crap bosch plugs of the wrong grade I will be going back to the dealer as I think this is not just a "detonation" problem. Ive seen enough holed pistons with racing two strokes , the plug grade is a factor although of course the fuel is too. Why didnt I fit the plugs ? If I had taken the old ones out I would have spotted the sooty one, compression tested it and saved some damage, still would have needed a rebuild of course. When I get the pics from abbey and the details of the whole rebuild Ill document it all and post here so others can learn from my misfortune. I am lucky enough to be in a job that pays for it and be single enough not to care ! But this could be a disaster for the unwary . Any more tales of expensive blow ups ? While its in bits I may as well do whatever it needs. I have thought of supercharging but wont as Tony at abbey assures me that the up rev will transform it and with the other mods and the new hi comp pistons, skimmed heads and set up it should be a very health quick car. Now where can I get some cheap avgas... ? Once had an old 6 litre Buick in Canada that we ran on Avgas we pinched from the Beaver aircraft we had , That car went like hell. until it blew up..... hmmmmm I seem to have wrecked a few engines in my time.. Back to the snow and ice. - 15 here and getting colder . Quote Link to comment Share on other sites More sharing options...
adam1942 Posted February 21, 2012 Share Posted February 21, 2012 So silly question but can someone confirm why 97 RON is acceptable to use? Obviously its a high octane fuel but its not 98 what's the difference between the two? (apart from 1 ron octane level!) Quote Link to comment Share on other sites More sharing options...
MaDMaXX Posted February 22, 2012 Share Posted February 22, 2012 It's quite literally that, one RON different. It's ever so slightly less resistant to detonation. Quote Link to comment Share on other sites More sharing options...
spursmaddave Posted February 22, 2012 Share Posted February 22, 2012 One ron is acceptable two rons or more would not be so good 1 Quote Link to comment Share on other sites More sharing options...
Ekona Posted February 22, 2012 Share Posted February 22, 2012 PSML Post of the year, right there. Quote Link to comment Share on other sites More sharing options...
M9O OEY Posted February 22, 2012 Share Posted February 22, 2012 Im thinking of getting a postal remap done by abbey, they are doing a 95 octane map , I'm guessing they will be changing the detonation ? Will this affect the performance of the car ? I'm guessing so . Quote Link to comment Share on other sites More sharing options...
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