And the Sunoco article you are referring to is for race fuel only and states not for pump gas Sent from my iPhone using FerrariChat
I can post as many references as you want. There is no correlation to octane and burn rate. And certainly false to say the higher the octane the slower the burn rate. Here's a chart you can reference showing burn rate of pump fuel as the same for 86 to 93 octane. https://www.speedperf6rmanc3.com/content/Racing%20Fuel%20Characteristics.pdf
Image Unavailable, Please Login Please in the opening statement of the Sunoco article says “As a matter of fact, those statements only have some merit in the street gas world where 93 octane fuel is king and 87 is used by most. In the world of racing gasolines where higher octane choices abound, sharp engine builders and racers know they need to look beyond octane to find the right fuel.” This article is about how Sunoco formulates racing fuels for higher octanes and faster burn rate these type of fuels are used in racing and Aviation and contain additives to help with and make faster burning fuel this type of fuel is not found at the local stations We can go all day with this the average guy here does not buy those type of fuels and pump gas is what is in his and probably everyone else tank even yours Sent from my iPhone using FerrariChat
Sure if you like. Antiknock ability is _not_ substantially related to:- The flame speed of the conventionally ignited mixture, this should be evident from the similarities of the two reference hydrocarbons. Although flame speed does play a minor part, there are many other factors that are far more important. ( such as compression ratio, stoichiometry, combustion chamber shape, chemical structure of the fuel, presence of antiknock additives, number and position of spark plugs, turbulence etc.) Flame speed does not correlate with octane. http://www.factorypro.com/tech/gasoline.html
Thanks. I have a cheap pocket oscilloscope, but I don't think I have an attachment to couple with the leads. I imagine I would need some kind of inductive coupling.
There are ways on using the scope on the primary circuit side that will have a Image which mirrors the secondary Circuit ——- check google too see if anyone has info on checking this way I have done it in the pass but I was looking for a problem where I was losing power too the coils or pick up sensors I found a bad coil shorted out internally from vibrations of the engine which is not what you are having a problem with But if you are unsure of what you are looking at it might not help you having a shop or the right equipment to see secondary is really the way to check it Hope you find the problem Sent from my iPhone using FerrariChat
Update: Just got my car back. After a spark plug change (eight) and a single fuel injector change, the engine is running very smoothly (and the gearbox rattle has gone). I don't know if the temperatures were rechecked. I may do that at a later date myself (I have a temperature gun). Why spark plugs with so few kilometers on them and almost no sign of problems would cause this rough running, I don't know. Anyway, thanks again for all the input.
One possibility is fake NGK plugs but it is usually the Iridium ones that are faked. Otherwise, it is possible that the spark plugs also deteriorate over time as the oil and whatever slowly soaks into the ceramic insulator. This may be exacerbated by little use and frequent running at idle when the deposits on the plugs do not get a chance to be well burned-off. A few months ago, in my similarly like your 355 little used 348, I suddenly had slight uneven idle. After I initially started suspecting the injectors, coils, HT leads, I decided to first remove and inspect the spark plugs - one of them had a small piece of carbon lodged between the electrodes. I replace all of them as they were already ~8 years in the engine.
Interesting. Hopefully not platinum ones, too. I bought some NGK Laser Platinum PMR8B's recently. The packaging looked official and had Made in Japan written on the box, but the package came from Hong Kong. They were a few dollars cheaper than local outlets, but not significantly.
Thanks, John. Sounds like just what everyone needs. Analysing the waveforms seems relatively easy following this video. I spent an hour or two without success, though, trying to find an equivalent tool to the, no doubt, very expensive SnapOn "Modis" for amateurs.
Yes that was a great video and for the cars we play with should be something to use that’s why I suggested and yes snap-on Modis is a very good tool but costly for hobbies I have 2 scopes that I use regularly one is a old LS2000 which I had for almost 30years and it still works great easy to use and does everything I need and the other is a laptop base unit “TIE PIE engineering scope” both work great on automotive application and are not that expensive the LS can be pick up from eBay for around $150 “usd” the tiepie software is free and the cheapest interface is around $500 “usd” but either way any one have with the right hook ups can save you time and money This type of diagnostics is be coming a lost art it’s a shame the newer techs don’t learn it and older techs who do are harder to find Sent from my iPhone using FerrariChat
The LS2000 is a "Snap-On Sun LS2000 Automotive Oscilloscope Diagnostic Scanner"? eBay and Amazon seem to be showing nil stock at the moment.
Not a scanner just scope I have the mt2500 scanner too might be looking to sale it soon Sent from my iPhone using FerrariChat
