Does any one really know

[keithu]

  hi i was wondering does anyone really no whats the best fuel to run in  my 186 stock motor all i seem to here is yeah use lrp or unleaded is ok with lube in tank or lube kit or use  vortex hi octain special fuel ??
GGGGGGGs i get so many different storys  can anybody help here, id really like to here from all you guys what you run in your old girls . im confussed with all the different storys im getting on this please help out guys ,
and let me know what is the best,  plenty of comments will show whats the most used or best fuel to use  if we all put two cents worth  in   here i guess  so come on guys lets here from you all . ;)signed yours sincerly .

[FE_225]

I've found Optimax to be very good compared to LRP. I ran it in my old 308 and there was quite a noticeable difference, more power, no pinging and it ran so much smoother,  the exhaust note even sounded deeper. Even in the wifes' V8 VT, Optimax is far better than ULP. But at a $1.06 a litre, it gets quite dear filling a 76 litre fuel tank a couple of times a week, that's the only drawback I found with it.
Hope this helps
Cheers
Tony

[fcfromscratch]

Team,

I've been interested over the last year or so to see the comments on this discussion page regarding options for fuels used in the ol' girls...from additive packages to lead sinkers in the fuel tanks!!

I have worked in the oil industry for 24 years, the last 12 in blending petrol/avgas/diesel products for shipment all round Aust/NZ from Kwinana Refinery in WA.  I am NOT a qualified mechanic or engineer, but I have dabbled with Holden Reds for about 20 years. I don't know it all, but I know something about fuels and how the fuel scene has developed in Aust over the last 12 years...lead phase-out, clean fuels, operability specs etc etc.  BP was pretty much at the forefront of these changes in WA and Qld, driving the change to cleaner fuels.

There is a lot of myth and "clouded" evidence put forward by some as to what is the "gospel" on fuels, particularly the newer fuels...."my mechanic mate tells me that....", "I heard from so-and-so...".  The fact is that the fuel is only part of a complex design and operation that is an internal combustion engine.  Sure the grey and red sixes are simpler compared to the fuel injected monsters that inhabit the engine bays of later models...but they are still a complex balance of design, age/maintenance, tune and fuel.  Not many of us get all of these right ALL the time.

I have written a bit of a document trying to answer Keith's questions above (too long to be posted as is).  It doesn't try to tell anyone what is THE way to go, but to spell out the core considerations (I think) in deciding what fuel you want to run.  It's my offering on the subject, feel free to express your opinions, or ask questions about it...like I said, I don't know it all...but I do have a different perspective to most.  I've attached it as a WORD doc but can email as a .rtf to anyone who doesn't have WORD 2000.

I think that there is still a lot to be said about the benefits of different additive systems for those who choose to go that way, so Keith's invitation to put in your two cents worth should be taken up!  I certainly am not looking to stifle discussion on the issue, just provide some technical background to fuel issues.

Brad

[Digger]

Brad,

Gees for a bloke that don’t know it all your not far off the mark.  

Very interesting reading Brad thanks for passing on your knowledge.

steve.

[normd]

WOWWWWW
    All I can say is "Thanks Brad"  
      I've saved the doc. so I can read it closely, have only had a quick peek so far , but really appreciate you shareing this with us.

      Norm d

[keithu]

 ;)hey Brad thats really interesting and so true mhhhhhhh?? now youve given the guys somthing to really talk about and sdiscuss i hope we  get a few more   coments on this subject  come on fellas let all join in and have our say   i think we'd like to here more from you thow brad ??   well im going to be waiting and verey interested to see were this aLL END S UP  cheers  to all and how bout ya two cent worth guys  . signing of for now ,keep them old girls runin,
cheers keith

[FE_UTE]

Brad
Great read ,I have a couple of mates in Perth with grey motors who have asked me this question and until now I could not give them an answer.So if its ok with you I will give them a copy to read.

Keith
Thanks for starting this topic and I am sure we will all get a lot more info on it

Gary

[FCwagon]

Thanks Brad for what I can gather was an unbiased explanation of the fuel types. Very informative info all up.
Being a mechanic I have my own plans for the LRP phase-out but I do have a question about fuels for you if that's ok.
I've been told the "shelf life" of LRP is seriously reduced by the avsr and so goes stale very quickly. Is this right
I came to believe that statement after switching from LRP to straight ULP. I found it easier to start my beast after it had been sitting for a long time and I also changed the fuel in the 4 stroke mower to ULP because it was a bitch to start on LRP but now starts easy (with no other changes).  
cheers,
Leigh

[RET]

I've heard this too - very interested in your reply Brad.

[keithu]

  hello again all well looks like things are going to b interesting  on this topic  cheers to gary fe ute and good comment about the lrp stailness ret  ive heard this too well come on guys im sure theres still alot more to be said  so lets get the two cents rollin along ,  later know  cheers keith

[keithu]

 ;)sorry i mean leigh good comment about stale fuel  

[fcfromscratch]

Leigh,

I'll ask our technical gurus (Melb Office) the question about the "shelf life" of LRP with the additive.  At least they won't try to bulls**t me.

Just thinking to myself though, it could be to do with volatility.  Certainly the ULP is made from more volatile, lower octane components, whereas the volatility of LRP and PULP comes more significantly from added butane which can vaporise off quite quickly in a poorly sealed system.  Without the butane, the driveability index is reduced leading to poor cold start performance.  If this is right, it is less to do with the avsr and more to do with componenture of higher octane fuels....i.e. not easily solved .

But I'll try to get a fuller answer in the next cupla days.

One other thing I meant to talk about in the posting above was spark plugs.  It often appears with ULP and PULP that the plugs foul more.  The leaded fuel used to leave that light grey PbO coating, while the ULP/PULP leave a "pure" carbon coating.  We were told by the gurus in the early days of LRP in WA that one way to improve combustion of the fuel was to run spark plugs 1 - 2 heat ranges hotter, burning off more of the carbon, leading to less misfiring etc and generally better plug performance.  I'll ask them whether this is still their recommendation as well.  I know this won't suit everyone as I remember reading about people experimenting with cooler plugs for other reasons.  It will be interesting to know if hotter is still better...'cause for those who need to run cooler, it may contribute to poorer fuel performance.

more soon.......Brad

[fcfromscratch]

Hi Leigh,

I asked the above questions of the technical gurus in head office and got pretty much the answers I expected.

They hear the stories about LRP having a lower shelf life than (say) ULP too, but there's apparently no science behind why this should be (that's not to say you're all imagining the evidence, just that there's probably other reasons for what you see happening).  It is not directly attributable to the AVSR additive in LRP.

The volatility thing is real...if you lose the light ends from the fuel container not being sealed properly, the fuel will deteriorate in its drivability index and be harder to start the engine, be it car, lawnmower, boat etc.  LRP and PULP will suffer similarly with this problem.  Well sealed containers are critical for storage of petrol.  Shelf life should be around 6 months, but there are other issues....

I guess some may not know that petrol has a monthly volatility specification.  That is, at the start of a new month, the maximum vapour pressure of petrol changes.  Each month as summer approaches, the maximum vapour pressure of petrol reduces as the risk of vapour lock in carburetted systems increases.  As winter approaches, the vapour pressure goes up as the vapour lock issue subsides and the need for more light-ends in the fuel for cold starting increases.  There are probably 15 zones around Australia that have a different vapour pressure for EACH month of the year.  Add to that the ups and downs of refinery operation where the petrol may not be maximised to the vapour pressure limit (usually is though for economics) and you further increase the permutations.

So, if you try and use petrol you bought in Jan in Sydney to run a lawnmower in Canberra the following June, you could well have problems starting it.  Bear this in mind when laying up fuel supplies or storing the fuel for longer than a few weeks.  It may not be the fuel itself, but the timing between when you bought it and used it that causes the problem. A similar issue occurs with diesel and "cloud point", or "cold filter plugging point".  If you buy Summer diesel with a cloud point of 8 degC and try to use it in a vehicle in winter when the temp is around 5 degC , it may well go waxy & solid in the fuel lines or block your filters...farmers love this one at seeding time!!!  Oil companies do make an honest attempt at fitness for purpose of a fuel (the ramifications are horrendous when it goes wrong, ask Mobil folks about Avgas!!), but the buyer/user has a responsibility in how the product is used as well.  It can be a bit like using a flat blade screwdriver to undo a phillips head screw and blaming the tool when it doesn't work that well.

Also, with spark plugs, the experts are saying that it is only advisable to go for higher heat ranges if you are suffering continually fouled spark plugs and there is no other obvious reason why the motor should be laying down too much carbon on the plugs....not a universal recommendation to increase heat range of the plugs.

Anyway, I have a useful "fact sheet" that they sent me that I have forwarded to RET which may end up as a Tech Info page.  It says some of what I said in my attachement above and lots more too.

(oh-oh....another bl***y essay)

cheers.....Brad

[craiga]

Brad,

I'm sure everyone here is like me and really appreciates the information and depth of knowledge you have on this subject.

I have a question for you - why does LRP coat the plugs so severely? For those who haven't seen it, LRP leaves a coating on the plugs that looks like dullish copper (best description I can think of :-/ ) My concern is that if the plugs are like this, then what does the rest of the compression chamber and associated components look like, and what are the longer term effects, if any?

Thanks again,

Craig.

[fcfromscratch]

Craig,

don't really know the answer here.

I'm guessing that how much the plugs coat will depend on how good is the overall combustion...if ignition & carburetion are ok, should be a light coating of black carbon.

could be that the copper coloured coating is from another oil company's choice of AVSR...certainly the BP experts expect a black coating...do you use BP or another? (that may or may not mean anything anyway as BP doesn't have a terminal in Sydney, so may not have their own gantries and AVSR adding facilities...I'm not sure...may be the same as other companies in NSW after all)

if all that has happened is that you've changed the light grey deposits of leaded Super for the dullish copper deposit of your LRP...no real problem...just different...so long as you have sufficient octane and the starting/running performance is ok

the colour of the coating is probably not so important as the thickness/heaviness of the coating as an indicator of how much deposit there may be in the upper cylinder.  I guess the main long term effect is an increase in compression ratio due to the space taken up by the deposits, may actually require a slightly higher octane fuel if increase in compression ratio higher than (say) 5 - 10%.

regards.......Brad

[craiga]

Brad,

The engine has only done about 2500 miles since rebuilt (a long time ago) and runs perfectly although it pings very slightly on full accelleration. I found I had to fiddle with the timing as the setting recommended by Holden was too retarded with LRP. I used a timing light with digital advance and a quality dwell tach so everything should have been perfect. The standard setting lead to weak idling and sluggish operation so I advanced it a few degrees to about 9 degrees BTDC and all is OK. I also found that I had to run the idle mixture richer than with Super if I wanted a smooth strong idle. Is this because of the AVSR or has the octance rating affected these settings?

I haven't had it on a 4/5 gas analyser since LRP came in but I'll try and do it soon and post some figures, as well as some pictures of the plugs.

Thanks again for your input to the forum.

Cheers,

Craig

BTW I'm the original petrol harlot - if it's cheap and close, count me in!!!!  

[fcfromscratch]

Hi there,

RET has been busy again and "edited" the attachment I put to a previous post in this thread and added it into Tech Articles on the NSW(?) club website for future reference.  There's some fresh info in it so it might be worth a look...

Tech Info Article

Also, there should soon be (if not already) a new Tech Article from "one of the oil companies"   on differences to expect in engines when using LRP.  Something I got from "Head Office".

Something else that caught my attention recently on Current Affair was the dosing of petrol in NSW/Qld/Vic with Ethanol (we haven't done anything with this in the west).  Seems some servo operators have been putting > 20% ethanol in petrol without warning users.  I'll try and find out more about this through my sources.  If you are getting some of this stuff in your FE-FC you'll probably notice a difference...but not necessarily know why!!

There are benefits to using ethanol at a reasonable level...any alcohol/ether has improved combustion as it already chemically contains oxygen...all things being equal it leads to cleaner burning.  Main benefit to servo operators is that it is excise free....you don't have to charge that ~47c/litre on behalf of Mr Costello.  That enables them to offer cheaper fuel yet maintain a healthy margin.  Problem is that your average independent servo operator knows very little about quality control and is always tempted to "overdo" a good thing.  

Ethanol is also hygroscopic...tends to favour water and will come out of the hydrocarbon phase (to a degree)and into the water phase if water is present.....Aust's fuel distribution system is NOT a dry system....so some of the ethanol inevitably will end up in ground water systems....that's why the Californian EPA are REMOVING MTBE (methyl-tert-butyl-ether) from fuel in their state after making it mandatory for the last 10 or so years.....their water table is stuffed!!

Brad