Somewhere I have read that our AVGAS lead content is based on the european standards which are much lower than the USA standards. Also I believe all our lead values in AVGAS is much the same ie AVGAS and LL100 is much the same. John Viney do you recall or was it Chris Kiehn I heard it from or did I read it. I do know a friend at Armidale NSW (3500ft asl) had real problems with 98 about 12 months ago (think BP) and then we found one of their tricks in refinery they have 98 down on rating so they bubble butane thru the bad 98 to bump it to 98 but normally this fuel goes out to be sold in capital city areas real quick. Occasionally it makes its way up the range and this is the fuel that should not fly as the butane immediately comes out of solution and you no longer have 98!
I tend to take bets both ways with a blend of 98 and Avgas but give it full avgas just before a plug inspection. When compared to Pawnee L 540 I have little or no issues with leaded up plugs and this is in 2 and 4 strokes As you may or may not have heard the local BP man owns all 8 BP in the area is probably going to jail over diluting 98 fuel. His stations were auctioned off last week- BP are forcing him out. Estimates are he made $500K to $1M (been going on for years local mechanics say) as he gave $150K to local charities The whistle blower was a Ballina RAAus pilot. Father and many sons were involved It is all a bit of a worry Ian McPhee 2008/7/9 Nigel Baker <[EMAIL PROTECTED]>: > They tell me it is as rich as the needles will go which makes me > suspicious. I will get the Carbs and check myself as I think I know what is > wrong. When it was overhauled the needles were set as per the book but hey > have been playing with it since. > Cheers. > Nige. > > > ----- Original Message ----- > *From:* Rob Thompson <[EMAIL PROTECTED]> > *To:* [email protected] > *Sent:* Wednesday, July 09, 2008 1:51 PM > *Subject:* Re: [DOG mailing list] RE: Fw: GUD > > The twin SU carbies are generally zenith brand ...the mixture adjusting > tool can be purchased from many of the VW enthusiasts shops for about $25. > To do the initial set up on the carbs refer to the Limbach manual. After > that I find the best way to fine tune mixture is to go by the spark plug > colour - when you adjust the carbs make the same adjustment to each one. > > The valve seats in Nigel's photos are pretty tragic...the compression and > performance must have been noticably on the decline for a > while.......running too lean will burn valves and seats (mixture still > burning as it leaves the chamber). Also the standard VW seats and valves are > prone to corrosion...Nigel tells me the new Limbach alloy valves are > anecdotally good. Running stellite seats with standard valves also is much > better than standard seats. Don't be tempted to use hard valves with hard > stellite seats however as the combination has been reported to fail in some > VW motors. > Rob > > > PO Box 129, > Lawson, NSW, 2783. > phone 02 47592307 > mobile 0429 493828 > > > > > > > > > > > > > > > > > > > > > > > > > > ............................................. > > ----- Original Message ---- > From: Sean Jorgensen-Day <[EMAIL PROTECTED]> > To: Nigel Baker <[EMAIL PROTECTED]>; DOGS <[email protected]> > Sent: Wednesday, 9 July, 2008 10:42:35 AM > Subject: [DOG mailing list] RE: Fw: GUD > > > Nige, > What options are there to get the thing running richer? > > Sean > > -----Original Message----- > From: Nigel Baker [mailto:[EMAIL PROTECTED] > Sent: Wednesday, 9 July 2008 10:03 AM > To: DOGS > Cc: Sean Jorgensen-Day; Sean Jorgensen; Russell White; Rob Hanbury; > Redmond Quinn; Michael Shirley; Kevin Lewis; Keith Gateley; John Hudson; > Harry Bache; graham marsh; Gavin Wrigley; Damien O'Reilly; Colin Turner; > Catherine Conway; Baylee Roberts > Subject: Fw: Fw: GUD > > G'day Dogs and others. > I have added other Limbach users to this mail for their interest. > The attached images are from a L2000 as fitted to the Grob109 which is > essentially the same base engine as used in the Dimona. > The aircraft had some suspicious damage to the Prop which required a > Bulk Strip. > The Crank was cracked and a new shortblock engine has been ordered. > When we stripped the engine I did not like the look of the Valve seats > so sent these images to the factory for comment which is below. > Also one valve was noted to be "sticking" when turning the engine over > during disassembly. > > Whenever Peter says something needs to be "controlled" he means > "Checked". > I rang to clarify a few points. > By "Valve Play" he is referring to Tappet Clearance not Valve Stem > clearance. > By poor carburetion he means "Poor as apposed to Rich" thus he means > "Lean Mixture". > He has suggested that the corrosion has come from the use of Avgas. > He stated that in Europe they normally have trouble with corrosion on > engines using Avgas and seldom found on engines running on Unleaded. > In the past Peter has said they prefer the engine be run on Unleaded > instead of Avgas. > Avgas 100LL of course is still acceptable. > This is of course 98oct unleaded so Premium Unleaded. This must be the > 98oct variety and not the 95oct. > I use BP Ultimate. > Of course I have a problem looming. The eastern states are now > requiring 10% Alcohol content in car fuel and expect that will spread > through all states. I understand the US is in the same position and much > of Europe. > The Limbach Engine is rated for 5% Alcohol and the last time I discussed > this with Peter (a while ago now) he said they would be changing it to > 10% or higher. Brazil's fuel spec for instance is much higher being over > 20%. > > While my fuel hoses are rated for Alcohol I still have the FRP fuel tank > which I believe is not. So changing to the Alloy tank is pending for me. > > That leaves the Fuel Cock and Electric Fuel Pump left in the circuit to > worry about. The seals I put in the Fuel Cock are OK with Alcohol but > will have to check up on the Pump. > Something for you all to ponder if running unleaded like myself. > > Below is the correspondence as mentioned. > Cheers. > Nige. > > > > ----- Original Message ----- > From: "Peter Salomon" <[EMAIL PROTECTED]> > To: "Nigel Baker" <[EMAIL PROTECTED]> > Sent: Friday, July 04, 2008 7:30 PM > Subject: Re: Fw: GUD > > > > Nigel Baker schrieb: > >> G'Day Peter. > >> Attached photo's of the Cylinder heads off the engine that had the > Shock > >> Load. > >> Can you give me an opinion on the corosion to the Valve Seats. > >> This aircraft was being flown every month but the Airfeild is near > the > >> Ocean. The climate here though is not humid. > >> There is also a grey/white powder over the surfaces of the intake > ports > >> and cobustion chamber. > >> Any ideas of why it is this bad. It is 48 hours since overhaul. > >> Regs. > >> Nigel. > >> > > > Hi Nigel, > > > > blimey, what type of fuel fly your client? > > After your pictures can I find some problems with the heads. > > 1.) I think the left head on your picture is from the right engine > site. > > I can see that the exhaust valve from cylinder no 2 have burn tracks. > > No valve play! > > Slight leaky between cylinder and head. > > Overheating failing could be poor carburation! > > The corrosion on the seats could come from using AVGAS! > > The beading in the ports show me very high exhaust temperature! > > On cylinder one the intake valve have also burn tracks outside. > > Please control this valve. No valve play could be the reason. > > > > A new (complete) engine will help. ;-) > > > > Best regards and nice weekend. > > > > Peter > > > > > > --------------------------------------------------------------------- > You are subscribed to the Dimona Owners Group mailing list. > To unsubscribe, send email to: [EMAIL PROTECTED] > > > ------------------------------ > Start at the new Yahoo!7 for a better online experience - Start > Here<http://au.rd.yahoo.com/mail/taglines/au/y7mail/default/*http://au.docs.yahoo.com/somethingwonderful/index.php?p1=brand&p2=other&p3=au&p4=tagline> > . > >
