American Muscle Cars Australia

Tech Talk & Articles => AMCCA Members Tech Talk => Topic started by: sms777 on November 23, 2009, 11:22:58 PM

Title: Do not use Shell Optimax in carburetted V8
Post by: sms777 on November 23, 2009, 11:22:58 PM: It has been frustrating. Over the last 6 years of tuning carbied V8's i have come to the conclusion that there is something wrong with Optimax. There has been too many occasions when vehicles turn up in my workshop on tow trucks due to carbies flooding, engine stalls, loss of power etc. Investigating cause always reveals deposits of gasket, rubber, copper residue inside fuel bowl of carby. First thing to do, interrogate customer. How do you drive your car?When was last service? Have you changed your fuel filter? Has the vehicle been in storage resulting corrosion in fuel system? Where have you fuelled up recently.... at Shell....
Hmmmmmm. always the same answer to the last question....Shell. But i alwas thought Shell was the best fuel!....Hmmmm again. Is it?...... I think Shell use some form of additive in their fuel that attacks material used by carby manufacturers before recent changes to emmission rules that obviously have not been tested properly.I have been aware of this problem for a while so i only use BP Ultimate or Caltex 98 or Mobil Synergy and i have no problems. My 426 Hemi loves it so take my advice, if you own a muscle car with carby, stay clear of Shell fuels or you will and up in my workshop for a serious tune and carby rebuild.
Let me know if you experienced similar problems, i am more than happy to help you .

Cheers, Chris.
Title: Do not use Shell Optimax in carburetted V8
Post by: 69DirtyRat on November 24, 2009, 12:01:40 AM: Shell used to have ethanol in there 100-octane, but im not sure what they are doing with there top octane petrol now? Could the Ethanol be eating the gaskets, & causing metal deterioration of the carby parts? I never use Shell!
Title: Do not use Shell Optimax in carburetted V8
Post by: cpu on November 24, 2009, 12:20:50 AM: Quote from: sms777 link=topic=2609.msg14348#msg14348
It has been frustrating. Over the last 6 years of tuning carbied V8's i have come to the conclusion that there is something wrong with Optimax. ........................

Cheers, Chris.

That's not the first time I have heard that. Have always wandered if it was an urban myth or not.
Title: Do not use Shell Optimax in carburetted V8
Post by: GT SALLY on November 24, 2009, 06:40:21 AM: Does this apply to their normal unleaded, which BTW is getting very scarce. The Shell servo at Brighton has just been renovated & they no longer sell unleaded, only E10 & high octane.
Title: Do not use Shell Optimax in carburetted V8
Post by: SMOKEM on November 24, 2009, 08:42:05 AM: This has been an ongoing problem with Shell for years , bikes 1st complained of the problem . So i don't use Shell period .
Title: Do not use Shell Optimax in carburetted V8
Post by: usa383 on November 24, 2009, 11:57:21 AM: Optimax caused us plenty of headaches in race bikes
Title: Do not use Shell Optimax in carburetted V8
Post by: GTA390 on November 24, 2009, 06:45:50 PM: I use Vortex 98 never had a problem with it, only getting it sometimes.
David.
Title: Do not use Shell Optimax in carburetted V8
Post by: sell4u on November 24, 2009, 08:53:23 PM: I use to use Optimax all the time in the HSV but when I switched to the 57 was given the same advise to use anything but as the carbs dont like it?