C2- BB hard to run

[Tom Merkel]

I have a '67 SB. This is about my friend's '66 BB.

He claims that it'll fire up, but when around 60mph, and he puts his foot down, it breaks up, rattles, and just won't deliver power the way it should.

I know that the subject of octane, "today's" gas mixtures, etc. has been delt with many time along this forum.

My one question for those with '66 BB: What gas to you use, and were you ever confronted with a similar situation?

Thanks.

Tom

[William C.]

Re: C2- BB hard to run

I had a 425HP or two along the way, ran fine on hi-test (93 octane) unleaded. Try different suppliers, not all "93" octane formulations deliver the same results, and partially it differs depending on your geography, special EPA rules for your area etc.

[roy braatz]

Re: C2- BB hard to run

I'm posting this only to OLD guys like myself that know adding a cup of Acetone to five gallons of gas will increase 91 octane to 100 octane or more.Yes! you must be careful not to spill it on the paint, but mixed it won't hurt any thing in the carb.I'v been doing this for 30 years in various Corvettes I had and still do in my 55 Corvette and 67 Corvette and the many BB Corvettes I have had. %99 of people won't beliave me or won't try it and that's OK I understand. But I was wondering if any of you old farts have???

[Clem Z.]

Re: C2- BB hard to run

tolulene is better but both will dissolve any plastic parts in the fuel system and the when i rebuild a carb that has used "octane booster" which contain tolulene and other chemicals i can see where the plating on the zink parts of the carbs has be attacked and once the plating goes the zink will corrode.

[Peter M.]

Re: C2- BB hard to run

I run my stock 66 427/425 on 50% 93 unleaded and 50% Sunoco standard leaded race fuel. It runs strong with full power and no ping.

[Mark L.]

Re: C2- BB hard to run

Tom, I have a 66 425 which is built to GM specs. I run 94 Sunoco with one pint of lead additive and performance is fine. I can even run without the lead if the foot doesn't get too heavy. Based on the description of the problem I wonder if the coil or ignition connections are a problem. I've seen a bad coil act in a manner that is similar to what you describe.

[Larry S.]

Re: C2- BB hard to run

My car 66 427/425 at 60 mph it at about 3250 rpm about 2000 rpm shy of when its really waking up.Before he says its the gas have him do some simple diagnostic's on the motor itself.I am running 94 sunaco and have the timing retarded for NO knocks Under xceleration makes less power but it runs like a champ in every load condtion and stays cool.

I still think to myself how cool would it of been to purchase this car new out of the showroom and have all this power at your fingertips.I mean the poor car salesmen having to go for test drives in them

[John L.]

Re: C2- BB hard to run

I also have a 427/425 and run the exact same mixture as Peter above.

[Tom Merkel]

Re: C2- BB hard to run

Thank you, gentlemen, for all your comments.

Personally, I believe it is NOT gas that's causing this observation. My reccomendation to the friend is to do a bottoms-up check of all items. Plugs, points, coil, etc.

Tom