AVANTI AND TODAYS GAS

The best you can buy, not good enough, but the best you can do.

63t-cab wrote:

I use the mid-grade in my 78 Avanti and although it's not a REAL Avanti, the SBC in it puts out close to 300 hp and it runs fine on the

89 octane, providing the timing is set properly and it's not 100+ degrees outside. I've experimented with all three grades and even with adding in octane booster and the addtional octane didn't seem to make THAT big a difference.

Providing I set the timing back a tad when running the lower grades, it still performed well and didn't 'knock' under load, even with the AC running full-speed.

What DID seem to cause the biggest drop in power is what kills EVERY engine and that's the super-heated air of the high 90's - 100 degrees. With temps in Central Texas in that area most of the time from June til September, I usually go with the higher grade fuel if I drive it in the heat of the day.

I'd be curious to know how much the computer-controlled cars with fuel injection retard the timing and what their fuel-spray curve looks like as the heat increases. I can understand why an inter-cooler is such an important piece of equipment on a turbo equipped car.

Bob

63t-cab wrote:

If you want it to run the way it should, you need to blend some race gas in (5 gallons or so per tank). I use avgas, it's still got lead and runs around 100 octane, cost is around $3.60/gal which beats hell out of $5.50 for race fuel at the 76 station.

Otherwise, you'll need to retard the timing until it doesn't ping on the

91 octane they call premium these days.

63t-cab wrote:

Hi!

I was the one who picked up my '63 Avanti R2 in Issaquah, WA, and drove it back to North Texas in 3 days (~2300 miles). Put 3 bottles of the "concentrated" Techron, and used Chevron Techron supreme all the way. Ran rough for the first 500 miles, gain full strength at about 900 miles. The next miles were on Chevron Supreme, except for one tank of another name brand premium. Baby did NOT like the other premium. Been keeping it on Chevron Supreme ever since with no issues.

Of course, I have not pulled the plugs or checked the timing, so I can only speak to 14.9 average MPG at Interstate speeds coming over the Continental Divide.

For what it is worth....

I wonder why Spearco stopped making their fairly cheap water injector for normally aspirated engines? They worked real well for stopping detonation. They still make a unit for turbocharged engines but it is over $400 dollars.

My R2 runs fine on Amoco "Ultima", from the local BP station. I'll check the advertised octane later, today. It's important to clean and lube the ball bearing between the breaker plate halves, so the advance works freely. Make sure the distributor is in good shape. Some people have set their timing using the wrong mark on the damper. There are three marks, on mine. Some of the dampers have the two parts shifted on the rubber, so the marks are off. An R1, with the standard heads, has a higher compression ratio than an R2; so it's more likely to ping at normal speeds. The R2 heads are listed as optional on the R1 engines in the Dec. '63 parts book. Mike M.

Amoco "Ultimate" at my BP station is labeled 93 octane. Mike M.

I drove my '64 R-2 Avanti 6,000 miles (Potomac Chapter Route 66 Trip-2003) using only regular unleaded (87 octane or less) with no detonation. It was bored .060 with hypereutetic (?) cupped pistons which probably brought the compression down a little. On the other hand, JP got my extra high compression R-1 engine in trade for a '64 289 back in the 70s because I couldn't buy good enough gas to keep it from pinging. BTW, that engine followed the '64 Daytona convertible that now belongs to Jim Turner via JP, Skip Lackie, JP, Nate, and JP. Paul Johnson

Build your own:

Alex Magdaleno wrote:

I use only minimum 93 Octane premium with NO ETHENOL in my 63 R2. Even at that only Shell Premium has been entirely knock free.

BP Amaco premium works well 95% of the time also but I have had occassional pinging under load with the BP. I have also tried Quick Trip premium gas occassionally without a problem but have not run enough through to make any conclusive determination. Any other brand is a crap shoot maybe 50-50 you'll get no pinging.

Don't know why Shell seams better as all brands should do the same if rated equally. My guess is the Shell gas is really slightly higher octane to insure quality/rating maybe 94 or 95.

Jason Ford "1963R2" R4478

63t-cab wrote:

I'm going with one of these for the 54, I have lots of room for a large tank now that the battery is in the trunk. I'll let you know how it works, Avgas is expensive and a pain to get.

John Poulos wrote: