You are the one with real world experience.
Continue what you are doing. Cheap insurance for your goals. Talk is cheap. No one advising you here is going to financially back you should problems arise.
You may even have higher compression with an untouched engine of that age with carbon buildup.
Your engine is no where near the modern design to lessen knock; chamber design, oil control, fuel management, cooling etc.

A fuel storage additive certainly won't hurt for engines that aren't DD. especially in hotter climates. StarTron is 7¢/gal, if you aren't going to drive for a couple months, throw it in.

As far as E10 parts compatibility, here are 150+ posts on today's parts that are not. Again, some real world hands on experience.
http://forums.corvetteforum.com/c3-t...t-quality.html

 

Glad they did it, but it will be interesting to see how many stations really bother to switch back and the price of course.

 

with today's gasoline you are rolling the dice. some stations are pumping higher than 10% ethanol in regular fuel. the mileage is terrible. today's gas has a shelf life of only about 30 days before it starts to degrade. in the summer humidity startron added to each fill up is a wise idea, especially if you are using regular fuel.

 

Who would only drive there car 2,000 miles per year?????? Shoot that is done easy in one month. And our car is not a daily driver either. Come on guys, start using your cars. Maybe we drive more. I know last year I bought just over $18K in fuel for our vehicles. Yes, this includes the Vette Al

 

Best slow down- you've made another pile of assumptions and leaps of logic.

The gas rating system in North America changed in the mid 70s from RON to AKI. That means what used to be labelled as 95 is now 91. 91 is now 87, etc. The 100 octane you're draining your wallet with would been called 104 or 105 back then.

The stories of gas being better back in the old days is about 99% myth and is based on the unfortunate combination of five big, almost simultaneous, changes in the car and petroleum industries.

1) elimination of lead in gas

2) increase in engine pollution regulations

3) requirement to run on low octane gas

4) re-rating of engine power from gross to net

5) changeover from RON to AKI in pump labelling practice.

If each of these had occurred individually or was properly understood by the average owner, none of the myths would still be circulating almost 40 years later

Real world results from the above:

1) we now know that the elimination of lead had no detrimental effects and the changeover to hardened valve seats by GM was unnecessary on cars similar to Corvettes. Cars pulling trailers over the Rockies, dump trucks and boats yes. Corvettes no. On the other hand, unleaded gas allows plugs to last possibly 5x their former life as well as having much cleaner combustion chambers and less contamination of the oil. Unleaded is the best thing that ever happened to gas, IMHO.

2) addition of smog equipment and smog tuning cost zero to maybe 5% of engine power. Early cat converters and restricted ignition timing were the killers here.

3) the arbitrary decision that all cars must run on regular fuel was the big culprit as it meant that 11:1 compression was out the window. 8 or 9:1 became the practical maximum and power took a nose dive.

4) the re-rating of engine power caused the advertised power to decrease overnight by up to 25% even though the engines had not changed one bit.

5) see comments up above about octane rating equivalency.

Put all of these changes together and it can easily be seen why base engine Corvettes went from 300 advertised HP in 1970 to 165 HP in 1975.

The average consumer didn't know about or understand the five changes above and chose to blame 'the gas'. In your case, only points 1 and 5 are of relevance. Your 11:1 engine was built to run on premium gas- which is today's 91 or 93. The lead is irrelevant.

Tell you what- go over to the C2 section where there's lots of guys with the same engine as you and ask what they're doing. One of my buddies from Indiana will be glad to tell you how he runs many of his mid-years on mid-grade with no issues at all.

Knowledge is power, rumours are for punks.

Edit: to answer your question directly, if for some reason you do experience detonation with a properly configured and adjusted engine, a simple reduction in ignition advance will avoid the problem. This is how modern cars, equipped with knock sensors, deal with it. No reduction of compression required.

 

Everything Mike says is correct. I think he even pulled out some of the GM/SAE data that I've referenced in the past on these subjects.

As for additives: I've had the same 3/4 tank of 10% ethanol gas in my GTO Judge for 2 years now. It starts and runs great every time I take it out of the warehouse to burn another layer off the tires. You don't need no stinkin' additives if you have a non-vented fuel system and limit the air volume over the fuel level.

Treat your fuel tank like Scotch: It'll stay fine as long as it's near full. If you get down below 1/2, enjoy life and finish it off.

Mr. Grumpy (aka Lars)

 

Yes, in addition to similar research done by other OEMs, but most significantly from the archives of my own employer dug out just prior to my retirement when I had some free time on my hands and could (almost) justify doing it on company time. Of course, the data all jives with what the other OEMs found and completely flies in the face of bubba and the other shade tree scaremongers.

By sheer coincidence, I ran into one of the authors of one of these paper written in the mid-70's (when much of the changeover occurred) at a British car show last weekend. Hadn't seen him since the late '90s when he retired. We didn't discuss this subject, I'm sure he hears the same stories with his gang ...............

Mr. Nasty

 

So there ya go, all you ignorant punks, bubbas and shade tree scaremongers out there. Enough of this anti-ethanol rhetoric.

 

"forum members don't listen to them,it's a commie plot to ruin our engines".

 

 

I mentioned up above attending a British cars show recently where I ran into one of the authors of the engineering studies. I found out about this show via another discussion board I frequent that specializes in the make of car I use as my daily beater.

The discussion over there is pretty much the same as here- E10 is new to many of the members, especially those in the UK or continental Europe. Much like in the '70s during the transitions away from leaded gas, any and all difficulties with the car 'must be due to the crap fuel, why can't it be like the good old days'.

What's amusing is the owners are convinced that their problems are due to ethanol yet about 30% of the fleet is diesel powered.

Instead of punk, bubbas etc, they use terms like pillock, tosser and pratt. Just as appropriate though.