Hello there Im from Europe - Poland. I got 1968 Skylark GS California with 350-4 V8 engine. We got here only unleaded 95 and unleaded 98 octane fuel. I dont know what will be best to tank to my car. Does i need to put to the unleaded fuel some additives ? When i tank unleaded 95 without additives, i hear some knocking from the engine. Thanks for answers
You get knocking with 95? our best without going to race or aviation fuel is 92 or 93 and even that is in select areas. Either you have a cam in it or the cam isn't degreed correctly, or your ignition timing is way advanced (more timing is usally good and makes more power but it may lead to knocking.) If you would rather run on 95 try to back the ignition timing off. If you don't mind using 98 try a nearly complete tank of 98. if the knocking goes away run that. It will also depend on outside tempatures if it's hotter outside the engine is more prone to knocking. if you come back with what cam, or stock cam, what fuel you'd like to run. you'll also get asked what your current timing is set to as well. i'm sure you can get some more help from here. -nate
Pinging has been my nemesis since day one, even after rebuilding the heads, carb, additives and various fuels. I used the equivalent of sea foam too and no change. I reckon it's carbon on the pistons. If ATF can be used in the tank, how much? Is it best to add to less then a full tank, or fill it up? If the car sits for a week, will the ATF separate from the fuel?
If you use atf or other things to remove the carbon deposits you need to change your plugs after as they will foul. The best thing to do is remove the heads, clean the carbon deposits and re-assemble. Pollish the head chanbers while your at it and you'll eliminate the ping for sure!
You probably need the 98. If it were me, I'd look into having cylinder heads with hardened exhaust seats installed. Either by putting hardened seats in YOUR heads; or by installing different heads. Then you have no need for any gasoline additives. You could just run without additives--you may or may not have valve seat wear--but since the fix is to pull the heads and install hardened seats, what have you got to lose? Not everyone uses the same octane rating system. The numbers in Europe are much higher than our numbers in the USA--but it doesn't mean the fuel is better. The system in the USA is to do two tests on the gasoline--rate the octane by both the "Research Method" and the "Motor Method" and then average the results. Europe doesn't do it that way, so you can't compare the numbers. Don't bother with ATF. Next time you're due for an oil change--warm up the engine, put the carb on FAST IDLE (about 1500 rpm--more is better) and dribble a "urine stream" of plain old water into the carb primaries. Go back and forth so that the engine doesn't start missing. A quart "should" do it, but I say anything worth doing is worth over-doing. I use a gallon--or a garden hose with the nozzle set to a very, very small stream. Change oil when you're done. The steam will make the carbon TOTALLY DISAPPEAR--and no oily residue on the plugs, and you won't smoke the neighbors out of their house or have the fire department called on you like with the ATF.
A guy I know at another site told me about pouring ATF straight into the gas tank. I grilled him on it and it seemed to be a legit claim, so I tried it in my Mazda truck. Lo and behold, I noticed a difference! My truck immediately gained power and ran noticably smoother. Subsiquent tankfulls showed less of a difference. After 3 tankfulls (not consecutive), I figure what I was noticing was the ATF cleaning the cylinders. I've run that truck for 15 years on the cheap stuff and, except for Shell, I've had no problems. My friend says he uses one bottle of ATF per tank and his is 25 gallons. Mine is 14.8. I suggest if you wanna try using ATF, just get a bottle and pour in the tank at your next fill-up. ...and I had no problems with my plugs fouling. Elvis
I heard that not everyone can just go out and get Av gas. Check with your local airport to be sure. Why? I don't know. With a low c.r. engine, what you'll notice out of better (i.e., higher octane rating) gas is a smoother idle during warmup. I doubt you'll notice any difference in power. My truck runs 8.6:1 and I tend to use Premium once in a while. Usually around this time of year, since the more severe weather can make it harder to get the truck started and warm-up takes longer (using regular). Other than that, it doesn't care if I use high-test or piss in the tank after a night of heavy drinking. It all burns the same in that thing. If your '72 is using an early smog engine (which would be stock for any '72), then I don't think Av Gas would really make much of a difference over Premieum. The better gas basically allows you to run more advance (timing) with a higher compression engine. Elvis
Almost every American V8 built in the 1960's used a c.r. of around 10:1 for the 4-bbl. version of an engine. The 2-bbl. version used a c.r. of around 9:1. The "performance" version of any American V8 built in the 1960's usually used a c.r. of 10.5:1 or more and featured the 4-bbl. carb and dual exhaust (at the very least). This was the factory's way of coercing you to get the more expensive option, in order to reap ALL of the benefits of the 4-bbl. version. The figures listed here are generalized, "across the board". Elvis
I heard that not everyone can just go out and get Av gas. Check with your local airport to be sure. Why? I don't know. well, here's a couple of reasons: 1. AvGas is not legal for "on-road" use. it's leaded, remember? so don't be pulling your hot rod onto the taxi-way and trying to pump straight into your gas tank. having the DOT called on them is aggravation the FBO doesn't need to deal with. always bring 5 gallon cans or even a 55gal drum. 2. your larger airports / FBO's might not be interested in retail or non-commercial sales. it's not unusual for the FBO to request your airplane # before purchase or at the pump. if faced with this, simply look around and copy one off of the tail of a plane sitting nearby. 3. as with leaded race gas, AvGas is not illegal for use in vehicles that are not registered for use on the street. FBO's will sell to private citizens for airboats ( which often use airplane engines ), experimental aircraft owners, motocross bikes, whomever. i've even seen AvGas for sale at both a BP and a Citgo gas station down here, so you don't even have to go to an FBO. you ought to be calling around to find the best price anyways. or use AirNav to get a price report: http://airnav.com/fuel/local.html
Down here, in some areas where petrol sniffing is a problem among the aborigines on reservations, you can only buy diesel and avgas at the pumps. Too far for me to go though.
