I see that Connecticut has but a dozen non ethanol fuel sources. One is just a few miles from me with only three stop signs and two traffic lights between us...but their octane is 112...ouch!
Could this be diluted 50/50 with 87 octane (10% ethanol) resulting in a street fuel rated at 99 octane but only 5% ethanol?...or is 99 octane still too wickedly high for engine longevity?
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Carl,
Gasoline with an octane that is higher than you need will likely have no effect on engine longevity. It will have no positive effect either, so a thrifty guy like you is just paying for something he doesn't need.
Do a search on "octane rating", and it might become more clear. The more prone an engine is to pre-ignite (knock), the higher the octane fuel required. Higher compression, hotter running engines generally need higher octane fuel. The more ignition advance you run, the higher octane fuel you will need.
112 is race gas, and likely costs 2-3x what normal 91-93 "premium" fuel costs. It likely doesn't have ethanol because gasoline has a higher btu content than ethanol, so it packs more "punch" per gallon. Your 8:1 engine doesn't need it.
I know Jay Leno has everybody in a froth about ethanol, but if you jet for it it actually has some nice characteristics for an air-cooled engine with cooling problems. I can get 93 ocante fuel with no ethanol 5 miles from my house but I don't. Why? Because I'm jetted for 10% ethanol, my CR is about a half point higher than it would be if I was set up for "pure" gasoline, and I don't want to be tethered to a 100 mile radius of a station 5 miles from my house.
My advice, for the little it's worth is to run normal E10 premium gas, fill up your tank and put stay-bil in the gas before you put it away in the fall, and figure on replacing your rubber fuel lines every 5 years or so. If you have to send your carbs off every few years to get them rebuilt, it'll be cheaper and easier than trying to play chemist with gasoline.
Drive 'em.
What Stan said!
My car is jetted and timed for 93 Octane 10% ethanol. I'm running 9.8:1 compression. Of course, I also have a "bad gas" ignition map that drops the advance a little. Most should set the timing a little back from the ragged edge that I'm at.
My advice for Carl: run 89-93 octane if you want, and don't sweat the ethanol.
I've had the same issue with the floats and I've lost a couple of 1-2 year old yard trimmers due to carb damage from ethanol. I avoid it whenever possible.
It's always surprising how just one little shim can make such a difference. I believe you want the tension so you can push the belt over a hair more than 1/2". (9/16)
I jyst did that and saw that the outer part of the pulley---the half towards the back of the car,
washad grooves in it from the belt wearing against the metal. Not just a little bit either, so I replaced the rear half of the pully. There is a fair amount of dirt and grit that enters the engine compartment and I believe that grit got between the belt and the pully half to wear the pully like it did.
When I attended the Morro Bay event, one Speedster's pully became broken and there was no replacement at the winery we were at way out of town so after seeing that, I've always had a spare. Now I hope I can replace just that half.
Glad you have your car back from Cory!
"....and.....wait for it Land Anderson.......I think I finally have a clogged idle jet after 5 years and 20,000 miles."
'bout damn time.
The only reason to mix in race gas is to increase the octane of your fuel beyond what it already is if your engine requires more octane to avoid knock/pinging. I really doubt your engine needs 99 octane fuel to run properly. Which makes the excess octane rating a waste of money. Octane boosting is the same reason they mix in the ethanol to begin with. Start with 85 octane gas (which wouldn't work in most cars, that's why 85 is called sub-octane) and add 110 octane ethanol to get 87 octane E10. Or 87 gas -> 89 E10, etc.
Yes, mixing race gas with E10 would reduce the % of ethanol, but the primary problem with ethanol is from phase separation (water sitting in bottom of system, octane reduction) that occurs after it has absorbed too much water. E10 can absorb about 1/2 oz of water per gallon before separation. If you reduce the ethanol %, it takes less total water to cause phase separation, about 1/4 oz per gallon for your proposed E5 mix. So really you've made fuel that will just "go bad" sooner.
Lower temperatures reduce the water content that will cause phase separation too, that's why Heet/Dry-Gas products get used in winter. You're just dumping pure alcohol into the tank so the fuel's able to absorb more water before separation occurs.
Yes, there is also a problem if you use ethanol with rubber and plastics that are not resistant to it. Cutting the ethanol to 5% is going to slow the process, not eliminate it, and you will have spent more money on the race fuel in the meantime than you would just replacing the incompatible parts with compatible versions. Or even just replacing those parts on a regular maintenance schedule.
Rubber fuel hose every couple years as a precaution, it'll get hard and crack from heat and age. If you buy actual automotive fuel hose rather than generic/cheap rubber hose, it's going to be E10 compatible.
Carb gaskets and diaphragm could be a problem, but most rebuild kits should have compatible parts these days. No guarantee with the cheap junk also out there. You're probably going to be rebuilding them occasionally anyway to clean the gunk out. Replace incompatible plastic floats with brass versions if you can get them. Otherwise, you'll want to replace the plastic floats if you see deterioration during the rebuild.
Fuel filters get replaced often, so not a particular issue. If running E85, paper element fuel filters can break down. A stainless steel element, sintered bronze element, or just a filter off a flex-fuel vehicle will fix that.
Mechanical fuel pump diaphragms could be an issue depending on age and where they came from. Commonly not user serviceable without replacing the pump. Cheap electric pumps are hit or miss on their internals.
Old plastic float on an original fuel level sender could be a problem, newer plastic/aftermarket sender probably not an issue. Could replace with a brass float if desired, but often easier just to replace the sender if the float's bad.
The last thing would be to occasionally, if not all the time, run the tank down near empty before a fill-up if you were instead in the habit of continuously topping off. That way you burn all the fuel that has absorbed water and replace it with fresh fuel.
@ justin...Thanks.
OK, here's the deal on fuel hoses, from what I found when researching the issue. I believe you need to see SAE 30R9 on the side of the hose. Check this link.
http://www.goodyearrubberprodu...wnloads/page0032.pdf
also, just google SAE 30R9, and see what you can see. It says the hose is good for fuel injection, so it can deal w/ high pressure. But the chemical thing is it resists permeation of the fuel (something CA is all huffy about), and it is specifically compatible w/ ethanol, and a host of other stuff. I had evidence that the "super high grade" hose used on my car was having some trouble, so I changed out what I could get to in the engine compartment w/ this stuff. It costs more, but I believe it is the right stuff,and should not require changing out every couple of years -- which procedure I would find to be a royal pain the butt. Do it once w/ the right product, and be done w/ it.
That's a good point. 30R9 rated hose is good even for E85 use.
Not a typical tank setup here, but for a submerged in-tank fuel pickup hose, you'd need 30R10. The outer cover of it is resistant to fuel as well, not just the inner liner.
Thanks for the info, Kelly. I knew the stuff was out there, and now we all know what it's called...
Well worth the effort and extra expense.
Kelly..... Thats the exact same hose I used when I re-plumbed the first Spyder....
The ethanol had eaten up the carbs excelerator pump diaphragms, so I went from tank to carbs with this hose where required....It was in there the better part of 6 years with no problems when I sold the car....
Just an FYI....we found a gas station a couple miles from the Courtyard Marriot that sells Ethanol free Regular gas. Ya gotta dose it up with octane booster if you so need. I think it's still there.
~WB
Not trying to bitch anything up here, but how come I've driven about 45,000 miles in the USA / in the last 4 years, likely mostly ethanol included and nary a problem ? This is with existing 32 year old rubber bits in the fuel line and an old stock 1600 type carb, and one newer and one new Weber 32/ 36.
David, God loves you mad Canadians...That's why!
I'm just gonna say that it is the 45,000 miles. If you keep the wheels spinnin', you're less likely to have trouble. Plus also that bit about God loving c'nuks, as I am sure he does, eh?
Someone (Justin?) mentioned that ethanol can affect the fuel tank sending unit.
My VS 's gauge always worked until recently. Before it would read 'F' without too much movement...then it would drop like a stone to nearly 'E'...Now it wiggles a bit when the ignition is initially turned on, but then rests on 'E'
I've checked electrical connections both at the tank and the gauge and everything is solidly connected...so I think that leaves the immerged sending unit (electrical contact activated by the float) as faulty. How do I visually check it? What is it supposed to look like?...or do I simply replace it?
Hi Carl- If the "float" part of the sending unit is plastic then ethanol may eat at it, and will fill with fuel (and no longer float). Pull the sending unit out of the tank and check if it has gas in it.
Someone (Justin?) mentioned that ethanol can affect the fuel tank sending unit.
My VS 's gauge always worked until recently. Before it would read 'F' without too much movement...then it would drop like a stone to nearly 'E'...Now it wiggles a bit when the ignition is initially turned on, but then rests on 'E'
I've checked electrical connections both at the tank and the gauge and everything is solidly connected...so I think that leaves the immerged sending unit (electrical contact activated by the float) as faulty. How do I visually check it? What is it supposed to look like?...or do I simply replace it?
Assuming you have a VW sender:
1. Test gauge:
1a. With key on, remove signal wire from sending unit. Don't let it touch anything. Gauge should read Empty.
1b: Touch wire to ground. Gauge should read Full.
1c: Reattach sender wire to sending unit.
2. Test sender:
2a. Remove signal and ground wires from sender. Remove sender from tank.
2b. Inspect float for holes or any fluid inside. Fill your sink, stick your sender in it, and verify the float actually floats.
2c. Measure resistance between signal terminal and ground tab (or mounting flange). As you move the float arm it, should read around 73 ohms empty and 10 ohms full. It should vary smoothly between the two as you move the arm.
2d. Reattach signal wire to sender. Make sure ground terminal or sender's mounting flange is connected to ground.
2e. With key on, move float arm up, gauge should read Full
2f. Move float down, gauge should read Empty
2g. Reinstall sender.
Which step(s) does it fail on?
