Probably just clean. To see if it's terne plate i think you have to heat it with a big soldering iron on the outside and watch for any melting on the surface nearby on the inside.

After cleaning the tank it looks to be galvanised. Is it? or is it just really clean inside.

The subaru's in question were flex fuel vehicles, but theyre only good for about 50/50 petrol and ethanol. any higher ethanol content and they have problems supplying up in higher revs (3000+), 'check engine' lights and what not.

But enough about them, back to the real cars.

There are plenty of flex fuel vehicles so I'm sure a standard engine would be happy on e85 with a jet change and new rubber fuel hoses, assuming the pump is big enough and compatible.

The thing about lining tanks and metal fuel lines that I've read is soft metals like zinc, aluminium, lead corrode as the ethanol dissolves the oxide layer. The concern is a little extra water in the fuel. My feeling is in a dry climate where the car lives inside or the fuel is consumed and replaced regularly metal corrosion is probably less of an issue.

Since I don't drive mine much and am going efi I figure the right materials in the fuel lines/ tank will be cheaper than replacing 8 injectors. With a carb you could probably just see how it goes.

I had a look today and the tank sheet appears to be about 1.2-1.4mm thick. drained and drying in the sun.

So engine changes are not needed (not required to change pistons or compression ratio).

Are these the only Fuel line/ tank mods required for e85?
* Tank must be lined
* fuel lines replaced
* Carb jets replaced with bigger ones

The best way to compare more/ less power is to look at the lower heating values of the fuels and then compare the stociometry.
Ethanol 28.865 MJ/kg
Octane 44.427 MJ/kg
I've chosen Octane but really the heating value is about the same for C6-C12 hydrocarbons.
Ethanol burns at 9:1 and petrol 14.6:1 so the equivalent heating value of ethanol in replacing petrol is....
28.86x14.6
----------
9
=46.8

So slightly higher than petrol supporting the argument of slightly more power with nothing but fueling mods for a high ethanol blend. You also get more cooling and potentially more air into the engine.

Reading thru the subie forum, i think they said you use about 15% more e85, not all that much worse than normal petrol. I've seen a 1600 race car with a N/a SR20 with separate throttle bodies getting 209kw ATW with unleaded 98, and 214 off E85.

The Subaru crowd in the US is big on E85. The main guy on all the e85 forums, 'hotrod' has been running e85 in a near stock subaru of his for a couple of years now. The only things he has changed is the ECU and the injectors, only because the stock ones only just fell short of the 25-30% higher volume of e85 they had to put in.

Do a search for E85 on Google and you'll be sure to find that guy's name somewhere in each article.

Quote:
So have I. But the chevy engine crowd figure 13.5 is the safe level. E85 has mininum properties, which are guaranteed. Any batch you buy will be at least that good, and often better. If it is better mix, you can run higher compression ratios. But you cannot count on it long term.


Quote:
Yes, it's the same with any high-octane fuel, E85 or petrol. Engine needs different tuning to take advantage of it.

13.5:1 compression ratio or Air Fuel ratio?
I've heard of engine with higher compression ratio with E85 then 13.5:1. Stoichiometric Air Fuel ratio is 14.7:1 for petrol and 9.7:1 for E85, hence why you need to use more fuel for a given amount of air, which in turn decreases your fuel economy.
.
The key with E85 is the ability to run more ignition advance which generally equates to more power.
This is due to the increased knock/pre ignition propories in E85 which is evident by it's RON/MON number.

Most manufacturers of plastics will give an indication of it's resistance to chemical. Rubber is not very resistant to alcohols/ethanol. For me, the peace of mind that my multi thousand dollar engine rebuild will not be jeperdised by a couple of low $ rubber hose is a good investment.