E85 in 2001 Civic DX - It works!

[ProDigit]

My advice?
Forget about it.
MPG drops as E-levels rise.
I own a Fiesta ST. Done several tests on it.
Get 34mpg on 87oct, 33mpg on E12 (87+E15 in a 50/50 ratio), and 32.5 at E15.
All the while it gets better performance with E12.
The car recommended no more than E20. I ran E30 once, and immediately noticed a drop of a few (ten) HP.

In reality, it runs best on 87oct. But the added E15 cools the engine better, and compensates for the fiesta's rich burn.
Alas the mixture.

E85 will only run better with higher compression, or higher boost, and advanced timing, and still will get lower mpg, because Crapanol still has lower energy density than gasoline.

Thus, higher E values can get you better performance, but no better fuel economy. Think about it, lower energy density, and higher performance, there has to be a drawback. And the drawback is increased fuel consumption.

On a stock car, you'd have to bump compression from the default (10:1, or 11:1) to 14:1 when running plain E85, and use an engine heater block in cold climates.
Worst case, you can start the car spraying starting fluid in the air intake, until it's warm enough, usually about 5 seconds will do (more when the weather is colder)

[cRiPpLe_rOoStEr]

Originally Posted by ProDigit

The car recommended no more than E20. I ran E30 once, and immediately noticed a drop of a few (ten) HP.

That's surprising to say the least. I could easily expect a car to keep its performance unchanged while using a high amount of ethanol, but not to decrease it.

On a stock car, you'd have to bump compression from the default (10:1, or 11:1) to 14:1 when running plain E85, and use an engine heater block in cold climates.

Many older dedicated-ethanol cars here in Brazil actually had a lower CR, and pure ethanol (with some residual water) was used instead of E85. Most of the port-injection flexfuels also rarely go beyond 13:1.

Worst case, you can start the car spraying starting fluid in the air intake, until it's warm enough, usually about 5 seconds will do (more when the weather is colder)

Dedicated-ethanol (either carburettor-fed or with EFI) and earlier port-injection flexfuels in Brazil had a small auxiliary tank for gasoline, meant to be used for cold starting. Nowadays most resort to a heated fuel rail, while others have turned to direct injection which doesn't require the fuel to be pre-heated.

[ProDigit]

Originally Posted by cRiPpLe_rOoStEr

That's surprising to say the least. I could easily expect a car to keep its performance unchanged while using a high amount of ethanol, but not to decrease it.




Many older dedicated-ethanol cars here in Brazil actually had a lower CR, and pure ethanol (with some residual water) was used instead of E85. Most of the port-injection flexfuels also rarely go beyond 13:1.




Dedicated-ethanol (either carburettor-fed or with EFI) and earlier port-injection flexfuels in Brazil had a small auxiliary tank for gasoline, meant to be used for cold starting. Nowadays most resort to a heated fuel rail, while others have turned to direct injection which doesn't require the fuel to be pre-heated.

Yes, most stock turbo cars, made to run on 87, have worse performance on E85. Those that run on 91-93 octane, usually have similar performance with E30, and don't perform any better, unless the boost is increased.
As far as N/A, they run worse on E85 vs 87 octane, with the exception if your engine is an atkinson engine (most atkinson engines on the market are 2.0 I4 engines). The atkinson engine can increase compression even under load to match the fuel type you're pouring in it.

I admit not knowing the exact compression ratio, but 14.7:1 seems about the max compression ratio for premium gasoline, usually used by motorcycles.
This is for 93 octane fuel. At 100-105 octane for E85, the compression can be further increased. I've read an article a while ago, with numbers as high as 16:1 for E85 compression ratio, but this was on a performance vehicle, tuned by professionals; not the average joe mechanic.


With the starting fluid, I was merely commenting on the person who had trouble starting his car on E85, but said it ran fine once warm.
At cold start, any car runs rich.
His injectors are not providing enough fuel to keep it running in sub zero temps, so he needs some combustible fluid like started fluid.

[19bonestock88]

In theory, couldn’t a high compression engine(11:1 vs 9.5:1) with advanced timing about match the mileage of a it’s lower performance counterpart running E10-87octane? Seems as if since the ethanol cools the burn and resists detonation really well(some say even better than an octane equivalent gasoline, like E47 vs 100octane), lean burn could help even more?

[ProDigit]

From a performance point of view, people use turbos to increase power on an engine. The turbo does in some ways 'increase compression ratio', due to it increasing the amount of air entering the cylinder. This larger amount of air will now be compressed in the same size as the non turbo version, so in that sense, there's a higher compression.

It's much easier to increase power on an engine than increase compression.
Or even reducing airflow, by creating a hot air intake for better mileage.

But increasing compression, by reducing the gasket thickness, or possibly creating a smaller cylinder head; I haven't seen a lot of people do.
Despite the results,

Ethanol still remains a lower density fuel, attracts water vapor (which increases torque but eats HP) and overall water is even less energy dense than ethanol.
On average, an E85 blend has about 30% less energy than 87 octane fuel.
In order for you to match the same power output, you'd have to give the engine 30% more fuel (on E100), or,...

There is a possibility that with an increased compression ratio, you do get away with less fuel, and get the same mileage as gasoline.
That is, if you can get 30% more compression without any issues (like knock, ping...).
In theory it would work, going from 11:1 to 14.3:1.
In practice, as far as I know, it's never been done before.

[sameb]

Maybe it has been done now. I've got mine running. I just ordered a power steering belt that should fit so it will stop sounding like a banshee. I fixed the alternator belt problem. Now I am left with a hole in the timing belt cover. Take a look at my website. samnet.sytes.net/civicSX.html Basically I took a stock 2001 civic that is 1.7 L, lowered the displacement to 1.6L by using a crankshaft with a shorter throw, and put in domed pistons that gave me 12:1 CR according to this calculator Honda D-Series Compression Calculator by ZealAutowerks For some reason I through I was going to get closer to 13:1... oh well.

[19bonestock88]

I read somewhere that they actually made a high compression D17 from the factory, but was meant for CNG...

Were I wanting higher compression, I’d just do the pistons. While there is a shorter stroke crankshaft for my engine, it doesn’t bolt to my stock flywheel... my main reasoning for wanting high compression and E47 is to make more power, on slightly cheaper fuel... some tuners say that you get *most of* the benefit of running ethanol at E47 and it doesn’t have quite the same trouble with cold starts as E85, and (big surprise) it gets better mileage than E85... I imagin that with an engine optimized for the fuel, E47 could out-do regular unleaded on all fronts...

[ProDigit]

There is another option for increasing compression without doing much engine mods.
Coating the cylinders.
I've seen companies coat cylinders with some hard material.
It's possible to just add a coating on the piston, that will hopefully last.
Or, like mentioned, just change the piston shape or size, to one that's giving you a higher compression.

As far as smaller crankshaft, I would avoid if possible.
A smaller crankshaft reduces torque by a large amount, and doesn't allow the fuel to burn completely.
If you're going to do a crankshaft swap, it would make sense to get a longer crankshaft throw. They're more optimized to use all the energy available in the fuel, meaning cooler exhaust, less wasted energy, and more torque.

Short throw crankshafts are good if you want higher RPM.

[sameb]

The pistons used in the lng civic are rare. The one's I used are cheap (for now).

If I would have used the original crank with these pistons the CR would have been too high.


If you want more power use a turbo.

[cRiPpLe_rOoStEr]

Originally Posted by sameb

The pistons used in the lng civic are rare.

I guess you actually meant CNG. Unlike propane, natural gas can't be supplied to the engine at the liquid phase. Plus the storage system for LNG is usually only deemed economically viable in trucks.