ethanol conversion query

Hi,

I've been reading up lately on the technical aspects of converting gasoline vehicles (e.g. a Saab c900 turbo) to run on ethanol or ethanol/gasoline blends. I'd appreciate any input on the ideas, and of course any experience anyone might have doing such a project.

I've been considering the following facts: 1. gasoline is now rather expensive (and is likely to stay that way); 2. ethanol is likely to become increasingly available; and 3. c900 turbos are relatively inexpensive these days. Also, I understand that turbo engines are particularly suited to running on ethanol because they can take full advantage of high octane fuels.

It looks like there are two primary obstacles to running a gasoline engine on ethanol: compatibility of the fuel delivery system with ethanol, and the need to inject more fuel per mass of air.

  1. Fuel storage/delivery

a. Compatibility of fuel tank and fuel lines with ethanol.

I'm not really sure what the c900's fuel tank is made of. Is it stainless steel? Also, not sure about fuel line compatibility. Does anyone have any idea?

b. Fuel pump

The fuel pump may contain internal seals or other parts that dissolve in ethanol. Probably not an impossible obstacle though.

c. Fuel injector O-rings

... must verify that injector o-rings are not ethanol-soluble. Probably not a big obstacle to overcome.

  1. Air/fuel mixture

My understanding is that the c900 can tolerate 10% or maybe even 20% ethanol/gasoline mixtures, as the ECU can detect and compensate for lean/rich mixtures via the oxygen sensor. But running on > 20% ethanol probably screws up the air/fuel mixture by a greater degree than the ECU can compensate for.

The solution to this problem must be to inject more fuel. One way to do that is to enlarge the injector ports, but that introduces assorted other problems (i.e. spray pattern and mixture-too-rich when running on gasoline). So another solution is to change the injection pulse length. There seems to be an aftermarket product designed to do just this (see xcelplus.com - not affiliated, etc). It apparently intercepts the signal from the ECU to the injectors and lengthens the pulse, and you can still switch it off to run on gasoline. They claim to be compatible with Bosch fuel injection.

The same people also sell some sort of engine treatment, which they claim coats certain engine parts to protect them from ethanol/water induced corrosion. That's probably the scariest part of this whole thing as far as I'm concerned. Oh, and they also warn that the ethanol will clean out lots of gunk from the fuel tank, necessitating a couple of fuel filter changes.

So, does this sound like it would be a worthwhile experiment? The total cost would likely be $2000 - $3000, including the car...

John

Reply to
John B
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Ok, that's a problem. Running new fuel lines would be a bit of a pain, but is obviously very possible. What about the fuel tank, though?

Is it likely that a more modern (and ethanol-compatible) fuel tank could be found which would fit into the existing fuel pump setup?

Yep, I'm in the US, and we are indeed running 10% ethanol. E85 is available, though not widely so.

Aren't all T16s Bosch?

Well, I certainly want to give it a try if the consensus is favorable. Selling the wife on a 3rd Saab might be the trickiest part :)

John

Reply to
John B

in article slrnealc42.cbu.rotten_NOSPAM snipped-for-privacy@oragam.example.com, John B at rotten_NOSPAM snipped-for-privacy@ccil.org wrote on 04/07/2006 18:19:

Existing fuel lines will be corroded by an ethanol mix of greater than about

10% to petrol.

... As above ...

Probably okay, so long as they are new.

I'm led to believe that 10% ethanol from the pump is already commonplace across the US (and elsewhere?), so there is a fair chance you're already running it. Older pre-ECU C900s are probably okay just knocking the timing back a bit - the fuel pressure is much higher than the later ECU controlled cars.

I do know that non-Biopowered SAAB 9-5s are okay with E85 .. Not sure about long-term usage, but as a one-off, it worked for a tankful. I've seen an NG900 setup for E85 on garaget.org, so I presume it's not a quantum leap back to the C900 T16 ... Are you thinking Bosch or Lucas FI system?

I think you're already ahead of us here ... I'll watch with interest; other may have direct experience.

Try it out for one tank fuel prior to your next fuel filter change? Fill up, drive 25 miles and then top up with ethanol. That'll be just short of 10%, give or take content already in the "petrol".

I think it does!

Paul

1989 900 Turbo S
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Reply to
Paul Halliday

in article slrnealh1t.cj6.rotten_NOSPAM snipped-for-privacy@oragam.example.com, John B at rotten_NOSPAM snipped-for-privacy@ccil.org wrote on 04/07/2006 19:43:

I would think if it is a concern, then it should be replaced. The last thing you want is a fuel leak ... They always happen at times when you are unable to contain them :(

I'm sure a replacement could be procured for a reasonable amount. It might be that a lightweight metal tank could be fitted into the boot/trunk. I'm sure a motorsport tank and pump must exist for cars running "funny fuel".

Follow up to the front with a new fuel line from the same setup. Again, I think a suitable FPR and rings, grommets and what-not can be had for this setup. If I find something useful in my plethora of motorsport catalogues, I'll post up the details.

Sorry - I wasn't sure at first where you hail from. You guys didn't get the LPT C900. That was a Lucas controlled light pressure turbo model, rated to

145 BHP and no intercooler. I tend to overlook the normally aspirated 16V cars (again, did you guys get those?) which I think are Bosch controlled.

Have a look at

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- You'll find some information (andnecessary programs) for re-programming the Bosch ECU. If you're going that far, it might well be the time to retro-fit a nice 2.3 head and DI system. The 1988 9000 CD is the most suitable donor car. Take a look at the DI article under 'DIY' on the 900 Aero website or at this thread from David Fisher (sadly, no longer with us) on UK SAABs:

Re-timing/programming DI is going to be a lot easier than the stock distributor setup.

Just tell her it's for spares :)

So long as she sees the petrol tank come off, a lot of pipes ripped out and the head come off she might believe you ...

Paul

1989 900 Turbo S
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Reply to
Paul Halliday

I don't know how much value this will be, but I already went through some of this exercise with my 1991 9000T (Bosch LH-Jetronic). The experiment ended - at least temporarily - two weeks ago after 3 tankfulls and about

1000 miles with a fuel pump failure. I'm not saying that the E-85 fuel made the pump expire - 150,000 miles of use likely contributed to the situation.

My findings: I tried E-85 with an unmodified fuel system and found that about 30% was acceptable. With ethanol concentrations higher than that, the "Check Engine" light would illuminate. The experiment continued with the installation of the FlexTek device. It fit the Bosch fuel injector connectors without issue. No polarity adapter needed. FYI, a competing device called FlexTune is also available at

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The FlexTek people call it a "cheap knock-off". I don't know much about it except it has more configuration settings for economy vs. performance and to account for different concentrations of ethanol. It also has a provision to operate a small gasoline tank to assist in cold weather starting when 100% ethanol (as is availabile in Brazil) is used. I didn't change anything else. The original FlexTek website (based in Brazil where FlexTek is manufactured - I don't have the site address handy) actually states that cars designed to handle 10% ethanol are overdesigned and will also handle 85% without a problem (in their opinion). The Xcelplus people have many fine chemicals that they want to sell, which could explain their differing opintion. FlexTek occasionally shows up on E-Bay at about half the price that Xcelplus is asking - but without the "Engine Preparation Kit".

[snip]

The cleaning properties are accurate - no fuel injector cleaner needed after you put in a few gallons of E-85. My fuel economy went up about 10% after the first few gallons of E-85 ran through the system. FYI: The E-85 capable Chevrolet Impala owners manual warns that fuel additives must not be used when the car is fueled with E-85. The Brazilain FlexTek site recommends that the fuel filter be changed once, after about two tankfulls or 500 miles of E-85 usage.

My total cost was about $250, including the fuel filter. Oh, plus $750 for the shop to install a new fuel pump ;-( If I missed answering anything, please let me know. I am in full agreement with your recount of the benefits of E-85. At the very least it allows for an alternate fuel should gasoline become unavailable. One last FYI trivia: The original mass-produced vehicle, the Model T (and Model A) Ford cars were designed to operate on gasoline or ethanol and can operate perfectly well on the E-85 fuel available today.

Walt Kienzle

Reply to
Walt Kienzle

The 900s is the 16v NA in the US. I do not if the naming covention was the same across the pond.

JB

Reply to
Jeremy

in article goHqg.317273$ snipped-for-privacy@bgtnsc05-news.ops.worldnet.att.net, Jeremy at snipped-for-privacy@att.net wrote on 05/07/2006 05:39:

No, then. The 900S was the LPT model here. NA cars were simply based 900i with the "16 Valve" badge underneath.

Paul

1989 900 Turbo S
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Reply to
Paul Halliday

Interesting. From what I've read, I gather that fuel pump failure is rather common after conversion. I think a preemptive fuel pump replacement might be a good idea.

So, installing the FlexTek device allowed running on E85 with no check engine light or other problems (except the fuel pump)?

John

Reply to
John B

True, plus dribbling flammable liquid around the exhaust pipe is generally a bad idea. However, I'm not sure how credible the risk to the tank and fuel lines is, as I don't know what material they are lined with.

Good point, the FPR might very well need to be replaced, depending on its internal composition.

Yep, we have lots of NA 16V cars on the road in the US. My daily driver is a NA

16V 2.1L model.

Well, the down-side to reprogramming the ECU to deliver more fuel is that it's not easily reversible when you need to fill up with E10. That's where the FlexTek thing seems like a good idea.

John

Reply to
John B

Exactly, although the Check Engine light came on for a few minutes after I first installed the FlexTek. This was before I fueled with E-85 and with FlexTek in the "gasoline" setting. In hindsight, the subsequent and occasional illumination of the check engine light was probably due to the weak/failing fuel pump. Surprisingly, there was no check engine light after my first E-85 fillup when I switched FlexTek to the "ethanol" setting and gasoline was likely still in much of the fuel lines.

One other item of note is that the average fuel economy reading from the trip computer was no longer realistic. Normal readings around 25 to 30 mpg shot up to around 45 to 60 mpg after FlexTek was installed. I was expecting somewhat reduced fuel economy and was a bit shocked until I realized that the fuel flow is not determined by a dedicated sensor, but is gleaned from the fuel injection system. Actual fuel economy calculations indicated a 5% reduction in fuel economy with E-85.

Walt

1991 9000T
Reply to
Walt Kienzle

I've got an 81 900T 8V which has been running almost exclusively for the last three years on a 98 RON 10% ethanol blend in Aus. Note - it is *NOT* happy on 92 RON, ethanol or not! When I got it, the fuel tank was leaking on fillup because all the rubber grommets that the lines pass through had almost completely rotted away. Previous owner had possibly used a local ethanol blend distributor who was experimenting with 18-20% blends at the pump. I dropped the tank and replaced all of those and changed the filter. It's done about 40,000kms over the last three years with no other fuel related attention except for new injectors. They were well on the way to stuffed when I bought it anyway ... The valve seats are hardened in all the turbos so no problems there.

Be aware your fuel conusmption will increase a bit, but IME only about

3-4% with 10% Ethanol. If you're running any pre APC engine it won't be very happy with a significant RON drop so watch that if it's appropriate. Higher percentage blends than 10% regularly and 16% occasionally I can't tell you anything about as no experience with them. Cheers
Reply to
hippo

[snip]

Thank you for the information, but 10% ethanol has been commonplace in many parts of the US for about 25 years. My 2 cars have rarely used anything else because an "oxygenator", typically ethanol, is required in my area. There were a few problems with carbureted cars (and there were many more around back then) when this first became available, but after the built-up varnish was cleaned out, most cars operated without a problem on 10% ethanol.

Walt Kienzle

1991 9000T 1990 Taurus SHO
Reply to
Walt Kienzle

We have probably had some small amount of ethanol in fuel here for years too as part of the 'cocktail', but the proper 10 percent ethanol fuel is very new, only being available here for not much more than a year or so since the federal government changed the legislation so that there are 'incentives' to make ethanol-based fuels available to consumers.

Shell was the first to launch one - Optimax Extreme is what they call their

10 percent ethanol blend here.

So most people have no experience with it here, and I think a lot of people are reluctant because of the potential problems with running older cars on it (not just Saab's).

Craig.

Reply to
Craig's Saab C900 Site

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