aftermarket flexfuel vehicle mods

[Deviant Ollam]

i'm looking in skroo's direction on this one. (you don't seem to have PM enabled or else i'd have just shot you a message and not started a whole thread)

so... i'm pleased that .us automakers are finally embracing alternatives to gasoline in one way or another. as many of us have discussed in other threads, it would be nice to see more diesel support, but what can you do. i am pleased at GM, however, since they are making ethanol compatible vehicles a lot more now.

since (particularly where i live) one can't obtain ethanol easily, i particularly like how many of the newest variants of these cars and trucks are FlexFuel vehicles. (with engines that can burn gas, ethanol, or eth-blends like E85... they have sensors which monitor the fuel mixture and adjust engine timing, performance, etc accordingly)

what i would like to know is if it's possible to add one of these sensor / flexfuel arrays to my existing truck. I drive a 1999 GMC Yukon. under the hood is the same 5.3L Vortec V8 that has been in their FlexFuel tahoe and yukon since 2002. (at least i think it's the same, just minus the sensor array, etc)

can one add such flex hardware from aftermarket kits? i haven't been able to find anything useful in most of my searches. sadly, many of the ethanol forums i'm coming across have been sparesly-populated and contain few posts. the community just isn't big enough yet for me to find a great deal of info online.

thoughts? advice?

[skroo]

i'm looking in skroo's direction on this one. (you don't seem to have PM enabled or else i'd have just shot you a message and not started a whole thread)

Yes, I'm sneaky that way ;)

so... i'm pleased that .us automakers are finally embracing alternatives to gasoline in one way or another. as many of us have discussed in other threads, it would be nice to see more diesel support, but what can you do. i am pleased at GM, however, since they are making ethanol compatible vehicles a lot more now.

Ford and Chrysler have also been doing the same for some time now. Ford's flex-fuel vehicles are typically from the mid-/late-'90s up, and are badged either 'FFV', have a logo of a leaf on a branch somewhere on the vehicle, or a combination of the two to denote them. A good starting point for a list of models can be found here.

since (particularly where i live) one can't obtain ethanol easily, i particularly like how many of the newest variants of these cars and trucks are FlexFuel vehicles. (with engines that can burn gas, ethanol, or eth-blends like E85... they have sensors which monitor the fuel mixture and adjust engine timing, performance, etc accordingly)

Yep. Problem is, finding even E85 can be a nightmare - California only has (IIRC) three or four publically-accessible stations selling E85 in the entire state. One of the guys here ran into this recently when he bought an S-10 pickup, was really excited that he could run it on E85 - and then found that the nearest filling station selling it was two hours away in San Diego (go here for an alt-fuel station map). All the flex-fuel vehicles seem to have done for anyone is earn the manufacturers some feelgood publicity and a few EPA credits.

what i would like to know is if it's possible to add one of these sensor / flexfuel arrays to my existing truck. I drive a 1999 GMC Yukon. under the hood is the same 5.3L Vortec V8 that has been in their FlexFuel tahoe and yukon since 2002. (at least i think it's the same, just minus the sensor array, etc)

The short answer is a definite 'maybe'.

The longer answer comes down to (as you mentioned) adding the appropriate sensors as well as the metallurgy of the engine, fuel lines and tank, and suitability of any rubber lines or gaskets in the fuel delivery path to hold up to anything other than gasoline going through it. Basically, ethanol (and alcohol) are more corrosive than gasoline to standard engine components such as the above. While the fuel may combust in the chambers, it may also cause serious damage if the entire fuel system and powerplant weren't originally built for it.

I'm pretty sure that GM had flex-fuel vehicles on the road in 1999, but could be wrong on that. I'd recommend hitting up the Yukon / Tahoe / Silverado / etc. owners' forums and seeing what people have to say. For all I know you could get lucky on this and have a relatively easy time of converting it, but I wouldn't want to give you bad info and have you end up rotting out the fuel system or worse.

can one add such flex hardware from aftermarket kits? i haven't been able to find anything useful in most of my searches. sadly, many of the ethanol forums i'm coming across have been sparesly-populated and contain few posts. the community just isn't big enough yet for me to find a great deal of info online.

Most of the aftermarket stuff I've seen has been for LPG - ethanol's a little too specific in its construction requirements to make it work across a broad range of vehicles. LPG is more widely available, but necessitates having a second tank unless you're able to never have to worry about LPG availability (which is actually pretty decent in most places). That second tank typically means less cargo area, and also reduces performance noticeably. Not so much that it makes the vehicle unliveable, but you will notice it.

If you've got the Vortec (good engine, BTW), my recommendation would be to try to find an insurance write-off with a Duramax diesel in it and swap to that. No idea how complex this would be for your vehicle, but I'm playing with the idea currently of swapping the 2.8-litre CRD engine from a current-model Liberty into my Cherokee. For that conversion I'm going to have to change out the fuel tank, all fuel lines, ECM, intake metering, and possibly instruments as well. It'd almost be easier to get the Libery and convert it to a solid front axle than try to plant its drivetrain into the Cherokee. GM stuff is a lot more modular than what I've got to work with from what I understand, though.

[Deviant Ollam]

does the flexfuel equipment do what i'm assuming it does? after monitoring the feed does it merely adjust engine timing, fuel ratios, etc... shit like that? (i.e. - just changing the operation of standard engine valves, injectors, etc... operating at an exclusively electronically and logical level) or is there more involved... custom nozzles, pumps, or even headers, etc?

if it's just a matter of monitoring which leads to changed electronic controls, then it really does seem like (potentially) as easy an upgrade as you're describing. a monitor in the fuel line plugging into the drive computer and woot, there you go. (assuming, of course, the whole corrosivity issue doesn't foul the fuel system's plumbing)

[skroo]

does the flexfuel equipment do what i'm assuming it does? after monitoring the feed does it merely adjust engine timing, fuel ratios, etc... shit like that? (i.e. - just changing the operation of standard engine valves, injectors, etc... operating at an exclusively electronically and logical level) or is there more involved... custom nozzles, pumps, or even headers, etc?

In principle it's no different to fuel monitoring for gasoline enignes, though it does change timing, ignition, etc. based on the type and mix of fuel in use. Can't really answer about changes to the mechanical bits - my best guess is that things like injectors and valves are probably the same as their gasoline counterparts, but I really can't give a solid answer on this.

if it's just a matter of monitoring which leads to changed electronic controls, then it really does seem like (potentially) as easy an upgrade as you're describing. a monitor in the fuel line plugging into the drive computer and woot, there you go. (assuming, of course, the whole corrosivity issue doesn't foul the fuel system's plumbing)

Yeah... And I seem to think it's slightly more involved than that, but I'm really unable to answer for specific vehicles (or, at least, ones I don't have experience with). Seriously, check out some of the owners' forums. I'm willing to bet this is a relatively standard question - and at the very least you should be able to find someone with the experience necessary to answer.

[Deviant Ollam]

it seems about 75 ~ 90% unlikely that i can do this easily with my truck. (for those who also might have a late 90s / early 00s GMC tahoe/yukon... check the eighth character in your VIN. if it's a Z you're in luck. if not, chances are your fuel plumbing isn't rated for ethanol.)

you were spot-on... owners' forums had the details. sadly, the majority of posts about ethanol (and other alt fuel systems) were not about mechanics and technology but about vauge (and often error-filled) discussions of how such fuels are made, what they actually consist of, etc etc etc. seems the defcon forums are hardly the only place on the 'net where people cannot use the search function or operate google.


side question to skroo or anyone else... something i've never been certain of (and have heard defined both ways before) is a vehicle's tonnage rating. when a truck is a "half-ton" does that refer to max payload weight or towing capacity? (i know it's not curb weight, which i thought is what the figure represented when i was really little... "wow, that jeep only weighs 500 pounds?!?" i was heard to remark when i was about 7 or 8)

i certainly don't think my yukon measures up to a deuce and a half, but she surpasses that figure in towing capacity.

EDIT: google answered my above question. tonnage in a vehicle's description is payload, not what it can haul. the M35 could actually contain over 5000 lbs in its bed, supposedly it could haul something like six tons. my truck, while it can haul a little over 3 or 4, is only rated as a three quarter ton within the confines of its frame. maybe i could look into this bad boy as a spare toy. only $5400 for a relatively good condition 2½. not bad, really.

[Virosa]

maybe i could look into this bad boy as a spare toy. only $5400 for a relatively good condition 2½. not bad, really.

Nice. I've never driven those, but I used to drive 5-tons back in the day (automatic transmission 925's and 923's - there were a few stick-shift 813's around, but those were being phased out). I imagine they are very similar. LOTS of fun for offroading!

One thing I'll caution you on is that on the 5-tons, everything was pneumatic-assisted, and inside the cab was this warning siren that went off any time the air pressure wasn't high enough to run everything. When I first heard it, it was ball-shrivellingly loud. By the time 6 years had passed, I hardly noticed it anymore. I'm sure that my hearing curve has a big ol' notch taken out of it at the exact frequency of that siren. Protect your ears or rip out the damned siren if you do buy one.

If you do buy it and you need an A-driver, be sure to look up Veruus. He was a pretty good one (remember Camp Upshur? )

[Gobniu]

maybe i could look into this bad boy as a spare toy. only $5400 for a relatively good condition 2½. not bad, really.

What you need is one of the old ones that I've heard about from WWII that had the "flex-fuel" engines. They could run on diesel or regular gas as I recall. Also another nice feature was a manifold lock that would close of the air intake for driving through deep water.

[Deviant Ollam]

What you need is one of the old ones that I've heard about from WWII that had the "flex-fuel" engines. They could run on diesel or regular gas as I recall. Also another nice feature was a manifold lock that would close of the air intake for driving through deep water.

as far as i know, the term "flex fuel" is a relatively new one, referring to combustion engines which can burn gas, eth, or some combo of the two.

what you may be referring to are "multi-fuel" deuce and a halves. these trucks, which are diesel, i believe simply have such strong engine blocks and operate at such extreme compression ratios that just about anything you pour in the tank will fire in the chamber, but i'm not sure. (and from what i have seen, they aren't exclusively WWII vintage... modern M35s have mutli-fuel engines) of course, i wouldn't try to run one on non-diesel (or non-bio-oil-diesel) for any extended period of time.

i have heard, however of navy seal boats whose outboard motors can run on all grades of gasoline, agricultural vehicle fuels, and even strong liquor.

the manifold lock is pretty cool. i'm personally thinking of installing a snorkel. (side note on that... since i think they look pretty lame attached to a daily driver vehicle, i am planning on doing a hack job under the hood... keeping the stock air intake as it is and forking off a second tube that will run to a removable snorkle. valves on the inside will control which air source the engine breathes. add it all up with a gas-cap-flap type addition to the body panel and i'll have a snorkel that i can attach and enable in about a minute's time without the need to drive around with it 24/7. i'll post some photos if i ever get around to doing that this summer.)

[Gobniu]

Ahhh Yes multi-fuel is the term I was grasping for. Couldn't think of it at the time. also sorry to imply that only WWII models had those, that is just the ones I heard about.

[skroo]

The other fun part about a Deuce-and-a-Half: you can run them underwater for up to four hours with the proper modifications :)

i'm personally thinking of installing a snorkel. (side note on that... since i think they look pretty lame attached to a daily driver vehicle, i am planning on doing a hack job under the hood... keeping the stock air intake as it is and forking off a second tube that will run to a removable snorkle. valves on the inside will control which air source the engine breathes. add it all up with a gas-cap-flap type addition to the body panel and i'll have a snorkel that i can attach and enable in about a minute's time without the need to drive around with it 24/7. i'll post some photos if i ever get around to doing that this summer.)

The manifold lock's a good idea, but only works if you have an intake manifold with two switchable intake points since air still has to make it down past the throttle body to get to the cylinders. I'd actually be more inclined to go with a relocatable or quick-disconnect airtube for simplicity's sake rather than having a custom manifold cast, which would likely be expensive.

One advantage to a snorkel on a DD: cold air intake. Just be sure to point it backwards if it's raining. Agreed that they're lame on anything other than a trail-only rig, though, but I like the gas cap idea.

[Deviant Ollam]

Just be sure to point it backwards if it's raining.

actually, i've been thinking of getting a head cap from a safari snorkel kit (they sell them separately in some places) and affixing that to the rest of my custom aparatus. i'm told they do a really decent job of filtering out any water flying in (they have a sort of internal venting/drip catching design which results in water allegedly draining out the side holes instead of going down to the engine)

that video of the eager beaver deuce is hillariously cool, btw.

[erehwon]

Y'know, I've been toying with the idea of buying a relatively low mileage (100,000 miles) Mercedes Benz diesel from a fairly rust-free state and having getting a LoveCraft conversion.

Soybean oil is way cheaper than diesel right now.

[astcell]

Diesel used to be cheap...it was 16 cents a gallong when regular was 69 cents and unleaded was 72 cents. Now diesel proliferated and drive the price up from the demand.

At this rate you will drive up the cost of soybean oil. Don't complain to me when French Fries are $50 a serving.

[Gadsden]

Yet another benefit!

At this rate you will drive up the cost of soybean oil. Don't complain to me when French Fries are $50 a serving.

[Deviant Ollam]

a LoveCraft conversion

they seem to be a wealth of information... but what's with the badly-photoshopped image on their home page pretending to show their "new filling station"? it kinda made me think the whole website was some sort of joke until i read more of their material.