S10 diesel conversion

At first thought, the biggest problem that come to mind fitting issues aside is the extreme extra weight of this mod. If you want to try something wild, how about a engine with 12 or 13 to one compression runing on Propane. Propane has very high octane and costs about 40% less than gas and such a conversion would yeild a power gain too and with higher compression you would also get simular MPG to gas in a stock motor. Where propane conversions fail of sorts is that they run stock compression and fail to raise CR to take advantage of the much higher fuel octane and the higher CR also improves thermal efficency too. Propane is about the most "perfect" motor fuel out there today and vehciles running on it as basically zero emissions vehicles. (this is why forklifts in buildings run on Propane)

----------------- TheSnoMan.com

The idea is ok, except that the fuel mileage efficiency is far greater with more torque using a diesel engine. There are a number of diesel engines out there that are not that much greater in physical dimensions which would offer a greater efficiency to power ratio. In the event that I would consider the Propane avenue, are there any good sites offering conversion kits and technical information?

Also consider the smaller Cummins if you decide to do this... the 4cyl

4BT (turbo) in an S-10 would be pretty stout. It shouldn't be too much of a weight issue, as I've seen them in Jeep CJ's.

~jp

Jeeps CJ's have a solid axle and leaf springs up front. S-10's (At least mine '01) have IFS... the weight of a ditzle will destroy the front of an IFS front S-10

True, however, a solid-axle conversion would probably be less work than what's required to drop a diesel into an S-10.

If it were me, I'd just put a small block in there and call it done. There's already kits for that.

~jp

Many strive to put diesels in vehicles but never consider the weight issue and be it a s10 or a CJ extra weight up front is not a asset off road. When I mentioned Propane earlier, a properly modified gas motor designed to run on propane can make more power than possble on pump gas and if you raise compression ratio (to increase efficeny) to 12 or

13 to 1 to take advantage of propanes 110 octane you will likely get MPG equal to or slightly better than gas running lower compression and propane cost less, a good bit less bulk than gas or diesel. While you need a heavier tank, it is more than offset by the fact that propane weighs 4 lbs a gallon and vehicles running on it are nearly emission free. Where propane conversions fail of sorts is when they do not raise compression of engine and remap timing to take full advantage of it and rather try to keep it dual fuel so CR and timing is conservative. Off road you never have to worry about fuel starvation or flooding either at strange operating angles.

----------------- TheSnoMan.com

Don't get me wrong, I'm with you the propane thing... It's just that as things stand right now, it'd be highly impractical in a regularly driven vehicle unless you had a good local supply of fuel. Even then, you're limited as to how far you can travel without careful planning to make sure you'll have fuel to get back.

But yes, I agree...running on LPG would be outstanding.

~jp

I do agree you would have to plan a bit more but you could install a fair sized tank and a extra feed line coupler to fit portable tanks used on propane powered forklifts and such so that you can switch to a reserve supply easily if need be. I have a old 79 J20 that I have owned for about 22 years now that is my barn in storage awaiting restoration. (I retired it from plowing snow and want to make it nearly like new someday) I am going to do something different with the engine and fuel but I have not decided what yet (I still have lots of time) . It is going to be one of 3 routes, rebuild it with about 10.5 to one or better CR and run it on 93 octane, build it with around 12 to one CR to use alchols based fuels which have a high octane too or propane with 12 to 13 to 1 CR with no dual fuel abilty. It also has a

360 in it now that I am thinking of downsizing as well. It is not going to be a lifted truck nor a work truck and it will be stock in a apperance when restored so I have no need to have a big engine in it. I will keep it AMC powered and I am leaning toward a nice 304 if I can find one cheap to rebuild over time and then swap into truck (current 360 still runs well) and the premium fuel option which costs a bit more vs 87 but is is small percentage wise and it is possible to get better power and efficency from a engine running on 93 octane and "tuned" for it to more than offset extra fuel cost.

----------------- TheSnoMan.com

I like those old J-trucks...very cool.

Of your 3 options, I personally like the idea of running on alcohol- based fuels. If and when E85 becomes widely available it would make much more sense to have a ethanol-only vehicle rather than a "flex fuel" vehicle that can't take advantage of the higher octane rating. With readily available ethanol and a high compression engine, you'd have a nice running truck with reduced emissions and decent fuel economy.

I'm still waiting to see if E85 is going to become a viable alternate fuel. If that happens, I'll probably be doing something very similar.

~jp

I read about 4 to 6 months ago that Walmart wants to be the first gas retailer to offer E85 nationally. They were try line up some large deleiver contracts to start sometime in 2008. The volume of E85 is not out there to market so it will take some time to arrange it. Another fuel to keep a eye on is biobutanol. It has a lower octane than eth but a much higher energy content (about 90% or gas vs about

60% for eth) and it will run in most cars made in last 25 years without modification. The "problem" is making it. It is made from same stock as eth can be made but they have not found a cost effective emzyne to make it practical yet. It will be at least a few more years before it yeilds some"fruit".

I do agree that if you plan to run E85, you should build a engine to run only E85 only to get most power and economy out of it. E85 can have issues in extreme cold starting though (below zero) so it is not the perfect fuel either. Around where I live, I can buy bulk propane for vehicles pretty easy.

----------------- TheSnoMan.com

So far the only place that had multiple locations of readily available propane was U-Haul. At least, in the Atlanta area, that's all I could find online.

The cold-starting problem with E-85...once the car's running does it run just fine?

I wonder if a priming setup that used an auxilary tank with propane or regular gas for starting would cure that...that could be as complicated as one wanted to make it, but the average electronics hobbyist could rig up a system with a microcontroller that would inject a measured amount of whatever the starting fluid was into the carb when you hit the key. You know, like a single pulse of propane or something.

~jp

As luck would have it there is 3 places within 7 miles of my house that can fuel propane powered motor vehicle. Two of them do not even advertise it but have added the coupler needed to do it.

Once engine is runnign and making some heat it is not a problem. E85 with 15% gas is a attempt to lessen starting issues.

I have not read into this but I have heard on priming senarios for extreme cold. Gas is a tuff act to beat as a motor fuel over a wide temp range with good starting performance even in cold weather. Propane can do it to. Propane stays a liquid at sea level pressure at about 44 F below zero. Above that it converts to a gas. Most propane conversions heat the propane before it is expanded so that regulator does not freeze up from expansion chilling it. In extreme cold Propane could still be effectively used by preheating atomizer/regulator before engine start (kinda like glow plugs in a diesel) with electric heating that is replaced with engine coolant heating once engine is warmed up.

----------------- TheSnoMan.com

Not really because that chassis is not realy designed for than kind of weight in it plus if you plan to use it off road, a heavy front end is not a asset.

----------------- TheSnoMan.com

Hey guy, th newest issue of Diesel Power has a small article from some one that is doing exactly what you are going to attempt. They briefly talk about the transmission, t-case, from axle, et all he is using. Might want to get a copy and check it out.

Don't let hte nay sayers in here tell you that you "can't do it"

I haven't personally owned an S-10, but the folks I know who do or have don't report great gas mileage to begin with. It's a small truck, but it's still a truck. Not the most aerodynamic body. A friend of mine drove a newer 4cyl S-10 for years, and reported an average of 20mpg. My girlfriend's bigger and heavier Tahoe with the

4.8L V8 gets around 22 average. On paper, a bigger engine in a bigger vehicle should equal a proportional increase in gas consumption, but that isn't always the case.

Furthermore, in my experience, the best pulling engines (by pulling, I assume you mean low-speed torque) are usually the ones that'll give you the best fuel economy. My current 350 is horrendous for pulling, and not coincidentally, the fuel economy is miserable (around 7-8mpg in town).

In terms of money, I'm betting that you'll spend a lot more up front doing a custom diesel conversion than you would for a small block swap kit, and it'll take a considerable amount of time for the diesel vs. gas fuel savings to make up for the increased cost of conversion.

I'm not in any way trying to change your mind, just offering an alternative suggestion.

I guess someone needs to ask...what's your application? You mention "pulling". Do you mean pulling a trailer? Pulling up hills and obstacles off road? Or do you mean low-speed torque for in-town, or what? Is this a 2WD or 4WD truck?

By the way, I understand the desire to do something "different" ;-)

~jp