I have a 1988 S10 and I'm thinking about a diesel conversion possibly a
Detroit 4 cylinder with a 4/5 speed manual transmission. Any thoughts out
there,would love to hear from someone whom may have "been there done that"!
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)
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
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.
On Tue, 12 Jun 2007 05:23:56 -0700, "Jon R. Pickens"
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.
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.
On Wed, 13 Jun 2007 05:21:39 -0700, "Jon R. Pickens"
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.
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
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.
On Wed, 13 Jun 2007 07:50:47 -0700, "Jon R. Pickens"
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.
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
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
On Thu, 14 Jun 2007 04:56:38 -0700, "Jon R. Pickens"
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
JP, Everyone's done a small block conversion, The fuel costs and mpg out
strip the practicalness of such a conversion. I'm looking for low cost of
operation with pulling power. Furthermore the Ifs issue is a correctable
issue using custom wound front coils and larger rotors
Jon R. Pickens wrote:
Message posted via CarKB.com
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 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
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" ;-)
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"
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