I would appreciate opinions on optimum IDI build, all fantasies welcome.

[BDCarrillo]

Well for the sake of simplicity, the IDI would be ideal. Do consider running WMO... it's an essentially free fuel source that could be dual purposed for emergency heating. A small filtering apparatus onboard and you'll have as much fuel as you can collect.

Evap cooling isn't really that effective unless you are at WOT all the time. A properly sized intercooler won't heat soak.

Crafty exhaust routing would let you put a saddle tank on the passenger side as well. A small transfer pump and you'll have an ~18 gallon reserve.

A small DIY wind generator may not be a bad idea as well. A solar water heater would also be a nifty addition, or heat exhanger off the engine coolant loop.

Do keep in mind that 18mpg is a good figure for an empty 2wd truck... add weight and a heavy duty driveline and that will plunge. You won't get that putting around trails either.

Have you kicked around any ideas for a small support trailer? That'd be a good way to carry expendables to your base "camp" then venture out from there.

 

[Trashnomancer]

Well for the sake of simplicity, the IDI would be ideal. Do consider running WMO... it's an essentially free fuel source that could be dual purposed for emergency heating. A small filtering apparatus onboard and you'll have as much fuel as you can collect.

The first gen 12v Cummins was full mechanical and I had read it had fewer parts. I had researched the use of WVO and designed a few filter systems. But I have heard so many stories of bad endings. Not to mention every bad OM617 Mercedes I have seen were converted. Do people have any issues with WMO? Seems like it would be a much finer choice. Just haven't done the reading.

Evap cooling isn't really that effective unless you are at WOT all the time. A properly sized intercooler won't heat soak.

Good to know.

Crafty exhaust routing would let you put a saddle tank on the passenger side as well. A small transfer pump and you'll have an ~18 gallon reserve.

Good call!

A small DIY wind generator may not be a bad idea as well. A solar water heater would also be a nifty addition, or heat exhanger off the engine coolant loop.

I doubt I will need the wind generator based on calculated power use, but it sure would be nice on overcast days. Solar heater is planned. Will likely also use a heater core also.

Do keep in mind that 18mpg is a good figure for an empty 2wd truck... add weight and a heavy duty driveline and that will plunge. You won't get that putting around trails either.

I got 15, 17, 17, 17, 21, 17, and 18mpg during my trip from CA to WI with a 1992 4x4 F250 with small Garret turbo and about 800lbs in the bed. I was having injection pump issues. So I would drive one fillup at a time. No stopping.

Have you kicked around any ideas for a small support trailer? That'd be a good way to carry expendables to your base "camp" then venture out from there.

My vary first design for this life style was an 18' airstream base camp behind my ELC and a Kawisaki Super Sherpa on the back. But I don't like the added liability of owning two/three "things" on the road. I am afraid I will come back to my vehicle or base camp, and there it is, gone. So I decided to cut back to bear essentials and fit it in a compact RV.

 

[Trashnomancer]

As for the engine, 300,000 and max power don't go together. A good tradeoff that would make reliable power would be doing the motor right, down to every detail. It can be costly, but you absorb a lot of the cost if you can machine yourself. There a quite a few guys on here who have built engines on a perfectionist level and make good, if not crazy power. Get one of the cams that are available, do the proper machine work, and order the conestoga injection parts would be a good start. Pick your turbo, pick your charge cooler and make them work.

Personally, I would also look into one of the medium duty transmissions. If you can do all this fabbing, take weak points out of the equation and try one of those. But I haven't done this work before and your proposed option would and has worked for many.

Just my ideas.


Sent from my iPhone using Tapatalk

Stealth, your strategy is exactly what I am aiming at. An optimum build for durability and reliability, power is more or less an afterthought. The IDI seems to have all the power anyone needs, assuming they are not in a rush. Me saying I want a large turbo was a miswording. More so, the biggest turbo I can use without effecting longevity.

Any suggestions as to a preferable transmission?

 

[Trashnomancer]

this is a build thread that got built, dont know if its installed yet.
http://www.oilburners.net/forums/sh...ing-for-Input-on-boring-6-9-to-7-3&highlight=

This is a good link.

To bad it quit early, otherwise it would be quite a cookbook.

 

[david85]

Trashnomancer: Are you decided on what platform you want to build on? I'll base my suggestions on a 1980-96 ford F-250HD but feel free to ignore this if you want to go in a different direction.

I like the idea of composites but once you start taking off fenders, hood, doors, etc, you'll find that there isn't a whole lot of weight savings. A cab&chassis concept might be enough for what you need. Oh, and avoid adding anything that would increase the frontal area of the truck.

Run stock tires. 235/85/16s are just about the best compromise for a truck tire that needs to be good both on, and off road. Bigger tires do nothing for fuel economy on pavement, and will put more strain on the running gear when you leave the pavement.

I might get linched for suggesting TTB, but it won't raise your truck has high off the ground compared to a D60, which will save some MPGs when on pavement. Just something to keep in mind.

There is room for at least one saddle tank on the passenger side, but you can also swap out the rear tank with a deeper one, provided you have somewhere else to put the spare tire (i.e. front bumper)

Engines:

I'd start with a good 1985.5-up 6.9L engine core. 1987 with the newer style rockers would be ideal but its not as critical as many seem to think. You can always change over to the newer style rockers but I haven't had any issues with the older style.

Why go with a 6.9 instead of a 7.3L? The 7.3 has hotter running heads that can negate the advantage of running an engine with bigger head bolts. The 7.3s are simply more prone to overheating than the 6.9s so I'm not convinced your head gaskets stand a better chance in a 7.3 compared to a 6.9.

Another hit against the 7.3 is the positioning of the glow plugs. The 6.9 allows a small fraction of injector spray to hit the glow plug directly, the 7.3 doesn't. In theory it might get slightly better MPG out of the 7.3 design once warmed up (likely a trade off with slightly lower CR the 7.3 came with) but it gives the 6.9 the advantage for cold starting if you're out in the middle of no-where.

If range and fuel economy is a concern, don't drop compression ratio on the 6.9. Yes, 22.5:1 is high if its turbocharged, but if you cap your boost at 10-15 PSI, and stud the heads, there will be plenty of power for where you need to go and pose no significant risk of a head gasket failure.

Run an intercooler and a nice wastegated turbo of your choice. Non gated turbos might theoretically run lower EGTs under full load, but you will never match the low end torque of a gated setup.

Use code BB fuel injectors and a good quality injector pump. Just about anyone here will vouch for Agnem's moose line of pumps - including me

Depending on how much you're willing to sacrifice for fuel economy, there are a few more options:

Serpentine belts are more efficient, but if any one accessory or pulley goes, you're stranded.

12V Electric vacuum pumps and even power steering are available. Diddo with electric cooling fans. The idea with electric accessories isn't that they will out perform the mechanical equivalent, but they come on only when needed. So on long paved roads, you don't really need the vacuum pump turning constantly. Electric power steering can be tuned for reduced power at high speed to have similar results. As for fans, I don't even run a fan in the winter on my truck.

Regarding the cummins,

I'd caution against running alternative fuels like bio, WVO or WEO with any DIRECT INJECTED engine. DIs work great for what they were intended to do. However IDIs give more time for the fuel to burn because combustion begins in the prechamber before reaching the piston crown. This means less chance for unburnt fuel to get past the crown and reach the rings were it could cause coking or in some cases, a seized engine. Alternative fuels generally have higher ignition flash points and could pose problems if used in a DI engine. IDI systems are just more forgiving because they were designed back in the 1920-1930s when fuel injection couldn't be anywhere near as precise as it is today on computer controlled engines.

 

[BDCarrillo]

WMO, once filtered, can be mixed directly into diesel. A 50/50 blend should keep away any cold weather start issues.

WVO is much more sensitive to temperature and the end product quality varies depending on how much heat and how long the original stock was used. Turning it into proper biodiesel also takes some chemistry work and a good sized heating vessel, then washing out unreacted chemicals and fats... nuts to that.

WMO: filter, burn.

I was actually burning some slightly water contaminated WMO to heat my garage. Works like a charm!

The Ford bodybuilders website actually has plans showing the frame sizes and recommended mounting options for "second unit bodies" as they call it. Not sure about airbags between the frame and rear shell... I'd think that coil springs and a dampener would be a bit more robust and lower maintenance.

 

[marmot]

Sounds like a quigley conversion package in an 80's E250 would be right up your alley. My friend has one and it is awesome. Search around for a quigley they did a lot of ambulances and conversion vans or do your own 4x4 conversion.

 

[Black dawg]

Trashnomancer:
Regarding the cummins,

I'd caution against running alternative fuels like bio, WVO or WEO with any DIRECT INJECTED engine. DIs work great for what they were intended to do. However IDIs give more time for the fuel to burn because combustion begins in the prechamber before reaching the piston crown. This means less chance for unburnt fuel to get past the crown and reach the rings were it could cause coking or in some cases, a seized engine. Alternative fuels generally have higher ignition flash points and could pose problems if used in a DI engine. IDI systems are just more forgiving because they were designed back in the 1920-1930s when fuel injection couldn't be anywhere near as precise as it is today on computer controlled engines.

I have yet to see anything work as good as a p pumped cummins on wmo.

 

[TahoeTom]

http://turtleexpedition.com/vehicles/vehicles-
Check out this page. The Turtle III and Turtle IV were powered by 7.3 IDIs. It looks like the current version uses a 7.3 Powerstroke.

 

[david85]

I have yet to see anything work as good as a p pumped cummins on wmo.

I don't mean to say it can't be done, but DI engines are less forgiving for the reasons I mentioned. The engines themselves can also tolerate a wider compression discrepancy between the cylinders and still run reasonably well (diddo for discrepancies from one injector to the next - IDIs simply don't demand as much precision). Although if you'r running blended fuel and avoid rolling coal, it can still be made to work. I ran up to 60% WMO in my truck and it worked great. Startup was a bit fussy but it still worked. I haven't tried it since putting the moose pump in though. I am not equipped to properly filter the fuel.

 

[Trashnomancer]

Good golly. There are so many great responses I don't know where to start. THANK YOU ALL!

David85, so far I have planned to use my 1992 4x4 ford diesel for a frame. But that would leave me with the TTB. Though I can likely get better fuel ecconomy with the lower stance, and a much more comfortable ride, along with better stability considering the height of an RV, durability is my number one priority, so a solid front axle seems natural. Though it seems the TTB hold out plenty well that the bonus of a solid axle may be moot. Opinions?

The '73 El Camino I have will have a wider grill though shorter in height. But I gain aerodynamics with the windshield angle. And it looks cool...

Stock tires seem fine, I had not given it much thought. Though I was considering something just a hair taller and as skinny as I could get to reduce rolling resistance and to be able to lower rpm's at high speed just a bit. I feel you on the dependability part. And sourcing new ones would be much easier.

Moving the tire and installing a deep well tank sounds like it will be something I will have to think about. I have thought about a full length belly pan for aerodynamics and to keep random twigs and rocks out of the brake lines.

I never thought about an electric power steering pump. But it sounds good. Are there any brands that stand out?

BDCarrillo wrote:

The Ford bodybuilders website actually has plans showing the frame sizes and recommended mounting options for "second unit bodies" as they call it. Not sure about airbags between the frame and rear shell... I'd think that coil springs and a dampener would be a bit more robust and lower maintenance.

And I can not thank you enough. I have looked and looked for information on the body swap but found so little of use. That term has opened up a whole new chapter of research for me.

When I spoke of air bags between sections, I wasn't talking about between the body and the frame, I was speaking between the cab and the RV enclosure, and the divorced bed and the RV enclosure. This being done to prevent air and water infiltration.

I still had not figured out what I thought about the frame to body mounts. Steel tied urethane mounts similar to motor mounts were what I had thought initially.

I have so much reading ahead of me involving "second unit bodies". Can't wait.

Quigley's are really neat, I have seen a few. But they seem a little short in the legs and tall in the body. I have also heard mixed reviews on the long term reliability of them. I had no idea they worked on ambulances. I sure would like to see one of those.

http://turtleexpedition.com/vehicles/vehicles- The turtles are exactly what I plan to put the poor little vehicle through. That was a great link and a great read. It makes me feel I am really on the right track with the Ford. I can't argue with a Truck holding it's own at -97 degrees without windchill. I have only experienced -70 with windchill, and I didn't hold up well enough to make it across Russia...

Speaking of temps. BDCarrillo, when you say that a large enough intercooler will not heat soak... What if I happen to be in Death Valley, digging around at Furnace Creek, on the hottest day on record... Will my intercooler still work at 134 degrees in the shade, well going down the road with the sun beating down and the heat radiating up off the blacktop, without an evaporator system? Obviously I will do all I can not to be there, then, but just in case, inquiring minds like mine want to know...

So it sounds like starting with the 6.9l is the preferred method. I really like the Moose products myself. I was planning on one of the baby moose. Guessing the moose injectors too, but I hear so many other suggestions it makes me wonder how different they are.

I think I hit all the bases... Though likely not.

Thank you again everyone for your input and suggestions. I am off to read about "second unit bodies"... I will report back

 

[opusd2]

Marshfield? Well, you are just down the road from me!

Any preparations should include a small gennie to help with the block heater on these sub ZERO days. A secondary or larger fuel cell is just the solution for you. And if you build the project with room for a saddle tank, that's a good way to haul fuel. And as far as running WMO, it's not bad if you filter it well enough. Plus there are always biodiesel places to stop at and fill up with. I know there's a HUGE bio plant in Cottage Grove.


But it sounds like a pretty cool project and I can't wait to see pictures. Another WI Frankentruck being built. It's just how we go...

 

[david85]

I never thought about an electric power steering pump. But it sounds good. Are there any brands that stand out?

There are aftermarket drop in kits available, but you can sometimes find vehicles in wrecking yards with the components you need. Just depends on how much time you want to put in it. One of the earliest cars to come from factory with an electro-hydraulic power steering was the subaru XT. The toyota MR2 also came with it due to the central engine location. Hybrids also need them for running short distances on battery power. In general, import cars (japanese in particular) were early adopters but domestic brands are coming up with them now too (the grand cherokee now has it).

 

[IDIoit]

http://www.summitracing.com/parts/ens-9-4101g
these are what i use for body mounting. inexpensive and will last a long time.

if i were you, id be looking into 10 lug F450+ stuff
build off the strongest you can!

 

[Trashnomancer]

http://www.summitracing.com/parts/ens-9-4101g
these are what i use for body mounting. inexpensive and will last a long time.

if i were you, id be looking into 10 lug F450+ stuff
build off the strongest you can!

Did they make the F450 in 4x4 back in the day(when they made trucks... pre 1994.5)?
Can I gear the axles down low enough to "hypermile"(funny idea in an RV)?
I know very little of the larger Fords.

I see they have some new models that are 4x4, but I know nothing of their reliability. If it is just a frame and running gear, I could imaging Ford could still manage reliability(I don't think they can add that many bells and whistles to a frame... But I bet i am wrong.), but then I would need all custom motor and transmission mounts.

I am trying to do NO modifications to the frame in any way(frame mods seem to end poorly more often then not), except maybe a bobtail job to keep the RV as short as possible to fit between the trees on a tight turn. I still need to measure the El Camino but there is a berm of snow up to my waist and it hides all but a couple corners right now.

After seeing your 6 door conversion IDIot, I am reminded of a hillbilly limo I saw on Craigslist a few months back. It must have been a 12 door or better. You have to love Wisconsin's modified vehicles laws. We can make our own from scratch, as long as it fits a short list of requirements we could make them out of toothpicks, or jello. One of the few things I truly love about this state. Weather is terrible though.

It is a four season state,

Mud season for two months,
Mosquito season for four,
Fall(which is beautiful) for one month,
and Salt season for the last 5.

The body mounts you linked to look ok, but it doesn't look like they have much movement. I will need to see if I can find some numbers describing frame flex in crawling applications to see if I am over thinking the mounts. Anyone around here know what type of numbers would be involved? I would think even 1/2" would be enough to rip apart the RV box over time, maybe even 1/4". Most of the box joints will be urethaned together without fasteners to prevent flex fatigue. I spent way to much time trying to figure out the joint systems... woof... four books on yacht and boat building.

opusd2, where is BFE, WI? I must not get out much.

I am figuring a block heater will be of little use to me as I plan to snow bird with this RV as much as possible. Florence County WI during the summer, and AZ and CA during the winter.

david85 I will search for some of the electric pump kits. I want to find one that is well sized for my application.

Thanks again one and all, keep it coming, always good to have something to keep me from going stir crazy with cabin fever. I will keep on my research and try to find a few pics of the El Camino to share.