70 C-20 4x4 Suburban Father/Son project

[1leglance]

Jack..nothing wrong with your question but a 6BT would be a real tight squeeze and a big jump in wgt.

I have found a couple of lines on bare blocks and complete engines (6.2's) so it is just a matter of seeing what is not cracked

I agree that the 700r4 could be used with my 350 after a change in torque converter and gov and I am sure the shop that rebuilt it would do that for little to no money as I have not installed anything yet.

Funny that this should happen now as I just got my latest issue of 4wd Action out of Aus and the cover story is a big comparison between diesel, petrol, lpg (either solo or adding to petrol/diesel).
They did a great job of tracking service cost over 10yrs (diesel is double the petrol), mpg (diesel is 25% to 50% ahead) and fuel cost lpg is cheapest then diesel then petrol which means the best setup is a diesel/lpg except for the service cost.

Really it makes me think about staying with my 350 and shoving the 700r4 behind it (I might be able to keep my NP205 then).....but first let's see what comes of the block/engine hunt

If I was going to go with another diesel maker I like the 7.3 International as I understand it works well with bio/veggie oil...granted not as well as the 12v Cummins but those are much more money it seems.

I do love the old simple diesel engines though.

Oh and suprised no one has mentioned putting the trusty old Mercedes diesel in there They really do well with bio/veggie oil.

 

[bftank]

your burb is way too heavy for the mercedes motor.

powerstrokes are good with bio/veg because the fuel is run through the head before injection heating it up. i have on my noticed pstroke with 240k mikes, that due to the injection system being hydraulicly actuated there are tons of seals that need to not leak in order for you to maintain pressure to fire injectors smoothly. the electonic throttle peddle can have quirks when it is cold. i much prefer the mechanical motors, which is why i suggested the idi.

a 4bt would be cool as well, not as heavy as the 6bt, and still be able to get you around. a dana 44 would survive if you weren't rough on it. down side; they are expensive little boogers. usually a 6bt is cheaper, but then you have the added expense of a dana 60.

 

[shortbus4x4]

You beat me to it, a Mercedes would be a wee bit underpowered for a Sub especially one loaded up for a week in the bush.

A 4bt could be made to work but a 6 is cheaper, runs smoother, and makes more power stock. The downside is that its a little harder to install and is heavier.

The easiest way to get a diesel is the way you are doing it. Use a GM 6.2/6.5, its the closest thing to a bolt in diesel swap you can get for your rig.

 

[BCHauler]

I'm going to offer up my opinion from out here in left field. I think the 350 setup for dual fuel gasoline / propane would be great. If you go carbed or tbi, the conversion kits are inexpensive. The 350 is cheap, easy to maintain, relatively efficient for a gas v8, and parts are cheap and plentiful. You could install quick connect fittings at the back of the truck to hook up camp stove, portable water heater, portable heater, etc for travel. You could use the 700r4 as it is a factory fit with the 350. I think it would be a really neat and versatile setup. LPG is nice and cheap as well.

 

[1leglance]

Hey Todd,
Very cool idea on the propane and one that I spent alot of time thinking about last night when reading my latest issue of 4wd Action. That is one reason I spend so much to have the mag shipped over from Aus, it is almost 300 pages each issue filled with real life good info & amazing trips.
There comparison of lpg, petrol, diesel came down on the side of petrol/lpg system where you can switch back & forth based on which fuel was aval.
Here in Arizona we used to have a big gov kickback if you converted a new vehicle but never much support for older rigs...however propane isn't hard to find due to all the RVer's around the southwest.

It is something to consider as you mentioned the 350 is super simple & cheap to find parts for.
And a big propane tank along with upgrading to the 40gal fuel tank I already have sitting & waiting would give me some nice mileage numbers and range.

So what does everything guess that a TBI 350 with a 700r4 and 4.10 gears would give for mpg...think I could hit 15??

 

[98dango]

15 might be doable with proper driving and a solid tune. Make sure all is well I would also add a stand a lone air fuel ratio gauge so you can keep an eye on what is happning. We install them on all turbo cars to help avoid a short engine life.

 

[toddz69]

So what does everything guess that a TBI 350 with a 700r4 and 4.10 gears would give for mpg...think I could hit 15??

Ntsqd here on the board had a very similar combo (I don't recall his axle ratios) in his Suburban - hopefully he'll chime in with some real world data.

Todd Z.

 

[ExpoMike]

My $.02...

After 2 re-motors (Casa Azul & Mayahual), I'm Thinking that regardless of the slightly lower mileage of the 350 gas motor in Rocky... I'll be financially far ahead given the cost of the diesel motor, and the consumption of time that it takes to do a top-shelf re-motor. Granted, if you want the experience of re-motoring with a diesel (especially doing with your son) I say by all means do it! Just don't be surprised if after it was all said and done... You might have preferred putting the money into gas and the time into adventuring.



Isn't that just a vacuum gauge?

In a lot of ways Jack has hit the nail on the head. I ran into that with my M1010 project. It would have made a super cool rig but I figured out that I didn't want to spend the next 1-2 years building it when I could be out camping instead. That is what motivated us to go with the Dodge and the FWC setup. In the end the cost was about the same (or even less for the Dodge/FWC combo) and we have been out using it and not "thinking about using it some day".

Jack, an air/fuel ratio meter is a meter that uses a oxygen (O2) sensor in the exhaust and it reads what the ratio of air to fuel. Ideal is 14.1. Higher the number, the more lean it is, lower the number, the richer it is. It's a great tuning tool as it can give you real time numbers while you're driving.

 

[Larry]

The only surefire way to persuade Lance into gas powertrain is to somehow figure out a way for one of us to have Roothy from the Australian 4WD Action magazine send Lance a personal email telling him that going gas is not breaking any international Overlanding code of conduct. Or the other option would be for Roothy to run a feature article on a gas swap into an early 70’s Suburban. You know, those Australian magazines seem to carry a lot of weight being they are experts on the US motorized adventure scene and all.

Hehehe, just razzing you Lance.

98dango, I too am curious about this stand a lone air fuel ratio gauge as well. Sounds neat but what good is it when you have no control over the air fuel mixture on a computer controlled EFI engine unless you are a tuner with a laptop running a vehicle on a dyno. In a perfect world a computer controlled EFI gas engine should be running at Stoichiometry (14.7:1) and when it is not…..well, there isn’t much you can do about that from the driver’s seat flying down the highway or bouncing down the trail.

 

[98dango]

One of my other hobbies Is hot rod Volvos sorry the sweeds make a good car and you can get monster power in a small package. I know you cant adjust much on the fly but it can be adjusted and the computers are good i just like to know. I ran the older version of this gauge with great success in my 87 740 turbo brick.


http://www.innovatemotorsports.com/products/MTXL.php

 

[1leglance]

Hey Larry....I love the fun & friendly ribbing so don't stop just cuz I am crying over in the corner

The only reason the Aus mag's are so good is cuz the US mags are so bad I would have to buy 4 US mags to equal the 300 pgs I get per issue of 4wd action...and a DVD each month.

I will be perfectly honest and admit that one reason this build is going slow is cuz I am loving just driving the rig as it is...the 10mpg sucks and the 20 gal tank kills my range.
Of course I have a 40gal tank waiting to go in and believe me I am seriously thinking about the gas/TBI/propane thing now vs diesel.

I have plenty of room under the rig to mount a small to med size lpg/propane tank and I am sure I can google a ton of info on the conversion setups.

I get that the 700r4 I just had rebuilt could be easily converted back to gas use...and the diesel torque converter is still in the box.
Figure sell off the injection pump and other bits I have been buying and I might not be out much money at all.

Tough choice as I really love the simplicity of the mech inject diesel, the great mpg (although if I could get a gas rig to 15 then it might be a wash with the fuel cost/maint cost diff) and the fun of a build.

Here is what I figure I have to do in order to swap to the 6.2:
find a good block/engine
rebuild it (kit at cost through my wife)
rebuild injectors
Get the DIY4x crossmember
Fab a new core support for the diesel rad/ac condensor
Ditch my heater core to make room for the turbo and go to a Summit Mojave Heater.
Rebuild/mod a transfer case to mate up to the 700r4 and have fixed yokes
A complete wiring harness as the current one is pretty old and been hacked on.
Manual glow plug switch/relay/wiring
Fab up 2 battery trays since I will have a custom core support.
Fab up a trans cross member
Mod the driveshafts
Fab exhaust (which sucks as I just had new dual exhaust put on the 350)
I figure a few thousand dollars in parts and fab work even doing it all myself..with the help of friends of course


Granted the 700r4 swap might cause me to do some of the above...but I don't think as much.
The gas tank will be upgraded no matter what.

If I stick with gas I am looking at
TBI swap (if I ever want Larry to leave me alone
Maybe propane conversion
700r4 swap since I have the fresh trans sitting here

On paper it really makes a case for sticking with gas if I can get into the 15mpg range...with a 40 gal tank that would get me 600 mile range pushing things.

Of course beyond the engine swap I have plenty to do like
axle swap
building the rear storage sleep setup
figuring out the custom A/C with center console
paint
sound deadening/insulation
building a rear swing out bumper
adding an underbody water tank
and I would really like to pop top this so me & the wife can sleep above and the kid below

Oh and let's not forget building a new small workshop/carport to do all this....
Yikes...this is why I don't like to write it all down

 

[Billhilly]

Don't know if you'll ever get a genuine 15mpg with a four wheel drive vehicle of this vintage? Might go close with injection/overdrive, and depending on 'driving style'. Larry probably has plenty of real world miles under his belt. I know over on the 'other' board, 15 is pretty rare. TBI/Propane looks interesting http://www.rasoenterprises.com/index.php?option=com_content&view=article&id=55:dual-fuel-tbi&catid=59:applications&Itemid=48
I'm going the dual fuel route, no TBI. No miles done to give mpg.

 

[NOIBN]

Here is my take on the situation:

Hey Larry....I love the fun & friendly ribbing so don't stop just cuz I am crying over in the corner

The only reason the Aus mag's are so good is cuz the US mags are so bad I would have to buy 4 US mags to equal the 300 pgs I get per issue of 4wd action...and a DVD each month.

I will be perfectly honest and admit that one reason this build is going slow is cuz I am loving just driving the rig as it is...the 10mpg sucks and the 20 gal tank kills my range.
Of course I have a 40gal tank waiting to go in and believe me I am seriously thinking about the gas/TBI/propane thing now vs diesel.

I have plenty of room under the rig to mount a small to med size lpg/propane tank and I am sure I can google a ton of info on the conversion setups. As low as your rig is, I would be leery about mounting a LP tank under there and dragging it across a rock on a trail

I get that the 700r4 I just had rebuilt could be easily converted back to gas use...and the diesel torque converter is still in the box. True


Figure sell off the injection pump and other bits I have been buying and I might not be out much money at all.

Tough choice as I really love the simplicity of the mech inject diesel, the great mpg (although if I could get a gas rig to 15 then it might be a wash with the fuel cost/maint cost diff) and the fun of a build. I STILL say you are going to be lucky to get 12mpg with overdrive and fuel injection. The only way you are going to get your desired range is with a diesel engine. If you decide to amend your range requirements, the gas engine will become much more plausible at that point.

Here is what I figure I have to do in order to swap to the 6.2:
find a good block/engine
rebuild it (kit at cost through my wife)
rebuild injectors
Get the DIY4x crossmember
Fab a new core support for the diesel rad/ac condensor
Ditch my heater core to make room for the turbo and go to a Summit Mojave Heater. Probably still want to do this to free up underhood space
Rebuild/mod a transfer case to mate up to the 700r4 and have fixed yokes If you do a 700R4, you are still going to have to do this.
A complete wiring harness as the current one is pretty old and been hacked on. Still going to have to do this. Leaving a gas engine is not going to make the harness better.
Manual glow plug switch/relay/wiring N/A with a gas engine
Fab up 2 battery trays since I will have a custom core support.
Fab up a trans cross member may still end up doing this depending on the clock position of the new t/case
Mod the driveshafts You will be doing this with a 700R4 trans swap
Fab exhaust (which sucks as I just had new dual exhaust put on the 350)
I figure a few thousand dollars in parts and fab work even doing it all myself..with the help of friends of course


Granted the 700r4 swap might cause me to do some of the above...but I don't think as much.
The gas tank will be upgraded no matter what. Your diesel tank will not work well with TBI. You need a tank that was originally TBI as it has baffles in it required for good fuel scavenging. I know people have done swaps without it (I have myself) and I will never do another one without it as it really sucks when you are hard on the brakes or in a left turn and the motor shuts off. Maybe it's just me??

If I stick with gas I am looking at
TBI swap (if I ever want Larry to leave me alone If you stick with gas, I would highly recommend it.
Maybe propane conversion
700r4 swap since I have the fresh trans sitting here

On paper it really makes a case for sticking with gas if I can get into the 15mpg range...with a 40 gal tank that would get me 600 mile range pushing things. I still don't think it is plausible to plan on 15mpg. Maybe I am wrong, but I don't think I have ever gotten close to 15mpg out of a 350 in a truck as heavy as these are.

Of course beyond the engine swap I have plenty to do like
axle swap
building the rear storage sleep setup
figuring out the custom A/C with center console
paint
sound deadening/insulation
building a rear swing out bumper
adding an underbody water tank
and I would really like to pop top this so me & the wife can sleep above and the kid below

Oh and let's not forget building a new small workshop/carport to do all this....
Yikes...this is why I don't like to write it all down

 

[dorton]

Very cool build thread. I just read from beginning to present. I'm glad I checked it out, as I've found plenty of info that will help on mine.

 

[redthies]

Roothy rocks! Just ask "the handbrake"... :sombrero: