Choosing a step van

[KarlH]

I have put some thought into reducing drag...

Some more thoughts about that:

- A guy I used to work with designed the suspension and steering for the University of Minnesota's Aurora3 solar car, and he said that adding fairings behind the wheels made a much bigger difference than he expected. They were using semi-aerodynamic motorcycle tires, so it might make an even bigger difference on a dually. The fairing needs to extend down as close to the ground as possible, so it should probably be attached to the suspension.

- I can't find it right now, but somewhere on the internet there is a website with a huge amount of technical information about the VW diesel Rabbit and Caddy from the late '70s and early '80s. The engineer who maintains the site claimed that he was able to improve the aerodynamics of his Caddy camper by installing air dams on the sides of his raised top to force the air to go over it instead of spilling off onto the sides. I don't understand his reasoning for trying it, but he claimed to have a lot of test data proving that it worked.

 

[JD GUMBEE]

If your unit does not have brakes to spare...watch out about this.
Those brakes are designed to pull the air through to cool them.
Keeping it stagnant means you lose more than one stop in most cases.
Brake components that cannot efficiently dump heat...lay down and die VERY fast, when you most need it.
(In a larger unit, this becomes more critical.)
There is more engineering than people think in trucks.
Teams of design engineers have tweaked them to provide optimum MPG for the size...trust me.
10% MPG increase in a fleet means more profit. A lot more. Natural competition motivates the best minds to make this happen.
"Hypermiler" tricks are often more "keyboard commando" than real-world useful.
(Like stopping a turbo diesel at every light. The worst thing you can do for the engine longevity.)
(Or "2 stroking" an engine. Meaning to surge full power, then shut the engine off and coast back to 45, pop the clutch and repeat. This is how most "hypermilers" claim their BS online. ...and it is BS. It works for two strokes because the oil is fuel delivered. In a diesel, especially a force fed one...it KILLS the engines ability to dissipate heat. You literally bring on a ton of boost and heat...but instead of keeping things flowing, so the cooling system can take it away...you kill the engine at the WORST POSSIBLE moment. This stop oil flow to the bearings at the WORST time. You bake even synthetic stuff on the turbo bearings tsk tsk, Bad form, Jack...bad form. Even on engines that need oil sprayed on the bottom of the piston for heat control (a LOT of the industrials (CAT/CUMMINS/DETROIT) do this) sit there and literally cook themselves because of this insane cycling to save a few drops of fuel. Lower your speed to reduce wind load if you want to save fuel. Don't destroy your engine.

Coming off the highway, idle down your turbo diesel for at least 5 minutes before shutting it. Counting the off ramp time is fine if you GENTLY put put into the service station/rest area. Refueling to take off again, you will do your diesel a solid service by letting her idle 20 minutes. Fact.
Temperature extremes/cycling kills engines. Diesels make so many more miles in big trucks, partly because they run 14 hours a day without being shut down. Get to operating temp and leave them there.
Same applies to an overworked gasoline 454 or V10 in an RV.
Gentle gentle gentle off the ramp...reduce speed and let the right foot relax for 1/4 mile minimum before you hit the ramp. Put put put to the fuel island.

These are the pickup engines that make 120,000 in a 32' class A unit.
Baking oil on everything like a dumba@@ is a big contributor to the 40-60K lifespans in many RV's.

The less stress an engine crankshaft sees (ie clutch popping...taking up the "slack" in the geartrain) the better it is.
Smooth shifting (think about a big truck...pro drivers dont even use the clutch.) keeping the load all in one direction and gentle upswing on boost...will be your engines friend.

 

[JD GUMBEE]

Pardon the double post.
I forgot one more thing.
A P chassis has upper control arms that go loose @ 100K.
They cost like hell to have done and most wrenches pay a front end shop to recondition them instead of even trying it.
(I mean a biiiiiiiit#@ to deal with.)

All things being equal, a stepvan like Tyll's is what you want.
Allison or even better, a Spicer/Clark/New Venture with a clutch.
Straight front axle.

(I own two P30's and they may be a bargain. Not saying they are not worthy...but make sure you check those upper control arm bushings and understand the money it takes to redo them.)

Also...if you get a gasser cheap enough, a boneyard "LS swap" with a pre-made harness can make a hell of a truck. 5.3 or preferably 6.0 liter. A wrecked van with a 6 liter/L80 120,000 or less and stick it in.
(There are shops all over the net that specialize in this. Talk about how 345 injected HP will wake up the average P30...still don't pull like the "Gorilla" though. Even big blocks wet themselves on the hills beside the B series. Just no comparison.)

 

[29chico]

Have you considered an Express/Savana based box truck?  Lots of them out there.  Finding one with barn doors on the rear would not be difficult.  
The single rear wheel ones have boxes that are just wider than the cab and most come with the superb 4.8L L20 engine.  Great mileage.  The dual rear wheel units have 8 foot wide boxes and will have the probably even better 6.0L L96 engine.  Either way will drive and ride better than a step van.  Older units will come with the very solid 4L80E 4speed trans.  2010 and up units will come with the even better 6L90E 6 speed trans for much better performance and mileage.  
You can cut a pass way into the box from the cab.
For a truly upgraded box truck check out the Unicell units.  High quality fiberglass box with a very aerodynamic over the cab section that can be used as a sleeper.  Lots of them come with a factory pass thru.

 

[JD GUMBEE]

I agree that a van snouted box truck solves most of the issues built into step vans.
However, box/step data (mine anyway) certainly does not support "much better" performance or mileage in the 6 speeds. (In any of the units actually.) Not sure where you are getting this info.
On the highway, once in high/locked up, it does nothing whatsoever to improve MPG AFAIK.
Even the newspaper trucks with the newer trannys that drive the speeds where they supposedly make a difference...show very very little, if any, improvement. Still pretty reliable though.

 

[KarlH]

Pardon the double post.

Feel free to triple- or quadruple-post

A P chassis has upper control arms that go loose @ 100K.
They cost like hell to have done and most wrenches pay a front end shop to recondition them instead of even trying it.
[...]

(I own two P30's and they may be a bargain. Not saying they are not worthy...but make sure you check those upper control arm bushings and understand the money it takes to redo them.)

Thanks for the warning.

The only advantage I saw in P30s is that the older ones have almost no plastic trim in the cab. It's a little easier to plan the conversion when you can tell from the pictures where the insulation and panelling will attach, but not a big difference.

Also...if you get a gasser cheap enough, a boneyard "LS swap" with a pre-made harness can make a hell of a truck. 5.3 or preferably 6.0 liter.  A wrecked van with a 6 liter/L80 120,000 or less and stick it in.
(There are shops all over the net that specialize in this. Talk about how 345 injected HP will wake up the average P30...still don't pull like the "Gorilla" though. Even big blocks wet themselves on the hills beside the B series. Just no comparison.)

 

[KarlH]

Pardon the double post.

Not at all, and thanks for the info on the P chassis. That explains why some of the sellers are cagey. I mainly liked the bare cab interior (for a conversion) and the low miles. The other point in their favor is that the Chevy transmissions are supposed to have a heavier flywheel that helps with the 4BT vibration.

I've never had brakes overheat here because there are no hills and it's deadly cold half of the year, but it would be a problem driving out West. Here anything around the wheels needs to be loose to avoid getting packed with snow.

 

[KarlH]

For a truly upgraded box truck check out the Unicell units.  High quality fiberglass box with a very aerodynamic over the cab section that can be used as a sleeper.  Lots of them come with a factory pass thru.

There was an Aerocell van for sale here that looked really nice. Until recently I didn't know much about the different types of cargo vans (1500 vs. 2500 vs. 3500 vs. E-series). This site has been really informative about that. Businesses here seem to drive them into the ground, so that's one of the reasons I looked at step vans as an alternative. The only pristine used vehicles here for under $10k are six-door limos and hearses.

I had a quirky reason for preferring fully mechanical diesels, but some of what I've read about maintenance on the forum is making me re-think that. (I can hear dog-whistle sounds that most people can't hear at all, and a lot of newer digital controls have power supplies that switch at 10-30 KHz and sound like a smoke detector going off if you can hear it. If your dog hates being indoors, that might be why.)

 

[JD GUMBEE]

Nothing quirky about that.
The flyback transformers in the old TV's used to drive me NUTS also.

...and the good ole mechanical injection components (especially the "P-Pump") continue to be among the very most reliable ever made.

 

[29chico]

JD Gumbee posted:
However, box/step data (mine anyway) certainly does not support "much better" performance or mileage in the 6 speeds. (In any of the units actually.) Not sure where you are getting this info. 
On the highway, once in high/locked up, it does nothing whatsoever to improve MPG AFAIK.
Even the newspaper trucks with the newer trannys that drive the speeds where they supposedly make a difference...show very very little, if any, improvement. Still pretty reliable though.

End cut and paste.

I have had a lot of experience in total with three vehicles with the 6L90E trans in them.  

The first was a 2015 Express 2500 extended rental cargo van with the 4.8L L20 engine on a long trip about the SW. It got 15-16 mpg at 65 mph hauling a lot of gear.

I liked the rental van so much that I bought a 2012 GMC Savana extended cargo van with the same drivetrain from Penske with 53k miles.  At first it got 16-17 mpg loaded. Once I put the Airlander roof top tent on I got 2 more mpg.  Towing a high profile & loaded cargo trailer it got 13-14  mpg driving 51 mph for about 20k miles.

My rv has the 6.0L L96 gas engine and the 6L90E trans.  It is has dual rear wheels and all 6 wheels can be driven.  So call it a 4x4 if you want.  It a has a fair amount of wind profile and I tow the aforementioned trailer pretty much all the time and get 11-12 mpg at 51 mph in most conditions.  Guessing that my current setup is about 15k pounds.

Having driven plenty of old school 3 and 4 speed automatic trans equipped rigs I can say for sure that the 3 above equipped vehicles perform better and also get better mpg.  Especially when dragging heavy loads up mountains.  Just not enough gear choices in the old units to keep the engines spinning at the correct RPM’s most of the time. 

The trans in question has TWO overdrives.  The low first gear and manual shifting mode help lots also.  Correctly using the manual shifting mode to it’s best advantage is key to good performance & mpg.

 

[KarlH]

Nothing  quirky about that.
The flyback transformers in the old TV's used to drive me NUTS also.

I never knew what component inside was responsible, but sure couldn't forget the sound.

 

[KarlH]

JD, do you have any thoughts on the quality of other bodies or chassis? The most common name badges on the used market seem to be Freightliner, International, GM and Utilimaster. Grumman/Morgan-Olson, Peterbilt, and Oshkosh vans are out there too,

The GM vans from around 1990 had a different body style, but am I guessing right that they were similar underneath?

(BTW, thanks for the suggestions about saving fuel. There's usually a de facto "truck lane" on the highways around here.)

 

[JD GUMBEE]

First off, tell me which engine powered those "old school" vehicles you mention.
I am not knocking the newer trans...but it does not make as much difference as you think in hwy MPG.
(Most pf the reason you get the figures there is the 51MPH...not the extra choice in gears.)
If you can afford the newer and you like it...go for it.
Just...don't think you HAVE to have it. Normal hwy running will make little difference. Especially in the 2001-forward engines.

Question: The GM vans from around 1990 had a different body style, but am I guessing right that they were similar underneath?

The GM vans from that era are decent...but not head-and-shoulders above the Fords of that time.
Maybe a little better...but Ford did some things well also back then.
When GM went to the 4.8/5.3/6.0 "LS" engines...they ran away with the trophy and Ford has never caught them to this day.
(Beware about the new direct injection though. I would go for a leftover myself. Too new to know...could be another 6.0 Ford diesel engine just as easy as a reliable engine. In 3 or 4 years, I will be able to tell you...(or I will be in the ground LOL)


I think for someone on a very tight budget, this represents a true bargain not often found on GSA:

https://vanlivingforum.com/showthread.php?tid=35332

Don't laugh. That thing is loaded with "I sat for a long time" issues.
10 to 1 the fuel filter is full of rust, for example...and the fuel turned total varnish does the same thing.
(Pour fuel in the carb and it runs...stop pouring fuel and it dies.)
VERY unlikely if it starts...that this has enough use to have harmed itself.
Fluid flush...tires...maybe a new tank even (cheaper than most think and delivered second day) but totally worthwhile to check out.

I just posted a gold mine of Nomad-worthy cheap vehicles.
The step van with the 6.2 in it...is a freaking BARGAIN if it goes for less than 2500 dollars.
Do not be fooled by keyboard commandos opinions, that year 6.2 is a very solid motor as long as you do not try cranking the fuel up or adding a turbo. It does the job very effectively. Especially in a smaller step van like that one. Perfect for van life and SHINY red to boot.

 

[KarlH]

I think for someone on a very tight budget, this represents a true bargain not often found on GSA:

https://vanlivingforum.com/showthread.php?tid=35332

For what it's worth, I can justify paying a lot more for a van that's in good shape and likely to be maintainable for a reasonable amount of time. I just don't know enough yet to judge that.