Economy modding my Chevrolet Astro work van (diesel 5-speed conversion)

[JB3]

Originally Posted by Giovanni LiCalsi

The Sprinter van (8,500lbs.) gets around 30mpg.
Your van should achieve at least that if not 35mpg.

The sprinter van is using a mercedes CRD engine, which is an order of magnitude more efficient than the engines I have installed in this van.

Computer controlled common rail diesel with direct injection will beat mechanical injection pump and iron head IDI motor any day of the week, but the tradeoff is that the high pressure pump or even a single injector for the benz CRD motors costs more than 3 or 4 yard 616 or 617 motors.

Even in the small MB sedans, these 61X series diesels would be hard pressed to break 30mpg with normal use. The reason I love them is they are damn near impossible to kill, but there is no denying that they are late 70s cutting edge diesel technology.

[JB3]

Originally Posted by 2007 ion2

fairing the rear wheels can lead to issues if the vehicle is driven in the winter, as snow and ice will build up. taller (and yes, they are wider) tires are heavier, and changes the drive ratio. this will likely lower your economy. my car starts out almost as aerodynamic as a prius, but a rear underpan is the only aerodynamic mod that in and of itself made a noticeable difference. everything else was a minor cumulative effect.

235 (width in mm) 75 (sidewall height as a percentage of the tread width) R (radial) 15 (rim diameter in inches).

this is a cool mod, looking forward to seeing the efficiency numbers with the more practical engine. American vehicles just aren't built as light and aerodynamic as the euro vans are. they also have a lot smaller tires and shorter gearing to keep rolling mass down and make more out of the power. bringing the aerodynamics up to snuff is a great next step given the small engine you have. filling body gaps with sticky foam weatherstripping, silling door handle recesses to the point where you can just get your hand under the handle, fairing windshield wipers (be careful, you'll still need to be able to get in there to clean snow out), cleaning up the front end, fairing chumky window frames with shaped sticky foam weatherstripping, and under pans will all yield better efficiency, and make your engine effectively more powerful. I'm a fan of coroplast, it's cheap, easy to work with, and looks decent.

im looking forward to underside aero mods id like to do. Right now im hamstrung by a stubborn clutch issue, but once I get the thing nailed down, I can start flattening out the mountain range I have going on down there

[slownugly]

Don't mean to get off topic bit what is involved with the lean hack for the L05 350? What injection system is it related to? Throttle body or spider injection? Year range? That is really impressive mileage.

[2007 ion2]

if you can get away with it, one sheet of coroplast (or at least two joined well at the seam) will yield the best results, focusing on getting the leading and trailing edges tucked as close to the front and rear bumper covers as possible. sheets of aluminum can be used to shield the plastic from exhaust pipes, and/or header wrap those areas that come close to the plastic so you only have to cut reliefs where the pipe would touch or come below the plane of the plastic. though, thinking about it, wrapping the whole exhaust might be best so you don't overheat the whole cavity created by the coroplast.

another way to go is just cut relief holes where anything pokes below where you would like the plastic to be, and/or leave a channel for the exhaust. both will compromise MPG and engine load, though.

[eco_generator]

Originally Posted by JB3

im looking forward to underside aero mods id like to do. Right now im hamstrung by a stubborn clutch issue, but once I get the thing nailed down, I can start flattening out the mountain range I have going on down there

Excellent job so far. Looking forward to seeing your van back in action.

[cRiPpLe_rOoStEr]

Originally Posted by JB3

Even in the small MB sedans, these 61X series diesels would be hard pressed to break 30mpg with normal use. The reason I love them is they are damn near impossible to kill, but there is no denying that they are late 70s cutting edge diesel technology.

I'm not the most die-hard IDI enthusiast, but gotta recognize its cheaper rebuinding cost and the suitability to operate with vegetable oils as an alternative fuel are still good reasons to love them

[JB3]

Just a quick update-

Blundered big time on engine balance issue. What I thought was a clutch issue is more like an imbalanced flywheel issue. The 5cyl motors some have a biased balanced flywheel to make up for crank balance, and I stupidly didn't mark that, and the factory mark is long gone.
Reality of this mistake is engine crank has to come out and be balanced with the flywheel and harmonic balncer as a unit. Major surgery time.

The job is partially done, and on hold till some major jobs are completed for work.

[Christ]

I remember reading about this on another forum somewhere... Peach parts? Have you documented the build process elsewhere? Im positive I've seen this van lol.

[JB3]

Originally Posted by Christ

I remember reading about this on another forum somewhere... Peach parts? Have you documented the build process elsewhere? Im positive I've seen this van lol.

I posted build threads about it on a bunch of forums, definitely PP. By planting the seeds far and wide, a vast harvest on useful kernels of information have been accrued for the swap.

I think on each forum with a build thread, I picked up some useful data that impacted the swap for the positive

[Christ]

I'm on PP long enough to check for local deals and see what kind of neat work some of the guys are doing to deal with NLA parts or what have you.. I dont frequent it like I do this forum. I just remember seeing your swap and the troubles you had with it for whatever reason.