Improving a Gruman LLV

[Javarod]

Ok, consider this a challenge, and its all theoretical, I don't think these are even available to the general public quite yet.

The Gruman LLV was created under contract for the government, LLV stands for Long Life Vehicle, and 20 years is the projected life span. Part of GM's S family (Bravado, Jimmy, S-Blazer, Safari and Astro), its Iron Duke 4 cylinder gets a whopping 16 or so MPG.

The goal? No less than high 20s, with low 30s being preferable, but how to do it? I think an engine swap right off the bat, the old Iron Duke just isn't enough engine, and an engine constantly straining to move the vehicle uses more gas than it should, and has a shorter life span than you'd expect. Re-gearing would also likely be a good idea, but beyond those, how would you wring more mileage out of it?

[theholycow]

Heh...are you, by any chance, a mail carrier?

I looked it up and found this:
http://en.wikipedia.org/wiki/Grumman_LLV


And, your vehicle is named "Flying Post Box"...

[Dalez0r]

Hmmm, might start with aero mods..............

[GasSavers_RoadWarrior]

I think the easiest thing to do would be to swap the RHD steering setup into an early S10 or S15 with that engine or the FI 2.8 ... if that's the only attraction of it...

[GasSavers_landon]

Keep the motor, swap the trans. High load kills mileage with an automatic, but reaps huge benefits with a manual.

[GasSavers_RoadWarrior]

Yeah, TC stall point climbs higher with applied load (or increased torque) you can compensate by increasing the mass density of the fluid (bottles of Lucas tranny fix)

[Javarod]

Chuckles, "Courier actually, see my thread in car reviews, still taking opinions, thoughts, ideas, etc over there. Not sure diesel is possible in this case, what would you swap? I'd think a VW diesel'd be over tasked, and the engines typically used in a full sized truck would be too heavy, no? As to keeping the engine and swapping the tranny, that's certainly an easy change, but how good an engine is the Iron Duke? That was used in the first generation of the S series, but I believe they used other fours later on, as well as a number of V6's, would another of those be better? I'm also suspecting that a change in the axle ratio'd be a good idea, since these are typically used for low speed local driving, I suspect that the ratio might not be the best for longer drives."

Grins at theholycow, "BTW, congrats on figuring out what I was referring too, couldn't resist being cryptic. When I worked at an auto parts store, some of the 'catalogs' identified these as a Chevy T10."

[GasSavers_landon]

On second thought diesel would be nice. With a manual box of course. You could get a TDI with the same power, more torque, great mileage.

[ihatemybike]

Originally Posted by wiki

Other notable features are an exceptionally tight turning radius and a low-geared transmission for pulling heavy cargo.

I'd find out which trans is used and what ratios. Also find out what the ratio the rear end is. I'm thinking the gearing is your main problem. The Iron Duke was also used in Astro vans and got pretty good mileage.

[ihatemybike]

EPA, the 2.5L was rated 18/24 mpg compared to the 15/20 for the 4.3L. Not to bad for a RWD mid-size van. Checking the full-size 4x4s in the Garage on this site where people are trying, the 2.5 did get better mileage. However, vans in general will never get great mileage without extensive aero/mechanical improvements. Hell, I'm quite happy seeing 20+ mpg on Green's info center.