Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - Best engine for a mini-RV?

ThomCat316 · 07-10-2013, 06:04 PM

So.... I had the first reply typed up yesterday, but things were so hectic that I didn't notice I hadn't sent it. Therefor, it's all gonna be in one post:

JRMichler:
That's pretty much what I'm planning, except....

Move the rear wheels back about four feet.
Get rid of the bed.
Make a replacement "bed" that starts out at the section of the cab and follows the "template" as closely as is reasonable to a small low oval truncated tail.

Overall length from the cab back of ca. 8-9 ft. - small "real RV" length and wheelbase, just in a smaller cross-section. I've also been thinking that a 4-door Blazer/Jimmy body might make a nice starting point - cut it off behind the rear doors and make a steel/composite full-length uni-box rather than a separate bed replacement.

UltArc:
I'm already past 30MPG with the naked, stock truck - heck, I get 24-26MPG towing my 5'x12' teardrop trailer. I know there's going to be an increase in surface (not frontal) area, but I think I can make up for it by carefully designing the cab-back section to have no areas of detached flow. As for weight, I know how to build light. I don't think I'll be exceeding the weight of the bed (to be deleted) by more than 250 lbs., maybe even as little as 200.

SportyModder:
Thanks for the good read! I really loved the link to the NASA "build-a-box" paper - really eye-opening! What I really want is a Vixen TD, but I can do this for about $10-15K less, and I don't have the spare money.

JRMichler & elhigh:
I think I'm going to keep it entirely a hard shell, perhaps with an opening hatch in the back for the galley. I've already built a nice 5'x12' teardrop trailer in fiberglass and epoxy over honeycomb, and that came out at 345 lbs. - I'm thinking I'll weld up a framework for this that will include the bed mounts, bolt some forms into it, build it over the forms as either top & bottom or right & left parts, remove the forms, and bond the parts together and to the shell frame. I'll also likely use compliant mounts between the shell and the truck frame to keep stress to a minimum.

So, after all these words, it's all still vaporware. I just wanted to bounce the engine question off those more experienced than I. I have also read some other forums, and I don't think there's a strongly compelling argument to put a diesel into this thing. I do think I'll plan on putting a custom gas tank in it, though, because stopping for gas every two days is somehow appealing...

Thanks to everyone!

07-10-2013, 06:04 PM	#8 (permalink)
ThomCat316 EcoModding Lurker Join Date: Sep 2012 Location: Fort Lauderdale, FL Posts: 36 Thanks: 5 Thanked 15 Times in 10 Posts	So.... I had the first reply typed up yesterday, but things were so hectic that I didn't notice I hadn't sent it. Therefor, it's all gonna be in one post: JRMichler: That's pretty much what I'm planning, except.... Move the rear wheels back about four feet. Get rid of the bed. Make a replacement "bed" that starts out at the section of the cab and follows the "template" as closely as is reasonable to a small low oval truncated tail. Overall length from the cab back of ca. 8-9 ft. - small "real RV" length and wheelbase, just in a smaller cross-section. I've also been thinking that a 4-door Blazer/Jimmy body might make a nice starting point - cut it off behind the rear doors and make a steel/composite full-length uni-box rather than a separate bed replacement. UltArc: I'm already past 30MPG with the naked, stock truck - heck, I get 24-26MPG towing my 5'x12' teardrop trailer. I know there's going to be an increase in surface (not frontal) area, but I think I can make up for it by carefully designing the cab-back section to have no areas of detached flow. As for weight, I know how to build light. I don't think I'll be exceeding the weight of the bed (to be deleted) by more than 250 lbs., maybe even as little as 200. SportyModder: Thanks for the good read! I really loved the link to the NASA "build-a-box" paper - really eye-opening! What I really want is a Vixen TD, but I can do this for about $10-15K less, and I don't have the spare money. JRMichler & elhigh: I think I'm going to keep it entirely a hard shell, perhaps with an opening hatch in the back for the galley. I've already built a nice 5'x12' teardrop trailer in fiberglass and epoxy over honeycomb, and that came out at 345 lbs. - I'm thinking I'll weld up a framework for this that will include the bed mounts, bolt some forms into it, build it over the forms as either top & bottom or right & left parts, remove the forms, and bond the parts together and to the shell frame. I'll also likely use compliant mounts between the shell and the truck frame to keep stress to a minimum. So, after all these words, it's all still vaporware. I just wanted to bounce the engine question off those more experienced than I. I have also read some other forums, and I don't think there's a strongly compelling argument to put a diesel into this thing. I do think I'll plan on putting a custom gas tank in it, though, because stopping for gas every two days is somehow appealing... Thanks to everyone!