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Fuel economy ideas for an old RV

Ummduh said:
My rig generally won't pull or even maintain speed once it's in OD unless it's really flat or downhill. We're probably similarly powered, I have a 95 F250 460/e4od, 4.10s and a 26' fifth wheel. Stock ratings were 245/400. I run 3500rpm at 70 in 3rd, 2500 in OD at 75. Also running 3500 rpm in 3rd really causes the trans to heat up.
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What is your total weight? Probably a LOT more than mine. This is a 20.5' RV pulling a 16' trailer that probably weighs 3-3.5k loaded. I should put it on a scale before heading out this year... I bet I am under 12K total weight with a full fresh tank and the Harley in the trailer.
 
My thoughts on the aftermarket EFI for 440 vs newer engine swap is this. If you or family are going to have this in 20-30yrs will that aftermarket company still be around for parts? Even if they are will they still support a product from that long ago? I guessing no to the latter at least. Will auto parts stores still carry a part for a 20-30 year old OEM engine and trans setup? I would bet yes considering you can still get parts for 50's and 60's era vehicles. If you want to stay chrysler maybe a junkyard 2wd 6.4 setup from a 2500 truck would be good fit. Hell whats the newest Ram van 2500-3500 made before they switched to the FWD BS 2003? Maybe do full drivetrain swap and get 23 year newer AC\ suspension\ brakes\ rear axle along with newer engine and trans.
 
DRTDEVL said:
What is your total weight? Probably a LOT more than mine. This is a 20.5' RV pulling a 16' trailer that probably weighs 3-3.5k loaded. I should put it on a scale before heading out this year... I bet I am under 12K total weight with a full fresh tank and the Harley in the trailer.
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I haven't weighed the total combo, but the camper is gvw 7700, and I know my f250 actual weight is 6200. I don't tow with water on board.

It's the wind, man. If I tow with a tail wind, it's not terrible(but also not great). But it seems like no matter where I go or when, I'm heading into a 30mph headwind. It knocks my combo on its ass.
 
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Projectjunkie said:
FWIW, maybe compare it to a similar era ford, I know of 2 successful econoline class c 12v swaps, but, those were also specd for an inline 6...
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And that's exactly the difference.

Until you get to shit that was designed for a cummins Dodge/Chrysler has crappy short (both length and height) engine bays because the slant 6 and the big block were the bulkiest things they figured they'd need to fit.
 
arse_sidewards said:
And that's exactly the difference.

Until you get to shit that was designed for a cummins Dodge/Chrysler has crappy short (both length and height) engine bays because the slant 6 and the big block were the bulkiest things they figured they'd need to fit.
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4bt.

:flipoff2:
 
Why not 6.9 or 7.3 idi with turbo and c6?
Let it sing and get decent mpg
 
DRTDEVL said:
How happy would either of those be spending all day cruising at over 3,000 rpm?
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mine's perfectly happy at 2900ish, and it sees whatever the governor's set at on every shift. I think its something like 3500 that it winds out to?

this is not to say that it is a happy engine though
it has holes in at least one cylinder wall and destroys starters pretty regularly
I could recommend a 6.9, but certainly not a 7.3 as I'm two for two on both issues with 7.3s
 
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This was this poor trucks daily routine. 7.3's will live at least 220K running at 3K down the highway:lmao:. This 550 was loaded down too, full service bed with welder and crane.
 
iirc the 6.2/6.5s are a lot smaller externally, and they're prolly a lot cheaper
same pump, so same limited hp (well the 7.3 idi got the bigger plungers than the GM stuff and the 6.9 but whatever, they're all underpowered turds)
 
buying more gas over life is likely cheaper than pouring $$$$ into drivetrain. Spend remainder on beer, hookers or both.

Else swap and sell your 'vintage 440' to some mopar 'tard for more than an junkyard motor/trans combo. Install side pipes, grow mullet.
 
You can run factory EFI on obsolete engines. The International guys do on their old "boat anchors" even drilling the intake to run multi point injection rather than just TBI. "START HERE"--Fuel Injection FAQ--"START HERE"

I think the biggest gain would be an OD transmission, but if you just run the cruising speed up because the engines not screaming anymore that will cancel out any gains pretty quick.
 
Ranchtruck said:
You can run factory EFI on obsolete engines. The International guys do on their old "boat anchors" even drilling the intake to run multi point injection rather than just TBI. "START HERE"--Fuel Injection FAQ--"START HERE"

I think the biggest gain would be an OD transmission, but if you just run the cruising speed up because the engines not screaming anymore that will cancel out any gains pretty quick.
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I'm a pretty patient guy... but on longer stretches, I already push the thing to 65. If I am already pushing 3100 RPM at 65, of course I would feel more comfortable at 2200 RPM at 70. Yes, the fuel economy will take a bit of a hit from these 5 mph, but I'm not sure it would be more of a hit in drag than the gains from the OD.
 
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