"NICE 454 GETS ABOUT 10 MPG AT 60 MPH"

Hmmm...

Does anyone with a gasser get 10 mpg?

quote:

Originally posted by Steve VW:
"NICE 454 GETS ABOUT 10 MPG AT 60 MPH"

Hmmm...

Does anyone with a gasser get 10 mpg?

The owners of my previous 27 ft Southwind claimed they did on flat land. They went cross country a lot. They were as surprised as I was. The Southwind had a steeply raked windshield, so it would have had less air drag than a Barth.

I never check mileage.

Knowing your mileage is like knowing what your teenager is up to. You just don't wanna know.

quote:

Originally posted by bill h:
[QUOTE]Originally posted by Steve VW:
"NICE 454 GETS ABOUT 10 MPG AT 60 MPH"

The Southwind had a steeply raked windshield, so it would have had less air drag than a Barth.

In as much as the REAR of each is essentially the same, the DRAG may be essentially the same. Frontal area is a different issue.

Hey Bill--I get 15 mpg with my Toyota motorhome! Never saw anywhere near double digits with any of my many Class A motorhomes!

The 8.00R-19.5 tires on 86 Barth claim 613 revs per mile. Most of the gassers have no overdrive and 4.56 rear axle ratio.

So at 60 mph, (1 mile per minute) the rear axles turn 613 rpm. Times 4.56 gives you engine speed of about 2800 rpm, assuming no transmission slippage.

This is actually about what I'm seeing at 60 mph...
My 454 turning 2800 rpm gave me 6-6.5 mpg with carburetor and now 6.5-7 mpg with fuel injection.

10 mpg would be a dream. (Now give me real gasoline (non ethanol), 10 to 1 compression, a Gear Vendor overdrive, etc we might have chance)

(Bill is right, I don't usually check it unless I made some mods, etc. It just upsets you and you can't change it!)

quote:

Originally posted by Steve VW:
"NICE 454 GETS ABOUT 10 MPG AT 60 MPH"

Hmmm...

Does anyone with a gasser get 10 mpg?

about
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quote:

Originally posted by Mogan David:

quote:

Originally posted by bill h:
[QUOTE]Originally posted by Steve VW:
"NICE 454 GETS ABOUT 10 MPG AT 60 MPH"

The Southwind had a steeply raked windshield, so it would have had less air drag than a Barth.

In as much as the REAR of each is essentially the same, the DRAG may be essentially the same. Frontal area is a different issue.

In my post, I use drag and wind resistance somewhat interchangeably.

There is certainly no doubt that the low pressure area behind a Barth is very similar to a Southwind of the same era.

Without getting into Ray Harroun and the Marmon Wasp, I think it is safe to say that both front and rear streamlining are very important.

Oh, Heck, here we go........The wasp tail on the Marmon was actually designed to eliminate the low pressure area behind the car that allowed someone to stay behind you with a lighter throttle setting, saving fuel and engine life, and awaiting an opportunity to pull out and pass. One could even build up speed in the "draft", and pull out at the last minute in a burst of speed (slingshot)that could catch the leader unawares. (Harroun also invented the rear view mirror, just to watch for drafters.)

Anyway, he found that the streamlined tail not only did all of the above, but it made him faster, with lower fuel consumption and an easier time on the engine. And his fixation with drafters that led to his invention of the rear view mirror, allowed him to design the car without the riding mechanic, who also acted as lookout for drafters. The result was a narrower, lighter car. And, of course, narrower meant less wind resistance.

End of the Marmon Wasp fan club meeting.

Moving on, we see all manner of streamlining on the front of semi trucks, which is surely beneficial in reducing wind resistance. So far, not much attention given to the rear end, not even spoilers or deflectors.

I had an elderly station wagon that got slightly better mileage with those deflectors that kept the rear window clean and allowed you to drive without gassing yourself from exhaust fumes.

And, so far, we haven't seen trucks with (God Forbid) vortex generators.

I can see it now, the lucrative aftermarket for "streamliner" motorhome conversions!
We'll have fairings for the front end and wasp tails, side skirts, front air dams, fairings for the AC.

Your drag coefficient will go from almost a flat plate (i.e. 1) to about .95! Better mileage, handling, crosswind resistance! (Almost 10 mpg!)

Of course, it will weigh more...

Then again, air drag goes up with the square of velocity... maybe slow down?

When I bought Old Blue from Jon Bourke back in 2005, Jon, who is not only the vice president of a company that flies helicopters for the US Forest Service and other concerns, but also is a top flight air frame mechanic, had installed a set of 'Nology Hot Wires and Berea plugs on Old Blue. Other than that, she was stock. (synthetic lubricants) On the way back from Arizona, I managed between 9.5 and 10 mpg driving at 58/60 mph. I used the odometer to measure mileage as well as mileage markers in the interstate. Since then, I've installed a 6-speed Gear Vendors, bought new Goodyear 670 tires, and the usual $10000+ in maintenance and upgrades. It still gets the same mileage, but I can drive about 61/62 now. Google Nology Hot Wires. It's not some gimmick. A bunch of top fuel dragsters have some comments about it. I, too, have read many of the negative comments about this product, some of them being well thought out. All I can do is tell you what I have. I haven't changed the plugs or wires in 8 years, and if you pull a plug you will see a clean plug with very little wear on the electrode. So, if it works, don't fix it.
Jim
Jim

Interesting. I wonder what your axle ratio is... they had 3.73, 4.10 and 4.56 depending on GVWR. Maybe yours is 4.10?

I had considered a gear vendor for overdrive but the engine didn't have the torque. With the fuel injection it now has better torque, but if I want overdrive I can now swap in a TH480 4 spd overdrive since I now have a computer module that can talk to it. If the TH400 acts up I might go that route now.

quote:

Ray Harroun and the Marmon Wasp

I'm surprised you don't see Kammback's on motorhomes and such. It's basically a cut off version of an aerodynamic teardrop. You see it all the time on cars, and that's the extension pieces you see bolted onto some truck trailers now.

I (D) got 9.3 mpg with our 25' Barth and the 454. Driving technique, wind and terrain are a factor. Plus I keep logs on all cars and trucks with fuel and miles written down.
But I have to admit when running the genny for the AC it took it down to about 8.2 mpg.
Some folks swear by them airtabs and fairings on the big trucks.

"

Hmmm...

Does anyone with a gasser get 10 mpg?[/QUOTE]

I do get an honest 10 mpg in my Barth gasser. 350ci in my class C. The best in the Reagal, just at 8mpg at 55 mph. Running flat land to Milfor GTG with wind at back both ways. It is probably a ton or more heavier than this coach. A friend of mine use to claim 9.5 to 10 mpg in his 25' Barth. ABOUT Covers it all.

Not being a techie I find all this information interesting. In my case "it is what it is" and if I have gas money I go and if not I stay home. I would like to be able to go more often but not enough to get a job to have available funds, being retired for 10 years has kinda spoiled me.