Strykersd's 1971 C20 Brave

Froggy1936 · March 15, 2017, 10:14 PM

Hmm I never knew they used a Chev chassis on a Eyebrow mdl Winnie ! Frank

tmsnyder · March 16, 2017, 07:56 AM

"7 mpg in mostly mountainous Utah" sounds like outstanding gas mileage actually. On flat ground, I've read of RVs getting as low as 6 and as high as 10, maybe. 7? in hills? Outstanding! I've been getting just over 8 with a 454 in mixed hills and flat.

I think you're on the right track, do the upgrades that are cheap. Cheapest is to leave it along, it seems like it's running really great as is.

As far as paying back the cost of modifications with improved mpg's, there's not a lot you can do that will ever make financial sense b/c you'll never get much more mpg out of it no matter what you do, short of putting a diesel in it

Especially if you're only driving it a couple thousand miles a year.

Froggy1936 · March 16, 2017, 03:12 PM

I concur I have updated my 77 Chev 350 Quadrajet Turbo 400 3 speed .That recorded a range from 7 to 11 MPG Depending on a lot of different conditions , To a rebuilt 1995 5.7 TBI W 4L80E W OD & Lockup and have not seen any improvement ! Still avg about 9MPG Even tho engine is turning approx 1000 RPM less But still driveing @ 65 MPH I cannot find the patience to try a 45 MPH run ! I am going to try to remove some weight for this summers adventure Last weigh in was 12,000 Lb Frank

strykersd · March 16, 2017, 03:32 PM

I don't mind the 7MPG, I'd just prefer if my engine wasn't running all out all the time. If I can get to a decent amount of vacuum while cruising on a flat surface, I'll be happy

tmsnyder · March 17, 2017, 09:00 AM

They have to do some work to push 100sf of frontal area down the road at 60mph. Your foot is going to be on the accelerator pedal a lot deeper than on a car.

I think my 454 runs at about 10 inHg vacuum while on flat ground, have to check my notes. Definitely check the timing, that can effect vacuum.

turbinebronze · March 17, 2017, 11:26 AM

I've wondered about this topic of trying to get better millage out of a gas engine pushing a brick down the road. It seems that gas engines will get around 8-10 MPG no matter what is done to them (Headers, fuel injection). Has anyone tried to reduce the aerodynamic drag on the vehicle? I see semis running skirts under trailers, lowered front bumpers, smooth wheel covers, and tail cones(?) on the trailers, all in an effort to reduce aero drag.
Has anyone chased those changes, and seen any real results?

I think this is another topic, and should be in another subject...but I kinda saw things running in a different direction, so I tossed it out there. Sorry if I screwed things up....
Random thoughts, Craig

LJ-TJ · March 17, 2017, 01:38 PM

So here's my two cents worth. Classic Winnebago 1966 to 1978 flat faced. I've been around here since 2003. I've followed it all from headers to ignition systems to tires you name it. All the modification I herd might have gotten the owner a mile per gallon or two more on a one time deal. Never Constant every time they've gone out. In many cases it cost more for the carb etc than if they had of just paid for the gas. The best your going to get out of these old girls is on average 7 to 8 miles to the gallon. Sometimes 5 sometimes 10. The best milage you'll ever get and piss yourself off at the same time is LET THE WIFE drive. They seem to get better mileage than any of us guys. D:oH!

M & J · March 17, 2017, 05:53 PM

That sounded like the voice of experience TJ..

Rickf1985 · March 17, 2017, 08:31 PM

Not MY wife! 12 MPG in a Honda Civic!!!!!!! I get 33 in the same car and I don't really baby it.

There was a MPG thread on here somewhere, That is the one you need to find and wake up for this discussion. I think on it I mention dollars per mile as a reference for how long it takes to pay off an upgrade or modification before you actually start seeing any actual savings. It is many, many miles. Usually many years before you even break even on the modification.

tmsnyder · March 29, 2017, 08:22 AM

Here's the formula for figuring out how many miles someone would need to drive in order for the cost of an mpg improving upgrade to pay for itself, ...the break even point.

If we let:

M = the number of miles to break even on the upgrade
C = cost of the upgrade, $
G = cost of gas, $/gal
E1 = efficiency before upgrade, miles/gal
E2 = efficiency after upgrade, miles/gal

Then:

M=C/(G(1/E1-1/E2))

As an example, using the formula above, if gas costs $2.50/gal and the upgrade costs $2000, and mpg went from 7 to 12mpg, the break even point would be at 13440 miles. If the mpg went from 7 to 8mpg, then the break even point would be 44800 miles.

stanDman111 · March 29, 2017, 08:47 AM

good equation = real life

Rickf1985 · March 29, 2017, 08:52 AM

And remember, with gas prices always changing that formula get complicated. It is best to project a higher gas price into the formula just to be on the safe side since gas seldom goes down.

Rickf1985 · March 29, 2017, 08:55 AM

And to carry that equation one more step figure how many miles per year you drive the vehicle and divide the total miles to the breakpoint by the miles per year to get how many years to break even. then you know whether it is worth it or if you plan on buying a different vehicle before that point.

tmsnyder · March 29, 2017, 10:51 AM

I work best by examples, it tends to make complex scenarios easier to understand. That's why I included the example above:

$2000 upgrade (that's cheap for any major upgrade)
7mpg starting (that's typical)
12mg final (that's optimistic)
$2.50 gas (that's on the high side to account for some increase in time)
Result: 13000+ miles to break even

13,000 mile break even ?! That's like 10 years for me! And will I actually get 12mpg? No. So the break even is probably going to take even longer! Better to just keep the engine in tune; spark plugs, wires, distributor, air filter, oil and filter changes, keep tires inflated properly, etc and run it as is.

Concentrate on smiles per mile instead of miles per gallon.

Long story short, it would take very expensive gas, or a miraculous change in mpg to make any major upgrade worth it.

Rickf1985 · March 29, 2017, 11:11 AM

Bingo! The only good point is the extra power you get with the upgrades which is what gives the better mileage but in turn when you use the extra power you lose the better mileage so in the long run you pretty much end up in the same range as before but with more power. Damned if you do and damned if you don't.

strykersd · March 30, 2017, 08:32 AM

Do any of you guys subscribe to Motor Trend on Demand? Their show Engine Masters just did an episode on cooling fans on a small block Chevy and I was shocked by the results.

SBC with no fan
Torque: 406.9 ft-lbs
Horsepower: 349

OEM Clutch Fan
Torque: 400 ft-lbs
Horsepower: 335 hp

OEM Steel Fan
Torque: 388 ft-lbs
Horsepower: 318.6hp

I could definitely use that extra 10-20ft-lbs in torque. Definitely worth the $100-150 cost of converting to me. Off to start piecing this together!

Rickf1985 · March 30, 2017, 08:16 PM

Yea, but how much do you lose when the alternator is making up that 20 amp draw? They don't test that!

stanDman111 · March 30, 2017, 09:01 PM

good point

strykersd · March 31, 2017, 10:28 AM

A fan around this size would probably pull around 40 amps on startup and about 20 amps while running. With alternator efficiency and belt slip we can assume the system is about 50% efficient, so let's say my alternator needs to make 40 amps when the fan is running. While the fan is running it's consuming 40 amps at 12 volts, which is 480 watts, which is about 2/3 a horsepower. Plus if I'm driving during the day I normally combine the batteries so my solar panels contribute electricity too. This is just theorizing but am I missing anything?

Rickf1985 · March 31, 2017, 01:41 PM

Belt drag, which is surprisingly high. I have gained tenths at the dragstip by losing the belts.
And the other thing you need to consider is airflow over the engine and through he engine compartment. Without that clutch fan constantly turning slowly there is no airflow over and around the engine. Those exhaust manifolds are just blasting heat at the dogbox and radiating it throughout the wiring and rest of the components in the engine compartment. It is not like a car or pickup where there is a lot of open space under the hood.

Sasquatch · March 31, 2017, 10:26 PM

The advantage of an electric fan are much more than MPG or power. It is QUIET. The stock cooling fan on my 440 with the fan clutch was very loud. Went to silent with electric. That made the drive much nicer. And, when you are figuring HP lost through the alternator, you need to remember that the fan only kicks in when needed. Very rarely should it ever kick in at above 35-40 mph as the air being forced through the radiator is more than the fan can pull anyway.

The one thing not factored into the modification payoff equation is the joy that the mod brings you. My fuel injection system alone will probably never be paid off at the pump. But, and it is a big but, it was paid off in pure drivability the first trip. It ran perfectly everywhere. More power, smoother, easy starts, etc. Worth every penny in my book.

Love what you are doing with the old girl. Save it from an early grave.

strykersd · June 26, 2017, 06:35 PM

After taking a few months off from working on the Brave to get caught up on my Jeep and drag racing truck, I'm starting to tinker with it again. I bought a reverse camera for it in January but never got around to installing it. The camera kit comes with a 7" screen and infared LEDs for night vision. I was originally drawn to it since it was wireless but to use the wireless option you'd have to manually switch inputs on the screen each time you use it. It's not a huge inconveince but I just want to have a user friendly RV so anyone could hop in the driver seat and drive it without instruction.

Here's a shot of the screen on my dashboard

I repainted the camera white and installed it way up top so that I can see past my spare tire carrier

And the whole setup in action! https://flic.kr/p/YCV1BM

strykersd · September 11, 2017, 05:38 PM

Life has been hectic lately so I haven't had much time to work on the Winnebago. In the last three months I've house sat for seven weeks, moved, totaled my car in a crash and got a new job that I start in a few months. Starting a new job means an opportunity to take some time off between jobs and take the Winnebago on a trip so I have some work to do!

I've been debating what to do about my cooling fan. My solid cooling fan is robbing me of a ton of power and although a electric fan would be more efficient I decided I like the simplicity of a clutch fan. What Rick said about airflow around the engine stuck with me and I figured it wouldn't hurt to always have some air moving around the exhaust manifolds. From talking to other classic Winnebago owners, everyone with Dodge 440s or Chevy 454s dog houses are warm to the touch. With the little SBC in my engine bay, my doghouse is cool to the touch and I want to keep it that way! I just stopped by the local junkyard and picked up a used clutch and fan for just $20!

I was hoping for a seven blade fan but only found five blade fans. If it's an issue I'll purchase a seven blade fan to replace this one.

Rickf1985 · September 11, 2017, 06:01 PM

That is a funky looking fan.

Looks like the clutch has been replaced in the not too distant past. Should do the job for you depending on how hard the engine is working. Be sure to check all of the fan blades around the rivets for cracks, do that with your other one too just in case you decide to use it again. they have a bad habit of shedding blades at higher rpms, mostly an issue with the flex fans but I have seen it with the clutch fans also.

strykersd · September 11, 2017, 06:26 PM

The biggest issue I've had was my broken water heater. I pulled my old water heater tank and found my leak.

I started weighing my options on what to do next. I could replace just the tank in my water heater for $190, replace my whole water heater for another manual-pilot light unit for $250, replace my water heater for an electronic pilot light unit for $340 or replace my water heater with a water heater with an electronic pilot light and an electric heater exchanger for $400 so that I don't always have to run it on propane. On our last trip there was a time we were up at 7,000ft altitude in Utah, in 20 degree weather and 20mph winds where I had to light the pilot light of our water heater outside out RV and would pay to never have to do that again. After lots of debate I decided I want something completely new and thinking about how I hope to keep this RV for a long time I should put the best water heater I can in it. So I bought the water heater that has an electronic pilot light, electronic heater and even an engine coolant heat exchanger (that I don't plan on using).

I don't have a pic of the water heater installed on the RV, but it looks like every water heater on an RV so you get the picture. Here is a shot of the controls for the water heater right next to my water control panel.

Although I haven't used it on a trip yet, I love it so far. It's so nice not having to use propane when I have electricity at a campground and to no longer have to manually light the pilot light.