'71 El Camino is a GAS HOG!
 

Hello,
New to the EcoModder community. I was expecting to see a bunch of hippies (no offense) on this forum, however digging deeper it seems like the rest of you guys are fed up with paying high prices for gas as well.

Anyway, I picked up my '71 El Camino a couple of months ago for $3400. The car so far has needed minimum investment to have it running, but it's certainly not optimized. Right now I am getting 8mpg, mostly city driving and short commutes to and from school and work (less than 5 miles each way).

Two things I am sure need changing are carburetor and intake. The current 2 barrel Rochester 2 Jet gets dirty pretty quickly and I'm pretty sure its coming from the PCV valve that goes into my intake, PCV is getting changed when the part arrives. Carburetor's choke isn't working right either.

The second one is a wheel alignment, not sure how much of a gas killer that is but it pulls to the left.

That being said, thanks for listening. I know, I shouldn't be expecting incredible mileage but if I can get close to 15mpg like I was getting in my Crown Victoria I would be ecstatic.
-Mike

https://lh6.googleusercontent.com/-l...21738133_n.jpg
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Don't worry, the loose tailpipe on a chain was fixed immediately!

15? You need to set the bar higher. Back in the day my '74 Nova got low-mid 20's.

What did your setup look like? I'm amazed I'm getting this mileage with a 2bbl

I'm amazed too. It had a 2bbl Rochester, TH350.

My '59 Bel Air, 283, 2bbl, Powerglide gets low 20's too. However my driving is not intense city like yours.

8 mpg indicates something is very wrong. Could be the driving, could be not running on all 8, who knows. No burnouts or stoplight gran prix are allowed if you are seeking to maximize your economy.

You suspect alignment cuz it pulls left, but if the tire wear is even then I'd say your front left brake caliper is not releasing. Jack it up and see how easy the wheel spins. Check 'em all. Make sure the tires are all aired up properly.

Put a manual choke in. Or in CA you should be able to disable the choke altogether. The 59's choke is disabled; I just pump a few times to start. It hasn't been an issue (thus my failure to fix it or add a manual choke).

There is probably nothing wrong with the intake, although the crossover passage for intake heating could be plugged up. That would hurt mileage. There is also a crossover thermostatically controlled valve in the exhaust system that needs to be freely working if that warming system is to be functional.

It is said that a 4bbl can achieve better fuel economy than a 2bbl IF you can stay outta the secondaries. I haven't tested that theory.

You suspect excess PCV contamination. Maybe there's a stuck piston ring, or excessive wear throughout. Do compression and leak-down tests.

Maybe it's flooding. They can flood and still manage to run decently. Could be a hung-up or not floating carb float.

Could even be a fuel leak somewhere.

Does the motor oil stay clean or does it get diluted thin with gas?

Your trips are too short. That big V8 lump is not getting to operating temp. NO I'M NOT SUGGESTING YOU LET IT SIT THERE IDLING TO "WARM UP". The big old carb'd stuff was simply far worse in that respect than today's EFI stuff. To mitigate it some you can use a block heater, engine compartment blanket, convert to e-fan, perhaps some grille blocking, perhaps a warmer t-stat.

But seriously- trips of only a couple miles are better done on bicycles, scooters, or any number of things more suited for the task. What you have is a hobby car more than a daily driver.

Frank, this is all good stuff. I'll diagnose all this ASAP. thanks again!

San Fran is pretty hilly. I can only imagine - full sized car with V-8, short enough trip not to warm up, extra gas to go up a hill, then stoplight. Extra gas again, then another light.... Or the other way, DOWNHILL to stoplight, BRAKE. down to the next stoplight - BRAKE.

Yeah, I can see 8 .... and in those conditions, 15 would be super-human!!! (super-car? - no, that would be a Lamborghini or Veyron - - ????)

(guess that's where a hybrid would really shine, huh?)

Hills, hills everywhere! Hence why I'd be ecstatic to get the 15mpg I was used to in my '99 Crown Vic. My '86 Cutlass with a 307 V8 and 200r4 got comparable mileage to the '71 with a 350/350. Dunno what gives :confused:

Could be this is your hint to break the V8 addiction.

frank I was thinking the exact same thing!!!!

Let's not get too hasty now. I do admit, I grew up with these cars so NOT having a V8 is something of a blasphemy. My overall goal is to get what I think is decent mileage (for a V8) and still get raw V8 power (cuz horsepower & torque is fun). Enough to haul some landscaping tools, which is the trade I'm going into. Frank, I do thank you for the insight though.

i grew up with v8s too but nothing wrong with a little 4 cyl beater. but if you dont drive very far and dont mind spending the money on gas then hey, go nuts. could always plan an ls swap with an overdrive auto. then you could keep the v8 and add fuel mileage (and power) conversion mounts and headers are getting more readily available and cheaper!!

if not, start tweeking!! take the carb apart, rebuild it, play with jet sizes, throw an afr gauge on it to help fine tune it. get rid of points if still equipped and put a more reliable ignition in it.

If you need a v8 put in a 5.7 olds diesel with a 5mt, grade 8 headbolts and a fuel water separator, not only does it sound better, it also should get 20-30mpg highway without trying and about 50%-75% better in town if in proper gears.

Cheers
Ryan

If tradition means 8 MPG with gas there at close to $4 a gallon, if not more, then you can have that tradition. Worse gas hog I ever had was a 383 Formula S Barracuda, a 67 white Coupe that got 10 MPG. I was burning 100 gallons a week, but that was before the 1973 oil embargo.

You're tossing a buck out the window for every two miles (50 cents a mile or $4/8miles). In 1968 I was tossing a penny a mile out the window (32 MPG @ 32 cents a gallon), just 2% of what your are spending today.

regards
Mech

I grew up with V8s too but then I outgrew most of them. :thumbup:

So you're accustomed to paying through the nose for your fuel because you've never known anything else. Once you get used to buying a lot less fuel, you will wonder how and why you ever put up with heavy fuel usage for as long as you did. Just about any and everything is funner to put your money into than a gas tank. At, say, 250 miles/week @ 8 mpg that is 31 g/week x 4.3 = 133 g/mo x $4 = $532 every month vs 30 mpg equalling $143/mo..... :eek:

And unless your V8s are built up and/or have low geared axles, they really aren't all that powerful- as in thrilling- anyway.

Taking this thought one step further, a useful metric is to think of your transportation costs in cents/mile; AAA says the average sedan costs 60.8 cents/mile to operate in '13! :eek: I haven't run all the numbers recently but I'm at or under 10 cents/mile; in other words- take any particular trip for an example- for every time the average motorist makes that trip, I can do it SIX TIMES for the same money. :eek: All I can do is shake my head when people don't think twice about spending a couple bucks to go the same distance I easily walk in a short time. :rolleyes:

http://ecomodder.com/forum/showthrea...1-a-17052.html

http://newsroom.aaa.com/tag/your-driving-costs/

no sweat....it's all in good fun! :thumbup:

remember....it's not about driving eco-boxes.....it's about driving smarter! :cool:

I think in his case he needs to wrench smart first to get the thing
1. Straight
2. Drag free (brakes)
3. Tuned
4. XMSN/fluids/etc in working order.

1] Mechanical/Electrical baseline first: No assumptions that systems are good until checked thoroughly.

2] Smart Use: Combine all trips. Go to farthest point first via freeway if possible, and work back to house

3] Smart driving: The reduced number of annual miles driven better.

My rather recently retired 1971 big block Chrysler could achieve 14-16 mpg in town. Nearly 19 on the highway. And it weighed, with driver, full fuel and permanent gear aboard 4,780-lbs.

Were I you I'd start there: what's it weigh?

.

This.

Make sure it's firing on all 8 cylinders. I've seen a 7 cylinder V8 that ran perfectly smooth.

Another poster recently found that his mileage was low because the ignition timing was retarded.

SCHOOL BUSSES get 8 mpg. True! :eek:

Let's be nice to him. He DID say that he wants to get better mileage. And the advice to work on the basics first is spot on.

I have wondered what I could do with a 60's car. Let's see - mileage cam, rebuild engine for minimum friction, Megasquirt, wide ratio 6 speed and rear end for about 1400 RPM at 60 MPH, kill switch, electronic ignition, LRR tires, some aero tweaks to the front end to get attached flow over the hood, wheel covers, grille block, ....

Say 30 MPG? Or at least high 20's?

22 mpg solo at 65 would be good enough for me. The "returns" in money and viability decline rapidly after that point, IMO. An Elky can pull a decent-sized travel trailer. But greater FE might well mean degrading that capability . . ergo, get a vehicle better suited past that point.

Mileage Increase
 

Hey everybody, just wanted to update everybody on my mileage increase. I'm up to 10mpg! That's that half of my tank consisted of work miles carrying landscaping equipment and hauling debris. This isn't incredible but its a definite improvement.

Adjustments:
Kept myself from trying out full throttle (Its a 2 barrel)
Lowered fast idle mixture
Cleaned carburetor thoroughly of gunky oil buildup
Changed PCV valve
Utilizing Neutral especially when coasting steep downhills
Conserving Momentum
Reduced ride height at the rear (bled air from air shocks)

Checked to see if the brake is grabbing as recommended and it seems fine. Just seems like it needs an alignment still.

PS: Anybody have tips, articles, etc. on an aerodynamic El Camino build? I was thinking of finding an aftermarket/fabricating a front air dam and tonneau cover for starters.

An Aerolid and the recommendations for a pickup: partial grille block & partial bellypan. Read all the other pickup truck threads here.

I'm not so favorable to extreme aero modding as some folks here are, but you might take a look at some racing versions of the Brazilian Chevrolet Opala to get some inspiration for the aero mods. And a tonneau cover always leads to some good improvements :thumbup:

71 El Camino Mileage.
 

Afternoon everyone! I just found this thread and decided to chime in with my responce!

I too own a 71 El Camino and I love my truck! On a recent trip I just took via back highway, going through alot of small towns to slow down for and a couple of stops i averaged 16.8 MPG with mine. Mine does have a 350 transmission with a recent rebuild on it and a 130,XXX mile old 307 small block, 2 barrel carb, and points ignition.

My biggest advice is if you want to keep the truck for along time and get good mileage, Pull that 350 and replace it with a 305. Chevy when they hit the 350 engine mark they turned into gas hogs, going with the smaller engine and possibly opting in an overdrive transmission can gain alot!

My dad as an 87 Elky with the 305 52,xxx mileage and a 200r4 trans 102,XXX mileage. He averages about 22 MPG, and thats with alot of city mileage.

You could go the LS engine route but with the changes with headers, computers mounts and everything it runs about 1500 to drop the 5.3 ltr engine in. The 305's can about be bought a dime a dozen as everyone wants the swap in the 350s. And a 305 can be swapped out in a day or 2 easily and still reuse exhaust, transmission, hoses and everything else.

Just some food for thought!

A 6.5L turbo diesel with a TH700R4 transmission with 3.08 rear gears would be more than enough to move that car, pull stuff and get mid to high 20 MPGs.

Except that it weighs more than a V8-454. Imagine the FF/RR weight imbalance, empty.

FWIW, I keep a K-5 around for emergencies and some topless fun in the summer, and it gets 10mpg pretty routinely, even with the top off.

Its a mix-match of other trucks but what i know for sure is it has a sickly '73 350 v-8 (more like 7) with a leaky Quadrajet from an '82 350 (oh yeah, its got HEI from '75+), TH350 w/ NP203 (AWD), the axles are 3.08:1, and 31" all terrain tires. Dual exhaust also.

Maybe you can go up slightly on tire size to get a mpg. I'm 100% certain you can do better than my Hauls-All

I used to own a 73 El Camino with 350 and 2 BBL carburetor. It was terrible on gas and this was long before I had knowledge of modifications for mileage. It was easy to trade it on a small Datsun truck and gain some easy mileage.

With the age of a vehicle from 1971, one might also want to investigate the condition of the wheel bearings. Synthetic oil in the motor is always a good way to kick up the mileage with just an oil change. An underdrive pulley kit might be a easy way to gain some mileage. Get rid of the spare tire and big heavy jack to loose some weight.

I had a '78 Camaro with the 5" rear spoiler do 25 MPG at 65 MPH with the centrifugal advance not working, and a mystery Q-Jet. That was a 350, I swapped a junkyard 700R-4, it had a 3.08:1 axle, and I still have every detail to duplicate it, but the point is, hoping for 15 is a joke. It should already do that just as you got it.

Not really. Weight is really close. Maybe 20 pounds, nothing to worry about. But the cost to build a 700R-4 to live behind a 6.5 isn't worth it. If you salvage from a '92-'93 you can get the 4L80E and the controller. Being nose-heavy isn't of any real concern since this car obviously isn't being prepped for 1G cornering.

Not to mention any type of automatic transmission behind either of Detroits classic NA diesels is a waste of fuel power and reliability, best to stick in a proper manual transmission and be done with it.

Welcome!

I think that 15 could be doable in an El Camino, with lots of hard work that is. The first thing would probably be to change driving habits (in SF it's kinda tough because of all the traffic) then do some mods. Some wheel skirts would be nice to see on that thing, as well as some kind of aerocap that we see on trucks here.

Like others here are saying, V8 addictions are not good for FE at all. I can get 8 MPG in my Civic going WOT the whole time (I wish I was kidding). Be sure to read up on the 100+ hypermiling tips. The best mod that you can do to your car is done to yourself!