new member-vintage ecomodder

[Funny]

By the way, since you are tuning your carb, check out this thread: Carb Tuning

I hope this helps. -Funny-

[wagonman76]

Nice ride. Always nice to see cars from the good old days in nice shape.

[elhigh]

Don't forget that back then the EPA ratings were about as realistic as manufacturer's claimed horsepower was in the 60's.

That said, I think you could wring 50mpg out of it. There's some dirty aero details on there that need fixing, but the overall shape is right about where you want to be.

[CharlieBucket]

sorrry i took a little vacation this weekend. thanks for all the responces.

joe bloe-what would be the advantage to the megasquirt? i have heard about it but never knew what it was besides fuel injection for a carbed car.

funny-let me know what i need to tell you about the car to get those exaust figures.

cfg83-did your car have those hubcaps? funny how my car came with honeybee hubcaps and some of the acual honeybee's didn't. cool car i love the honey's but prefer the hatch's bodystyle.

[Ptero]

Charlie, no way can you get mileage like that. Pull the cap of the distributor and suck on the spark advance vacuum hose. Is it moving or is it stuck? That could be part of the problem. Are the points fried. Do they even open?

But looking at your engine compartment, I suspect you are pumping raw gas into that engine because of mal-adjustment, wrong carburator, vacuum leaks or improper vacuum routing, and/or a sticking float. Something is seriously wrong with your carb system. You need to fix that first. Start by rebuilding the carb. Replace your fuel filters - there might be one you havent found so trace back to the gas tank.

Toss that too-small aircleaner and go to a junkyard and get an OEM air cleaner and hook it up properly so that it routes warm air from the exhaust manifold into the intake when it starts up, like it's designed to do. Find a vacuum diagram and route your hoses back the way they were originally. I bet you're sucking air into the intake manifold through a misrouted hose and trying to make up the power loss by running way over-rich. I've seen it a million times. Really hard on the pistons and rings. You can find vacuum leaks with starting fluid if you don't catch on fire. The engine will tip you off by running faster.

If you have a mechanical, crankcase-mounted fuel pump, be sure also to check that the pump isn't leaking gas into the crankcase through a torn diaphram. Your oil will smell like gas and if you blow into the line from the carb to the fuel pump, you will hear air hissing at the pump. If you drive a car with a leaking fuel pump, you can thin the oil to the point of seizing the engine and burning the car up. Literally.

[CharlieBucket]

Ptero-thanks man, lots of good advise there. the previous owner pu the small aircleaner on and did what he called "de-smogged" the carb. i wish he would of left it alone and didn't trash my oem air cleaner. i am going to study your post and i will let you know the results. thanks again

[Ptero]

Yeah, the middle seventies were nightmare years for the manufacturers in trying to comply with the new emissions regs. They mostly worked out kludges and emission tech didn't get sophisticated until the 90s. A huge problem today is where people who didn't understand the purpose or effects of smog control systems went in with tools flying and screwed everything up.

I recently purchased an F800 boom truck on the east coast and brought it back to California. It had been stripped of its emissions equipment and the yahoos had installed an Edelbrock 4-barrel carb on it. It got 5 miles per gallon.

I was told by so-called experts that it would be impossible to refit the smog system, but I've done it before on other vehicles. To get it registered, I installed twin air pumps, an OEM carb, air injection manifolds and new emissions valves. That doubled the mileage and made the truck marketable in California - which added around $20,000 to its value. So don't believe everything you hear about stripping out smog equipment to get better performance.

One of the worst things people do is stick a sucking, hissing vacuum hose in the wrong place. That brings the idle up and they think they solved the problem but what they actually did is disable the vacuum advance for their distributor. Then they fiddle with the idle screw to try to make up for the loss of power by running over-rich. This gives more power at throttle but it kills their mileage and their idle stinks of raw fuel.

There is often a temnperature-controled vacuum distribution valve somewhere on the water jacket with several nipples. If you get those vacuum lines mixed up, your distributor won't advance properly and you can cut your mileage in half. I suspect you have several simple-to-fix goof-ups that are compounding the problem.

The best way to approach this is to read the general discussion of emissions controls in a 70s-era Chilton manual. They're really not that complicated in theory, and once you get an understanding of the three basic systems - exhaust gas recirculation, air injection and temperature-controlled timing advance - things start to make sense real fast across a wide range of engines.

I'm not trying to say that you can't get better performance by bypassing emissions controls. I am saying that you absolutely have to know what you are doing - and why - to get a real benefit.

[Intrigued]

Originally Posted by Ptero

Charlie, no way can you get mileage like that.

50 mpg from a B210? Bet he could Ptero, I can tell you've been a car guy for a while. There's a lot of good ideas there. Oh, to check for vacuum leaks, spray the choke cleaner or starting fluid around the base of the carb, throttle shaft, vacuum lines, etc. but not IN the carb, nor toward anything that makes/uses electricity - and keep a fire extinguisher handy

Re-grease the wheel bearings with a good lithium grease, (back the axle nut off up to a 1/4 turn from snug to re-pin it) and keep the tires as close to the max printed on them as possible without making the ride rough - eventually suspension movement will start robbing mpgs.

If you want that fifty, you can do stuff like re-curve your distributor. You'll have to talk to an old car guy about how to "adjust" the weights, but it's fairly simple once you get the idea. You'd have to play some - on a hot day you can find out you went too far, and have to back off base timing, which defeats your purpose. I've seen guys clamp a bar to their distributor body, loosen the nut/bolt just a little that keeps it from turning, and attach a hand throttle cable to the other end, and adjust their timing on the fly to whatever temp/load is present at the time (old drag-racing trick).

Alternatively, you can just move up base timing about 2 degrees (more advanced) from stock and see if you get spark knocking under a load (BAD thing!). I've seen many a car with the distributor gears worn more than that after 100K miles. Try it on your truck too! There's something funny about what mileage you're getting there...my son's '95 GMC Sierra is at 4 degrees above stock right now...at 216K miles...

There's more mechanical stuff to do, but I don't want to overload you. Besides, there's a smell of homemade bread coming from the kitchen...

[Ptero]

Intrigued, I was referring to this quote by Charlie.

i get dreadful milage. i'm talking like 12-13 miles a gallon.

Also, you bring up an interesting point. As an ASE mechanic, you know about drag measurement of wheel bearing loading, such as that specified for Toyotas. A quarter turn back out has been standard practice since forever on Detroit products, but I wonder how far can we go. As a mechanic myself, I've always used spec settings, of course. But a as a hypermiler, how loose can we go without damage or risk? Have you ever experimented with this? I bet there's a general rule that is specific to bearing diameter and weight footprint.

I'm a old dry lake sailcar nut. We always used vasoline on all our bearings back in the day and never noticed any wear. Of course, there was hardly any loading and we frequently repacked - as loose as possible. Probably today a synthetic would work even better. Any thoughts as to how this would apply to hypermiling?

I do have one bone to pick. You say that suspension movement "eventually" robs your potential return on increasing tire pressure, I disagree because in my experience max pressure as marked on the sidewall provides enough cushion on most pavement surfaces to override by far any loss. In fact, thus far, increased tire psi results in increased mpg on a steady cruve. If a claim is made that suspension movement is robbing mpg performance, I suspect the argument is theoretical.

Handling is a different matter. Increased tire pressure can lead to dangerous and unreliable grip, which also seems to manifest itself on a steadily rising tire pressure curve.

[Intrigued]

OOPS! My bad on the mileage quote. I got to wondering about that halfway throught the post...Yeah, there's something not square about that truck, unless it has gigantic mudders! Vacuum line sucked shut, or something...

On the wheel bearing grease, I bet a synthetic grease would do better. I've heard of the vaseline trick on drag cars, back before they started going over 200 mph a pass... (Hey, I said "OLD" ASE Master...of course now it is "old" as in former...) On going any looser with the wheel bearing nut, it doesn't take too much until you see misalignment, and a smaller contact area, which leads to premature failure: about 58 miles...away from home...don't ask...

I can't argue with your sidewall max pressure point, for the most part. I just remember a study somewhere back in the '70s or 80's fuel crunch where a group (Car Craft, maybe???) put some tires other than factory (now that I think of it, these may have been 8-ply and aired up to @65 psi) on a car, and at a certain point mileage actually began to suffer. I'm guessing the hybrid car tires nowadays that run at so much pressure aren't 8-ply, so there wouldn't be the same issue. Yeah, I gotta give you that one.

This does remind me of the girl that brought in the Sunbird for a lube job, and the (OEM) tires all read in the 50-60 range. That'll make you pucker up...and I ain't talkin' lips...