So the other day the mechanic mentioned to me that these engines were designed to run on 95 octane gas. Nowadays, in Amarillo at least, premium is only 90. He said I might want to try a bottle of octane booster and see if it gets any extra mileage out of the engine. So I did.
Then yesterday as we left town I noticed that the water temp gauge was actually moving. This engine never got hot, and in fact I was pretty sure that the gauge didn’t even work. So when I saw the needle climb I said to Ali, “Oh, it looks like they got the temperature gauge working.” I thought maybe they noticed a loose wire or something. The temp gauge is really worthless though as it is nothing but a couple of dash marks and tells nothing about the actual temperature.
Anyway, we hit the road this morning and all was good. Cute little town situated two blocks off of the highway, meaning that it is basically abandoned.
I wasn’t really paying any attention to the gauges as we rolled down the highway at 55. About fifteen miles out of town I suddenly smelled the sticky sweet of overheating coolant. We pulled over and watched as coolant blew out of the radiator cap.
We waited a while for the engine to cool, double-checked the oil, filled the radiator with water, and turned around. We didn’t hesitate to turn around because this was the sign we spotted on our way out of town.
We kept it at about 40 as we drove back, making it about nine miles before the temp gauge started moving off of normal.
We didn’t overheat this time. Coolant flowed into the expansion tank, and after twenty minutes or so it flowed back into the radiator. We continued on.
As an aside, if your spouse ever starts talking about becoming a vegetarian, do not, I repeat, do not drive down Highway 54. You’d really think they’d move these cow holding pens, or whatever they are, a little further off the road. Because it is a truly disgusting sight seeing thousands, if not tens of thousands, of cows standing shoulder to shoulder in dirt pits. As you drive past them the sky is filled with dust and shit. You hold your breath and hope that is the last one.
We only made it four miles before it felt like we were closing in on overheating again. We pulled over to let it cool, but this time no coolant filled the expansion tank. Maybe it wasn’t as hot as I thought.
After letting it cool we finished the drive back into town and to the RV park.
That afternoon I brainstormed what could have caused the overheating. The only things I could really come up with were the thermostat, the radiator, or the carb running way too lean. And just for the hell of it, I replaced the spark plugs. They looked okay, maybe a little lean, but not overly.
This morning I decided to flush out the radiator a couple of times, thinking it may be dirty or corroded. It looks okay, but really, what do I know? We also ran to NAPA and bought a new thermostat and infrared temperature gun. There did indeed turn out to be a thermostat in there, 160 degrees, which I replaced with a 195 degree unit. I think 195 is original. In fact I had a 195 that was in the pile of parts on the bus. This morning before we left I dropped it in a pot of boiling water to see if it was good—it wasn’t.
Last thing I did before we got back on the road for the day was fill the tank. I put in 90 octane, but no booster this time. I was surprised when I did the math and found that we had only gotten about 6.8 mpg the previous two days, way under the 9.0 that had become our normal lately. So much for gaining miles with the higher octane.
We ran down the same highway, this time stopping every ten or twenty miles to lift the engine hood and shoot everything with my new toy—I mean tool—the infrared temp gauge. Everything ran normal all day. The coolant temp right on the thermostat was right at 200 and the top radiator tube was 170.
It wasn’t until we were about fifty miles in when it occurred to me that the octane booster was the only thing that had really changed. I’d forgotten all about it up until then. It makes sense that immediately after adding it to the gas the temperature gauge started climbing—eventually overheating. Today, with twenty gallons of fresh gas in the tank it went right back to running normal.
Sure it could have been the thermostat, but the timing of that would be way too coincidental.
Anyway, I’ll put to bed this long boring story about yet another Bumfuzzle engine overheating. I do however think it is worth noting that the air-cooled ’58 VW bus, and the air-cooled ’65 Porsche, are the only engines that have never overheated on us.
I forget the name of this town we passed through today, and frankly, it’s not worth standing up to grab the map. Just another town in a long line that have prospered and perished. This one had a huge abandoned brick building at the edge of town that I at first mistook for a large high school. It struck me as odd, way out here. Then I saw the sign—Rec Center. That struck me as even more odd. In it’s heyday the entire town and every last bit of extended family they could have dredged up would have fit in that building.
Now four lanes barrel through without so much as letting up on the gas. The only things open are a motel, and the ubiquitous Post Office. Every small town in America has one. It’s not uncommon at all that this would be one of only two businesses in an entire town. Small wonder that forty-six cents a letter isn’t profitable.
We ended the day at Ute Lake State Park. Nice quiet spot with a playground and a lake for the kids to throw rocks in and make mud pies on the shore of.
22 Comments on “What else is new?”
In all probability, it was the thermostat. You’ll likely be OK with the new one, but I would either have put in a lower temp. one, or none at all, especially if i was going to be in hot climates, but to each his own. Good luck.
I actually agree with John. I’ve had my share of bad thermostats. Even had a bad alternator once, brand new out of the box.
I think your mechanic was mistaken on the octane. The 318 2bl in is not a very high compression engine and I think that most folks with this engine are running 87octane. If you run too low of octane on stock timing you will hear the engine start to ping and or you will have engine run on after you have turned of the ignition. I would try dropping down to mid grade and see if you get any ping, if not I would then drop to lower grade and see if you get any ping. You will get no benefit from running more octane than required.
As far as the thermostat goes I think you did well going back with a stock one. Shade tree mechanics used to lower them or remove them all together. The engine would run cooler (until it didn’t). With a wide open or no thermostat, once the engine does get hot the water never stops and gets enough time with airflow over the radiator to cool off; additionally, when it isn’t too hot it is running too cool and inefficient.
What you might use instead of octane boost is a little lead substitute unless your valve train was updated at some point.
Also, remember that you carb was dialed in at 3600′ of altitude so you could be a touch lean once you go back down to sea level.
Just my unsolicited 2 cents, but I don’t know crap. 🙂
Back in 66, 95 octane was racing fuel, so not sure what the mechanic was thinking either. On the thermostat, you should see better fuel mileage if this engine’s operating temperature really is supposed to be 195 (seems high back in 66). Having said that, I would go back to a 160 at the first sign of overheating. With regards to running lean, maybe at 10,000 feet, not sea level. One last thing: make sure that you have a 50/50 coolant mix after flushing. Cooling will improve (higher boiling point) and the rust inhibitors should prevent internal rust. Just my $0.02 and I don’t know crap either,
Sam has all good stuff in this post, one minor edit, I believe he will start running richer when they come down to sea level.
Octane and mpg are inversely proportional…
Octane is oft misunderstood. At a basic level, all things being equal, higher compression engines make more horsepower, but higher compression also increases the chances of pre-detonation (aka pinging) which is very bad for an engine. Pinging is essentially fuel igniting due to compression instead of the spark plug firing.
An additive is added to the fuel to increase octane, octane being a rating that indicates the fuel’s resistance to pre-detonation. The additive has fewer BTUs per gallon compared to the gasoline itself do the more you add the fewr BTUs in the gas. The net result is that the higher the octane, the lower the energy in a given gallon of fuel. Since the energy(BTUs) are reduced, you need more of it to produce a given power output from the engine, resulting in lower MPG.
As Sam mentioned, you should use the lowest octane fuel that the engine will tolerate without pinging. Doing so will
Provide the most horsepower and best MPG.
Leaner carb settings and/or increased (advanced) distributor timing will generat increase horsepower but also increase the propensity for pre-detonation.
As an aside, running a cooler thermostat is often used to keep the engine cooler, which slightly reduces the temperature of the intake air, which increases the density of said air, resulting on more oxygen per combustion cycle. This increases horsepower, but again increass pre-detonation, and also doesn’t allow the engine to operate at design temperature, reducing efficiency.
All in, for best mpg, use stock thermostat, tune timing and distributor to factory specs, and run the lowest octane you can get away with.
Hope that helps
Richard
Amen to everything Richard said.
We stayed in Ute last October. We were the only people there so it was great. So glad you made it to New Mexico. The state parks here are wonderful. We’re at Elephant Butte now.
You probably already know this but if you buy the New Mexico State Park annual pass ($225) you can camp in an electric and water site for only four bucks a night or zero for dry camping sites. The pass is totally worth it if you plan to be in New Mexico for more than a month. So far we’ve stayed at Storrie, Caballo, Bottomless Lakes, Elephant Butte, Ute, Sumner Lake and Santa Rosa so we’ve definitely gotten our money’s worth from the pass. Ute and Santa Rosa were my least favorites but they were still nicer than any RV park.
That same feedlot made me go vegetetarian! My husband and I are long haul truckers and the stench there has actually woken us up as the other drives thru.
One of my first times driving to Amarillo I saw what I thought was smoke on the freeway so I slowed down and turned on my hazards… Turns out I was just driving thru millions of cow farts!
What??? Now THAT is a lot of gas. ROFL
“Turns out I was just driving thru millions of cow farts!” Best comment ever – made me LOL!
You might like to head north and check out http://www.nps.gov/dino/index.htm Dinosaur National Monument
I remember making this drive a few years back on a camping trip. We also rolled our windows up, turned on our headlights in preparation of the impending ‘rainstorm’ on the horizon. Nope. Literally drove through a storm of sh$t. Even came through the vents with the A/C on! A story we still tell our northern friends today.
Good to hear you got the bus sorted Pat and Ali. Best wishes.
Richard is right on the money.
The version of the 318 in an RV would have had the lowest compression ration of any versions of the engine made: So pinging very unlikely. The carburetor put on the engine by Dodge for an RV application would have had the best jet sizes for running with a heavy load. The 413 in our RV worked fine at all altitudes – even up at 10,000 ft, though getting up that high meant hours of slow going. Ours had the 4.88 ratio differential, yours might have the 5.18 ratio.
I had used all 3 temp ranges for the thermostat in our Dodge based Winnebago; 190, 180, and 160. With a good radiator and 50-50 coolant mixture they all worked equally well – except in winter tempers, the hotter thermostats provide better results from the front heater. I preferred the Stant ‘superstat’ thermostats.
Everyone knows gasoline and tires are consumables. But so are coolant hoses, thermostats, radiators, radiator caps, water pumps and v-belts. They are just consumed s-l-o-w-l-y. Fuel filters too.
You might want to seek a new temp sensor for your water temp gauge. Those sensors also age, and may have a corroded connector.
Well at least nobody has told you to replace the engine in this thread… yet. heh heh
There’s no way they ran on 95 octane in the 60’s. That’s just silly. Was the mechaninc that told you that even alive in the 60s? And higher octane provides no advantage if you dont advance the timing. Just run the cheapest gas you can find. If it pings retard your timing a degree or two until it stops.
As a New Yorker living in West Texas, actually on the ranch that Cadillac Ranch is part of, you hit it right with the feedlots. Between them, the drought, the dust storms and the friggin’ heat…I mean what made anyone in a covered wagon stop here and think, “Yeah, this just the place”? Thankfully the people make up for it.
But you’re not wrong about the cow farts. My neighbor studies such things (for a living) – yes, there are people who actually do that – they politely call it “fecal fog”. Everyone else just calls it “shog”.
Answers here: http://m.youtube.com/watch?v=L-D824LHti4
Cowschwitz
The infrared thermometer is Jon’s favourite toy-tool too… but then he starts getting obsessive about the temperature differences between cylinders and I have to hide the batteries from him 😀
*Love* reading about your latest adventures!!
Pics like that remind me that the $8/lb locally farmed beef I buy is more than worth it. I know my farmer, I know how they take care of their cows; grass pastures from infant to slaughter, no feed lots whatsoever.
New Mexico is one of my very favorite places on earth. Enjoy!