A theory to ponder

[rob-the-oil-nut]

I hope this is the right place to post this question. I think I brought it up last winter but maybe that was a PM or email.
See also "Is it alright to cover your radiator in the winter" by 2003TRD...but THIS post deals more with how, in theory, to get more heat coming from the actual combustion process...here goes...
It's the cold of winter. Say -20 or colder. The cold is getting to you and the car never really gets warm, even in 30+ mile trips. Would this work, has anyone ever tried it, and how would you test it?
What if you used higher-octane gasoline? Not for more horsepower; not for better mileage. For more heat.
I confess I have just plain forgotten; does higher-octane actually burn slower? Or contain more heat energy, potential heat, BTU's, latent heat, etc? This is important to the theory, at least in part.
What I am thinking is, the air-fuel mixture is ignited and the flame front propagates as it pushes down on the piston. If the flame-front propagation is slowed / lasts longer by higher octane, or is just plain inefficient due to cold weather, would it not cause more heat energy to go into the coolant, and wouldn't THAT lead to higher temperatures in the coolant jacket / heater core?
Is my theory moot unless the block or block + radiator can be covered in insulation? Is it moot as long as ambient temperature is so low that gobs of heat energy vanish into the air anyway?
Your thoughts are welcome but I'm hoping for more scientific replies

Thanks!
Rob

 

[rugerman1]

Moving to:Mechanical /Maintenance Problems, Tips, and Tricks

 

[dropitby]

When I used to live in Chicago we put a piece of cardboard on the radiator.Not long just till it was warm in the car.

 

[TallPaul]

I once had a pickup that for years just would not get the water very hot in the winter. I ran a cardboard all the time through the winter, but it had a hole (maybe 12 inch diameter) in the center of the cardboard to allow some airflow. Worked pretty good as I recall.

As for higher octane gas, I would think it would burn less efficiently and maybe leave deposits.

 

[Ray H]

Two Peugeots I owned over the years came with a flexible rubbery appliance in the trunk that attached over the grill to limit the amount of air admitted to the radiator - even had a sliding rubbery "gate" arrangement to customize the amount of air flow. It always mystified me why these would be of any benefit since it seemed to me the engine's thermostat would limit the amount of cooled water from the radiator that would circulate through the engine anyway. I s'pose, on reflection now, that limiting the amount of cold air flowing through the radiator was secondary to limiting the amount of cold air flowing over the engine upon startup as a means to hasten the warm-up process. In any event, in my area, it's a non-issue anyway. Off topic, but I sure miss those Peugeots. The French must either have abominable roads or awfully tender butts (or both...). French cars seem to have "yards" of suspension travel - they absorb road irrecularities like a sponge absorbs a spill. The Peugeot shocks were valved to allow relatively unimpeeded compression for all but the harshest bumps, but a highly controlled rebound with little or no overshoot. The combination of a relatively long wheelbase in relation to the car's overall length, generous suspension travel geometry, and the chosen damper valving parameters resulted in astonishingly comfortable, yet non-floaty ride characteristics. Viva la France!

 

[Brett Miller]

I may be wrong, but I believe higer octane gas has less BTU's per gallon due to the slower burn.
Another point to ponder is you do not want to block all airflow because the air conditioner condensor needs some air for the defroster to work properly.

 

[rob-the-oil-nut]

At the risk of digressing the thread even furthur, I worked for an internet service and a customer called in, and judging by his account particulars, he was a huge Citroen fanatic. He knew of, or had, one of those Citroens where the rad fluid, PS fluid, brake fluid, ATF, etc were all the same fluid. Incredible and complex and not something any car-maker would want to try, but Citroen did it, in more than one production model. He went on to tell me that the load-balancing was so sophisticated, it could drive on THREE tires...at least in theory. He told me that he was eager to test this theory, and removed a wheel and headed out to the highway with 3 wheels hitting the pavement, instead of 4...at this point, if you want to stop believing this story I agree that's understandable but as I recall, it's what he said...he got pulled over (any RCMP or OPP / Ontario Provincial Police reading this??) and he assured me that he took no flak from the cop. "Where in the Highway Traffic Act does it say a car has to have 4 tires hitting the road? Well? No, it doesn't! You see cops pulling over motorcycles with side-cars? NO! Oh, I tell you, I'm taking this to court, I'm fighting THIS one..." Right about then I wish I hadn't said anything, and REALLY wished I wasn't being monitored. I wasn't, and since I'm digressing from warmth of cars in Winnipeg winters anyway, I'd like to take this opportunity to publicly thank God for that.
Hope I made you LOL. YES it is what he said (close to 4 years ago)
Rob

 

[rob-the-oil-nut]

Thanks Brett. Yes; what I wonder is if the slower burn puts more heat into the coolant, even if less is used to push down on the piston.
The mechanic I mentioned that knew just where to place the cardboard and was asking good questions, well one of the questions was 'does the car have air conditioning' and when I said yes, he said something like 'I know JUST where to put the hole, and how big it should be'
FWIW I mentioned this to another mechanic who scoffed that A/C's are NOT used in the winter.
He had gone to school and been certified over 20 years, I didn't want to tell him he didn't know what he was talking about. His 'because you are a friend of a man I have known 20 years, I'll give you a special rate...' rate was within 1% of what a dealership charges, so I haven't seen much of him lately

Thanks!
Rob

 

[rob-the-oil-nut]

BTW I should mention: This all started when my friend TA thought it wise to buy premium when it was profoundly cold. Another guy cut him down and asked what the (*) for, and I decided to argue a case for my friend. I'm not out to insist that the points I made are 100% correct, but they DO sort of make sense...in a way...
BTW, as for deposits, at colder than -20 I think it's safe to say the engine will build up some carbon, and some highway miles are a good cure. I am really talking about what to do when every degree counts, and you can drive on the highway 1/2 hour and the heat never gets above about the 70 (C) mark. Whereas in summer it routinely does. If you've never personally waved to a snow plough in grateful appreciation (otherwise you cannot leave your street) maybe you can't quite relate

 

[thinshavings]

The A/C systems are used during defrost settings but ONLY if the outdoor temperature is above a certain temperature, usually 40 to 45F.

 

[John K]

I think you need a new thermostat.

I used to drive a 1950 Opel that had a device like a venetian blind in front of the radiator that was operated by a lever under the dash. Also an old Volvo had a thing like a window blind that operated from a chain inside the car. They did speed up the heating up process, but unfortunately if(when?) you forgot about it then the car overheated. Even when the thermostat is closed there is still some flow through the radiator by way of a bypass hose. If there wasn't you wouldn't get any heat into the heater core until the thermostat opened up...

 

[XS650]

quote:

---

Originally posted by rob-the-oil-nut:
Thanks Brett. Yes; what I wonder is if the slower burn puts more heat into the coolant, even if less is used to push down on the piston.

Rob

---

If that were the case, it would show up in lower fuel economy from the reduced efficiency. I don't think it does make a difference measurable by the person filling the gas tank. We are most likely talking about differences of less than 1%.

 

[rob-the-oil-nut]

Golly! The replies are coming so fast I have to reply to 3 at once! THANKS!
Thinshavings: Will you pay the postage and the cost of a VHS tape, showing you the AC coming on at -20 when I hit the front window defogger?

LAST winter I took my camcorder to the car to show how the oil pressure guage stayed in the red zone 5, 6, even 7 seconds after starting, even with 0W30 GC. On one such instance the car *almost* started, but did not...I could TRY to get you that on tape, too. Gotta see it to believe it

John K: I THOUGHT I was over-heating in spring when the needle hit 90, but that was normal and stayed that way even after I made a special trip to have the same mechanic that put IN the cardboard, take it out. It wasn't overheating due to the cardboard; that was normal. I just never saw it that high before. I do tend to agree with you that generally if a car is under-heating, get a new thermostat, but mine was reading 90 under a month ago.
Also, you said "Even when the thermostat is closed there is still some flow through the radiator by way of a bypass hose."
....There is one exception: When it's cold to the point that your coolant jacket is the consistancy of a Slurpee

At the risk of bragging about our hideous winters, I have had the hood up and seen slushyness in the coolant recovery reservoir, wondered how on earth the rad cap sucks coolant from there. I believe it would do so when the rad is cooling off, but then again the reservoir never really gets totally liquid. Then again, neither does my glass of water as long as it has an ice cube in it

XS650: Gas mileage at -25 and colder is already so poor, you can't tell 5%, let alone 1%. But I tend to agree with you, too, since I have tried premium in winter and noticed no difference. Just looking for every possible % for those days when ya want every last degree (namely all of December and January, most of Feb, a good third or so of March...

Perhaps an electric heater that fits a block-heater sort of element within the heater core system. Expensive, and more common in heatless little 4-bangers, but I think I'll look into it.
Thanks, all!
Rob

 

[ikeepmychevytoo]

Packard had taken this seriously back in 1939. Plus their "form + function" approach through design is well beyond todays popular styling only pseudo-design.
http://www.tocmp.com/brochures/Packard/1939/1939PackardBrochure/PAGE22.html

Apart from that some new truck was offering similar automated flaps as optional equipment. I can't remember which one but it was either International, White or some other US truck.

For suspensions and the Citroën. If someone asks me the company with most radical and practial design-concious contributions to the industry my prompt answer would be the Citroën. However in the 90's, they simply sucked. Nowodays at least the higher-end models have some comfort and the drivability at the same time. In 1950 to 70's they were susp. and steering legends. A few mechanic understands their culprits which I feel resulted in some skewed troublesome image in public.

I actually saw a ~75 DX with a flat tire at least doing 60 kph and rim wasn't hitting the ground, but you could say from the sidewall that the tire was virtually airless. And it wasn't the highway but rather a bumpy tarmac. This was well advertised. This one doesn't directly relates to the sophisticated components IMO, just prime level balance.

Besides some selected Citroëns (DS, CX and new Xantia) my choice for bump, pothole and highway performance (read realworld roadabilty) is definitely the US cars. Some other French cars also give some good susp. travel but usually their steering needs continious alertness.

 

[Lumberg]

I think a factor that is being missed is the descrease in aerodynamic drag due to blosking off the radiator. I remember seeing an article in Hot Rod where putting cardboard in front of the grill got the writers like .1 second in the 1/4 mile on some old beater.

The more air you can deflect away from the car, the better. I think the idea is not so much to get the car warmer, but you do it because you can GET AWAY with a smaller opening in the grille for proper cooling, and get the benefits of less aerodynamic drag.

 

[mechtech]

Premium doesn't 'light off' as well as regular with a cold start on a real cold day. We have 'cured' a few cars with cold start problems in winter by recommending regular gas.
The BTUs per gallon of reg and prem are very close - that's not the problem with hard starting.
Some Volvos came with a crank under the dash to lower/raise a screen in front of the radiator for cold weather. I can't count the number of trucks I've sen with cardboard or such in front of the radiators.

 

[shortyb]

I don't think the octane rating has much to do with it. You need to look at the volatility numbers. Many areas blend fuel for winter with different RP (Reed Pressure) values to assist burn in colder weather as well as adjusting for emissions.

 

[doctorr]

I work in a gasoline/jet fuel refinery, in northern Canada....

In the 'old days' we just put a couple of grams of tetra-ethyl lead into the Regular, to make Super, so there would be ABSOLUTELY no difference, economy-wise or BTU content-wise, between the two.

Nowadays we have to blend higher octane components in, to get the octane # up.
Usually, these components are 'aromatics' which are high quality and expensive, we like to use them for chemicals or plastics, which bring more profit. They also burn well and have lots of BTUs, and some have 'motor octane ratings' as high as 120/130.

So, on average, todays hi-octane will have higher energy content, and will give more power.

The theory that they burn slower, is quite misleading, (the time difference may be there, but in the pico-second range) think of it as just 'more resistant to detonation'.
.
.
.
doc

 

[Matt_S]

The important factors here are 1: the heat energy released by the combustion, 2: the frequency of the combustion events and 3: the amount of time the cylinder walls are exposed to the combustion heat. 2 and 3 are only affected by the RPM of the engine at any given time. In other words, at a higher RPM, you'll have more frequent combustion events, which creates more heat, but allows less time for the byproducts of the combustion, including the heat, to remain in the cylinder, where the heat can be transferred to the engine block and coolant. Note that I've just implied that 3 is not affected by the length of time it takes for the fuel to fully ignite.

So the energy content of the fuel is the only factor, if we ignore the cooling system for the time being. I've seen conflicting information on this, but nothing I've read would indicate that the BTU output of premium gas is significantly different than that of regular. The reason you can get more power out of premium gas is that it allows for higher compression ratios and more advanced timing, not because it has more energy.

So basically I'm saying the fuel will make no difference. If the car takes too long to warm up, concentrate on the cooling system. Putting a moderate restriction in the airflow over the radiator, IMHO, would be the best way to address this.

 

[rob-the-oil-nut]

Thank you all yet again...
My reply will get very lengthy if I reply fully to all valid points; I'll try to be brief.

Lumberg: You recall that if a sheet of cardboard is put in front of the rad on a typical "beater" it reduces 1/4 mile time by a tenth? I would think the cardboard would increase the drag and DECREASE it by a tenth, or more. For highway driving I would think the cardboard would add heat by creating such an increase in drag as to make the engine work harder, and that would be a factor as well. Hmmmmm.
You also say "The more air you can deflect away from the car, the better" but in this context, perhaps you mean the more (cold) air you can deflect away from the *engine compartment* the better...???

Mechtech and Shortyb, I agree with you.
There are companies around that have 'winter gas' but I tend to think of that as mainly marketing. I like Mohawk gasohol and it would take really some posting to make me try Petro-Canada or whatever the next time it hits -35.

Doctorr, your posting is like hitting gold. Is "energy content" equal to BTU's or is there more to it than that? So is my postulation logical at least in theory?

Matt_S: Can the factor #1 be impeded with in severe cold weather? I ask because (can I get a volunteer to post a chart?) I referred back to that ancient textbook and a chart of a 60 hour gasoline engine test. It shows temps of 40, 100, 140, 160, and 180 F and correlating cyl wear, fuel consumption, and power. I recall the teacher saying the engines were packed in dry ice to maintain these temperatures for 60 hours
Wear at 40 .008"
Wear at 100 .002"
Wear at 140 .001"
Wear at 160 .0005"
Waer at 180 .0003"
I'll leave fuel consumption and HP out at this point.
Perhaps this thread should be closed, given that I am surely not interested in high RPM's to warm up the engine, at the expense of my wear numbers!

Anyway, Matt_S, your last sentence about essentially a winterfront or cardboard, makes sense and is *M*HO as well.

Cousin Cletus, I really like the name you chose! Tell us how you came upon that! ...not that your posting wasn't appreciated, I just have to call a rad shop about plans for the winter, and I'd like to do it ASAP.
THANKS
Rob