Technical Warming up an engine?

I was just reading a post here, about oil and a HAMBer mentioned “ warming up” an engine before taking off. I have my opinion and a way I was taught on the ranch, by my Dad. But I was wondering what the HAMB thought on this? Anybody? What are your beliefs, pro or con?



Bones

 

This should be an interesting discussion.

My opinions, newer fuel injected stuff, no. It doesnt not benefit from more than say a 30 second warm up. Fuilds are designed thinner to flow at colder temps.

Old carbed stuff with thicker oils, yes a warm is necessary to prevent potential stalling out and get the oil flowing properly to not starve bearings.

 

What I was told by the factory engineers was start it, give it ten or twenty seconds for the oil to circulate, and drive away. Ther is no advantage to letting it sit and idle.

 

Being from the frozen north wintertime I have always warmed them up. If the was snow or ice even more so.
Aways told my kids give it enough time to atleast get up to temp before jumping in and going.
My theory has always been, if cold and not enoigh time to get up to temp, when you start driving those aluminum pistons expand at a much faster rate than the block.
Would think newer stuff runs even tighter.
Just never really saw the risk in wanting to scuff a piston on something they spent hard earned cash on.
For the little amout of time, always gave it some time if the engine was dead cold.

 

The oils we use today leaves enough...'slickum' on all friction points that dry starts are a thing-of-the-past IMHO.
Oiling systems are closed & pressurized so as soon as you hit the key all the vital rubbing points are getting lubed by residual oil and more oil coming!
Think about 30-60psig squirting through a small orifice like an oil passage!! The RPM of an engine cranking
over is pretty low with that kind of oil squirting!
Unless you live and drive in sub freezing conditions "I THINK" extended warm-ups are not needed and probably do more harm than good.
Crank-it....put on your seat belt...light up a smoke/load up a chew/whatever......put it in gear...and GO!
I DO crank up the engine and immediately put the tranny in reverse (holding the brake) while I adjust the radio and such...to get the A/T fluid moving. (my parts chaser/D/D...my "M-word" hot rod is a 5 speed!)
These are my thoughts .from my tiny-little mind!
6sally6

 

I do live in sub-freezing temps, and I warm up (ten minutes) my daily driver all winter long. But I also let the hot rod warm up a little (one minute) in the summer before stumping on the pedal. I think it lets all the parts warm to their eventual size and clearances before putting stress on them. Maybe I'm wrong but I ain't gonna change.

 

Long warmups are not needed as long as loads are kept to a minimum until the oil is flowing well. Just keep revs down and acceleration at moderate levels for a few minutes. JMHO

 

I usually give it less than a minute warm up, then drive easy 'till the temp comes up to a hundred or so before I push it.
It's not only the various metals and oil heating up but the fuel delivery and spark is set up to burn better there too.

 

I've got a 150 foot driveway so thats all my cars get. Start them and go.

 

I expect you'll find that oil is everywhere, even being splashed on cylinder walls, within 15 seconds of starting the engine.

When I go drag racing, I would like to get the oil warm enough that the pressure drops to normal running levels..but that doesn't happen all the time....

 

My opinion is, both new and old cars. Start it up, allow it to idle long enough for oil to circulate, put it in gear and ease out and onto the road, taking it easy for the first mile or 2, by then the water temp should be up into the operating range, and go ahead and drive normal. IMO sitting and letting it idle is worse for it, it's better to get it up to temp as quick as possible, and that happens when it's moving a load, not when it's sitting and idling.

 

Living in a moderate climate my garage never gets below the mid 40*: the 327 in my '51 gets a few minutes (about 5) warmup in the garage, the wife's late model gets about two minutes, but in both cases I take a longer route out of the neighborhood at slow speed to let them acclimate a bit before I join the main traffic routes. No real reason other than habit.

 

I'd say that the most important thing is to not put a high load on a cold engine. So, "start - put in gear - start moving" should be just fine, as long as you take it easy for the first couple of minutes.
If you are going racing, wait until the oil is at least half way to normal operating temperature before you really put the foot down.

 

When drag racing I am one of those firing it up at 8am. like to bring the engine up to operating temp at least 1 hour before "if possible" to heat soak whole block warm, then bring it up to temp again once or twice before leaning on it going down the 1/4.
Summer time on the 5-30 oil OT daily its like you said "gone in 15 seconds" but hamb friendly cars get warmed up, During winter time in Wisconsin if the car is outside or in a unheated garage, I warm em up a minute or so

 

On my old Chevy truck, I let it run until the oil pressure gauge tops out. After that it's in gear and gone. The T-Bird and Model A have to come out of a garage, wait for me to close the door and open a gate to get out of the yard. Then I have to get out and close the gate. That's their warm up time.

My old race car driver, Jim Moughan, always wanted to be one of the first sprint cars pushed off for hot laps. He would get up top on the race track and run around slowly while other sprinters were being pushed off. He said that he liked to get the engine, in/out box and rear end bearings fully lubed before jumping on the throttle. Don't know if it helped, but we rarely broke anything.

 

I'm just glad when mine starts!

 

My Holley 950 hp has no choke provision so I have to at the very least warm it up for 2 minutes. Even then your left foot is on the brake to keep it from stalling until the engine gets a bit of heat into it.

 

the mechanic across the street has a remote start for his wife's Suburban. I hear the horn honk and the motor starts, then she comes out a bit later and leaves. he's a pretty sharp mechanic so there must be some good reason.

me? I just start and go. my OT Volvo I bought with 160K was to close to 300 K when the head gasket blew. no smoking and no issues, I had a minor accident before that tweeked the front end, other wise I'd have rebuilt the head and kept on going.

I think changing the oil at 3,000 miles for the entire time I had it is what kept it going.

 

had a buddy with a Baja 1000 race truck with a very expensive motor. he cranked it to send oil through the block, then hit the switch to start.

 

With a choked carb, I let it warm enough that the idle will drop with a throttle blip. With a manual choke, until I can open it a bit and not stall or flood with throttle application. Juggle it open to accelerate and close to idle at a stop till it's warm. Manual trans and choke readjust with each shift to match the rpm.
With fuel injection, the idle will drop on it's own. Time dependent how cold it is, usually under a minute, then drive off.

 

It makes a difference. Why do you think we arm em up at Bonneville and all other forms of motorsports? Even so much as mounting engine oil heaters to the pan?

But, nobody mentioned it is probably more important to warm up the TRANSMISSION!! Especially an auto. Learned this one from dad. Our temps can vary from -30 to +60 day to day. On a cold day you can hear and feel an auto struggle until it is warmed up. I will start my daily and let it warm up for 10 minutes THEN before driving off will lets the tranny warm up in drive with my foot on the brake for a few seconds. You can tell the difference

 

It is the three most important things in real estate: location, location, location.

Everything I own is EFI, except one motorcycle. That one motorcycle does not care, hot or cold. It does not even have conventional chokes.

Everything I own has a manual transmission, except the A, and the wife's car, and that one is a dual-wet-clutch direct-shift manual-style box. That one car has no detectable change in shifting, hot or cold.

The A gets a warm-up that is the time it takes to back it out of the garage. After that, there is not detectable change in shifting as it warms up. The garage has never had a recorded temperature under 58-degrees since I moved into it.

We have a few stray 100+ degree days inland. Coast-side we go from 45-75 degrees, with the occasional statistical anomaly. Right now we are in our traditional "Fools Spring". It is 75-degrees outside, and may hit 80-degrees inland.

 

I expect he did everything carefully, is why you rarely broke anything. Some guys are like that....it's not really what they do, but that they think about doing it.

 

It's like that with equipment operators and truck drivers. Some guys break everything they get into, of course it's never their fault. Other guys can run the same truck or tractor for years and never break anything. Than when they take a week off for vacation the other guy get's in and breaks it.

 

I run 36 to 60 trucks at any given time. This is true

 

I strategically tuned all of my carbs to need exactly one minute of warm up before they will hold an idle, that way they get a proper warm up before setting off in the morning.

 

Transmission . . . mentioned a little means a lot. The 10 speed in my OT Ford doesn’t like to move or shift without about 2 minutes. Sometimes I forget and it tells me.
My 62 Cruise-O-Matic torque converter drains back so without a cold warmup your not moving anyway. I have one of the chokes set just to the first higher level flat. Don’t need the choke in So Cal but the higher idle for a minute or 2 is good on everything.
I’m guessing the bypass in the oil filter is open anyway.

 

F1 cars cycle hot oil thru engines and drivetrains 30 minutes or so before they start 'em. And I'm guessing they know something about close tolerances. In my case, if it's really cold it idles till the windows are defosted. I hate getting in a frozen car. The rest of the time I vary accordingly.

 

I start the engine and drive away wihin 15 seconds.. But never subject the engine to heavy throttle until the oil is warmed up some.

 

Gimpy mentioned location as a variable.

I would suggest the HP/CID ratio is also a variable.

Personally, I have different warm-up criteria for different of my vehicles.

Jon