gnomesliv

Greetings all

This site is full of excellent information. I've learned more here in a few hours than I have in few years working on piston engines. I'm trying to do as much research as I can b/f my car arives.

This is my first rotary. My experience has been with piston engines all my life. As such, I've always been told that if you warm a car up...never just let it idle. When warming an engine up (w/out) giving it gas, move it around the parking lot (or where ever you are) until it reaches normal operating temperature. Supposedly, this inhibits carbon build up, and keeps the engine running cleaner. Is this the case for Rotary engines also?

Now, w/my RX-7...I know warm up is important if I want to prevent flooding the engine....but what I'd like to know is if anyone has any experience w/letting these engines idle and carbon build up.

If these engines also has issues with carbon build up..then if you release the clutch and let the engine carry the car around at low speeds (until warmup)....you risk stalling right? If it stalls and is not warmed up..then your dealing w/deflooding protocol.

Any ideas or advise. Thanks in advance.

13b_cookie_monster

iTrader: (14)

Like they say, a redline a day keeps a rebuild away. If you redline your car atleast once during use it should help with carbon build up but do this when the engine has warmed. I've never heard of a car building up carbon just by idling but I may be wrong.

And if your injectors are leaking it is good to warm up the car before shutting it right off to keep it from flooding. As for me, if I have to move the car, I move it and shut it off after 20 seconds. I dont have flooding issues but if ever the case I have a kill switch to deflood the car.

gnomesliv

thanks for the info...i didn't think about that.........

I think the first thing I'm going to do is put a switch inline for the fuel pump mod....so that if it ever happens I will be prepared.

misterstyx69

iTrader: (142)

Dude..unless your car is Flooding,why mess with it?..seriously,Half the Why doesn't My Car work right Threads are because People read **** on here and automatically Do it..Suggestion:keep it simple..IF the car goes "wonky" then look into it..why Fart around with 20 year old wiring,you are just asking for troubles...It may be a rotary but it's not a Baby it,or else type of vehicle..Drive it,check the fluids Often.maintain the Darn thing ,and it will treat you right..It's not a STUNT car though so,you know,keep the Crap within limits!..take care and Happy Driving!

Aaron Cake

iTrader: (1)

There's absolutely no reason to "warm a car up". Just get in the car, start it, put on your seatbelt, then drive off. "Warm ups" just waste fuel and time.

It's true that 2nd gens that are out of tune will tend to flood if short started. If the car is in good shape, then this is not an issue.

I'm not even sure what this means...

gnomesliv

Well, I know for a fact that piston engines need to be warmed up. The piston slightly changes shape (slight ellipse) during the warm up process and if you drive off cold you are slowly tearing up the jugs...then next thing you know...oil is getting past the rings.

I don't know how rotaries work...but I'm sure you shouldn't just punch it with any engine cold.....

gnomesliv

I just want to be perpared..if and when it happens so that I'm not on the interstate trying to pull out spark plugs ...spilling ATF everywhere...while semis blow by at 90mph.

Jpk3200

What Aaron is trying to say is that starting it and just sitting there waiting for the temp gauge to rise is a waste of gas/money/time. Starting it up and driving conservatively (i.e. try to keep it under 3000 RPM) until it reaches full operating temperature is a better idea. Engines (both piston and rotary) are engineered to be able to get started, and then drive off immediately. Remember, be conservative for the first few miles before you get on it hard.

Yep. Just don't punch it.

Aaron Cake

iTrader: (1)

One day I will find who started all these myths and slit their throats.

Whens the last time you've seen an owners manual for any car made in the last 40 years that says "You must let this car idle until it reaches full operating temperature before you drive it."?

Yes, all engines are designed with tolerances in mind and these tolerances don't get to their "sweet spot" until the engine has reached normal operating temperature. Yet all engines in normal vehicles are also designed to be used immediately after starting.

True. You should not drive hard on any cold engine, rotary or piston. Simply drive the vehicle with some restraint until it's at operating temperature.

MmSadda

iTrader: (2)

When my engine was rebuilt, Ken Carswell of Rotary Connection in Columbus, OH told me that I should give my car a 20-30 second warmup. Coincidentally, this is how long it takes me to choose a new CD to put in after starting up my car. I know Aaron will disagree with me and Ken on this, but I am inclined to listen to the man who rebuilt my engine.

MmSadda

iTrader: (2)

Isn't it better, though, to give an engine a small amount of time (20 seconds) before making the engine do any work, then keep it under 3.5k until you have reached normal operating temperature, at which point it is okay to work up to WOT and redline?

Acesanugal

iTrader: (5)

The time it takes you to put on your seatbelt and turn on the stereo and/or change station or CD is sufficient to fully build any oil pressure needed. If you're really that paranoid, you could always let your AWS do it's job before you drive off...but I dislike that system. And I'm sure Aaroncake does too.

Aaron Cake

iTrader: (1)

Oil pressure is made instantly after the engine starts. It is not necessary to "wait" for it to "build".

There is no reason to wait 20-30 seconds either.

People can do whatever they want with their cars, but the truth is that a warmup is not needed and any time spent waiting for such a thing is just a waste of time/fuel.

gnomesliv

I know when I get out of bed in the morning....I need to stretch a lil...yawn, maybe go sit my a*s on the crapper...take a shower...eat...brush my teeth......Then I feel like..my brain and body are ready to operate at their best.

If I am awakened...and forced to jump out the bed...run 3 miles w/out a warm up.....don't know how long my body would put up w/that.

Car is not in anyway a human...but I treat all my vehicles like I treat my own body.....maybe that's over kill, but I want my engines to go the distance, so I take care of them...hoping they will take care of me and not leave my *** stranded on the side of the road.....

13b_cookie_monster

iTrader: (14)

Honestly its always going to be opinion. When I take the car out and its cold I let it warm for atleast a minute to two... and I drive it under 3000 until it gets to normal temp.
-but also for the comment about the kill switch for the fuel pump, whats wrong with doing that now, it can also be used as a theft deterrent. It doesn't take a genius to wire that up either.

Aaron Cake

iTrader: (1)

Without risking beating a dead horse or arguing for arguments sake, it's not about opinion.

This is how cars are designed to operate in the factory. Engines are designed with clearances to run both hot and cold. Fuel injection systems are designed to compensate for cold starts. Thermostats are there to allow the engine to reach operating temperature and maintain that temperature quickly.

If you want to talk about "being nice to your engine", the you need to realise that a long drawn out warmup period is worse then simply driving the car. The vehicle will reach operating temperature far quicker if you just get in it and drive then let it idle for a few minutes.

gnomesliv

ar

I agree w/this...idle is from what I understand not good...but from the original question....is it better to let the high idle (w/out giving it gas) carry the car in gear for a couple hundred yards or so than it would be to just let it idle to warm or gas it (force it quicker) to warm. Carbon build up is an issue w/most engines....so I'm wondering if w/these engines what form of warm up contributes the least to carbon build up. Has anyone ever warmed their engine up by letting the idle carry it around in gear w/success? Or does it generally stall on most of these engines?

Aaron Cake

iTrader: (1)

I'm sorry, but it sounds like you want to put the car in gear at idle and drive it around? I'm really not sure what you are referring to. Are you referring to the 3K startup or the 1500 RPM fast idle?

This is getting very strange and complicated, and it does not have to be. Start the car, put on your seatbelt, and drive it. Just don't beat on it until it reaches operating temperature.

Carbon buildup is going to happen no matter what you do. Warming it up will have no effect on buildup. If you drive the car easily all the time and don't beat on the engine it will tend to build up more carbon then if you redlined it once and a while. If you make short trips, then you will also see more carbon buildup. If the car is in poor tune, you will get more carbon buildup.

Now, should you care about carbon buildup? No.

gnomesliv

Ok..you know how you get in the car...start it cold...the engine revs to 3k.....you can either (let it continue to idle), (press the clutch in ..put the car in gear..release the clutch slowly w/out giving it gas and the car will start to pull away and will continue to move w/out you putting touching the gas pedal)...(or just start it up cold..and drive it normally)....all three will warm the car up eventually. Aaron Cake...Your saying none of these methods has any effect on the engine as it relates to carbon build up.....therefore it really doesn't matter..

gnomesliv

excerpt

"Both engine oil and gasoline are hydrocarbons, so burning either of them incorrectly can result in a buildup of excess carbon deposits. These deposits are often caused by excessive oil burning in the combustion chamber, which is a sign that your engine needs a rebuild regardless. In addition, a rich mixture setting can also introduce more of the black soot that creates the carbon buildups in the engine. Short-trip driving and extended idling (not ideal running conditions for an engine) can also increase the buildup rate. "

Derek King

iTrader: (2)

you must enjoy the car and driving, dont make it a hassle or you will just get pissed over time

1s2sp

in order to enjoy a car you've gotta take care of it. Maybe thats why my 93 runs like ****. I start it up an go everytime. Does this carbon thing hold any water?

micah

How the hell. Pistons don't touch anything genius.. the rings do.

But, I don't know that FOR A FACT.

Jpk3200

Start it in gear to avoid the accelerated warm up process and go.

Aaron Cake

iTrader: (1)

The 3K startup is supposed to last for 17 seconds or so (I think, I could be a bit wrong on the time) when the engine is started dead cold. It's designed to light off the precat quickly to keep emissions under control. If you just tap the gas or start the car in gear, the 3K startup is cancelled.

In the case of the 3K startup, driving off with it could be weird. I've never actually done that as the moment the car is put into gear it should cancel. That said you won't hurt anything if you happen to drive off under the accelerated startup.

Regardless, none of this has any effect on carbon buildup which is primarily a function of the kind of fuel you use and how you drive.

Don't worry about carbon buildup.