shepski

ok, i was wondering as i stood in the sun.

if i left my black SA sitting in the sun on a day where the temps are around 35-40deg C would the temperature be adequate inside the engine bay to skip a warmup period, assuming the engine bay temps were around ~65 deg C.

MosesX605

I don't see the need to warm up the car before driving unless the temps are in the low single digits or lower. Just go easy on the throttle until the temps come up and keep it below 3500.

Nice SA, BTW.

shepski

hehe ta mate, hotwire 13" rims replacing those steelies soon.

JKM

I do the opposite...

Even if it's hot as hell outside, the engine still isn't going to be near operating temperature. Sure, it will take less time to be fully warmed up, but it's still relatively cold.

Of course, I'm not so **** as to say that you shouldn't DRIVE the car before it's warmed up, just do as Moses said and keep the RPMS down until fully warm.

blwfly

iTrader: (4)

takes me 15min before my carsnearly warms up
allways turns off at a traffic light lol

shepski

the magic of the auto-choke, means i can drive it like an auto, ease the clutch out and it starts moving coz its sitting at 2000 rpm.

blwfly

iTrader: (4)

hmm my choke goes to 3-4000 rpm

and i use a 1/4ter to old the choke out lol

H4Inf

i would still warm the car up - well not sit there revving it. the engine would already have some heat in it - tha radiator would have warm water in it and circulate around the engine.

Other things you want to warm up though are:
- gearbox
- diff

5-15 mins of driving will have those warmer and less likely to break.

Before I am going to thrash the car to buggery I go through this warmup process (if its a cold morning).
- Start car and hold revs around 2000 for 5 mins
- Next 5 mins take it pretty easy up to ~3k
- Next 5 mins up to ~5k but generally cruising around 2-3k
- Just normal driving for say another 10 mins
- Let her rip Slowly bring up revs to say 5k and cruise, then foot to the floor! bam >

Normally after say letting the car sit for ~30 mins on a cold day.. or out in the sun on 30-40 degree day, I wouldnt let it sit revving for more than 2 mins - just get driving right away pretty much - still not absolutely thrashing it for maybe 5 -10 mins because there are a lot of parts that need to warm up

Nicholas P.

iTrader: (1)

when your engine warms up

a rotary warms up from bottom to top.

means your seals are weak at that point.

you go running it hard when cold. your just screaming "i need a rebuild"

MosesX605

Pardon?

Running the engine hard when not fully warmed up will potentially warp the housings since they're different metals and expand at different rates, but I've never heard of the bottom-up warming. If anything the engine should warm from the drivers side first, since that's the hotspot where all the combustion takes place.

H4Inf

i dont think you read it the way he intended you to.

fuel+air is injected at the top, ignited on the side, burns on its way to the bottom. the most heat is generated in the stroke from side to bottom and then passed out thru the exhaust.

as the engine is warming up the thermostat is closed, so water is being pumped all around the housings and recirculated, the hottest area being at the bottom. as this water circulates it is spread to higher areas of the engine, only once the temp has increased enough will the coolant start flowing thru the radiator and will then the engine will have to heat up that water as well. Once all this water has an average temperature around 80 degrees C then we wait for heatsoak into all the various parts of the engine. this also occurs through oil circulation.

i would say if you look at the rotary from the front, the hottest section would be in the lower right to base and lower left areas