How to warm oil before first run? (Autocross)

[captain_pants]

I'm just entering my second season of autocrossing my 85 Citation FF (Kent engine). I've read is that you shouldn't load the engine until the oil temp is up to 160F or higher. How do you warm your oil sump? It takes a LOT of idling time to get the oil in the sump that warm. Of course, I'm running in temps ranging from 35F to 100F, with most days being closer to 70F.

I suspect that maybe the oil sump temp is less critical, and that the oil will quickly warm once it enters the hot engine.

What do you do to warm your oil, and how hot do you get it? Thanks in advance!

[DanW]

One way is to use an oil tank heater that wraps around your oil tank, but you need 120v AC power. Not very practical.

The best way is to use a water to oil heat exchanger. Sometimes they come up for sale here on Apexspeed.

http://www.apexspeed.com/forums/showthread.php?66710-Oil-to-Water-Heat-Exchanger-For-Sale&highlight=exchanger

[-pru-]

What do you do to warm your oil, and how hot do you get it?

Idling is the only method I have ever used. I do not have an oil temp sensor on my car so I use water temp as my guide. I wait until water temp >150 degF before making a run. I also have a Low Temp light set to 150 degF on my AiM to help monitor. I picked the 150 degF setpoint as that is when I know the thermostat is open.

On colder days (i.e. <60 degF), it does take a LONG time to reach temp. In that case, I will bump up the idle from ~900 to ~1200 rpm to help speed warm up.

Take care,

[chrisw52]

I don't have an oil temp gauge. What I did was watch the water temp and oil pressure. when the water temps go over 160 and the oil pressure (at idle) drops below 20 psi, then you are close to optimal oil temps.

After a couple of runs look at your oil pressure when the engine is fully hot. Compare how the psi changes when hot compared to when it's cold and you will see a significant difference. That's my gauge.

[captain_pants]

Cool stuff guys. Thanks for the experienced feedback.

Very good point to watch the oil pressure. I'll track that tomorrow during the warm up.

The oil tank takes 5+ times longer to come up to temp compared to the water. The water has to sit at 180F for quite a while before the oil temp gauge moves above it's 80F minimum. It just feels so wasteful, plus I'm too nervous to just abandon the car to go for a course walk like I did with a street car.

May you all have cone-free runs!

[Lynn]

Just take the steering wheel with you on the course walk.

[chrisw52]

Just take the steering wheel with you on the course walk.

and keep a spare wheel in the trunk

-- corus line --

[ahowe]

I use an oil tank heater (with a generator) to speed up the process, but idle is my primary method. The tank heater is required when it is cold, in my opinion... like ambient below 45 degrees cold. It takes forever to warm the oil up at idle when it is that cold.

Andy

[captain_pants]

Just take the steering wheel with you on the course walk.

Haha, I'm not worried about someone stealing it. Have you seen a newbie get into a Citation? I could finish my course walk before they could get the wheel on.

I'm worried about it overheating, spewing oil, etc. I have new-to-me car trust issues.

[OneWayOut]

I'm worried about it overheating, spewing oil, etc.

Wouldn't the overflow can catch all that?

Idling is the only method I have ever used.

Same for me. Idle is more than enough to get my car up to temp (water and oil).

[DanW]

Haha, I'm not worried about someone stealing it. Have you seen a newbie get into a Citation? I could finish my course walk before they could get the wheel on.

I'm worried about it overheating, spewing oil, etc. I have new-to-me car trust issues.

Mmm, I would never walk away from a running car.

[captain_pants]

You guys were completely correct. Watching the oil pressure, it dropped and stabilized long before the oil sump temp gauge even moved.

Thanks!

[CM/FFdriver]

So to confirm what Chris and Pru said because I have a oil temp gauge, get the temp's up to 180 and then watch your oil PSI.

I see after the first 180 temp heating at idle that the oil temp will see 50 degrees after my 5th run or so on a 80 degree day the oil temp will be at 80 degrees, I have never seen it go over this temp even if I get my car hot (200+).
On a super cold day in California 58 at Marina the oil temp only got to 60 after 5 runs, so other then something going wrong with your oiling system I think your good but I hope that helps.

Ben

PS. after reading others post I went and look at my gauge again and found the gauge reads 80 degrees Celsius which is 176+ degrees Fahrenheit

[captain_pants]

I found a good deal on a used oil-water heat exchanger in the classifieds, so I'll be installing that over the winter to assist both oil warm-up at autocross and oil cooling when I finally get out on a track day.

But, as stated above, the pressure drops as expected well before the oil sump temperature even registers a reading on the oil temp gauge. Completely fine with no special actions or extra stuff for autocross.

[DanW]

I found a good deal on a used oil-water heat exchanger in the classifieds, so I'll be installing that over the winter to assist both oil warm-up at autocross and oil cooling when I finally get out on a track day.

Bingo! An oil to water exchanger is the best way to warm the oil. You are giving up HP from parasitic drag with cold oil.

Dan

[S Lathrop]

When your car was built, if It came from my shop, there was an oil/water heat exchanger.

The way I set the system up was to modify the core plug at the rear of the cylinder head to have a 3/8 pipe fitting. I ran a thermostat at the front of the head but the -6 hose at the rear of the head would pass water through a Modec oil water heat exchanger. The water from the heat exchanger was then plumed into the cross over pipe between the 2 radiators.

The Modec heat exchanger fits between the oil filter and the oil filter base. This system heats the oil going into the engine if the water is hotter than the oil. It then cools the oil when the oil temperature exceeds the water temperature. In practice, the oil temperature would run about 220F and the water would run 190F.

This system worked very well and we used for all the Kent engine cars I built and ever used it on the FC Pinto engines.

[Hardingfv32]

Why would oil cooler than 160 deg be a bad think? Are they thinking that the oil would be too thick and cause excess oil pressure and blow the oil filter?

How about just using a lower viscosity oil? Same protection at a lower operating temp.

Brian

[Rick Kirchner]

That's what I was thinking Brian. As long as you have acceptable OP, why not just drop the viscosity? For that matter, without a wide operating temperature range, why not go with a straight 5W or 0W and forget about the complications of multi-vis?

[Jim Garry]

Steve,
That system was gone from the car before I bought it back in '98.

Jim

When your car was built, if It came from my shop, there was an oil/water heat exchanger.

The way I set the system up was to modify the core plug at the rear of the cylinder head to have a 3/8 pipe fitting. I ran a thermostat at the front of the head but the -6 hose at the rear of the head would pass water through a Modec oil water heat exchanger. The water from the heat exchanger was then plumed into the cross over pipe between the 2 radiators.

The Modec heat exchanger fits between the oil filter and the oil filter base. This system heats the oil going into the engine if the water is hotter than the oil. It then cools the oil when the oil temperature exceeds the water temperature. In practice, the oil temperature would run about 220F and the water would run 190F.

This system worked very well and we used for all the Kent engine cars I built and ever used it on the FC Pinto engines.

[Jim Garry]

When I ran C Mod that's what I did. I think I ran 5w-30 and never had problems. But I did always try to get the oil as warm as I could by getting water temp to at least 180 before heading out.

[captain_pants]

When I ran C Mod that's what I did. I think I ran 5w-30 and never had problems. But I did always try to get the oil as warm as I could by getting water temp to at least 180 before heading out.

After too much hand-wringing and monitoring temperatures, this is what I'm doing. Once I looked at pressures like chrisw52 suggested, I realized that it was just fine. 10-ish minutes of idling is more than enough to get everything in the 'happy' zone. With the heat exchanger, it'll probably come up even faster. And be more stable for track use.

What oil line should I put the heat exchanger in? I can't do the under-oil-filter Mocal unit as the oil pump I have points the oil filter at the starter. The added height would make it impossible to change the filter or remove the starter. Besides, the Mocal unit is no longer available.

[bassracer]

I have never heard of a symptom or failure in Solo resulting from not directly heating oil. I would not mess with making the oil system any more complex, or adding any more weight. It's just another thing to maintain and go wrong.


My practice is to warm up to near operating water temp right after rolling it off the trailer (going to tech/reg) and then getting to operating water temp prior to taking a run.

[Rick Kirchner]

Most of the time folks put it on the return to the tank, because it helps in breaking the bubble up for de-aeration, although it's somewhat less efficient. But it seems that on an autocross car if the intent is to transmit as much heat TO the oil as possible and to get that hot oil into the engine, then I'd think putting it on the pressure side would be the way to go, as long as the cooler can handle the pressure.

[S Lathrop]

What oil line should I put the heat exchanger in? I can't do the under-oil-filter Mocal unit as the oil pump I have points the oil filter at the starter. The added height would make it impossible to change the filter or remove the starter. Besides, the Mocal unit is no longer available.

My question would be, where will you get the water from?

The system I setup, I took the water from the back of the head. That water is about the hottest water in the system and is not controlled by a thermostat. The oil should come from the pressure side of the pump. I then run the oil to the oil gallery along the left side of the motor. There is a taper pipe tapped hole on the front of the block. That gallery feeds the main bearings first.

I then put the oil pressure line to the pipe plug under the right engine mount. This places the pressure sender down stream of the bearings and when you see low pressure here you have a bit of a safety margin.

A secondary advantage of taking water from the back of the head is that the rear cylinders get better cooling so the head temperatures, especially around the exhaust valves are more even.

I have built heat exchangers by taking oil coolers and enclosing them in an aluminum box. This does require some very careful welding but they worked very well.

[OneWayOut]

A secondary advantage of taking water from the back of the head is that the rear cylinders get better cooling so the head temperatures, especially around the exhaust valves are more even.

Is there a reason this isn't the standard setup? Is there a downside to moving the main coolant return and thermostat to the rear of the head?

I assume it depends on the design of the individual head, but someone must have tested this...

[S Lathrop]

Is there a reason this isn't the standard setup? Is there a downside to moving the main coolant return and thermostat to the rear of the head?

I assume it depends on the design of the individual head, but someone must have tested this...

You missed a small detail of my layout. The hose at the back of the head is only 3/8" ID, -6 size, This will not allow sufficient water flow to keep the engine cool. With this setup you run a thermostat. But is does help improve the cooling to the back cylinders. Keeping good block pressure is critical for good cooling as well so the hose at the rear needs to be small.

[OneWayOut]

The hose at the back of the head is only 3/8" ID, -6 size, This will not allow sufficient water flow to keep the engine cool.

Probably true. But you could remove the head's rear freeze plug and tap the hole. And if that still wasn't big enough, you could machine it to the size needed.