Engine Oil Preheater

As we race in these later months, I hate to start the racecar with cold coolant and oil (especially using the rat roaster type intake. It doesn't like cold weather). I installed a Moroso 23995 350 watt pad type heater on the bottom of our dragster style oil pan and was wondering how long I should keep it plugged in? Overnight before race day too long? Also, I'd love to have some type of immersion water heater that could go into the filler neck of a radiator to preheat the water, but haven't found anything. Is there anything out there?

That's a fair amount of wattage, I'd say 1/2 hour max; we used about 400W on a dry-sump tank (Sprint Car) for 20-30 minutes usually.
For coolant, either a core-plug (aka "freeze-plug") heater or one of those cast aluminum tanks you plumb into the system that heats and circulates. They're kinda heavy, but the one on my plow truck cuts the warmup time at least by half in temps you wouldn't drag-race in.

Why not just put a couple of core plug heaters in the side of the block? I used to buy factory core plug heaters at the Dodge dealer and install them in race engines. It really helps in cold weather. Just plug them in for a bit and the block gets warm. No need to heat the oil if the block and water are warm.

Water temperature isn't near as important as oil temperature. You need that oil to flow.
You can have the water hot but the oil is still cold.

If it were me, I would get a pan heater.

Don't the pro stock boys run ice water on the block and heat the oil either in the pan or outside like in the trailer and pour it in before leaving to run ?

Cold engine, very thin oil for Pro Stock. A very bad idea for a bracket car or street car.

If the OP is worried about cold start issues he should be using a 5 winter grade oil, or even a 0 winter grade.


I had a buddy that would only run 20w50 oil. He was stuck on that because that's what he always used, and like everyone else, he had a superstitious streak as big as Texas.

So I set him up on the loose side and let him use his oil. And naturally, every spring and fall, cold starts and even starting for eliminations could send the oil pressure through the roof. Sitting for a hour on a 55-60* day will drop the oil temp pretty quick.

So he decided on off season to install an oil heater. Did all the research. I said let's run a quality 5w30 oil, tighten up the bearing clearances and forget all that crap. He wouldn't budge.

The first thing he learns is it takes a while to heat the oil. You can't just get to the track and plug in the heater and an hour later be ready to go. So he decided it was better to leave the car out of the trailer and load up the day of the race so he could leave the car in the shop and leave the heater on.

Well, that didn't work too well. By the time he loaded up and drove the hour and a half to the track, the oil temp was back down to close to ambient. Back to the drawing board.

Somehow, he came up with a way to run the heater while the car was in the trailer. Went through all kinds of gyrations to make it work. The car could be loaded the day before and he could leave it on the heater over night and on the trip to the track. IIRC, he came up with some sort of way to control the oil temp so the pan heater didn't run all the time.

That worked ok, but it was a PITA for multiple day races. He either had to run the generator real early in the morning to get the oil heated, or hook it up to the system in the trailer, and use his two rig as a generator.


Finally, he decided it want worth it. We went in and freshened up his stuff, closed up the clearances and used a top quality 5w30 oil.


Problem solved.

I would if the engine was out of the car. It starts a whole lot better in warm weather and after warmup, but cold starts (<60 degrees) can be a little challenging, especially with the volume of the 440-25 intake. I know too many people that have blown them up on cold starts.

Yeah I know all about that. I had a max wedge cross ram on my daily driver when I was a kid and I lived in north Idaho. Almost impossible to get that cross ram fired up in the morning so I could go to school!

Yeah, those 20/50 guys are funny to listen to their reasoning. LOL