Oil coolers in parallel question

Curtis

Curtis

Well-known member
Would like to mount two oil coolers in parallel, not in series. Have done this before with identical coolers.

Question: if I mount in parallel one cooler (2x) much larger than the second will I get some flow through both of them? Or just through the smaller one offering less resistance? These are Sertrab type with -10 in and out.

Packaging space prevents me from mounting 2 big ones in good air, and I would like to have more cooling than two identical small coolers would provide.

Anybody done this? Been to engineering school and have an opinion?

Thanks,
 
You will get some flow through both of them. The flow will favor the least restrictive cooler. The flow rate through both coolers will balance out so that both coolers will have the same pressure drop.

Clear as mud?
 
Yes, thank you Thick mud LOL. Any opinions on just going in series. I have enough oil pump to handle any pressure drop. Just thinking the temperature difference between the hotter oil and air would be greater and cool more. Have been told a second cooler in series doesn't do much?
 
If the oil is still hot coming out of the first cooler, then the second one will help. If the oil coming out of the first cooler is "close to ambient", then you're not going to get any benefit from running it in series. Of course at that point, the second cooler isn't necessary anyway.
maybe a bit of oil temp data collection would be good to play with. of course if you can just hook up two in parallel, even if different sizes, then it'll help some.
 
Splitting the oil feed line, near the oil pump with help equalize the flow, I think. Placing a T right close the coolers will have the most inbalance. Maybe.
 
Any opinions on just going in series
Click to expand...
Going in series will offer the highest heat transfer because of the higher velocity of the oil (reduced boundary layer, higher Reynolds number). Think of a two pass cooler... that's essentially what you are doing. However, the dark side is that the oil flow pressure drop will be about 6 times greater (assuming coolers of the same size).
 
I ran two in series this past weekend at NJMP - ambient temp at race time was about 102, no idea what the track temp was. Oil ran a nice and controlled 240 (MG Midget HP LP). Main 16 row cooler in front of the water radiator, auxiliary behind right side headlight -
 
I have run two oil coolers in series for many years. One is to the right of the radiator and the other is behind the head light opening. When it is hot, I use an open head light cover with a screen mesh and when it is cooler, I use a head light cover that is solid to prevent air flow through the head light oil cooler. This system has worked well for me in temperature extremes from around 40 to over 100 degrees F.
 
You must log in or register to reply here.
Back
Top