AN -12 v.s. -16 lines for an oil cooler and cooler size recommendations?

[5:04]

Hey Guys,

I have a fairly built 2.7 in my track car. The previous owner never put an oil cooler in it and last weekend at buttonwillow the car was at 235-240 degrees within 3 laps with an ambient temp of 95 degrees. I pulled off track once they got that high and just didn't drive for the rest of the weekend since I don't like the idea of driving it with oil temps that high.

I have a Mocal oil cooler with AN -12 fittings, however I've heard varying opinions on AN -12 VS. AN -16. I haven't purchased the lines yet, but i would like to have some made soon so I can and then cooler installed.

My question is are AN -12 okay, or should i buy a new cooler with AN -16 ports. And what size would you guys recommend for the oil cooler. The car is a dedicated track car that I take to occasional meets.

[DW SD]

If you are giong to do it, might as well be conservative and go -16.
Various experts suggest that -16 sizing is correct. -12 is smaller diameter in some spots than the factory lines / hose. The difference in cost isn't too great, either.

I like the black nylon covered AN hose. It is easier with which to work than the stainless braided. I think most of the companies sell that variety now.

cheers,

Doug

[tadd]

All depends on where you put the tank. All you got feeding the engine is fluid density, gravity and height. Compression in fluids, not tension. So tanks mounted in the front seem to benifit from a bigger line Im told. Doesnt make sense from a zero order physics perspective, but I can see first order boundry problems a bigger pipe would solve (bends as restrictive points, ect).

Stock type rear locations can -12 just dandy.

Just don't forget to get the anti collapse type for the engine feed hose .

Best spot I have seen is inside the cabin mounted high on the rear cage structure. Taller the oil can the better the deareation. Air in the oil leads to microfractures in the bearing surface under heavy load (8k+).

t

[KTL]

The reason I believe AN-12 is often said to be inadequate is because AN-12 is slightly smaller than the metric-sized hose/tubing that Porsche originally installed in the car. Therefore if you want to go above and beyond what Porsche originally equipped the car with, then AN-16 is what you need to use.

That said, I can confirm AN-12 peforms OK. My 3.2L race car has been using AN-12 hose EVERYWHERE on the car for many many years. It has around 220 wheel HP, uses Weber carbs, small 226mm SC fan, and a very large AN-12 DB-30618 Fluidyne center front oil cooler. On the hottest of hot days, it just tips 220F on the temp gauge.

But i'll be honest that I am switching to -16 since I have to replumb the system for a new cooler in the future. I don't necessarily find a problem with my current system in -12. Just thought as long as i'm doing it, I might as well improve on it with -16. I can tell you from recent experience of collecting plumbing supplies, -16 hose and fittings add up to be expensive VERY quickly.

I would recommend the Fluidyne cooler to anybody. It is a big sturdy cooler that fits behind the IROC style front bumper very nicely.





My next cooler that is currently on order is an Earl's 60 row Temp A Cure cooler with -16 fittings. Very similar to a large center mount Mocal HD cooler in terms of size and type of construction, made in USA and reasonably priced at around $300.
Here's a picture of the -16 60 row Earl's cooler that JeremyD installed. I'll be using the same one

[moneymanager]

Add me to those who prefer -16. -12 may be just fine, but for a very few extra dollars you can get better than stock oil flow... a pretty good idea. My 2.7 runs at Willow, Buttonwillow etc. Like you I saw 240° plus after just a few summer laps. Adding the oil cooler took me down so I rarely saw over 225°. Mindful that many people think your magnesium block will hold up better if temps are held under 220 all the time, I added a fiberglass duct from the front bumper to vent a portion of the cooler. The result: I've only seen 225° at one of more than 20 events, most in desert heat. All this in a fender mounted cooler. The next step would be a front mounted unit with full air flow thru the bumper; I haven't needed to go this far. I'm also a big fan of Earls... you can have them make the biggest cooler you can stuff into your car and the quality is first rate. An afterthought... sell the -12 cooler and replace it with a -16. You want the oil to flow.

[Tinker]

I'm kind of on the same page with Mr Money.

I would suggest buying the -16 to start with as if you swap out that 2.7 for anything bigger you're going to want the extra capacity.

I didn't follow this advise and ended up re-plumbing my car at extra costs.

Do it once and do it right.

Tinker

[HawgRyder]

The thing to remember is that the smallest hose or pipe in the system is the restricting part of the system.
The over-all flow is governed by the smallest hole.
So...you could have a system that was -16 or even larger, the cooler with great big pipes and fins, and all bends being the best design available...BUT...if you have only one part of the whole system restricting the flow...then you have shot yourself in the foot so to speak!
There are many types of connectors...some of the -16 ones are not bigger than a good -12 inside diameter.
In the race cars I have built...I used the frame as an oil carrying medium if I could...some of those tubes were 2" in diameter ( increased the capacity of the system).
And...have as much air flow as possible around the piping and tubes if you can (more cooling).
Think the system through before you start and end up with a custom design that you can be both proud of and have the best cooling available.
Bob

[Eagledriver]

My opinion is that -12 is plenty large. The opening in the on engine oil cooler is pretty small compared to -12 fittings. The lines to the front cooler only open when the oil is hot (so therefore thin). The experiment to see if it's adequate would be to put a pressure guage on the cooler or in the lines somewhere. I've never done this but I'd be willing to bet it would show less than 10psi. This is much lower than the pressure circuit. -16 will work fine as well but is a waste of money and weight.

-Andy

[winders]

Use AN-16 fittings and hose. That is the right size to use on a built 2.7L. The oil cooler should have at least as large tubing.

Scott

[5:04]

Thank you for the great info guys, one of the reasons I love this forum!

[pksystems]

I picked up some an-16 to 964 oil cooler adapter fittings for my project. There is quite a restriction going from the lines into the coolers. M22 is tiny compared to An-16.