Stock oil cooler, Inlet/Outlet Options

[Chad911sc]

Which hole is the inlet for the stock oil cooler and which is the outlet. It flows up from the oil pump to one of the holes and into the stock oil cooler and then back into the engine. I need to know which one is which because my flow for my external oil cooler/fan combo is directionally dependent going through my oil thermostat. I was told it was outlet at the top and inlet on the bottom by the sales rep, but after looking closely at my case, it looks like the outlet is at the bottom.
I think the blue path is the outlet to the stock oil cooler, and the red path is the inlet back into the engine…is this correct??

[DennisV]

Which hole is the inlet for the stock oil cooler and which is the outlet.

I don't have access to my workshop manual, but I recall there was an oil circuit diagram in there. At least there is for the 914-6.

[GregAmy]

Just use one of these:

https://tangerineracing.com/shop/ols/produc...-oil-cooler-kit

[Chad911sc]

I already have the full system built, just want to make sure I do not need to reroute the hoses before first start

[BillC]

Maybe you could get an air nozzle and try blowing into each hole, and see which one comes out the hole for the oil pressure relief valve -- pretty sure that would be the cooler inlet hole (if I remember the diagram correctly).

[Chad911sc]

The engine is totally built and in the car with all the external oil system already built. I just want to make sure the oil is flowing in the correct direction before starting it.

[Superhawk996]

I’m on the road and don’t have access to a case.

Your lines are drawn wrong. The oil flow is not direct from the pump to the cooler as you’ve drawn it.

They flow from the oil pump to the oil filter console 1st - refer to the oiling diagram I posted in the other thread. This is why you had the issue with failure to prime.

After the oil departs the filter it flows to the galley shared by the oil cooler inlet, the oil pressure sensor hole, and the oil pressure relief piston. I believe this is the top hole you’ve marked in red. Apologize - on vacation and don’t have a case to 100% verify but I’m 99 % certain going from memory and the photo you posted + the one I’m posting below.




After the OE oil cooler the oil flow to the main galley

Here is the main galley in green


I should probably keep quiet but here goes. (IMG:style_emoticons/default/stirthepot.gif)

The aftermarket oil cooler as you have designed it is likely less effective than the OEM cooler. Why? Because your cooler design will be drawing hot air that’s under the trunk across the cooler rather than cool ambient air that the OEM cooler gets directly from the fan housing. The cool airflow volume provided by the OEM centrifugal fan will be much greater than what you can get from that blade fan. This under trunk air is hot and preheated by the engine and the exhaust. Especially when the car is not moving. Not very effective.

Usually these under trunk aux coolers are in addition to the OEM cooler not instead of the OEM cooler.

I don’t have engineering calculations at hand to prove this with certainty but I’d wager that if we put pencil to paper - the OEM cooler is more efficient.

I know you probably don’t want to hear that but it’s something you should consider that I suspect you’ve overlooked in the move toward aftermarket parts and the marketing claims they often make.

[Chad911sc]

Thanks for all your input, it is much appreciated. Your diagram is correct as I pulled off the hoses and the upper hole is the output from the oil pump path and the lower hole is the return back into the case.
You could be correct on your theory of the aftermarket external cooler compared to the factory cooler. I was just trying to fight the Florida heat ahead of time knowing how brutally hot and humid it is down here. I planned on placing a fresh air intake on the side of the passenger lower valance with a 3 inch hose to bring a cool supply of air into the cooler. Sometimes when you try to improve on a design, it ends up not working, but I’m hoping for the best.
Thanks again for all your time and input, it has been much appreciated.

[Superhawk996]

One more caveat: you need to block off the OE oil cooler air flow path since you’re not using the OE cooler.

Failure to block that OE oil cooler airflow path will divert a lot of air from cylinders 3/4 due to the large gaping hole and the airflow tendency to follow path of least resistance. It will also reduce airflow to cylinder 1/2 but to a lesser degree.

[Chad911sc]

I did do that when installing the fan housing. I pushed the flap down and screwed it to the tin so the airflow would be onto the cylinders and not down an empty hole.

[mate914]

Blow through it.
Matt

Which hole is the inlet for the stock oil cooler and which is the outlet. It flows up from the oil pump to one of the holes and into the stock oil cooler and then back into the engine. I need to know which one is which because my flow for my external oil cooler/fan combo is directionally dependent going through my oil thermostat. I was told it was outlet at the top and inlet on the bottom by the sales rep, but after looking closely at my case, it looks like the outlet is at the bottom.
I think the blue path is the outlet to the stock oil cooler, and the red path is the inlet back into the engine…is this correct??

[Superhawk996]

I did do that when installing the fan housing. I pushed the flap down and screwed it to the tin so the airflow would be onto the cylinders and not down an empty hole.

(IMG:style_emoticons/default/aktion035.gif) but you didn’t really block it.

Would be ideal to block it. Not sure exactly how yours looks with the cooler adapter but the flap actually diverts air below the flap.

Without the air resistance of the OE cooler there you still have a hole without the usual airflow resistance. Without that cooler airflow resistance more air will flow through that low resistance open hole below the flap and divert air from cylinder 3/4.

See graphic


I fully understand your desire for more cooling but between your under trunk cooler and the lack of a OE cooler + an unblocked hole Under the flap, you’re diminishing your cooling.

Take a close look up under there.

[Chad911sc]

Didn’t realize that…I’ll have to make some more modifications I guess.

[Superhawk996]

Didn’t realize that…I’ll have to make some more modifications I guess.

Good man! (IMG:style_emoticons/default/smilie_pokal.gif)

There is more to air cooling and these engines than appears to the eye.

I’m going to throw one more at you.

The vast majority of engine wear occurs to rings as the engine warms up. I’ll be happy to point you to many SAE papers in this topic if you care.

So by disabling the flaps and the thermostat you’re going to extend the warm up time of your engine. This is true even in Florida heat.

The air coooling on these engines is a well engineered system. When you start modifying it - you’re on your own to understand the implications so to speak.

On a hobby engine that maybe only gets driven on weekends - maybe the excess ring wear is acceptable. Not my place to decide but you should be aware of the trade-off being made.

(IMG:style_emoticons/default/beerchug.gif)

[Chad911sc]

Yeah the thermostat was missing from the system when I bought the car and the flaps were not functional. I should have done a bit more research on the factory system before jumping to this one. And as you know I fubared this one as well. Only learn by trying and making mistakes. I have a bunch of other cars, so it won’t see more than a thousand or so miles a year. I also have the cylinder head temp sensor in cylinder #3 so I can keep a good eye on those temps. What should I be looking for as far as acceptable temperatures on the cylinder heads?

[Superhawk996]

Head temp thread

http://www.914world.com/specs/JakeRabyHeadTemps.php

[Chad911sc]

The things I do for my car….nothing like some fresh 3rd degree burns in the armpit..lol.
But it’s done and hopefully my system will keep her Cool. Blocked off that factory oil cooler spot with a few tack welds and a smear of black RTV.
Going to be starting her for the first time this evening….fingers crossed!

[Superhawk996]

(IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/first.gif) Way better

[Chad911sc]

Thanks again for your guidance… My friend Scott is coming over in a couple hours and we’re gonna fire her up!