Is it practical for a street car with a 3 liter to run without an aux oil cooler? The motor has its own cooler, will not be a track car (other than for an occasional AX) and will never see temps about 95* since it lives in the NW. It shall be driven hard on back road outings. What say you?

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No problem. I've worked on one like that, it's been just fine on the street for 12 years.

I don't know, here in the SF Bay Area, specifically, the San Ramon Valley, my last six had a 3.0 and I had to add an external front oil cooler to keep it cool in the summer.

My present six has a 3.0 and the former owner had to add an external oil cooler to keep it cool too. Neither of these were tracked or raced but did see some spirited driving.....so I have to vote for an external cooler to be safe.

Individual results may vary...

Try it. keep an eye on the temp. if it starts getting hot, add a cooler.

Nice looking engine!

If not using HE's....block off the fan outlets for the HE's....will push more air over the cylinders/cooler.....

I agree with jt914-6. I ran my 3.0 on the street with no problems. Track is a different story. I installed a front cooler for that.
Van914

I run a 3.2 on the street and have an aux cooler, but according to my temps it rarely cuts over to the aux cooler. Mine is tucked up in the right rear fender area.

If I ever get back into track events, I'll end up moving it forward for better airflow, but for now it's been fine. But what I have found through different 6's and 4's over the past 15 years, each engine has its own personality. This 3.2 is by far the coolest running engine I've ever had. I do run block off plates as jt suggested.

Dion

In my shop, I insist on external coolers for 2.7 and larger.

I've never seen one that didn't use the aux cooler once it was warmed up.

Just my $.02.

Just a quick update while I'm thinking about it.....drove my car for 30 minutes at 75 mph on the highway in temps of the mid-80's, high humidity. The temp got to 210 and stuck there like glue.

Dion

This is interesting as Tomeric's recent 3.0 914-6 conversion sees 240 deg with an external cooler (next to transmission) and without the fan on, which is too hot for oil. With the fan on, it doesn't go past 220deg.

I wonder what the difference is between your 3.0 motor and his?

My 3.6 has never gotten over 210 deg. ... Front mounted cooler only, no engine cooler ...

Why would anyone put an oil cooler next to all the heat sources in the car? 220's too hot, and 240 is WAY too hot. Just because you call it an oil cooler doesn't mean it is.

The Cap'n

It's too easy to compare engines as if they are the same. there are too many variables- age, condition, compression, mileage, timing, etc. that could impact temps. Even the oil makes a big difference.

That engine is too pretty to fry. Just do it....

It depends where you drive too. In California, you will not do 75mph all the time and the temps here go over 100 in the summer. So if it's 110 outside and you are going 5mph on the freeway, you will need extra cooling.

Really!?!

No external on a 3.0 mid engine car?

The $1k spent on a external cooler (setup right BTW) is CHEAP insurance for such a pretty engine.

You're right, running 20+ feet worth of oil line to the front and introducing more air under the car makes more sense.

How hot do you think it gets under the rear trunk area? At speed, I think you'd be surprised.

To the OP, it's cheap insurance to install an external cooler.

Hot enough to fog (ruin) film inside the trunk in an hour and a half, at speed on the freeway. In the camera, in an insulated bag. BTDT.

The Cap'n

I'd never run anything that size without a front cooler.

You could mount a RX7 cooler in the engine lid, I have a thread with a pic from Henry Schmit (Supertec) a respected /6 builder.
If your not drivings in temp above 80F you should be OK with a like setup.

You can run it without, but oil not only cools, it lubricates, so if you hit the upper temps your oil will not be as effective a lubricant. It really depends on how and where you drive, but whay have a car that's limited to less than 100 (just picking a number) degree days?

Yes, it's an added expense, but if you were to buy a car /engine, would you spend more for one with (or that had been run) the external cooler?

I agree, inside the trunk will get hot because there is no airflow. Underside behind the engine at speed or with the cooler fan on is a different story.

Put a cooler in! The 3.0's were meant to run with external oil coolers (trombone style in front passenger wheel well). The 914 engine location doesn't cool as well as the same engine placed in a 911. I have a cooler on my carbed 3.0 and wouldn't run the car without it, I don't want to worry when I'm passing someone at 85 going up the Grapevine, I like to drive my car, not worry about it. Why have a 3.0 in your car if you don't drive it like you have a 3.0 in your car. Just my opinion.

Dan

It is the cumulative effect of running an engine hot and allowing it to cool back down that will kill it. Even 20 degrees is significant. The higher the upper limit the less engine life the engine will have, especially 3.0's. A $500 oil cooler is a lot better than a $7000 engine.

A difference, yes, but not that much, IMO.

The Cap'n.

So what about blocking off the stock oil cooler location with a 964 oil console and just running a big oil cooler in the front of the car?

My carbed 3.0 runs at 180 with a front oil cooler on the street On the track it can get up to 220 by the end of a session, if it creeps much higher than that I'll pull it off... Tuning will also effect the temp, a lean car will run hotter...

My 3.2 with no auxiliary oil cooler, so far, has not gone past 185 degrees on extended spirited freeway and back roads driving.

That's because you live in Wisconsin. It doesn't get much above freezing up there, right?

It's the unplanned hour long trafic jam in 95 degree weather with no place to pull off that I would be worried about. Happens all the time on the east coast.

Question about a front cooler, could you route the cooler to exhaust into the wheel wells...or would that make no sense at all?

I'm thinking to think what to do with my 2nd cooler ideas to still have some good storage space up front with a spare tire.

Just a thought....is there room to put a cooler in the passenger rear fender well (just opposite of where the oil tank is) and put a vent in the rear quarter like the boxsters have or even from a boxster?

Not really. The cooler would need to be no more than 3" wide and 10" tall. Even that's probably too big.

This is where mine is. Works fine.

Don't be a tease, show us some pics! Which cooler are you running?

I would, but my wonderful iPad won't let me post a pic to the thread. It's a smaller cooler than would go up front, but I think it's fine for my street driving. If I remember correctly, it's a Setrab 12 row cooler.

I got the idea from Perry Kiel a long time ago. If I ever track it, the cooler will go up front. I'll post pics tomorrow from my PC.

As promised..... Keep in mind, I have removable flares so access to this cooler is a bit easier than on a narrow body car. I have often thought about how to get more air circulation up under there without cutting a Boxster-like vent hole in the side. Maybe build a shallow scoop under the car with vent holes out of the top above the battery.

But until I see temps getting critical, or the cooler no longer being effective, I'm not going to change it. If it aint broke......