Oil Cooler goodness

[johnboy914]

I just finished my front oil cooler install. Wow, what an amazing difference. Normally on a day like today, 85+ degrees, the drive that I just did would result in an oil temp of just over 250+. That, is bad. But today, I had to drop it into 4th, nearly redline it on a 3 mile long steep hill, get it to about 95 mph just to get it to 210.

Was it cheap? No. All said and done it was about $550.

Is that cheaper than a new motor? You betcha.

So, to those pondering installing an oil cooler, I highly recommend it. After reading some on the subject, I wasn't really expecting that great of an improvement. I am convinced that the key to the success was to put the cooler in the front of the car, where it can get the fresh air. I figured that is where Porsche put them in their racing 914s, so that is where mine should be.

[Jim Smolka]

Congrats on the project,
Yes 250 degrees F is very bad.
Not sure why you temps were so high initially. What motor, mods, etc?

[johnboy914]

The motor is a 2.0 euro P&Cs, with a flycut job on the heads to boost the CR to 9.2 to 1. So, it was destined to run hot, but no more.

These are amazingly fun cars.

Oh and kudos to PP for getting me my new MOMO wheel and adapter so quickly. My car now feels like a go kart, a COOOOL running go kart.

[Zeke]

jonboy, can you post details about your cooler? Which cooler, what lines, which adaptor and location.

This would all be most helpfull for those of us that haven't gotten to that point yet.

[Rleog]

Johnboy - I'd also be interested in the details of your project. What type and size of cooler, size connections, difficulty fitting and plumbing the system. J.P. Stein posted some pictures of his installation awhile back. It would be helpful to hear or see how you did yours. Thanks, Bob G.

[confused]

I am installing a 3.0 in my 914 soon. I know I will need a oil cooler $550 isn't such a bad price, did that include thermostat and oil lines? What oil cooler did you use and where exactly did you put it? Did you cut up the front of the car.

[johnboy914]

Ok -

I did cut up the front of my car, but I really didn't have to. You can mount the front spoiler, or belly pan with a gap between that and the bumper and punch out the plastic covering the holes. That will get air flow, but not as much as a big hole in the front of your car.

I used a Earl's Oil Cooler. 14x 61/2 with -8 fittings. It mounts very nicely right behind the hood latch mechanism on 72 and earlier cars without the spare tire cutout. I used 90 degree elbows here because with the oil lines running straight up from the cooler, they came too close for comfort to the hood when closed. I chose to run -6 oil line for the increase in oil pressure over the -8 lines. So, I had to use -8 to -6 adapter fittings. To get the oil out of the motor, I used a Mocal sandwich adapter with a built in thermostat. This had -8 outs to so I had to use adapters there too and used 90 degree elbow as well. I ran one line through the firewall and one line behind the rocker panel. Both come out in the fender well and are routed up into the front trunk. It is also important to use the short oil filter. Bosch 3122, I believe. The stock filter will hit the engine mounting bar. It took 26 feet of oil line. My single biggest piece of advice is to tighten all of your fittings until your face is red and your hands hurt. I spent two days chasing drips.

I will try to post some pics in the next few.

[John Rogers]

I have a front mounted cooler on my race car and I learned several things: The largest Earl's cooler I could fit in the space below the hood latch works best. I made the ducting from sheet aluminum which was easily cut and bent by hand. I used dash 10 lines and fittings. I used Earl's braded hose (expensive!!) and let the Earl's tech cut the hose and put on the ends which eliminated a possible source for leaks. I flushed the hoses and pluged the ends before routing and I was surprised at the dirt that came out. I also flushed the cooler and all fittings after I did the hoses. I ran the hoses through the right side box area to keep the hot oil lines away from me. I bought some cheap water hose and used it to make patterns for how long the braded hose should be and even though I added a couple of extra inches, they ended up being just about right! I used racers screen over the front opening to protect the cooler during my off-road trips at places like Las Vegas or Willows where it is very rocky/dirty. Good luck.

[J P Stein]

My recomendations for those considering doing an external cooler
on a 6 clyinder installation:

12 AN hose, minimum.
Troutman thermostat.

Putting it in the nose is a PITA, but it is the most effective.

[maf 914]

John and Johnboy,

Is the front trunk location you describe (up against the front trunk wall) lower than the engine sump oil level? I guess I could wait and check for myself after I get home, but I was wondering if the oil in the cooler and oil lines stays where it is or if it drains back into the engine, giving high oil levels while at rest.

Thanks,
Mike

[John Rogers]

If you check the article on the PP site here on how I race my 914 in the 914 tech section, figures 24 and 27 show the ducting. The cooler is actually slanted at about a 30 degree angle since it is too tall to stand upright. The opening in the front has a 1/8 inch steel combing welded around the opening and the exhaust is out the bottom. My car has a 4 cylinder so we felt the dash 10 size is okay and oil temps don't get above 210 during a 30 minute race in 90 + weather. This is a pretty good project for home work but can be done if you are a competent mechanic and have the necessary tools and can get some help as needed. Good luck.

[Zeke]

john rogers, you don't have PM's enabled, so I'll ask here: When and where are you racing next? I'd like to see your car. Every time I go to POC events, there are hardly any 4 cyl 914's. I will be at HSR in two weeks (Fontana) in case you run there.

[Jim Smolka]

I agree with the above post.

For 4 cyl cars, Dash 10 AN (5/8") hoses and fittings are OK.

For 6 Cyl cars Dash 12 AN (3/4") hoses and fittings are the MIN. except the scavage Line, then either OEM or Dash 16 AN (1") hose and fittings. (Ref: BA's book)

Some folks who race 6 Cyl 914s, recommend using Dash 16 hoses throughout the cooling system.

Also for 6 cyl cars, the Mocal Thermostat has AN 12 and AN 16 fittings. Same with the coolers

[Rleog]

Have any of you found it necessary to run a check valve in the line from sandwich adapter to oil cooler?

And, J.P., any advantages with the Troutman thermostat?

Bob G.

[J P Stein]

Any theremostat is better than none.

On a 911 motor, the scavange side of the oil pump has no pressure controls. Hitting the oil cooler with cold oil pressure can blow it.....ask me how I know. It prolly took somewhere around 150 psi to do that.
Dunno if the t-4 oil pump can deliver that kind of flow/pressure, but I doubt it. Mr. Rogers would have that answer.

The Troutman thermo has a pressure relief that by passes the cooler *should* anything obstruct the flow, regardless of temp.....that little feature save me when I plumbed things wrong......don't ask.
All the lines and fittings held............

BTW:Fluidyne replaced the cooler FOC. They just wanted the blown one back. Good folks to do biddness with.

[John Rogers]

My race setup is without a thermostat as that is what was installed when I got the car. It is a dry sump system with about 12 qts total and we use 5-50 wt symthetic oil. The pump is a two stage Autocraft with a dash 12 suction line and others are dash 10. I am pretty careful to letthe oil warmup to 100 or so before I get running hard and that takes about 15 min or so of idle/easy running. The dash 12 suction was installed in March and the original line was a dash 8 but was not able to draw enough suction on the sump and oil would blow out the breather tank! Now at 6000 RPM there is actually a vacuum created in the sump which is great for more power! Good luck.