Oil Cooler

In the last installment of the 911 build, I was about to pick Scarlett up from the shop after the valve adjustment post engine break-in and the installation of the new seats but the debris in the oil filter had us revisiting the oil setup. Not wanting to risk contaminating the engine with debris, I opted to have the entire oil tank replaced with a brand new one. Since I wasn't sure if the oil lines were also disintegrating, I took the opportunity to upgrade the entire oil cooling system.

Elephant Racing Single Fender Cooler - 7-2-2020

Factory "trombone" setup

You get into a slippery slope sometimes when you decide to upgrade things but in the long run, this is the best choice. The factory setup is what's called a trombone cooler. It does nothing more than send oil to the front of the car, loop through a few times then goes all the way back to the tank. This works reasonably well especially if you stay in motion but if you get stuck in traffic on a very hot day and you have AC, you sit there nervously watching your oil temps creep up. The new oil cooler is a radiator "Carerra" style cooler with a fan that turns on if the oil temps get too high which helps cool the oil even when standing still.  The Elephant racing version is wide mouth which has a 3mm wider fitting that most typical oil coolers which actually increases the oil flow by 50%.

Finned oil lines

The kit also replacing all the hard oil lines with finned oil lines. This setup increases surface area and therefore increases heat dissipation 4x over the stock setup. It also features a valve where you can use air pressure to force oil through the oil cooler to have a more complete oil change. In the rear, I upgraded to high clearance oil lines that route the lines to the oil tank up into the wheel arch. This allows for a more aggressive tire and wheel setup if I choose to do so in the future.

High Clearance Oil Lines

The thermostat was also replaced with the Elephant Racing version which is far superior over stock. It features a pressure bypass that automatically loops the oil back into the oil tank should there be a clog in the oil cooler lines thereby preventing the engine from starving for oil.

New thermostat with high oil routing

Factory Thermostat with OEM oil routing 

The install wasn't without hiccups though. One thing I've learned the hard way throughout this build is that even though you might find a part that says it fits a wide range of generations of 911, small build differences/improvements over the years means that things are rarely bolt-on. They should probably come with a label "some fabrication required" instead. In this case, the location where the cooler wanted to be in had a bumper bracket and the factory horns in the way. This could be solved a few different ways but we opted to upgrade to 993 style horns which are more like your modern small "snail" shaped horns. This gave additional clearance but the fan it came with was simply too wide. With the car lowered, leaving the cooler where it was meant the tire would contact the stone guard so we wanted additional clearance. We went with a smaller SPAL fan which they bench tested and surprisingly pushed about 300% more air through the cooler.

993 horns and SPAL Fan (VA31-A101-46S)

Larger kit fan (left), Smaller SPAL fan (right)

I also noted from my previous test drives that I had a weird outage of my Speedometer and Odometer for about 40 miles then started working again. When both speedometer and odometer stop at the same time it usually means the speedometer impulse sensor is going so I had that replaced with a new one as well.

Finally out of the shop after a month - 7-2-2020
Speedsport Tuning - Danbury, CT

Of course, picking up the car should've been a simple process but as soon as I hopped in and tried to turn the AC on I noticed it wasn't blowing air nor was the compressor engaging. Ah the joys of classic cars! The guys at Speedsport Tuning were super helpful. It was the day before the long weekend and we were all just trying to get home. Instead, they spent a solid 2 hours going over electrical diagrams in the parking lot to figure out what happened. It turned out it was no one's fault. The relay that runs the circuit for all the AC stuff simply failed. Thankfully they had a spare so after a quick swap, I was back up and running and heading home.

Failed Ac relay in the "smuggler's box"

I'm just excited to get the car back. The engine runs so smoothly and I thoroughly enjoyed revving it all the way to redline all the way home. The gears are a little tall though so it's a bit surprising the speeds you get up to even at the top of 3rd. It's really not as slow as I thought it was. The new seats feel superb and my new, lower, seat height also means I can more easily see my gauges.

Maintenance Update:

Mileage: 165,144

- New oil tank and oil cooler
- New 993 horns
- Valve Adjustment
- 11 quarts of Driven DT-50 oil
- New Speedometer Impulse sensor