Suggestions for tracking stock 2.0L Options

[AndrewBlyholder]

I usually race a 914 race car, but it's engine expired at the end of 2019, and the rebuild is still in process. Many custom parts, suppliers on reduced capacity due to COVID, etc....

In the mean time, I started autocrossing my street 914, a solid, but unrestored '74 LE.

I had so much fun with that for the 2020 season, I decided to try it out at a DE track event in March. Everything was great, having a ball at Thunderhill (IMG:style_emoticons/default/driving.gif), until a rod bearing spun during the 5th run session late in the day. D'oh (IMG:style_emoticons/default/headbang.gif)

So now I have yet another engine to build before I get back to my race motor project. I plan to keep the rebuild mostly stock, but looking for suggestions to help make the new motor more reliable for DE track use. I finally have all the custom parts in hand for my race motor rebuild and I'm planning on getting that finished up in the next 2-3 months. So my street car probably won't get pressed into track use again soon, but you never know, so why not build something that can withstand some track usage.

The previous motor was just what was in the car when I bought it 25 years ago from a local Porsche mechanic. He got it from a client that couldn't pay for some repairs and ended up giving the mechanic the car. But that's all I know of it's history before me, so the pedigree of the motor was completely unknown. Because of that, I always considered the motor sacrificial. I figured I'd run it until it blows up and then build something proper. It took 25 years, but that's where we are now.

The motor was a bone-stock D-jet 2.0L. At the track it was running very hot, just under the red zone on the stock oil temp gauge. Air temp was 75. When the bearing spun and the loud noises started, I looked down at the temp gauge and it was solidly in the middle of the red. So more oil cooling is obviously top of the list.

I never noticed the oil pressure light coming on, so I don't think I was oil starving it, but I wasn't making a point of specifically checking it and the stock light is small and often blocked from view by my hands and the steering wheel, so I couldn't swear that it actually never came on.

While the car is a solid driver now, since it is an LE, I'd like to restore it to show car condition eventually. For that reason, I'll keep the rebuild as a D-jet with a stock external appearance. But I'm open to non-stock internal parts, and any new external systems (like oil coolers, deep sumps, etc.) that are easily reversible.

So those of you with some track experience with fairly stock motors, what would you suggest for both rebuild parts and additional systems that will allow a stock D-jet to stand up to DE track use?

Thanks,

Andrew Blyholder

[Driver174]

Is plumbing needed to bottom of engine, maybe to tuna can to scavenge oil from engine? How does system work? If oil pump is used to pressurize oil into the engine, what pulls oil from engine to the tank?

I currently have AN 10 braided lines between engine and front oil cooler. Maybe I can front mount a tank and utilize these lines.

Can someone diagram the oil flow for me?

Thanks,
Jim

[GregAmy]

It's easy.

Thay dry sump oil pump is a two-stage pump and is plumbed for two external AN lines: one going from the pump to the sump tank, and one going from the sump tank to the pump.

It's all done internally. One stage of the pump pulls oil using the stock pickup tube and routes the oil to the outlet fitting and then to the sump tank; the other stage of the pump pulls oil from the sump tank and pressurizes the engine. In effect, it routes oil like the stock oil pump, but instead of pickup tube-to-oil cooler-to-engine, it first routes it outside the engine to the tank, then back to the internal oil cooler to the engine.

One stage does all the work of pickup and delivering to the tank, the other stage does the work of recovering oil from the tank and pressurizing the engine. This way your engine-pressurizing stage is always using the tank reservoir of oil to deliver to the engine and doesn't have to worry about pickup tube starvation. If the pickup tube starves during cornering then no problem-o, since all that's doing is repleneshing the tank. As long as you have sufficient tank reserves for the pressurizing stage to access, you never lose engine oil pressure.

The CB pump is bolt on, no engine mods needed, and will fit behind the stock fan shroud. The lines go sideways. Just make sure you're running the right cam gear for it. If I think about it I can take a photo next time the car is on the lift.