The wrong oil pan will wreck your engine. Here's how to avoid catastrophe

If you've seen the latest episode (CLICK HERE) MOOG and his best mate Al (and some hanger-on bloke called Marty) have started ripping into the Fairlady refresh, and the first big job they knocked over was to change the sump. We all know oil is the lifeblood of your engine (and if you don't, READ THIS) so it makes sense that you need to firstly keep a constant supply to your engine, and secondly hold all that precious liquid gold where it needs to be held. 

The sump on MOOG's 240 was made by Al and the lads five years ago and it's been great, however it is quite tall. This has seen the precious pan hit the ground a couple of times, which is a very risky situation to find yourself in. 

One big thump on that thin bit of tin and you can split it wide open, dumping all the oil and killing your engine in seconds. I've done this before, and was lucky to save the engine with lightning-fast skills... and truckloads of luck.

Part of any engine conversion is working out what sump options your swap needs, from custom sumps to off-the-shelf items from other models which use a similar engine. Whatever sump you choose also needs to work with your projected ride height and bonnet clearance, as you don't want the engine to be too tall for the chassis.

MOOG's RB-powered 240Z uses a Patrol sump and pick-up tube modified to fit in the low-slung sports car, which was all that was available when the car was built, but there are now better options around.

You may have guessed it by now, but this innocuous little pipe is actually critical to not grenading your engine. The pick-up tube is how the oil pump sucks oil out of the sump, and spreads it around your glorious engine. This is why people freak out about bashed-in sumps, or even when someone has put too much RTV (sealant) in the engine, as the worry is the silicon will break off over time and eventually block the pick-up (don't laugh, it's happened countless times.

Different sumps will have different looking pick-up tubes, and it is ideal if that head features a screen to stop large bits of gunk being sucked into your oil pump. However, some shallow oil pans need a low-profile head to maintain a healthy amount of clearance, which will let the pump suck up oil nicely. 

And there are some other considerations when it comes to going to a shallower oil pan on your ride...

Low-profile sumps are common in the aftermarket world, as there are plenty of low-riding cars that need a thin pan for clearance. The ultimate in a thin pan is a dry sump set-up but that is a whole world more complex and vastly more expensive (you can READ MORE HERE). However, these are designed to hold their oil in an external tank and use a multi-stage, belt-fed oil pump, whereas a wet sump needs to keep it all in the pan on the bottom of the engine, which the oil pump sucks out of.

Keeping enough oil in the bottom of the engine forms a couple of important purposes. Firstly, it keeps adequate supply of oil near the pick-up, which keeps your engine lubricated and spinning nicely. 

Holding oil in your sump also helps keep your motor cool. Yes, your radiator and coolant also do that, but keeping oil temperatures in check will also help prevent the car from overheating. This is why some cars run external oil tanks to try and lift the total volume of oil in the system, which then should run cooler and help drag heat out of the engine block and cylinder head(s).

But you don't just want all that oil sloshing around in a big open bucket under your engine, like what manufacturers did in the '60s.

Factory sumps in 90s cars, like the modified Patrol sump used on the 240Z (shown above) often have to tread a fine line between cost and oil control. As Al explains in this week's video the purpose of the louvres in that sump is to act as a windage tray, which aims to prevent foaming and splashing of the oil by the spinning crankshaft. 

Nissan wanted to keep as much oil as possible in the bottom of the pan, near the oil pump pick-up, and these windage trays are how manufacturers most commonly do this. You can buy aftermarket windage trays if you are trying to spin an engine much harder than factory, or have a lot of lateral G-forces you're working against (like high cornering loads). 

Conversely, MOOG's aftermarket sump features a very thorough windage tray set-up, but also trap doors in the pan. High-performance aftermarket sumps often feature these doors to control oil slosh during high-speed cornering. They'll prevent oil from running away from the pick-up, which means your engine will enjoy stable oil pressure. Yay.

While aftermarket sumps can be expensive, getting a high-quality pan custom-made will make it painful to sit down enthusiastically for a few days. The amount of design and fabrication involved in high-quality sumps will have your head spinning, but then this is one of the most important parts of your car you're taking care of.