One thing people tend to add to modified engines is a catch can, which separates oil droplets from the crankcase ventilation hose to stop them being fed back into the air intake and burned.

Most catch cans are just a can, which fills up over time and needs periodic draining, which is messy and annoying - especially when it happens quite frequently on race engines!

Some engines actually have a catch can setup from the factory that returns the oil to the sump. This one came from a turbo diesel engine.

The oil return needed somewhere to go, so I made up a T fitting into the turbo oil return line.

This setup is still a bit experimental, but it will be interesting to see how it goes. The main concern is that if there is too much oil in the turbo oil return it could cause a restriction and force some oil past the turbine oil seal.

In theory there will be no difference in pressure in the system, but if there is too much flow from the catch can it could potentially cause problems.

I tend to prefer factory engines, even with relatively high k’s on them, than rebuilt engines - and this is the reason for that!

The car’s owner had the engine rebuilt, but it failed shortly after. It was repaired under warranty but wasn’t cleaned out properly, so metal filings then clogged up oil feeds and damaged other parts - including the turbo.

It’s been a bit of an ongoing saga - and after yet another repair it lasted a short time before making nasty noises from the top end of the engine.

I had a quick look and found two problems.

One was that the oil spray bar on the camshaft (visible through the oil filler hole) was not spraying oil - which usually means it’s clogged up with gunk from the engine.

The other problem, which is a bit of a worry, was that the remotely mounted oil filter had been plumbed in backwards! The filter has an anti drain back valve, so when it’s backwards it will block the oil flow - causing the relief valve in the engine to bypass the filter.

So, an engine likely to be full of metal filings had been running with no oil filtration!

After removing the cam cover, it was obvious that there was some damage to the cams due to the lack of oil - which was the cause of the noise.

It’s a bit saddening to see this happen to a brand new set of cams!

The engine really needs another teardown, inspection, and very thorough cleanup.

This car is being set up for racing use, with most of the interior stripped out, a roll cage, big brakes, and lots of power!

To keep the engine’s oil cool while it’s producing more than double its factory power,  I helped install an oil cooler.

After trying a few possible locations, it was decided to mount it in the traditional position in front of the radiator. This was the best compromise of air flow, mounting strength, and working with the lengths of the pipes in the oil cooler kit.

The air conditioning condenser and plumbing was removed (also the compressor and its bracket) to make space, as well as weight reduction. Unfortunately this meant draining the coolant and taking the radiator out for access!

Here’s the oil cooler installed between the intercooler and radiator:

The oil cooler kit also came with a filter relocator, which makes changing the oil filter much easier - much appreciated by anyone who has changed the oil filter on a Silvia (or pretty much any modern car). The relocator also has fittings for oil temp and pressure gauges.

A larger aftermarket aluminium sump was also installed. It holds more oil than the standard one and has hinged baffles inside to keep the oil near the oil pump pickup during hard cornering. There was a bit of a snag with the sump install because the drain plug thread was found to be damaged.

I re-tapped the thread to a larger size and replaced the factory drain plug with an off the shelf tapered plug, which should work well and be harder to damage in future.

The next job was to swap the ECU. The car was running an older Microtech ECU which worked ok but is a bit limited in the accuracy of its tuning and tends to be affected badly by changing weather conditions, etc.

The replacement ECU is an Apexi PowerFC D-Jetro - which used a MAP (Manifold Absolute Pressure) sensor like the Microtech, rather than the factory MAF (Mass Air Flow) sensor. A MAF sensed ECU is superior in a few ways, but since the car was already set up for MAP sensor the D-Jetro version of the PowerFC was an easier option.

Swapping it over required removing the Microtech wiring loom, which had been spliced into the factory engine loom, tidying up some other wiring (fuel pump control, etc) and plugging the PowerFC into the original ECU plug.

Since MAP sensed ECUs also need an air temp sensor, this had to be added into the wiring. The PowerFC’s air temp sensor has a different thread to the Microtech one, so the fitting in the intake pipe needed to be modified.

One of the PowerFC’s nice features is a readout from the engine’s knock sensor. This can be a very handy thing to have, as it can tell you if the engine is pinging (detonating) under certain conditions. It’s not foolproof, but it’s generally worth keeping en eye on, and never worth ignoring!

When the ECU was installed we found that the knock sensor wasn’t working. Upon closer inspection I found that the plug had fallen off the sensor, and was missing the small wire clip that holds it on. Not having a clip on hand, I found a paper clip and made a new one!

A minute or so with some needle nose pliers and it looks just like a real one

The knock sensor plug went back on and the ECU started giving the knock readout as it should!

The last job to do was to bleed the brakes because they were feeling very spongy after being upgraded to some very nice four piston AP racing calipers. Bleeding the brakes is pretty simple, as long as you have two people - but these calipers have two bleed nipples each! So, each caliper has to be bled twice, but once that was done the pedal felt nice and solid.