Here's something I posted a while ago:
Oil system philosophy:
Oil system design:
The proposed oil system modifications are:
Uprated oil pump:
This pump has the 17.5mm internal gear sets, instead of the standard 15mm gear sets and also has the stronger nitrided gears.
You can also have the back of the oil pump housing machined to accept an o-ring, so that when the oil pump pressure is raised, you don't get a drop in pressure due to leakage between the oil pump and front plate, and you also don't get air leaking into the pump, creating bubles in the oil.
With the high flowing oil pump, the next step is to increase the oil pressure by modifying the 2 oil pressure regulators:
There are 2 regulators. One in the front cover:
And another attached to the bottom of the rear plate:
The FB 12A is not designed to be adjustable. It can be crushed in a press to increase the pressure output though.
You can buy the MFR adjustable regulator.
The twin dizzy rear regulator can be opened up and modified to increase oil pressure and is a bolt in swap for the FB regulator.
To increase the oil pressue in the engine, you need to open the regulators and add a 3mm shim. This will increase the spring preload and increase the pressure from about 70psi to 80-85psi. FYI, the FD has 110psi as standard. This is a cheap and easy mod to do. You'll need a 26mm and 29mm spanner.
The next step is to modify the bearings, specifically the stationary gear bearings. It's not really necessary to mod the front bearing, just the rear stationary gear bearing as this is the one that controls oil flow to the eccentric shaft.
You can buy a multiwindow bearing for this purpose. It has a deeper oil channel and more than one hole to supply oil to the bearing and eccentric shaft.
The bearings can also be clearanced to add 0.0005" clearance so that the rotors and eccentric shaft are able to "float" more.
The other mod you can do is to add a loop line:
This is basically a separate oil line, normally run off a sandwich block under the oil filter which provides a direct oil feed to the front stationary gear. It connects to the side of the front plate where there is a blanking plug. You remove it, open the hole up a bit and tap it. Due to the design of the oil channels and galleries in the engine, the front stationary gear can receive as much as 10-12psi lower than the rear gear.
Next, you can cross-drill the eccentric shaft. The holes for providing oil to the eccentric shaft can be drilled all the way through from one side of the stationary gear journal to the other. Make sure that the new exit hole is countersunk to avoid damaging the bearings. This mod is performed as standard on FC and FD ecentric shafts.
The other mod for the eccentric shaft is to replace the standard oil jets with higher flowing units:
Note that the higher flowing jets do not use the spring and check ball and are therefore on all the time. Slower engine warm up will ensue but you should have better rotor cooling, which will help at high revs.
The sump volume can be increased to hold more oil. More oil means cooler oil, and less air bubbles mixed in the oil. Baffle plates can also help with this.
Note the additional strengthening where the bolts go through and the anti-slosh plate inside to reduce oil movement in the sump and ensure oil is available at the pick-up during hard cornering etc.
The other classic mod is the removal of the OMP. I'm not going to cover this here.
The oil galleries can also be opened up and smoothed to aid oil flow throughout the engine. I'm going to be looking into this more.
In addition to all these mods, a larger oil cooler can be added. I've now got one from an NA FC and will be using this in my project car.
Back in the UK for the summer, maybe longer......
