Question:
Hello, I’m looking for a for a bit of information. I’m running a Suzuki Hayabusa in stock condition. I’ve purchased your dry sump and tank which is working quite well. We set the engine up with dual radiators, and one single oil cooler. Water temps have been 170-180°F, oil temps have been 240°F and climbing. We have not allowed temps over 240°F. We’re not really sure what is normal oil temps for this engine, but were concerned were on the edge. Can you offer some info on this and some possible solutions?
Answer:
The Suzuki Hayabusa engine, as with many Suzuki engines, has evolved from the oil cooled engines and almost as much heat is transmitted into the oil system as the water system. The temperature of your oil at 240°F (116°C) is ok, but because the engine expands the bearing gaps increase dropping oil pressure. If the temperature could be kept closer to 230°F (100°C), this would help oil pressure as well. My suggestion would be to increase your oil cooler size significantly. You may also find that once you have managed to reduce the oil temperature, that this will also help to control your water temperature better as well.
When your engine is cold (oil temperature of 0 – 20°C) at tickover, I would expect to see between 50 – 60psi approximately and if revved over 100psi. Obviously this is not recommended until the engine is hot.
As the oil temperature rises, the tickover oil pressure will drop quite quickly and I would expect to see approximately 20psi when oil temperature is 60°C. As the engine is revved, peak oil pressure will probably be just under 100psi. I would recommend that you try and maintain between 80 – 100°C, this way your oil pressure at tickover will be in the region of 7psi and peak oil pressure 60 – 70psi.
The further the temperature rises, the lower the pressure will get, this drop in oil pressure is caused by 2 main factors; first of all the engine block grows dramatically with heat causing increased clearance between the bearings and the crank and secondly the oil itself gets thinner with heat, this is quite normal. If your engine was running a standard oil pump gear as opposed to our uprated gear, I would expect to see a 10% reduction in oil pressure throughout the range. It is not uncommon with oil temperatures in excess of 120°C being tickover oil pressure as low as 2psi and peak oil pressure down to 35psi. The most important thing to look out for is that the oil pressure follows the rpm, if you see any drops in oil pressure at higher rpm it is likely that your oil tank is carrying insufficient oil and therefore oil surge is occurring, which will cause engine damage.
Category:
Hayabusa Specific