Author Topic: Engine air/oil cooled? (Read 2417 times)

Rocketjock · « **on:** March 26, 2007, 10:42:22 AM »

I've always believed that the Gixer and Bandit design was a mixture of air and oil cooling. Last year I had a mechanic tell me that the oil circulation was for lube only and it was designed for air cooling. 'Oh, OK' I says and left it at that. But the more I think about it, the more I think how wrong the guy was. I need clarification here. If it's not oil jacketed, whay would it have such small fin areas and a large oil cooler? I'm sure this guy said it wasn't jacketed in oil. You guys tell me I'm wrong and then I'll believe it. I think it stemed from me talkin about how I always liked the Gixer engine look and felt it was way better looking than the new water cooled B12. And besides, wouldn't oil cooling protect parts a lot better than water?

Red01 · « **Reply #1 on:** March 26, 2007, 12:14:33 PM »

The early GSXR and the 600/1200 Bandit (and other models that used the SACS family of engines) are air & oil cooled. The oil cooling is not via jackets like the water in a typical watercooled motor though. The oil cooling is done with jets squirting oil on the hottest zones, like the underside of the pistons, and the top of the combustion chambers. The SACS motors have two-stage oil pumps. The high pressure/low volume stage handles lubrication and spraying the bottoms of the pistons and the low pressure/high volume stage cools the head.

DaveG · « **Reply #2 on:** March 26, 2007, 12:17:32 PM »

on the B12 at least the lubrication and oil cooling are 2 separate systems that share a common reservoir.

some other bikes the the kawasaki ZR7S just have an oil cooler that cools the lubrication oil.

Rocketjock · « **Reply #3 on:** March 26, 2007, 08:07:45 PM »

Rocketjock · « **Reply #4 on:** March 26, 2007, 08:08:13 PM »

rkfire · « **Reply #5 on:** March 27, 2007, 01:10:45 PM »

Find a new mechanic! lol Geesh, this engine's been around since 86 or so.

Squirting oil jets onto hot areas has been around since the days of radial airplane engines. They also had closely spaced fins like the bandit has. The fins aren't deep, but they are more closely spaced than older, air only cooled engines. Even the black paint was desgned to assist in efficiency.

If it had oil passages circulating oil for cooling, it would be called liguid cooled. I think water/anitfreeze mixture is a better coolant.

Now that Suzuki is doing away with SACS, I notice BMW, Moto Guzzi, and Harley are adopting it to keep the air cooled look to their engines.