The Cessna 120-140 Association Forum

I am shortly about to start the rebuild of my C85 and whilst I understand the rebuild process I have a question about the first run of the engine.

I assume that whilst the parts are being put back in the crankcase they would be pre lubricated with straight 100 oil or similar... But what happens prior to the first start?

I understand that obviously the sump will be full of oil, but it will take a while to build up pressure and then squirt it down the galleries once running, but surely the bearings will be running dry until that point?

Or am I thinking too hard about this?

Pack the oil pump with chassis grease on assembly. I use a 50/50 mix of STP oil treatment and Aeroshell 100 mineral oil for assembly lube. Pull the bottom plugs out and crank the engine with the starter until it builds oil pressure. (Sometimes it helps if you leave the oil pressure line off until the galleries fill with oil.)

Randy may have a better idea...

Agree with above and I have been using Federal Mogul assembly lube part #55-400. You'll find that if you'll lube all parts very well and follow all procedures by the time your done you will find how well it's lubed for first start. Also these lubes seem to adhere to steel without run off.

I have done it several ways. The main thing it to well lubricate the bearings and journals on assembly and use cam lube on the lifter faces and lobes . I assemble the oil pump with grease and the engine usually develops pressure in about 10 seconds. If it doesn't I have a pressure oiling system that I hook up at the oil temp probe entrance. ( This is a volkswagon oil pump in a coffee can with a hose that screws into the oil screen and is driven by a drill motor). My test stand has a clear tube to the oil pressure gauge so I can see the oil coming from the engine before the gauge reacts. My2cents

Great information, many thanks.

Looking forward to getting to the point of assembly.