Bored. Observation with cold ACD and valvetrain.

Messages
3,756
Location
CA
So this probably won't get any replies but I'm bored lol. I changed the oil yesterday. Ambient temp was 60 degrees. Engine had been off for a few hours so it was at or close to ambient. The EAO was not changed. This car has been on Amsoil ACD straight 30 for most of it's 74,000 miles. I filled it and waited about 15 minutes so any extra oil on the head would drain back. I pulled the fill cap off and had the girlfriend start it. I could barely see one cam lobe and two rockers. There was instantly splash, probably because the lobes sit in a pool of oil I'm assuming. The interesting thing was the flow. This oil at ambient temp was being flung and splashed around like I would expect a fully hot 20wt. Oil was going everywhere. I think if people would take the time to observe things like this the thick oil (within reason for the climate) fear would disappear. No lack of flow whatsoever. There was a steady stream of fast flowing oil going down one of the return holes through the head and this was with it cold. FWIW, the one lobe I could see looked brand new, it looked like the engine had never been fired.
 
Messages
2,995
Location
Cedarbrae, Ontario
Straight 30 weight is fine for your area, but up here, it would not be good for wintertime. Im sure a straight weight oil is better protecting, as the old detroit diesels (2 stroke) were to be run on straight 40 or 30 weight oil as multi-viscosity oil coult not withstand the shearing those motors impose on the oil.
 
Messages
4,431
Location
Massachusetts
 Originally Posted By: BuickGN
I think if people would take the time to observe things like this the thick oil (within reason for the climate) fear would disappear.
I agree. \:\!
 
Messages
10,060
Location
Central Washington
 Originally Posted By: xxch4osxx
Straight 30 weight is fine for your area, but up here, it would not be good for wintertime. Im sure a straight weight oil is better protecting, as the old detroit diesels (2 stroke) were to be run on straight 40 or 30 weight oil as multi-viscosity oil coult not withstand the shearing those motors impose on the oil.
Amsoil ACD is indeed a straight 30, but its a full synthetic and can qualify as a 10W30. Its a great oil.
 
Messages
22,599
Location
Dallas,Tx USA
My current fill is Valvoline white bottle dino 20W50 (which will be Royal Purple 20W50 come tomorrow) and I get whisper quiet startups even when the temp outside is in the 30s (which is rare here). When I remove the oil fill cap,I get a picture perfect view of the passenger side camshaft. Upon the very first crank of the starter,the camshaft is immediately saturated with oil and continues to be bathed in a thick coat of 20W50 goodness :^) Oil bath never slows down,thins,or anything.
 
Last edited:
Top