Trophy and a question

Carmine

Well Known Member
Supporting Member 6
#1
Hi everyone. Went to a car show today with my '62. About 60 cars. They gave out trophies for the top 10 cars. Voting done by some residents of an assisted living home, who sponsored it and spectator voting. I got one of the trophies. Nice looking trophy. Has purple on it. Little unusual at least here. Might have something to do with where the proceeds were going to, an Alzheimer association. Worthy cause. The car ran great. Really enjoy driving it. Not sure why I don't drive it more often instead of fooling with that other junk I have.
I think my engine is broken in by now and my excessive oil consumption is behind me with the installation of valve guides. I do have an observation and question.
I use 10w30 oil. When I first start the car, I have about 42 lbs. of oil pressure. After warm up reaching operating temp., idling at about 700 rpm's, I have about 22 lbs. of pressure. Driving at 50 mph, about 2300 rpm's, I will have about 42 lbs. again. It never seems to go above that. I've had the car up to 90-100 mph a few times, but too scared to look at the oil pressure. Don't want to take my eyes off the road. Is this oil pressure reading in the accepted range?? The reason I ask is this. My 348/434 has about 80 lbs. of oil pressure on start up. Not sure if that is high or even why. It will go down to about 65 lbs. on warm up and driving. I've never seen it much less then that. I think I use a heavier oil in that motor. Just wondering.
Get this. My speedometer and gas gauge are both off for accuracy. But my clock, keeps perfect time. Go figure, right. I posted a pic. Thanks for looking, Carmine

Trophy for  Impala 9.15.18.jpg
 

Carmine

Well Known Member
Supporting Member 6
#7
So 10 lbs of pressure if your car is idling at 1000 rpm's? Do you guys think that is ok? Sounds low to me. :dunno
Good question Bob. I happen to think that that rule of thumb, 10 lbs. per 1000 rpm's, might apply more when you're on the move. All the cars I've ever owned, at a 3 digit idle, never had less then 20 lbs. of oil pressure. I'm not sure, but 10 lbs. at 1000 rpm's does sound a bit low to me. On the trifives, I use to know how low the pressure got, at idle, before the red idiot light came on. From what I recall, it was pretty low. Maybe the same for our cars equipped with a light, Carmine.
 

Carmine

Well Known Member
Supporting Member 6
#9
Thanks Don. I can remember when I had my '55 Chevy with a 265 engine, sometimes at a stop light, the oil light would flicker. I think maybe the generator light also. Give it a little throttle and the light went out. I thought the trigger was kind of low. I think the engine idled around 450 rpm's. Boy, that was a smooth running engine. I swear you could put a glass of water on the air cleaner and not spill a drop, Carmine.
 

oldskydog

Well Known Member
Supporting Member 9
#11
10 per thousand is pretty much standard rule of thumb. My 470 ci engine in my airplane has a minimum in flight of 30psi and 10 psi at idle….idle is about 650 rpm. Looser engines will need more pressure but at load, not necessarily at idle. My 1820 ci radial has a minimum inflight of 65 psi but no idle limit specified, just needs to have "an indication of increasing OP immediately on start".
 

Fathead Racing

Well Known Member
Supporting Member 6
#12
Volume is more important than the pressure. Keeping an oil film between the moving parts is paramount. Pressure is of course resistance to flow. An engine with relatively large clearance's would have less pressure. If it makes you nervous drop the pan and change the spring in the pump or switch to 15W50 weight oil. I've ran engines with 5 lbs of pressure at idle even less with no problems.
 

Carmine

Well Known Member
Supporting Member 6
#14
Carmine; Does your 348, have a HV, or HP, oil Pump in it?:dunno Congrats, on the Trophy.:clap:bow
Thanks Skip. But that beats the hell out of me which pump it has. I think I probably went for a high volume one, whatever that is. been too long to recall exactly. Two other things that also work, my emergency brake light also blinks when the brake is on, and my green cold light comes on until the engine warms. You have no idea how important it is to me to have that green cold light work. Talk about mismatched priorities. It's a sickness I have LOL, Carmine.
 

bobs409

 
Administrator
#15
Thanks Skip. But that beats the hell out of me which pump it has. I think I probably went for a high volume one, whatever that is. been too long to recall exactly. Two other things that also work, my emergency brake light also blinks when the brake is on, and my green cold light comes on until the engine warms. You have no idea how important it is to me to have that green cold light work. Talk about mismatched priorities. It's a sickness I have LOL, Carmine.
The emergency brake light is supposed to flash. It's a special bulb I think #257? Everybody does love their green cold lights!!!