10-30 is a little too thin and oil pressure a little low
05-28-2012, 01:52 AM
#12
5th Gear Member
Join Date: Feb 2007
Location: Ramona, CA
Posts: 2,682
James, I would probably go to at least 10w-30, especially with the weather there in HI. Watch your oil pressure when you get off the highway and see what you get at a stop at idle. If you are atill in the 20's I would say its ok.. but then you do have the rpm top end.. Did you install roller lifters and rockers? That may be a consideration too. Before my build I would get 60psithem at start and on the hwy.. but nothing at idle once warm.
05-29-2012, 09:08 AM
#14
2nd Gear Member
Join Date: Nov 2006
Location:
Posts: 356
Your question is, somewhat, difficult to offer a definitive answer. It's all about bearing tolerances and the lack thereof. An accepted rule of thumb for oil pressure, is to have about 10lbs /1000 RPMs under speed. At idle 15-20 lb. would not be unacceptable. Above idle and upwards you should see a graduated gauge reach 25-40 Lbs. A cold engine will read higher for all of the obvious reasons. I run Castrol 10-40 in the mustang and the 20-50 in the Jag.
Yes, you can mask, to some extent, a "wearing" engine with an increase in a given oil's viscosity. But, as we all know, this is a band-aid and buys some time.
Happy Trails!
05-29-2012, 05:01 PM
#16
2nd Gear Member
Join Date: Feb 2010
Location: Ohio
Posts: 315
Hi,
Your question is, somewhat, difficult to offer a definitive answer. It's all about bearing tolerances and the lack thereof. An accepted rule of thumb for oil pressure, is to have about 10lbs /1000 RPMs under speed. At idle 15-20 lb. would not be unacceptable. Above idle and upwards you should see a graduated gauge reach 25-40 Lbs. A cold engine will read higher for all of the obvious reasons. I run Castrol 10-40 in the mustang and the 20-50 in the Jag.
Yes, you can mask, to some extent, a "wearing" engine with an increase in a given oil's viscosity. But, as we all know, this is a band-aid and buys some time.
Happy Trails!
Your question is, somewhat, difficult to offer a definitive answer. It's all about bearing tolerances and the lack thereof. An accepted rule of thumb for oil pressure, is to have about 10lbs /1000 RPMs under speed. At idle 15-20 lb. would not be unacceptable. Above idle and upwards you should see a graduated gauge reach 25-40 Lbs. A cold engine will read higher for all of the obvious reasons. I run Castrol 10-40 in the mustang and the 20-50 in the Jag.
Yes, you can mask, to some extent, a "wearing" engine with an increase in a given oil's viscosity. But, as we all know, this is a band-aid and buys some time.
Happy Trails!
05-30-2012, 07:54 AM
#18
2nd Gear Member
Thread Starter
Join Date: Mar 2009
Location: NH
Posts: 381
I am in 20's at idle and I don't know what at high driving RPM as I have the orig gauge. I do see the original gauge go lower than normal with 10-30. Also, last summer I was using 20-50 and the engine was rebuilt 2k before I bought it and used 20-50. I hear that people who switch back to 10-30 from 20-50 do have lower oil pressure than normal with 10-30, can this be? OI do see lower pressure so I think I will move to 10-40 and see if I find any issues.
05-31-2012, 01:37 PM
#19
5th Gear Member
Join Date: Aug 2004
Location: ABQ, NM, USA
Posts: 2,593
Without a real mechanical gage, who knows what the OPs pressure is or if there is a problem at all.
Knowing the bearing clearances will also help.
With those two pieces of data, we can maybe answer the questions.
Knowing the bearing clearances will also help.
With those two pieces of data, we can maybe answer the questions.
05-31-2012, 02:53 PM
#20
4th Gear Member
Join Date: Jun 2006
Location: Fontana, California
Posts: 1,483
Based on your posting, ask a simple question and you'll get a million different answers.
My .02: this is really a personal choice - I've used multigrade, single grade, racing oil and the only real data I can share is that with the lower multigrade combo's, the pressure seems to be lower at hot idle.
I like Castrol GTX 20w50 personally in older technology engines especially in warm locations. I see your from NH so 10-30 or 10-40 may be OK. If you have flat tappets, and use modern oil, (SL and higher certification) you should use a zinc additive of some type to help lubricate the cam/lifter interface.
My .02: this is really a personal choice - I've used multigrade, single grade, racing oil and the only real data I can share is that with the lower multigrade combo's, the pressure seems to be lower at hot idle.
I like Castrol GTX 20w50 personally in older technology engines especially in warm locations. I see your from NH so 10-30 or 10-40 may be OK. If you have flat tappets, and use modern oil, (SL and higher certification) you should use a zinc additive of some type to help lubricate the cam/lifter interface.