[C1] Mixed oil viscosity
#1
Racer
Thread Starter
Mixed oil viscosity
I bought five quarts of Valvolene, V-1, Hi-Zinc oil for my 1962, 327 solid lifter motor. I normally run the 5-40 weight, however, after changing the oil, I noticed that two quarts were 5-40 and three were 50 weight. I didn't check what was delivered, my bad. Is this an issue I should be concerned about.
Thanks, Jim
Thanks, Jim
#3
Team Owner
If you are running the car in Mississippi then I wouldn't worry about it until the next oil change... I run Mobil 1 15W-50W exclusively...
Last edited by Frankie the Fink; 02-03-2018 at 11:58 AM.
The following users liked this post:
Jhemp3 (02-03-2018)
#4
Race Director
Member Since: Apr 2015
Location: Fresno California
Posts: 17,503
Received 3,443 Likes
on
2,113 Posts
I wouldn't run anything with a 50 weight index in any of my cars....none are worn out enough. 15/40 is as thick as I would go, as an auto technician. 50 weight would be great in a race engine set up with loose tolerances and run in hot weather. Too thick to lubricate optimally in a non-worn-out engine.
#5
Drifting
I'd run it if your climate is warm,
But you COULD drain a quart off and dump in a qt of thinnest synthetic you could find. That will thin it out and add the protection of both the zddp and synthetic.
But you COULD drain a quart off and dump in a qt of thinnest synthetic you could find. That will thin it out and add the protection of both the zddp and synthetic.
#6
Racer
Thread Starter
Thanks, guys. I'm thinking I'll leave it like it is through the hot summer and Cruising the Coast (hot, hot, hot) and change it before cool weather.
The following users liked this post:
Jhemp3 (02-03-2018)
#8
Race Director
I wouldn't run anything with a 50 weight index in any of my cars....none are worn out enough. 15/40 is as thick as I would go, as an auto technician. 50 weight would be great in a race engine set up with loose tolerances and run in hot weather. Too thick to lubricate optimally in a non-worn-out engine.
#9
Team Owner
Member Since: Nov 2005
Location: Beach & High Desert Southern California
Posts: 25,445
Received 2,330 Likes
on
888 Posts
I bought five quarts of Valvolene, V-1, Hi-Zinc oil for my 1962, 327 solid lifter motor. I normally run the 5-40 weight, however, after changing the oil, I noticed that two quarts were 5-40 and three were 50 weight. I didn't check what was delivered, my bad. Is this an issue I should be concerned about.
Thanks, Jim
Thanks, Jim
The modern concern with heavy oil is oil pump horsepower draw, resulting in lower flywheel power and lower fuel mileage, and the need for quick start warm up to minimize pollution emissions volume during a prolonged warm up.
A separate bit of trivia is that before WW2 most engines were specified to run on straight 20 weight oil, and straight 5 weight in cold and straight 30 weight in hot climates. Extreme race practice employed oil warmers, a common site at venues like Indy and LeMans (including during Ford's LeMans victories in the 1960's).
Blended variable viscosity oils came about to address the WW2 needs of old engine designs modified to operate with high oil pressure and high bearing loads to improve their power output in the quick build up required to win the war. Oil viscosity treatments like STP was the common method to gain a multi-grade blend in the crankcase (and the STP sticker, alone , was worth a tenth of a second off your ET). Variable viscosity oil did not come into fashion until the car manufacturers included them to preserve emissions and warranty demands (much like the growing synthetic oil warranty demands today).
A good practice with old engines is to not exceed a high idle speed until the oil pressure does not rise above the normal operating range. This minimizes the oil volume bypassing the filter. Once the oil is warm, and the filter bypass valve seats, then you are good to go.
The following users liked this post:
Jhemp3 (02-04-2018)
#10
Drifting
Have you noticed any appreciable difference in oil pressure before and after the oil change?
Probably not except at start up. Forget about it.
Probably not except at start up. Forget about it.
Last edited by ejboyd5; 02-03-2018 at 08:15 PM.