Jhemp3

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

J.Moore

You mean 3 were 5-50? If so then I wouldn't worry. If 3 were straight 50wt. then I would drain it and get it right.

Frankie the Fink

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...

GTOguy

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.

karkrafter

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.

Jhemp3

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.

Dave Tracy

If you lived in Alaska, that would be a different story

tuxnharley

50 wt is too thick for a good condition street engine. Remember that good oil flow thru all engine passages - some of which are very small - and return to the crank case/ oil pan/pump are requirements of good lubricaion!

63 340HP

The greatest hobby driver concern with heavy weight oil is the time duration after start up that it takes to warm up and thin out the oil to seat the filter bypass valve. Thick oil bypasses the filter on start up, resulting in any debris in the sump next to the oil pump pick up being pumped around the filter and through the bearings. A new clean engine is not at much risk, but one with miles and poor filtered crankcase air ventilation can collect and pump debris into the oil galleries on every cold start up.

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.

ejboyd5

Have you noticed any appreciable difference in oil pressure before and after the oil change?
Probably not except at start up. Forget about it.

babbah

Ive been running 20-50 VR1 in my BB for decades - no issues whatsoever.