What weight oil are you running

-

moparker

Well-Known Member
Joined
May 25, 2008
Messages
2,464
Reaction score
640
I just had my 340 rebuilt. Was wondering is 10w-40 still ok? Im gonna put zink additive in as well. This is all after the break in. I have break in oil for that.
 
If you are not running it in winter, I'd use 30, or 20w50 Valvolive racing or Brad Penn. In winter run 10w30.
 
On my 367 combo;
with an HV pump,a large pick-up, and no 90* adapter,
and having done the oiling system mods per the sticky, except no valley cross-over tube;...15w40 blows oil out at the filter pad at higher rpms. (I have been known to shift at 7000/7200)
Even after; I doubled up the plates and doubled up the holes, and increased the hole sizes, and bored out the filter attaching adapter, and "ported" that circuit as far as I could, from pump to cam, and drilled out the oil-supply to the rocker shafts, and slightly increased the side clearances to the rocker arms.
After I switched to 10W30, all; was good.
 
Last edited:
No reason to run a heavy oil if you don't need it. It just will have a harder time making turns in the galley passages. 10-40 Valvoline VR-1 or Brad Penn.
 
Used it on my last summer road trip to the USA in my '72 318 SSP (rebuilt in 1979).

Castrol.png
 
10/30 here. My bearing clearances were tight. 25w/60 is pretty crazy. High mileage is right.
 
I use to be big on 20w-50. Now I run 10w-30.
Yes.. why compromise flow?

Unless you have unusually large bearing clearances, OP, you should be fine with 10W40.

How are you using the engine? Pure race? Driving around for fun? What part of the country are you in?
 
Rotella T 15w40.
Lots of Zinc, (1150ppm) great temp range for where I drive - New England .
Bearing clearance is where it was factory.
Both my 318 auto and 340 4 speed car get this and no issues.
 
I switched to Lucas hot rod oil, 20 -50. Older 360 with unknown mileage. Duster is only driven in the summer.
 
My hot 360 and stock bearing clearances always used 30 weight straight. For years VR-1. Know using Brad Penn. Also have a case of shaeffer 30wt for future use.
 
10W30 Valvoline and half bottle of Lucas break in treatment. (Zink)
 
Last edited:
Back in the '70's I was putting Penzoil 20w-40 racing oil in my parents new Road Runner, not realizing racing oil was non-detergent to prevent foaming.
 
I just had my 340 rebuilt. Was wondering is 10w-40 still ok? Im gonna put zink additive in as well. This is all after the break in. I have break in oil for that.
do you have the bearing clearance specs?
This ^^^^^^^^

Here's what was posted in:
Oil Viscosity vs Bearing Clearance
and discussed in posts here
Valvoline VR-1 vs. Lucas Hot Rod oil
Your engine builder may have some thoughts on this too.
For street & strip use the following SAE grades:
Rod bearings with
.0015 to .0018 use 20
.002 to .0024 use 30
.0025 to .0029 use 40
.0030 to .004 use 50

For main bearings:
.0015 to .002 use 20
.002 to .0025 use 30
.0026 to .003 use 40
.0031 to .0041 use 50

For general use, its usually better to use a multi-grade.
whateverW Same will provide better lubrication when the oil is not fully warmed up than a straight grade.

Some recommended rod bearing oil clearances for various oil viscosities:
.0015 to .0018 for 0W20 or 5W-20
.0020 to .0024 for 5W-30 or 10W30
.0025 to .0029 for 10W-40 or 15W40
.0030 to .0040 for 15W-50 or 20W-50

For main bearings:
.0015 to .0020 for 0W20 or 5W20
.0020 to .0025 for 5W-30 or 10W30
.0026 to .0030 for 10W-40 or 15W40
.0031 to .0041 for 15W-50 or 20W-50

After break-in, depending on how it was machined, probably best to use a conventional base stock for a few thousand miles.
One current option for a conventional with decent Zddp levels is "Ford Super Heavyduty" meets FORD WSS-M2C171-F1
PETROLEUM QUALITY INSTITUTE OF AMERICA TEST PROGRAM
 
I live near Phx. AZ
And always used penn grade 20w 50
Because I thought it needed it for the heat here.
It used to consume about a quart of oil in 3000
Miles or so, and the lifters would always clatter when starting after sitting more then an hour.
I switched to penn grade 10w 30
It no longer consumes oil and no more lifter clatter!
I don't know exactly why but it's much happier!
 
Interesting about the consumption. I would have guessed the other way for that guessing that would have been more volatile portions to cook off. And I'd be wrong.

As far as the clattering
When the oil is too thick you can think of it like this.
tenor-gif-gif.gif

The pump can push harder, but the additional pressure is not getting more flow to the top.
 
I build my engines on the loose side and run Penn Grade 10-30.
 
Last edited by a moderator:
I live near Phx. AZ
And always used penn grade 20w 50
Because I thought it needed it for the heat here.
It used to consume about a quart of oil in 3000
Miles or so, and the lifters would always clatter when starting after sitting more then an hour.
I switched to penn grade 10w 30
It no longer consumes oil and no more lifter clatter!
I don't know exactly why but it's much happier!
A quart every 3000 is healthy. A quart every 1000 is objectionable and a quart every 500 is a problem.
 
I do the eurospec 0W-40 for finger follower engines
Did not anyone watch the Webinar with Lake Speed last week
said flatly not to use any additives
and I agree
get them blended in
btw no need to run 20 or 10 or 5 W anymore
0W
any questions see Richards Corvair Oil article posted again recently
all the viscosity curves are there
Remember ZDDP only works when it's hot so not for a grocery getter
 
-
Back
Top