Mopah340
Member
10w30, 10w40 or 20w50 oil
Oil
- Thread starter Mopah340
- Start date
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Diesel, gas or jet engine?
Race engine? Northern or southern climate?
Info will help.
Race engine? Northern or southern climate?
Info will help.
Mopah340
Member
Massachusetts, summer only.
Oh no.
Mopah340
Member
I know. Another huge can of worms.
That didn't tell us much.
0-20w. ish
Mopah340
Member
Sorry guys I’m having technical difficulties here. Purchased matching #s Dart Swinger 340 4 years ago. Lots of documentation with car. Except for engine. Hand writ note saying “bored 30 over, hydraulic H cam. Purple bigger, compression ratio 10.5:1” I’ve been running VR1 20w50 based upon recommendation of local speed shop, but recently was told that oil was too heavy. Thanks guys!
I run 10/30 Valvoline Conventional and Rislone Zinc additive. I don't think you need 20/50. A 10/30 or 10/40 would be fine. Just make sure it has zinc (zddp) in it, usually 1000-1200ppm.
15w40 is an option. You're going to get 100000 different opinions.
I followed advice 40 years ago, Valvoline racing 20w50 is all I use in my Mopars.
never strayed and never had a failure, not one wasted cam.
I have to wonder about all the cam failures of recent years.
I followed advice 40 years ago, Valvoline racing 20w50 is all I use in my Mopars.
never strayed and never had a failure, not one wasted cam.
I have to wonder about all the cam failures of recent years.
I wonder when Tarzan is going to arrive. LOL
Man, just run 10w30 in the thing like Chrysler recommended. This ain't rocket science. Simply make sure to run an oil with plenty of ZDDP or run an additive. I run 10w30 Lucas Hot Rod Oil in my 75 F250 and in my 64 Valiant. It already has 2400 PPM of zinc. That's all they need. No need for anything fancy.
I tend to agree, but, if his oil pressure isn’t spectacular with the 20-50 going to 10-30 might not be ideal.
My factory 1973 W200 360 93000 miles 60 cold and 45 hot at idle rebounds quickly to 60 hot.
20w50 during the summer and 10/40 during the winter since 1983.
Quite respectable with factory tolerances. Would probably also be just fine with 10-30, ‘cause you don’t need 45 psi at hot idle.
Frank Mopar
Well-Known Member
Bearing clearance dictates oil weight.
Bulldozer
free ice cream sandwiches
the search feature for "oil" will turn up 200 threads. but ok, I'll play, 10/30, 10/40, 15/40 , but my advice is to use at least one quart of high ZDDP break in oil , or additive , well , just because I do and I have never lost a cam, lifter, or bearing
famous bob
mopar misfit
Interesting, I started my engine yesterday, about 35ish degrees , (not sure) . The oil presdsure was slower to come up than I`ve ever seen , and climbed way slower than I `ve ever seen. I let it get to operating temp on the gauge , and the pressure still dint come up to what it usually does. It has recently new 15w40 in it , from a main seal cap change .
I had a hair over .002 clearance when I put it together about 8ish yrs. ago . Hoping I didn't hurt the bearings , ether need warmer weather or lighter oil !
Mopah340
Member
I need to get a pressure gauge installed. It’s all original with original Rally Dash. All gauges operational. Oil pressure gauge slightly over 1/2 way point on start up and 1/2 way consistently. I’m a purist and didn’t want to add gauges to the interior. I may tuck a small one under the dash.
20w-50 with zinc is fine for summer only. Been running it for decades... Main thing is quality oil and zinc. 30, 10w-30, 20w50 it's all good.
Mopah340
Member
I’ve been running Valvoline VR1 20w50
(the VR1 with zinc in it)since I’ve had the car for the past 4 years. I run it spring, summer and a little in the fall on nice days here in Massachusetts. I change the oil at the end of every season, roughly every 1200-1500 miles.
You should should be good for the rest of your life.
thesiren74
Well-Known Member
Just use vr-1,it's one of the best imo.
OK. I'm going to try to connect the dots here for you.
Oil viscosity changes dramaticly with temperature.
The thicker the oil, the more difficult it is to pump and push through the galleries.
When the oil is cold, it is so thick that even at idle a bunch of it goes out the relief valve on the pump instead of through the engine.
When the oil gets up to operating temperature it needs to be thin enough that plenty flows through all the way to the top. It also needs to be in enough quantity and at high enough pressure to float all the bearings. In other words the metal parts should not touch but be supported by the oil flowing between.
So....
The oil pressure gage should show relatively high when starting. The actual temperature makes a difference.
The oil pressure on the gage at idle should go down as the oil warms up.
The oil pressure should be around 10-15 psi at idle and go up with increasing rpms. Old rule of thumb is 10 psi for every 1000 rpm.
It likely will max out at some rpm. That's normal. Might be 4000 rpm. Could be lower, could be higher.
That said, running too thick of an oil will cause the oil pressure to max out at too low of an rpm, and could result at oil starvation at much higher rpms.
Observe the temperature gage, the weather conditions, and the pressure gage. Then you can decide.
Unless it was intended as a race engine, or is really worn, its probably not that loose.
I'd start with a 10W-30 or 10W-40 and go from there.
With a purpleshaft it likely has higher pressure valve springs, so an oil using anti-wear package with decent amount of Zddp is a good idea.
However I would not fret over it either.
Ford Superduty 10W-30 is a relatively inexpensive and readily available choice.
Brad Penn has a wider selection of choices but is less readily available.
Some of the racing oils have less detergents and so forth, so check with the manufacture's info whether they are suitable for street use. Obviously you can ignore any concerns about catalytic converters.
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