My neighbor has 5 drag Mopars in his family and has been using Schaeffer's oil for years.
Is 20W-50 too heavy for my 340?
- Thread starter 340inabbody
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I just changed my 360 out from 10-30 to 20-50, oil pressure with the 10-30 would bottom out in gear when warm, now I hold steady at 10-50 pounds idle to under load. For reference its a mostly stock 1973 360 that as far as I know hasn't been rebuilt, so my guess is the bearings are pretty loose. It just depends on how worn the engine is, but if it's mostly stock I'd say your fine, especially with the Temps your working with
furrystump
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I run that exact oil, have forever. I’m sure I’m leaving HP on the table with it, but it’s working for me.
68 Coronet RT
68 GTS # 508 in Registry
Mobil 1 has a new 0W40 full Synthetic Super Car oil; I have been running it in my 440 and have very good oil pressure and I like the fact it lubricates very well at start up especially with my roller cam
I have mentioned this previously, but I formulated Delo 400 for Chevron for 6 years and did additive development for 12 years. I run Delo 400 SAE 15W-40 HDDO in my older vehicles with perfect success. HDDO Heavy Duty Diesel engine Oils) have the same Zinc content as older oils and work fine with flat tappet cams. Ran my '66 Hemi, '67 383 Cuda and '68 340 on this oil for decades. The HDDO has much more additive than conventional oils and really keeps the engine clean plus protects the cam from wear. Other similar products are Shell Rotella T and Mobil Delvac 1300. All will work. You can special order SAE 10W-30 which is perfect for older street engines. I do 3,000 mile drains to keep the oil fresh. Doesn't hurt to have clean oil.
15/40 Good stuff, least back in the 80's. Ran it in everything from Mack trucks, Cat dozers, fork lifts, even in the salesman cars. Salesmen beat the crap out of those cars. Only one flat chevy cam out of 10. Most had over 100K when we ordered up a new fleet. Macks 400K before rebuilds.
Really everything that took oil.
Ive been using Brad Penn (Penn Grade HP Oil) 20W-50 synthetic blend in my 3 cars for years now. No complaints.
Dave
Dave
We can keep saying what "we" use all day long here. The only real question is..."what does the OP need". He has yet to declare what he WAS using and the need if any to switch to anything else !
QuickDart360
Well-Known Member
I currently run Brad Penn 30wt in my 360 dart sport. Works great. I recently purchased schaeffers 30wt. Have heard good things about this oil. What do you all think?
..and everyone continues to miss the point. It's not about "you" !
Yup.
OMG
Run the thinnest oil you can still hold oil pressure with.
ya THINK?
The past is a little gray for me as it was 4-1/2 years ago AND another lifetime. It is indeed possible that I used the 20-50 VR1 just prior of shutting down for restorative work. I recall seeing “low” oil pressure from my inexpensive electric oil pressure gauge but never documented it nor verified it that I can recall with an accurate hard lined pressure gauge.
What I do know right now is that I currently have 5 quarts of 20-50 VR1 and using a mechanical hard lined oil pressure gauge measure 60 psi using a drill to prime @2000 rpm drill speed.
I have unfortunately gone medical again and can’t do anything at this point. Hoping I can get back on my feet soon god willing…
MOPAROFFICIAL
Oogliboogli
It's fine. Nothing wrong with a little extra viscosity.
When we share our experiences, it gives him valuable info. It's passing on knowledge and real time use of different oils.
I get that, but everyone saying what THEY run meant nothing up until the point that I wrote that! The OP had yet to tell anyone what he was originally running, when he asked about "switching".
Swinger 340
Well-Known Member
On one of my older 340's years ago, I ran 10W40, to 100,000 miles, then changed to 20W50, until 175 miles, then went to 50W, until I blew it up. By changing the oil viscosity as the motor aged, it kept the oil pressor up as needed. The reason a good oil gauge is important. I run 20W50 on my other 340's I use today. They have around 75,000 miles on them.
The 20/50 will run fine. It's not what I would run or recommend, but big whoop. I know this much. Every single person (and that's a lot) I've ever seen talk about 20/50 online or in person says they've gotten great service from it. I had some, I tried it and didn't like it. But that doesn't mean you'll have the same reaction, so run it. It certainly won't hurt anything.
Swinger 340
Well-Known Member
Every app. is different. There is no one answer. A all-out race car, I would use a thinner oil, as you say, but I would also use a High volume oil pump, which would also mean a deeper pan.
Newbomb Turk
Well-Known Member
Thinner oil needs neither a deep pan or an HV pump.
I’m going to run 0w20 on the street. I may end up with a 5w30 if the mains are a touch on the loose side but I’m banking on that 0w20.
One thing I think people miss is what the gauge says isn’t even close to the hydrodynamic wedge that’s formed in the bearing clearance.
As the clearance is opened up that greater space even with a 20w50 won’t have the same wedge developed. So you have less load carrying ability with the wider clearance.
When I was running aluminum rods the big deal was to send them out with at least .0035 clearance. That’s HUGE but at the time that’s what everyone said.
And the rod bearings always looked like roasted dog ****.
So I started closing up the clearance and the bearings looked better every time.
I forget where I ended up for clearance but it was probably a bit under .0025 or so.
It was on alcohol so I had to run a 40 grade oil to keep the rings sealed.
Which is one other reason I won’t do alcohol fuel again.
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