Which engine oil

[SteveR]

I am sure this has been asked countless times before but I do not seem to fine in in researching.

 

Which engine oil should be used. I hear high zink, 10w30 to 10w50, synthetic, mineral and a combination of the two

My engine is a 230 Dodge 1951

[Doug&Deb]

You’re going to get as many different answers as there are types of oil. If the engine has never been rebuilt non detergent 30W is recommended unless you drop the oil pan and clean the sludge out. If so then any modern oil is way better than what was used when the engine was new. I use Shell Rotella T 15W40 in my rebuilt 230. The higher zinc isn’t necessary but it certainly won’t hurt. 

[desoto1939]

Here is another question. Does the car have an oil filter install, it might be the type that looks like a metal oil can that can be discarded when it needs to be changed or does if have the type that has a removable lid and then inside the canister there isa removable oil filter?

 

If you  have an oil filter then you can use the multi-viscosity type oils like 10-40W or 5-w30.  I would not use any synthetic oil since they will cause the oil gaskets to leak.

 

ZDDP or the removal of zinc in the older oil was done because of the installation of catalytic converters on our modern cars.  I use Castrol GTX classic 20/50 in my 1939 desoto and this has one of the highest ZDDP rating of any generic motor oil, but can not be used in a modern car with the converter.

 

Also chrysler was ahead of the world when they build their flat head engines and used harden valve sets so running unleaded fuel is not a problem. Some people state thar we need ZDDP and others do not use it at all. It is a personal option. Since our flat head engines are low torque and we do not rev out our engines to high rpms from a stop light the tech person at Castrol stated to me on a phone call that the ZDDP was just an extra additive for the Classic brand. Also of note that there is sill amount of Zinc in modern oils so we still have coverage for our cars.

 

Motor oil is a personal choice. So use the Walmart store brand other more expensive brands. But the oil of today has to meet the standards od the SAE oil composition and wieghts.

 

Hope this is helpful.

 

Rich hartung

[Ivan_B]

15-40/20-50 synthetic.

Worked fine for this Tractor 😅

 

Edited May 21, 2025 by Ivan_B

[QEC]

Unless the inside is cleaner than most 230's you might be inclined to use non-detergent oil as was original. This does not try to breakdown the sludge as 'normal' oil might. The downside is the cost.

Personally, I'd use one of the 15-40 oils and change oil and filter on a short schedule.

[Los_Control]

C'mon fellas .... lets not be spreading disinformation on the forum  .... we can run a full synthetic detergent oil in a older engine that only ran non-detergent oil.

 

I have done a couple oil changes using 5-30 full synthetic with a quart of ATF added to it ....

This thread reminded me that I need to change the oil again before I actually start driving it .... I have a jug of old school Dinosaur oil straight 30 weight Rotella to put back in it.

 

I just spent the last 30-40 minutes under the truck watching the oil drain out and watching all the sludge that came with it.

The 30 minutes was me using a wire and bending it and scraping the bottom of the pan and pulling the sludge out of it.

There was enough sludge on the bottom of the pan, I could feel it moving the wire through it.

Thats why it took 40 minutes, until the pan actually felt clean from a wire .... We all know it is not .... But I would bet $$ there is not enough sludge left on the bottom to plug the pickup tube.

 

Funny thing is, I have a full engine gasket set and air tools .... could easily  drop the pan and clean it .....  I was never accused of being the sharpest tack in the box.

 

 

This is what is coming out of my engine that never ran detergent oil in the past ... stuff is nasty.

But it is coming out of it. .... At some point, I fully expect to pull the head and drop the pan ... I will do things differently then.

You better believe though, a old dirty engine that never ran detergent oil, can drop so much sludge into the pan and clog the pickup screen.

 

My method is maybe not the best, I'm not just getting the pan cleaned out .... the cam, lifters, oil passages .... everything is getting cleaned out and I'm scooping everything I can from it.

 

 

 

 

[keithb7]

When I drain my oil in a pan, then get called away and leave it , then add new oil 2 days later...It doesn't matter what oil I put in it. It flows out the drain immediately and into to the catch pan.

 

Hmm. Still not reading on the dip stick. Add a bit more. Hmm. Wait a second. I look under the car and realize the plug is on the floor. 1 gallon of new oil wasted as it blends with the dirty oil in the drain pan.  Man, getting old sucks.

 

It gets over 100F here every summer so I go with 20W40 or so. No Zinc. No other gimmicks. Just the detergent oil. The oil pan was removed a few years ago. Sludge was all cleaned out. Valve area too. It had a ton of sludge.  Also filter canister was de-sludged. All has been great ever since. 

Edited May 22, 2025 by keithb7

[Ivan_B]

1 hour ago, Los_Control said:

The 30 minutes was me using a wire and bending it and scraping the bottom of the pan and pulling the sludge out of it.

Come on, don't be lazy, drop the pan and clean it out like a man 😉

Also, you might want to wear some gloves, because this stuff in your oil pan is liquid cancer 😬

 

53 minutes ago, keithb7 said:

I look under the car and realize the plug is on the floor.

That's a good one 😅

[Los_Control]

4 minutes ago, Ivan_B said:

Come on, don't be lazy, drop the pan and clean it out like a man 😉

Well yeah I could ..... then I wont have a complete gasket set on the shelf   😕 

 

I just expect to run the engine 6 months or something ..... then be forced to lap the valves and install new rings. .... then I will need those gaskets    

Same time I nave a 1970 Dodge 318 engine with 114K original miles and just needs refreshed as it runs good ....time will tell which direction I go.

 

 

 

[Booger]

This dude I worked with at my service station years ago (gas was .23, thats how long ago) when he would change the oil in his car he would do a hillbilly flush and ad a qt of kerosene to 4 qts of oil. Running it for 10 mins drain and refill. my question is ...krazy or kool? Its petrolium based so...  before I go who remembers the purple oil? We worked at at a Chevron station. What? there were no synthetics back then

[Sniper]

22 hours ago, Los_Control said:

Well yeah I could ..... then I wont have a complete gasket set on the shelf   😕 

 

I have a couple of extra oil pan gasket sets ...

 

Rockauto had a clearance so I bought one, then later they had another clearance and I bought another.

 

I could donate one to the cause.

 

I also have a complete engine set.

[Los_Control]

C'mon  ... I'm just trying to inject a little humor into the group.

 

I have to admit I planned on just a quick oil change .... no big deal.

 

I was surprised at the amount of sludge that kept  coming out  .... so I thought ..... lets get a wire and see if I can assist the sludge coming out.

 

I had no idea I would be there for the next forty minutes dragging sludge out  .... If I had planned it, I would have worn gloves.

 

Thing is, it was such a good thing dragging the muck out .... I was actually cheering every time I scraped out a little more .... my hand got dirty and more dirty .... I just kept scraping.

 

 

So some in this thread has suggested to just keep running non detergent oil and just let sleeping dogs lay.

 

I'm the guy that will run detergent oil and knowing what my issues will be for running such a oil .... work around them .... because it is a better oil.

 

I fully expect to find out in the next few weeks if I will be working on the engine and replacing the rings .... bigger fish to fry soon.

Still happy to flush all the garbage I can down into the pan before I actually open it up.

[Ivan_B]

1 hour ago, Booger said:

Running it for 10 mins drain and refill. my question is ...krazy or kool?

I suspect that this might've actually been good for the engine.

 

45 minutes ago, Sniper said:

Rockauto had a clearance so I bought one, then later they had another clearance and I bought another.

Very good, I also like extra parts 😁

 

2 minutes ago, Los_Control said:

I'm the guy that will run detergent oil and knowing what my issues will be for running such a oil .... work around them .... because it is a better oil.

I also use modern oil and post pictures of my engines. You can "clearly" see the difference.

[kencombs]

22 minutes ago, Los_Control said:

C'mon  ... I'm just trying to inject a little humor into the group.

 

I have to admit I planned on just a quick oil change .... no big deal.

 

I was surprised at the amount of sludge that kept  coming out  .... so I thought ..... lets get a wire and see if I can assist the sludge coming out.

 

I had no idea I would be there for the next forty minutes dragging sludge out  .... If I had planned it, I would have worn gloves.

 

Thing is, it was such a good thing dragging the muck out .... I was actually cheering every time I scraped out a little more .... my hand got dirty and more dirty .... I just kept scraping.

 

 

So some in this thread has suggested to just keep running non detergent oil and just let sleeping dogs lay.

 

I'm the guy that will run detergent oil and knowing what my issues will be for running such a oil .... work around them .... because it is a better oil.

 

I fully expect to find out in the next few weeks if I will be working on the engine and replacing the rings .... bigger fish to fry soon.

Still happy to flush all the garbage I can down into the pan before I actually open it up.

I'm with you on the oil.  Detergent, filter changes and if possible convert to full flow filter in addition to the bypass.   Mine will be FF when I get the nerve to start bending lines.   The block has been drilled tapped and plugged. Borrowed the plan from another member here.   Fittings in the  block and filter mount has been installed.   All that remains is the lines themselves.   I'd like hard lines but not sure I can make the tight bends for a good fit.   It could be done with braided stainless hoses, but hard lines would look so much better.  Then there is the decision as to size.   Some folks have done similar with 3/8" and works fine.   The original line, pump to main gallery, is an odd thing.   3/8" pipe male into the block, then what appears to be a 7/16 steel line.    I'm unable to find that size anywhere.  3/8 or 1/2 is the question, along with hose or hard line.

 

Nicop doesn't appear to be available above 3/8 so that might be the deciding factor.   Could use 1/2" copper, but that would really make the bends difficult.

[9 foot box]

   To answer your original question, I run Valvoline 10-30 conventional oil, part no. 881156. It depends on what is available for you in England. I buy it by the case of 3-5 quart bottles. With the humidity in England, I would change the brake fluid at regular intervals. It might save you a lot of troubles, in the future.

Edited May 25, 2025 by 9 foot box
Spelling

[Doug&Deb]

Reguarding the kerosene I remember using a Napa product called engine flush that had kerosene in it. I used that in my D24 when I got it and changed oil every 100 miles or so until I cleaned it out. Then I ran modern detergent oil with no issues so the kerosene idea is a good one.

[matt167]

Yeah, gunk motor flush is basically kerosene. Works great 

[Los_Control]

On 5/22/2025 at 8:07 PM, kencombs said:

Nicop doesn't appear to be available above 3/8 so that might be the deciding factor.   Could use 1/2" copper, but that would really make the bends difficult.

It does come in 5/16" ... not sure if bigger is better here, is a idea .... I bought my 5/16" nicop from Amazon and lots of choices.

 

6 hours ago, Doug&Deb said:

Reguarding the kerosene I remember using a Napa product called engine flush that had kerosene in it. I used that in my D24 when I got it and changed oil every 100 miles or so until I cleaned it out. Then I ran modern detergent oil with no issues so the kerosene idea is a good one.

I agree also with this .... in my current situation, I was considering to just get a gallon of diesel fuel ... drain the oil and fill the engine, maybe 1.5 gallons.

 

Leave the ignition off and just use the starter to pump the fuel through the oil ports to flush the engine .... I figure it would do a pretty good job to clean things up.

Not sure if diesel or kerosene has more oil in it .... either one would work and cheaper then buying a store bough motor flush.

 

[kencombs]

On 5/24/2025 at 1:05 PM, Los_Control said:

It does come in 5/16" ... not sure if bigger is better here, is a idea .... I bought my 5/16" nicop from Amazon and lots of choices.

 

 

 

5/16th is way to small for the oil lines.   I'm even uneasy with 3/8 even though I know it's been done.   Really want the original 7/16 but it does not seem to be available anywhere.   1/2 just makes it really hard to bend/route in that area.

[QEC]

On 5/22/2025 at 3:52 PM, Booger said:

This dude I worked with at my service station years ago (gas was .23, thats how long ago) when he would change the oil in his car he would do a hillbilly flush and ad a qt of kerosene to 4 qts of oil. Running it for 10 mins drain and refill. my question is ...krazy or kool? Its petrolium based so...  before I go who remembers the purple oil? We worked at at a Chevron station. What? there were no synthetics back then

More than once I have changed oil that way in some questionable engines, only difference is that I used a qt of diesel.  Much cheaper to do with engines that have spin-on filters...but then, if you don't have a filter....hhhhmmmm

[Los_Control]

2 hours ago, kencombs said:

5/16th is way to small for the oil lines.   I'm even uneasy with 3/8 even though I know it's been done.   Really want the original 7/16 but it does not seem to be available anywhere.   1/2 just makes it really hard to bend/route in that area.

I'm not sure I would agree with that

4 different lines here ..... far left is 3/16" and what my truck used originally .... it does for the oil pressure gauge.

1/4" is double the size .... who cares.

5/16" is double the size of 1/4" and triple the size of factory 3/16"     To be honest, I might be skeered to run oil lines bigger then 5/`6" .... afraid it might appear as a oil leak on a bypass oiling system and lose oil pressure.

 

5/16" would be plenty big enough for any oiling system on my flathead 6

 

 

[kencombs]

1 hour ago, Los_Control said:

I'm not sure I would agree with that

4 different lines here ..... far left is 3/16" and what my truck used originally .... it does for the oil pressure gauge.

1/4" is double the size .... who cares.

5/16" is double the size of 1/4" and triple the size of factory 3/16"     To be honest, I might be skeered to run oil lines bigger then 5/`6" .... afraid it might appear as a oil leak on a bypass oiling system and lose oil pressure.

 

5/16" would be plenty big enough for any oiling system on my flathead 6

 

 

This is for the full flow conversion.   So ALL the oil goes through it before the bearings. The original size from the pump to oil gallery  is 7/16ths.

Edited May 26, 2025 by kencombs