Old Mopar Flat Head Engine Oil & Additives Poll....

[keithb7]

I am curious what folks are using for engine oil. Are you adding anything else if at all to your oil, in an attempt to slow down metal to metal wear? I've read  lots of opinions on ZDDP Zinc additive.  We've all heard about the tappets that may suffer early wear. Or maybe the camshaft lobes are suffering accelerated wear? Perhaps its the carbon build up in the top ring and valve seats that you focus on?  Or it's the additive that helps quell your excessive oil smoke out the exhaust pipe.

 

For the sake of interest only, among the members here, take the poll. It'll be interesting to see what folks are doing for oil and additives.

Feel free to add your comments. The poll is anonymous. Any data collected will not be used for anything other than sheer interest and discussion among us here in the P15-D24 group.

Have fun! - K

[desoto1939]

I run 10w-40 oil in my rebuilt engine and have done this since the engine was rebuilt.  Use regular 10w_40 oil right off the self.  Do recomend that you use a good breakin oil when fireing up the car for the first time after a total rebuild or even partial rebuild.

 

I have owned my car for over 32 years and have the bypass drop in filter. The car originally came with the PB1/2 trough away filter but changed to the metal canister when these old PB1/2 got to expensive.

 

I do not run any synthtic oils in the car still old regular oil and lubrications

GL1 in in trans  GL5 in rear and sterring.

 

Still not sure onthe ZDDP but a little STP can also help on a rebuild.

 

Just my 25 cents worth of input

Rich Hartung

desoto1939@aol.com

[Doug&Deb]

I use shell rotella 15/40 diesel oil. I figure a little extra zinc can’t hurt. I’m not convinced it really matters but why not?

[Tim Larson]

I am using a 30 weight non-detergent from Napa and a zinc additive.

 

Based on what I can tell my '49 Plymouth engine has never been rebuilt and it does burn oil and leak oil. Every time I park somewhere there will be a small dot of oil when I leave... The garage where I store it during the summer has developed a large area of oil so the rear seal is probably needing to be replaced.

[Doug&Deb]

It’s just marking it’s territory.

[Hamilton]

I've owned vehicles in which I used a zinc additive.  The `49 Plymouth I've owned for 30+ years (and my very recently-added '49 Dodge) isn't one of them.  I believe the combination of very limited RPMs, light (relatively speaking) valve spring pressures and very moderate cam lobe ramp angles make it unnecessary.   Will this approach eventually "wipe" my cam?  Only time will tell.

 

_

[Sniper]

I run 10w30, whatever the latest spec is.  Extra ZDDP won't hurt, but I'm not paying more for extra as my research into it really tells me it's not needed for a stock flattie.  But remember, my research means I pay the price if I'm wrong, so YMMV.

[Los_Control]

As a old carpenter that never rebuilt a automobile engine before. I have rebuilt older small engines for equipment.

I would be very careful on proper break in oil for our engines. After that, I figure anything on the shelf is way better then anything available in the 40's-50's.

I agree with @sniper here, I use castrol gtx ultraclean  from walmart in everything. 5/30 in wife's car, 10/30 in my cheby, using 10/40 in my old dodge.

I do get particular on the oil filters, I wont buy the crap walmart sells. Local parts store sells wix and Is same filter Napa sells with different name and price.

I have watched videos of dissecting different oil filters. Fram is the worse, all paper and cardboard inside. Accident waiting to happen. WIX is all steel and wire and welded & is good construction.

 

Without even reading through the previous post, I bet at least one is going to say to use a non detergent oil. Modern detergent oil will clean the old crap out and clog the pickup screen.

Thats exactly what I want. I will have to keep a eye out on the oil pressure gauge, drop the pan when needed, maybe even twice ... I want the motor cleeen! I will go the extra mile to get it clean.

Just all my opinion, worth what you paid.

[JBNeal]

When asked about maintaining older engines, I tell ppl that the cheaper store brand oil is the same as the more expensive name brand oil if'n ya compare the packaging, as the only difference will be the label...look at the container and the cap, and there's the answer as to which refinery it came from, kinda like them fuel delivery trucks go from station to station, delivering the same product in their tanks with different signs out front...$$$ is best spent on the high quality filters, like Wix, Baldwin, and Fleetguard, cuz oil doesn't kill an engine, but contaminants (and lack of oil) sure do

[RobertKB]

I use 20W50 in my engines with a lot of miles. I add STP also as I find the oil pressure stays higher when hot with it added, especially at idle. 
 

In my newly rebuilt engine in my ‘51 I use 10W30. 

Edited September 6, 2020 by RobertKB

[Sniper]

What's interesting is the FSM spec on oil pressure.  at idle any pressure is good, lol.  At 30 mph I think it's 40+ is good.  I meet those specs on 10w30.

[Plymouthy Adams]

the rule of thumb on these engines is 10psi per 1000rpm....and I think this is quoting the low side...

[Sniper]

That rule of thumb is from the SBC, not our flatheads.

[PT81PlymouthPickup]

I've been using Mobil 1 synthetic 10w-30 in my flathead. It's expensive and probably overkill, but having once worked for Mobil Oil Research and Development labs and witnessing engineering tests they did on this product, I was sold. I'm not sure about all synthetics, but one of the things that sold me was Mobil 1 will withstand extreme heat compared to all conventional oils. I figure it's cheap insurance in case the cooling system were to fail.

[James_Douglas]

I use straight 30 or 40 without any additives. The ZINC thing is in my opinion much ado about nothing. Years ago I talked with someone who does the testing of engine oils for a very large organization. They set the oil standards. They have a room of engines that are the most blueprinted and checked engines in the world. They have to be to detect what oil does or does not due to them.

 

They have found no wear issues with or without zinc in the engines. Period.

 

They have found that a number of camshafts in the 1990's, when a LOT of cam production moved out of the USA, hard issues with Rockwell Hardness on the lobes.

 

I suspect that proper hardness treating of cams and lifters drove much of the speculation about Zinc. I could not find one single "hard science" document on the subject. A lot of opinion, but nothing approaching the folks I know that actually ran engine with and without zinc and measured the wear differences.

 

My 1947 Desoto Suburban engine I built 15 years ago. It has about 70K miles on it. I run it in the Hills of San Francisco and the Interstate to my place out of town at 70 MPH. The car is about 5000 pounds. I looked at the cam a while back with the side covers off and a bore scope. The cam was NOS when it went in. It looks fine with no evidence of advanced wear. I never used any zinc.

 

James.

[laynrubber]

Fresh rebuild with 1800 miles. Rosella 10W30, with zinc added for first batch of oil.

[Worden18]

I have over 10k on the Meadowbrook's engine rebuild.  I've used Castrol 10w-30 and Rotella 15w-40.  No problems to report.  My builder only polished the original camshaft during the rebuild.  He said it was within spec and looked good.  I don't worry about how long any of it will last.  I've driven in severe heat and cold, rain, wind, snow.  The car will probably outlast me.

[Adam H P15 D30]

How many threads on this??  Our old flatheads with low valve spring pressures, and no rocker geometry probably don't require zinc.  Run too low of zinc in my HEMI and it will wipe a cam in short order.  Chinese parts make it worse and happen quicker

[HotRodTractor]

So roughly 20 years ago, someone gave me a bottle of ProLong engine additive when I graduated high school as part of a gift basket knowing that I was into cars/trucks. I never put much stock in any additive - but I decided to try it in my tired old 53 Pilothouse. I had already cleaned out the crankcase and was running modern detergent oil in it. I started the truck up, and gave it a quick drive around the block to get it up to temperature. With it RUNNING, I poured the contents of that bottle into the engine. Within seconds the tone of the engine changed, it quieted down and smoothed out a bobble that the engine had at idle. The truck didn't act as tired, and it certainly sounded better all around. Since then - I've used it on any unknown engine that I get into my possession. 

That said - I repeated the same exact experiment when I got Don's car up and running, hoping the catch that scenario listed above on video. It made zero noticeable difference to me. I assume that is because Don's engine was rebuilt and only had modern oils used it it since that time.

 

Its very likely that the 53 Dodge simply had an issue from age that the additive corrected, and every time I have used it since has been a waste of money. 

Take that information and do with it as you like.