positive valve stem seals

[chrysler1941]

Should I open a can of worms and mention 15W oil is too thin at 40 is to thick for these engines. Nope already over-discussed.

[Sniper]

Multi viscosity oil is a good solution for quick oil flow when the oil is cold and normal viscosity once the oil warms up.

 

No downside to a multiweight oil.  Now, which multiweight you choose might make a different.  I run 5w30 usually, 10w30 if I can't find 5w30. 

 

 

[chrysler1941]

I disagree. 5-15W when cold will give you quick flow, but not lubricate engine parts enough as they are made for tolerances for a 30W. 

40W is too thick for warm engine. When hot, any weight will do.

[Sniper]

You realize no oil is worse than thinner oil? 

 

You realize that when warmed up 5w30, 10w30 and 30 wt all have the same viscosity?

 

You realize that the 30 viscosity measurement is taken at 212F oil temperature, which is when it is considered warmed up.  How long you figure it takes that lump of iron we all love to get it's oil temps to 212?

 

You realize that 5w is measured at -30 and 10w at -25 oil temperature?

 

You realize that 5w and 10w30 oil will get pumped up into the engine faster than 30w will when the oil temperature is not up to 212F?

 

The proper choice of oil viscosity is the thinnest oil that gives you acceptable oil pressure.  What is oil pressure?  Resistance to flow.  If the tolerances of my engine was too loose for thinner oil viscosities then I would not have acceptable oil pressure, for the record I have acceptable oil pressures. 

 

Back when I had my Diplomat I would regularly monitor the oil pressure, when it dropped 10 psi from it's normal pressure at highway speeds it was time to change the oil.  One oil change later pressure was back up to normal.   

[chrysler1941]

It's all very logical when you think about it.

 

Flathead engines where fabricated with a certain tolerance and all (GM, Ford, Chrysler) manufacturers back then specified 30W.

Not until ca mid fifties when higher HP engines were in demand, tight specification demanded thinner oil.

Engines today are computer designed and assembled with super finish tolerance with short lifespan, they require 0 or 5W.

 

If your theory is that fast lubrication and thin oil is ok for flatheads, it's your choice. The big three disagree

 

 

[Sniper]

Right out of the 1957 Dodge service manual.  Same recommendations in the 55 and 56 manual as well.  Seems 1954 was the first year of multiviscosity oil so I would not expect to see a recommendation for it before then.

 

 

 

 

Edited October 10, 2021 by Sniper

[Young Ed]

Interesting they show 20w40. I don't recall ever seeing that one but I run 10w40 or 15w40 in all my flatheads

[Sniper]

I had to google it but apparently 20w40 is still made, motorcycles it appears, use it.

[chrysler1941]

This is also what I stated. ca mid fifties when higher HP OHV took over, multi grade was needed.

 

Notice they say "30W engine oil should be used" (meaning flatheads) and later gives you and alternative 10-30 would be satisfactory as single grade oil disappeared from normal consumer market.

 

So a multi grade oil is ok, but a 30W is correct. Nowadays 30W is available everywhere and no need for a lesser substitute. 

 

My car is a hobby, I spent a lot of time and money. Therefore it will get the best oil. 30W

 

This means his 15-40 and your 5-30 are not recommended. 

Edited October 10, 2021 by chrysler1941

[Sniper]

I cannot recall anytime ever that straight SAE30 oil was not available in the normal consumer market.  Maybe overseas, but not around here.

 

Nowhere in the oil recommendations from the manual does it say anything about any differences between the v8 or the L6 in regards to oil viscosity choices.  Multi viscosity oils were not developed because engines made more HP, but because cold oil flow requirements changed based on temperatures.  If you look at the factory recommended choices based on ambient temps you will see that.  All the the multi viscosity oils did was provide adequate lubrication across a wider temperature change, negating the need to change oils based on the seasons changing.  Because straight viscosity oil flow is inadequate at the lower ambient temperatures until the engine warmed up this would cause excessive wear.

 

You've been arguing that multi viscosity oil is bad for the flat head.  I said they were not, though the choice of what exact combo to use might be.  I show factory documented proof that as soon as multi viscosity oil became available the factory had no problem with it.

 

I will reiterate, multi viscosity oil is fine for the flat head engine.  The factory had no problem with it back when it was new and today's versions are substantially more developed than the stuff from the 50's. 

 

 

[chrysler1941]

No Mr. Sniper, I didn't say they where bad, only it's not the correct lubrications viscosity during startup.

 

All my statements are regarding flatheads and when engine is cold. As yourself have stated, all oils are thin when hot. 

You wrote about quick oil flow and using 5-30 as an argument. Thread starter mentions 15-40. I tried to explain this oil is not recommended and nor is 5-30 as they are too thin during cold engine as these have been made with tolerances for 30W.

Even the page you posted says 30W SHOULD be used and gives you an alternative 10-30 as satisfactory. 

 

In my world satisfactory is not good enough when for a few bucks more I can get the correct oil.

 

I also grew up thinking multi grade oil was sublime This is what we were told. No one would ever consider using "tractor oil"

But all this changed after invention of the internet. Today we have access to all the sorts of documents and findings and many of the old urban myths turned out to be wrong or misunderstandings.

 

Anyway this will be my last post in this thread. it takes me 20 min to type all this and struggle with translations.

You use your oil, I'll use mine

 

 

[kencombs]

Re multi vis oils reason for being:  Two things really drove the change to multi grade oils, higher compression and hydraulic lifters.   The first resulted in harder cranking, especially when cold.  The second requires continuous oil delivery from the main gallery, from initial start onward.  Multi vis oils addressed both of those, improving cranking speed and faster oil flow at low temps.

 

They weren't without problems though in the early years.  Most, if not all tended to loose viscosity due to wear.  One of the most popular in my area was probably the first to market, Phillips Trop-Arctic.  My boss (gas station owner) and his wife drove late model cars, 56 Merc 312 and 58 Cadillac respectively.  Both had there oil checked at every fill up and changed at 3000 miles.  Neither used any oil at about 1500 miles.  Both would be at qt low by 2500, and an additional qt at the 3000 mile change.  The viscosity modifiers 'sheared down' as explained to me by a Phillips engineer who was also a friend of the boss.

 

Lots of customers that had lifter clatter on start during cold weather switched to 10w30 and solved that problem.

 

Current products don't have that issue.  My Tundra never uses oil between changes with Mobil one,  Actually branded Toyota, but supplied by Mobil. 0w20.

 

I've used multiweight oil in everything for a really long time with no issues.  Flathead, OHV, OHC etc.

 

The bearing clearances speced by most makers didn't change in the 50s/60s when the multis came out.  Check a motors manual,  no difference over a 20 year span.

[Dodgeb4ya]

Talking oil is like talking politics....good luck!

If you want more...."Bob is the Oil Guy"

Endless oil talk...............

[kencombs]

4 hours ago, Dodgeb4ya said:

Talking oil is like talking politics....good luck!

If you want more...."Bob is the Oil Guy"

Endless oil talk...............

Nope, not goin' down that rabbit hole, again.   Reading BITOG can eat up a day at the computer.

[Adam H P15 D30]

Oil discussions.....  Always lively

I think we can all agree, oil has made significant improvements over the last 70 years, right?  Multi weights of the 50s were marginal at best, right?  All opinion with lots of links to prove one way or another.  aka ZINC

Claims about "old engines are looser" or had larger tolerances than today's engines can easily be proven or disproven.  These claims are often perpetuated here and all other automotive forums but let's take a look.  Let's compare our engine to a modern 5.7l HEMI and we shall see...

Rod bearing clearance: 230cu  0.0005 to 0.0015 / 5.7l  0.0007 to 0.0029 -----  oops

Main bearing clearance:  230cu  0.0005 to 0.0015  /  5.7l  0.0009 to 0.002 ---- another oops

 

Now that we have established our flatheads are actually built with slightly tighter bearing tolerances, this is where is gets less about the numbers...  Modern engines have much shorter strokes and much much lighter reciprocating parts.  Our long stroke, long heavy rod, fully skirted heavy pistoned engines are throwing ALOT more weight around.  This is where a heavier oil is needed for a 'cushion' as the rod bearings are smashed into the journals by all this rotating mass.  

 

Though I did not look up these specs, I would expect our cylinder wall clearances to be larger due to the sheer mass of our pistons and the associated expansion rates that come with that mass.  Another reason I advocate modern, lighter pistons on a rebuild.  There is no logical reason to keep our lead slugs?  Maybe cost?

 

No oil recommendations from me, use what tickles you and I know what weight I prefer.  

 

As to the OP, if you are getting oil sucked UP through your valve guides, adding positive seals is not the correct approach, find and fix the issue.

Edited October 11, 2021 by Adam H P15 D30

[Dodgeb4ya]

On our old MoPars wider clearance or loose worn bearings... worn cylinder walls...I would use a some what thicker oil.

New engine tight bearings, cylinder walls  thinner oils.. say 5/30 over 10/30.

The temperature range when you drive the car sets the type of oil to use as does the type of driving city/freeway etc.

Try out a couple different types/weights of oil including single weight 30.

Drive the old vehicle for a week month what ever.

Watch that oil gauge like a hawk.

IMO ..Use the oil that keeps the oil gauge reading the highest after a long hot drive at idle.

Modern cars ....this doesn't count.

Only use exactly what's stated on the oil filler cap or owners manual.

A must on newer cars.

[belvedere]

The argument that multi-viscosity oils such as 5W- and 10W- are “too thin when cold” makes no sense.  A cold 5W30 has a MUCH higher viscosity than a hot 30.

[Dodgeb4ya]

Oil pressure gauge tells all.

But also think of amount of oil flow volume....and on and on the oil story goes?

Edited October 11, 2021 by Dodgeb4ya

[49D-24BusCpe]

 

    The factory recommended oil for my brother's 840hp 2018 Challenger Demon is Pennzoil 0W-40!

[bigdaisy19k]

49 minutes ago, 49D-24BusCpe said:

 

    The factory recommended oil for my brother's 840hp 2018 Challenger Demon is Pennzoil 0W-40!

It's amazing what a good polymer can do.  Also, there's a whole testing service built around oil, SN was the last rating I remember, but as long as it's the highest S* rating it's good for anything built before that rating.  Mostly just don't let the oil oxidize past 90 days or so, once the additive package is used up change it.  No matter if it sat over time or ran the mileage.  Now using C-* oils rated for diesel engines is ok, but the additive package is deferent as CGI metals and high load cam facings require their own grading.

Modern engines run variable displacement on oil pumps to control oil flow for fuel economy.  It really is a rabbit hole as previously noted by other posters.  

 

Bottom line on sealing the valve stems, if you changing the guide material anyway, it might be fine.  But it's also your engine to do as you like, so we don't much matter when it comes to that end of it.