5w 30??

[1956322]

Anyone running a 5w 30 in their nailhead

[Beemon]

5W-30 seems a little thin, the book calls for 10W-30 and 20W-50 given the ambient temperatures. My last oil change I went from 20W-50 for the summer to straight 30W so I can see the oil pressure.

[1956322]

I normally run castrol syn 5w 50 but noticed it takes a second to build pressure and it's slow.. The previous owner was running castrol  gtx 5w 30 and it would build instantly and quickly... Hence my thinking of going back to that

[old-tank]

Why the concern over oil pressure rise?  As long as there are no rod or main bearing knocks on startup during the 'pressure lag', use the higher viscosity oil.  20w-50 or 30 would be more appropriate for a nail since those primitive engines expand and contract much more during use than modern engines.  And if the pistons have been changed to the available junk, you probably have some piston slap noises when cold and made worse by the lower viscosity oil or if shut down when extremely hot with any oil.

On the other hand, any oil if changed regularly will outlast you.

[Barney Eaton]

I believe where you live influences the weight you should choose.

In most cases we are talking collector cars that are seldom driven in temps below freezing.....so why use a thin oil.

5 weight oil is designed for easy starting in cold weather.......if it is not cold you don't need a thin oil.

 

[Airy Cat]

I have been using 10w-30 in all of my Buicks for the last 40 years and have had no problems with the engines.

[1956322]

I think this next oil change I'm going to try castrol gtx 10 30... Not really concerned with pressure rise just couldn't help but notice that with the 5 30 it pegged quick compared to the 5 50 I guess my assumption was if it pegged the gauge that fast it would be reaching other areas just as fast 

[NTX5467]

You have to consider the ambient temperature of the oil in the pan when the engine is started.  I believe the low number if for, basically, 32 degrees F (maybe 0 degrees Centigrade?), where it's got to be "thin" to flow well.  Higher ambient temperatures will result in a viscosity between the two numbers.  The other consideration is how long the vehicle is inactive between starts.  When 0W-30 came out, there was wondering why it was needed.  One of the reasons was that it got oil to the innards of the engine's oil galleys about 30% faster than the more normal 10W-30 oil did.  Hence, less "cold-start" wear.  But this might be splitting hairs, but it made good advertising copy!

 

When my '77 Camaro was new, for the first oil change (and for many 100Ks later) it got a popular 20W-50 oil.  When the temperature was in the 20s F, on the first cold start in the morning, it would turn over a little bit slower, but when it started (quickly), there was ONE lifter tick and then that went away.  One tick and then it got quiet as the oil filled it.

 

When the Nailheads were new (advanced for their time), I suspect the manual would recommend 30-weight for temperatures consistently above freezing.  20-weight down to 0 degrees F, and probably 10-weight for "polar" regions?  That tells me that the clearances would tolerate those thinner oils pretty well.

 

It was claimed that the early-1960s' 10W-30 multigrade oils would be more like 20W-20 after about 1000 miles of use.  Probably due to the earlier chemistry not being nearly what it is now.  The later-1960s oil chemistry allowed the old "super oils" of 10W-50 viscosity levels that would work as well in Alaska/Canada as in a TX summer.

 

With that background, I think I'd be fine with 10W-30 as that was the default replacement for straight-weight 30, back then.  I like that "C"-brand no-viscosity-break-down brand, too.  Modern oil chemistry doesn't need the higher viscosity numbers to work, as earlier oils did, for the best protection.

 

Your judgment call,

NTX5467

[avgwarhawk]

You should be fine with 5w-30.  I would not go lower. However, the manual recommends 10w-30.  

[avgwarhawk]

13 hours ago, old-tank said:

Why the concern over oil pressure rise?  As long as there are no rod or main bearing knocks on startup during the 'pressure lag', use the higher viscosity oil.  20w-50 or 30 would be more appropriate for a nail since those primitive engines expand and contract much more during use than modern engines.  And if the pistons have been changed to the available junk, you probably have some piston slap noises when cold and made worse by the lower viscosity oil or if shut down when extremely hot with any oil.

On the other hand, any oil if changed regularly will outlast you.

Concur on all Willie has posted.

[Barney Eaton]

I know this started with a question about what weight oil to use but that old zinc question came up.

Look at the Petroleum Quality Institute of America web site.    http://www.pqiamerica.com/

with a little searching you can get info on different brands of oil......also transmission fluid and antifreeze.

 

Here is what I found.......this is not all the oils,  just random brands I chose and looked at their zinc content.

Super Tech Heavy Duty (Wal Mart)   1,298

Shell Ro9tella T4 Triple (Diesel oil)  1,203

Valvoline Premium Blue (Diesel oil)  1,141

Mobil  Delvac 1300 Super (Diesel oil)  886

Super Tech Full Synthetic (Wal Mart)  838

Valvoline full synthetic   828

Amsoil  synthetic        826

Royal Purple synthetic  813

Edited August 20, 2017 by Barney Eaton (see edit history)

[1956322]

I didn't see any 10w 30 listed but looking at the castrol 5w 30 it has about 800ppm zinc which is supposedly what was in the oil back in the 50s

[old-tank]

Oh goody, zinc again.

Has there ever been an oil related failure in stock Buick engine due to lack of zinc? 

[Beemon]

Where did the zinc question come up?

[Barney Eaton]

My fault......continue on with normal business

[avgwarhawk]

9 hours ago, old-tank said:

Oh goody, zinc again.

Has there ever been an oil related failure in stock Buick engine due to lack of zinc? 

 

Not that I have detected.  Many run todays brands without issue.  I purchase Lucas Classic Car oil.  Cost about the same as other brands.    

[1956322]

Zinc didn't really come up although that was one of my concerns about running regular off the shelf oil..I  know  see it's a myth that really shouldn't affect most people

[Beemon]

Zinc isn't a myth, there's a reason why it was in the oil. But there are many other detergents and substances in modern oils that do equally, if not a better job than oils from 60 years ago. It's like people who say you need a PCV on a road draft tube car - it works great but under load when blow by is at its highest, there is no vacuum to pull the vapors and a road draft tube in that circumstance is definitively better. Too much reading on the Internet can get you into trouble quick if you don't use your own noggin, as I've come to learn anyways. 

[NTX5467]

IF the vehicle is not moving, those vapors are on their own to escape the crankcase.  The PCV valve at least gives some consistency to the pan evacuation activity.  On some modern engines, the "pcv" valve is just a gutted housing.  Time spent at low manifold vacuum levels is minimal compared to part-throttle and idle mode operation, by observation.  

 

Modern highways have much cleaner pavement than in the earlier '60s when all cars had road draft tubes and those tubes' vapors ended up on the pavement of highways and such.  Know what oil does when combined with moisture?  Other than "milky gunk", other things can be detrimental, too.

 

NTX5467

[1956322]

You're right zinc isn't a myth what is a myth is that there is zero zinc in modern oil.. That's not true even slightly.. What's also a myth is that there's not enough zinc in modern oil for old engines also not true for the large majority of old engines out there...

[60FlatTop]

15 hours ago, NTX5467 said:

Know what oil does when combined with moisture?  Other than "milky gunk", other things can be detrimental, too.

 

That reminds me of how cars stored in unheated locations with vented engines can condense water in the crankcase during temperature changes. Quite a bit can settle in the pan. And I have seen amazing amounts of water run out of rear ends and transmissions that have been sitting in junkyard piles.

 

Then you hear the old fable "Yep, she was sittin' in that barn near 30 year and we put in a fresh battery, a little gas in the carb and she ran like new." That story has made me cringe every time I hear it. And I am sure I will cringe again.

 

Some of those guys can go into the deepest detail on zinc, oil weights, and additives.

 

Anyone out there with a long term stored car who hasn't changed the rear end juice? Or did you do that when you put the new bearing in?

 

Zinc may not be a myth, but it could be a distraction.

 

Bernie

[KongaMan]

1 hour ago, 60FlatTop said:

Some of those guys can go into the deepest detail on zinc, oil weights, and additives.

 

You want deep?  Take a cruise through the Bob is the Oil Guy (BITOG) site.

 

1 hour ago, 60FlatTop said:

Anyone out there with a long term stored car who hasn't changed the rear end juice? Or did you do that when you put the new bearing in?

 

That's a problem with these cars: it's such a PITA to change the fluid.  I flushed the differential in a different rig yesterday.  It took well under an hour (not counting RTV cure time) to drain it, pull the cover, clean it out, clean the mating services, reinstall, and refill.  Didn't even have to jack it up.  To do the same thing on this car, you need to disconnect the drive shaft, pull both axle shafts, pull the carrier, etc.  Not to mention that's a lot of time spent flat on your back.

 

This is where you hit the intersection of efficiency and mission creep:  I want replace the rear control arm bushings. It seems to me that it's infinitely more sensible to pull the axle completely, clean and flush the differential where it's more accessible, then put it back in with new bushings and a new brake hose.  And while you're doing that, is it good maintenance or looking for trouble to replace various 50-year-old bearings and seals that you encounter?

[Beemon]

46 minutes ago, KongaMan said:

 And while you're doing that, is it good maintenance or looking for trouble to replace various 50-year-old bearings and seals that you encounter?

 

IF you can find them

[60FlatTop]

I have worked with a lot of mechanics on cars as a hobby and building or power plant mechanics to raise money for groceries. I would never be one to stereotype, but I can make generalizations from my experience.

 

A mechanic who would go into a deep discussion such as this would be a schmoozer. He would wear pressed jeans and shirt, have shined shoes, and a haircut never over 10 days old. All the people on his "walking route" would know all problems were caused by poor engineering design. Remember George Clooney the maintenance man?

 

That's the guy. Most recently he wanted to redesign a heating system due to customer complaints. I used leverage as an outsider to get him on a ladder above a ceiling with a bucket and hose to flush out a mud filled coil. He was not the least bit happy, system worked fine afterward, though.

 

That is the kind of thing that happens with old cars, too. Especially lubrication related items. Old grease and oil. Moisture and water contamination, almost any kind of rubber boot.

 

Above all, I think the rear end lube suffers the most. It is hard to change, sometimes  hard like you have to drop the pumpkin. But once you do, one sniff and you know it is due. Years ago I did three successive changes and flushes with 30 miles of driving between each of a fairly well known Pierce-Arrow convertible coupe. Each flush went into a plastic cup, from black to honey, it was dramatic. All done through one third member bolt hole.

I called Penzoil that time and was assured their 90W gear oil was a fine replacement for any vintage automotive application.

 

But you gotta get dirty.

Bernie

Edited August 22, 2017 by 60FlatTop (see edit history)

[avgwarhawk]

I zinc we have it.