[theriots]

is this oil too heavy for my 400 smallblock?

 

[SWHEATON]

What oil are you currently running and whats the oil pressure with motor hot @ idle & at cruise?

If its a fresh motor or motor with not many miles on it 20-50 isnt the best choice,10-30 or 10-40 would be better choice in that case.

But if the motor uses some oil ,has considerable miles on it then you could try 20-50 but i would not run 20-50 below approx 45-50derg f.

BTW,if its a flat tappet cam'd motor make sure your running oil with the proper/elevated zddp lvl thats important for FT cam longjevity.

scott

 

[JJ'65]

Yes; much too heavy, Where you live: 10-30 summer, 5-30 winter.

 

[Guest]

Yes; much too heavy, Where you live: 10-30 summer, 5-30 winter.

Actually, 5W30 is better than 10W30 all year long. Because they are both 30 weight at normal operating temperture. But at cold start-up, the 5 weight of the 5W30 will flow better/quicker to all the engine components, than the 10 weight of the 10W30, no matter what the ambient temperature is outside. There is no reason at all to run 10W30, if 5W30 is available in the oil you want to run.

 

[SWHEATON]

I respectfully disagree ,in anything but very cold temps like 0-20deg f 10w base oil in a 10-30 oil pumps up just fine/fast enough and isn't an issue at all.

The motor oil temps charts i have read from oil mfg's rate 10-30 safe down to 0deg f but to be safe i would not run it below 20 deg f.

The reason why i prefer /suggest 10w 30 over 5w-30 for street perf BBC/SBC motors is because the base stock 5w oil in a 5w-30 oil can shear/reduced in viscosity before the 10w base oil does in 10w-30 oil not to mention the additonal chemical additives in 5w-30 to get to 30wt when hot.

I have read oil tests done over the yrs that showed just that point so i feel going with 10w base oil in a 10-30 multi viscosity oil you get a little better protection against thermal/viscosity breakdown vs 5-30.

Another point is that they need to add more chemical additive to get 5w base oil to 30wt oil when oil gets up to proper operation temp then going from 10w base oil to 30wt oil when hot making the 10-30 a little more durable/stable then 5w-30 for hi perf use.

Are hi perf motors going to blow up because they are running 5-30 oil,not likely. But it still doesnt take away from the fact the 10-30 oil did a little better then 5-30 did with all else being = in the oil tests i had rvu'd . Again,that was due to the 10-30 multi visc oil having a 2x higher visc base oil (10w vs 5w) along with it also requiring less chemical additives in the oil to get it from 10w to 30wt when hot vs getting 5w oil up to 30wt oil when hot.

When both thoses oils are at proper operating temp the 5w-30 with lower visc 5w base oil & more additives to hit 30w sheared/broke down a little faster viscosity wise . It wasn't a day & night difference but non the less the 10-30 did better overall then 5-30 did & thats the point.

And the 10w base oil in a 10-30 on cold start isn't an issue at all in the temps we run these cars/motors in .

Starting/running a motor in a daily driver in 0-10deg f temps would be a different story and in that case i woiuld prefer 5w-30 over 10w-30 but the fact is most of us run these limited use /non daily driver cars in temps above 40-50 deg & 10w's not an issue there at all for cold startup.

And thats not even getting into the fact if somoe's running a semi blend or full syn oil that they flow better convetional oil does in cooler temps.

Just my $.02 on that.

Scott

 

[Nolowrider]

All this talk about 20/50 has got me thinking. I run it down here with no problems. 40-50 psi idle hot.

Does anyone see a problem with it?

 

[JC396]

All this talk about 20/50 has got me thinking. I run it down here with no problems. 40-50 psi idle hot.

Does anyone see a problem with it?

No....Typically 20W50 has additives relating to racing oils. ALWAYS ran this in our hi perf street motors for 35 years of playing with cars and have never blown a motor or lost a camshaft.............the fuss over thin oils has come into play due to late model engines and most of that in my opinion is for CAFE ratings........................................!

 

[Nolowrider]

I run the VR1 20-50. I have always ran that in my BBC.

You know how it is, when someone else starts talking about soething that you do, one tends to second guess themselves.

 

[justkyle]

I run 5w-30 in everything I own. A land rover (0w-30 in the winter), a 69 Chevelle, a 95 ford box van with a flat tappet 351, a 72 chevy pickup with a 350, my lawn mower, etc

I wouldn't run 20w-50 in anything that absolutely did not need it. 540 rat is correct about how much better the lower viscosity oils flow during start up.

 

[MEJ1990TM]

No....Typically 20W50 has additives relating to racing oils. ALWAYS ran this in our hi perf street motors for 35 years of playing with cars and have never blown a motor or lost a camshaft.............the fuss over thin oils has come into play due to late model engines and most of that in my opinion is for CAFE ratings........................................!

The '70 gets the VR1 20W50. That's only because of it's extra protection for the flat tappet.

 

[jonh]

Don't forget Delo 30. Your engine will outlast you. All seasons.
Jon

 

[Nolowrider]

The '70 gets the VR1 20W50. That's only because of it's extra protection for the flat tappet.

That's why I run it.

 

[marks412]

I am from WI. And when I drove the Chevelle in June, July, and August, I did use the Valvoline 20-50 racing oil. The rest of the year, thats another story. If you have the car up on blocks for the winter, get the 5-30 in it, and start it once and a while. Let it get up to 160f-170f, run it through the gears forward, then remove the same miles in reverse.

If it is a daily driver all year round, then just listen to Scott (SWEATON). He has done all the research on this subject for all of us. Read the stickys, it is more related to flat tappet cams, but after you read them, you know he knows what he is talking about.

 

[SWHEATON]

FYI,Since you brought up 10w-30 many stores dont stock valvoline's 10-30 VR1 series race oil with elevated zddp lvls for ft cams but any place that sells valvoline products can order it for you & get it in 1-2 days.

You can also order it from summit/jegs/etc.

Cam2's new hi perf oil for ft cam use also makes a 10-30 version as does Joe Gibbs too,see thier websites for details.

One more time/LOL!!!!!

Unless your talking extreemly cold temps (for ex 0-20deg f) there is no issue at all for cold motor startup with 10w base stock oil in 10-30 oil.

Most oil vs temp use charts i have read in the past from oil mfg's show 10-30 is safe down to 0 deg f though i would not run it to 0 deg,id run 5-30 in temps of 20 deg f or below.

Most people here arent running these cars/motors on a daily basis in anywhere near cold temps like that,most of us are running/driving our chevelles in temps well above 20 deg where the 10w base stock in 10-30 oil isnt an issue at all on cold startup.

But it's when the going gets tough in a perf motor 10-30 can out do/takea little more more abuse then 5-30 before shearing/vicosity loss . That's because the 10w base stock in 10-30 oil can handle more stress thenthe 50% thinner 5w base oil can. The 10-30 also has less chemical additives to make it reach 30wt grade oil when hot which also makes the 5-30 oil a little more suseptable to visc breakdown vs 10-30 . Thats why i feel 10-30 is a better choice protection wise for anyone wanting to run a multigrade 10-30 oil in a street perf motor that isn't run on a daily basis in 20deg f or lower temps.

Again,that's why i suggest 10-30 over 5-30 oil for old school sbc/bbs perf motors which is especially important for motors that are going to thrashed/abused from time to time.

Keep mind mind todays 35-40 yr newer design motors generally have lighter recipricating assembly's (lighter cranks-rods-pistons-valvetrain) with roller & or overhead cams that are designed to run on todays 5-20/5-30 oils are a different story that you can't compair to our 35-40 yr old design motors with somewhat differenet needs.

Scott

 

[Guest]

I respectfully disagree ,in anything but very cold temps like 0-20deg f 10w base oil in a 10-30 oil pumps up just fine/fast enough and isn't an issue at all.

The motor oil temps charts i have read from oil mfg's rate 10-30 safe down to 0deg f but to be safe i would not run it below 20 deg f.

The reason why i prefer /suggest 10w 30 over 5w-30 for street perf BBC/SBC motors is because the base stock 5w oil in a 5w-30 oil can shear/reduced in viscosity before the 10w base oil does in 10w-30 oil not to mention the additonal chemical additives in 5w-30 to get to 30wt when hot.

I have read oil tests done over the yrs that showed just that point so i feel going with 10w base oil in a 10-30 multi viscosity oil you get a little better protection against thermal/viscosity breakdown vs 5-30.

Another point is that they need to add more chemical additive to get 5w base oil to 30wt oil when oil gets up to proper operation temp then going from 10w base oil to 30wt oil when hot making the 10-30 a little more durable/stable then 5w-30 for hi perf use.

Are hi perf motors going to blow up because they are running 5-30 oil,not likely. But it still doesnt take away from the fact the 10-30 oil did a little better then 5-30 did with all else being = in the oil tests i had rvu'd . Again,that was due to the 10-30 multi visc oil having a 2x higher visc base oil (10w vs 5w) along with it also requiring less chemical additives in the oil to get it from 10w to 30wt when hot vs getting 5w oil up to 30wt oil when hot.

When both thoses oils are at proper operating temp the 5w-30 with lower visc 5w base oil & more additives to hit 30w sheared/broke down a little faster viscosity wise . It wasn't a day & night difference but non the less the 10-30 did better overall then 5-30 did & thats the point.

And the 10w base oil in a 10-30 on cold start isn't an issue at all in the temps we run these cars/motors in .

Starting/running a motor in a daily driver in 0-10deg f temps would be a different story and in that case i woiuld prefer 5w-30 over 10w-30 but the fact is most of us run these limited use /non daily driver cars in temps above 40-50 deg & 10w's not an issue there at all for cold startup.

And thats not even getting into the fact if somoe's running a semi blend or full syn oil that they flow better convetional oil does in cooler temps.

Just my $.02 on that.

Scott

Scott, I don’t disagree with the technical details you reference. But those hair splitting differences are negligible and don’t stack up to much of anything in running engines in the real world.

And for the record, I had in mind, premium quality full synthetic oil, when I wrote my response, though I neglected to specify that. I barely even consider dino oil anymore, and I sort of think of it like bias ply tires, a thing of the past.

The range between the cold viscosity rating number and the operating temp viscosity rating number of 5W30 is of course 25, while that number for 10W30 is of course 20. The difference between the two ranges is only 5. Not a huge difference, but that gives you cause for concern, because of base stocks and added chemicals.

Well, how about the range between the old favorites 10W40 or 20W50? Their range is 30, which is 5 more than the range for 5W30. Yet I doubt you ever had concern about them, since they have been used with great success for decades. So, with your line of thinking, 5W30’s range should be more desirable than theirs. To make it a little more clear, here is a list for easy comparison:

20W50 = 30 spread
10W40 = 30 spread
5W30 = 25 spread
10W30 = 20 spread

That puts 5W30’s spread right in between your preferred 10W30 and the old 10W40 and 20W50 favorites. I guess the 5W30 can’t be too bad, huh?

Lots of people, myself included, have run premium quality full synthetic 5W30’s in some stout running engines for years without any issue at all. Personally, I run it in all my stuff, including a 600hp Supercharged small block, an 800hp BBC, as well as a 430hp GTO, and in regular daily drivers. No problem so far……...in any of them. Bottom line, 5W30 works just fine in a wide range of applications, with no down side. Though with that said, I’d only use or recommend premium quality full synthetics.

Sacrificing cold flow ability for the misguided hope of getting infinitesimally better protection between 5W30 and 10W30 is a good way to shoot yourself in the foot, in my opinion.

Its commonly understood that around 90% of all engine wear occurs at cold start up, during the brief time before oil gets to all the engine’s internals. 5W30 will get there quicker than 10W30, no matter what the ambient temp is outside. And getting oil to all your engine’s components as quickly as possible, is a difference that offers real value.

 

[matt's66]

I think the average Joe Consumer will tear a car up quicker than most people realize, even the manufacturer sometimes. Most manufacturers spec 5w-30 in their engines, some 5w-20 and most new cars are getting 200,000 plus miles on them. Here's an interesting read on the "myth" of running thicker oil in hot weather etc.: http://www.ferrarichat.com/forum/faq.php?faq=haas_articles

 

[JJ'65]

All this talk about 20/50 has got me thinking. I run it down here with no problems. 40-50 psi idle hot.

Does anyone see a problem with it?

40-50 PSI at idle hot? If it was human, the doc would be diagnosing hypertension. As for me, I like the idea of oil flowing to the critical places sooner than later, and don't like the idea of excessive pumping losses and extra wear and tear on the oil pump and the mechanism that drives it...

My $0.02