30wt in summer?

[67chevy_hotrod]

Well I just finished my cam break in cycle it's been about 500 ish miles so it's time to change the oil. I picked up some valvoline 30wt and Lucas zddp additive. Got home and thought to myself why did I buy this weight oil? I never have before and I never see anyone else buy it. Well I figured it would be ok seeing how we are coming into the summer months and we won't drop below 50 (most likely) and the only new component( as crucial as it is) is the cam. I was thinking this viscosity might hurt the cam on those occasionally colder mornings.. Any thoughts? Should I just run 10w-30? Also is there any oil out there that's like the old stuff with zinc still in it that isn't crazy expensive? Thanks

[budman k20]

Not enough info to give you a good answer. How many miles since the engine was rebuilt? What weight oil did you use to break in the cam? What was your oil pressure (idle & WOT) with the oil you are running now? I assume you put a performance cam in it so 30W should be OK and may be better than 10-30W in the summer if you are going to have some fun with it.

['68OrangeSunshine]

That's what I run in my '68 C/10 w/ 292 L6. Valvoline SAE-30. Service SM and later, I add STP for the ZDDP.

[jdalexa84]

I have read that diesel oil has more zinc in it. It can be run in gas engines no problem. I would use non synthetic oil for the first 3000 miles... my cam said no synthetic for that long

[67chevy_hotrod]

I don't know how long ago it was rebuilt. I got it in another truck and it ran great(no smoke no blow by) i put that cam in it cause it had a bigger cam that was not very daily friendly. I used comp cam break in oil additive and valvoline 10w-30 to break it in. My oil press. Gauge is kinda wonky so when it is warmed up its about the 1/4 mark at idle but when puttin around or givin it the beans it usually goes all the way up to the max lol but it always has even with my old wore out 327 i had in before. And I never run synthetic anyways cause it's not a souped up engine. Just has that 268h not it stock everything else.

[gvw5400]

SAE 30w30 will work fine. It was the severe duty oil weight to use back in the day.
Watch your low temps as it is only OK down to 40F.
Don't rev the engine until warmed up.
All that said, I use Mobil 1 High Mileage 10W30 because it's only SL rated and has
OK DZZP levels.
All The best, Dirk

[davepl]

Diesel oil no longer has the same amount of zinc as it used to either... I also used a zddp additive on top of a diesel synthetic oil (which has some), Rotella T.

I wouldn't make a habit of running 30W in anything with an oil filter bypass, which we have. Your lawnmower doesn't. With that heavy oil it's not going to get filtered until your engine warms up. And go easy when its cold... I doubt you'd blow up the filter, but you might generate some high pressures. Do you have a gauge?

[67chevy_hotrod]

Yea like I said I have a gauge but it's just a guesstimate. 10w-30 at high idle it is pinned all the way to the right high idle is like 1500 at warm up. I will just get 10w-30 lol

[special-K]

You can run straight weight 30 all year round.

[dazza]

For any of you looking for more info regarding zinc content, here's some real world test data that someone posted on the Chevelle forum. His post is the second one down (post #32).

[Benny-]

Originally Posted by dazza

For any of you looking for more info regarding zinc content, here's some real world test data that someone posted on the Chevelle forum. His post is the second one down (post #32).

Wow, now that is some good stuff right there

[davepl]

Originally Posted by special-K

You can run straight weight 30 all year round.

What do you mean "can"? Do you mean...

...they used to do it in grandpappy's Model T?
...GM says its OK to?
...no one says you should but it'll work anyway?

Presumably there's a reason for multiviscosity oils. So I'm not sure what you mean. At a minimum you run unfiltered until the bypass pressure is no longer exceeded, and you risk grenading a filter at high pressure, right?

[dazza]

I've known/know people that run 30w all the time without any issues, of course the weather here rarely goes extreme in either direction. I think viscosity should be a concern in extreme cold or heat, and as for the variations there are way to many... marketing maybe? When I was growing up I only recall 30w and 10w-30, sometimes 10w-40 and vehicles seemed to be running just fine then, but like I said, I live in a moderate climate.

davepl - How much time are you talking about when you say, "until the bypass pressure is no longer exceeded"?

and is "grenading a filter at high pressure" something that happens in cold weather? I've never heard of it.

[davepl]

It depends on how strong the bypass spring is too, but oil filter bypass pressure can be as low as 20psi, so anything over that and the oil is mostly going around, not through, the filter. At hot idle and so on it's being filtered properly, but during that warmup until you can get the pressures down I think most of the oil is bypassing the filter entirely.

I've never had a filter explode, but the dealer warned me about it on my 427 Z06 dry sump car. It made over 100psi when cold, and the dealer warned me never to put a cheap filter on it and to try to avoid RPMs when cold.

A 4" filter has 12" of surface area, so that's 1200pound on the weld/seam of the filter at 100psi. That's the risk, but like I said, it's never actually happened to me.

[cypressbog]

I use 10W30 in winter and 10W40 in summer.

[mike16]

Originally Posted by jdalexa84

I have read that diesel oil has more zinc in it. It can be run in gas engines no problem. I would use non synthetic oil for the first 3000 miles... my cam said no synthetic for that long

30 wt will be fine all year round. The rotell is good choice too. its specified for diesles but because of its additive package its also good for older gas trucks. You may want to supliment it with an additive package as well.


I mix Rotella with Mobile 1. No problems.

[RichardJ]

The first chart shows relative viscosity at lower than operating temperatures. I added a couple of Fahrenheit conversion points for reference. In 90F daytime temps, I would expect the oil in the morning to be around the 65F point I placed on the chart.

The 30W oil viscosity is nearly twice that of the 10w-30. The 30W is also very close to the 15w-40 at that temp. The second image shows what the oil pump is trying to push through the oil galleys with 15w-40 and 30w would be nearly the same. As has been pointed out, that thick goo is not being filter, but carrying dirt from the oil pan through the galleys to the bearings.

The third image shows that 30w will do a very good job for an engine designed for 10w-30, but only when the engine has reached normal operating temp.

For those of you that like 15w-40, that chart shows that it is providing less than optimal performance until the oil reaches 108C or 226F.
How far above coolant temp does your oil run?

[ak808]

thread hijack here... but everybody and there brother has always run 20-50 in our inboard boats. Seeing that chart I now question why? I would think SAE 30 would be a little more reasonable...

Nothing fancy, just a 300hp 350. Runs about 3200 rpm, engine temp is around 140 or so depending on water temp.

Ideas?

[67chevy_hotrod]

You dudes rock. So much info.. I just threw 10-30 in it cause I needed the truck and that's what I usually run but will keep the 30 and run it next change, just watch my cold rpms.. So what's the consensus on filters? I usually run wix but anything but fram if not wix..

['68OrangeSunshine]

Originally Posted by 67chevy_hotrod

You dudes rock. So much info.. I just threw 10-30 in it cause I needed the truck and that's what I usually run but will keep the 30 and run it next change, just watch my cold rpms.. So what's the consensus on filters? I usually run wix but anything but fram if not wix..

I run WIX. NAPA is also WIX with a napa label. 51060 or 51061 I think. I like the taller 1 qt filters.
Sometimes I run 20W-50 in the winter in Arizona.
I built a 292 in 1977, in Yuma. I broke it in on Valvoline 30, then ran Valvoline Racing 30 for about 10 years, changing every 2000 miles. As the rings wore down, I went to Valvoline Racing 40, and by the time it had gone 250,000 and 25 years later, I was up to Valvoline Racing 50. In 2002, I rebuilt the original 292, and I'm running Valvoline 30. I can't find Valvoline Racing 30 on the retail shelves, I'd have to special order it by the case. But I heard it has a higher ZDDP content than the regular 30.

[67chevy_hotrod]

51060 I think, but that's a good record of how it went down..

[Z10]

Read and learn"540 Rat". By the way, I'm running 5w30 Mobil 1. This report pretty much confirms what I've been doing for years.

https://540ratblog.wordpress.com/201...-test-ranking/

[In The Ten Ring]

You mean you still have to change oil? Maybe that's why I keep having to get new engines around 100K miles.

My dad owned my truck before and he always used Valvoline 10w 30 conventional. That's what I plan to use in it once I get it running again. Hopefully the seals aren't bad now. The truck has spent its entire life in WV.

I run 30 wt Valvoline conventional in my Craftsman mower. I only use it in summer.

[dazza]

Originally Posted by Z10

Read and learn"540 Rat". By the way, I'm running 5w30 Mobil 1. This report pretty much confirms what I've been doing for years.

https://540ratblog.wordpress.com/201...-test-ranking/

I've been pointing people to a post of his over on the Chevelle forum but it's just a list of the results. Cool to see his blog on the subject and really great info. Thanks for the link.

[toolboxchev]

Originally Posted by '68OrangeSunshine

I run WIX. NAPA is also WIX with a napa label. 51060 or 51061 I think. I like the taller 1 qt filters.
Sometimes I run 20W-50 in the winter in Arizona.
I built a 292 in 1977, in Yuma. I broke it in on Valvoline 30, then ran Valvoline Racing 30 for about 10 years, changing every 2000 miles. As the rings wore down, I went to Valvoline Racing 40, and by the time it had gone 250,000 and 25 years later, I was up to Valvoline Racing 50. In 2002, I rebuilt the original 292, and I'm running Valvoline 30. I can't find Valvoline Racing 30 on the retail shelves, I'd have to special order it by the case. But I heard it has a higher ZDDP content than the regular 30.

50 k on my 350 top end rebuild, with VR1. Briefly looked at the data and it seems it comes out on top.

This would be the stuff! I have heard about Brads? Good stuff.

http://www.valvoline.com/our-product...vr1-racing-oil