10w30 vs 10w40/quieter engine vs better oil pressure

[caprice_2nv]

Originally Posted by rubberchicken
Originally Posted by maxdustington
Originally Posted by old1
Seems to me I have read not to long ago that 1 lb of pressure per 1000 rpm is sufficient.
I think that rule of thumb is from a time when any engine that was rebuilt got a HV oil pump. I think HV oil pumps fell out of favor on stock engines because they would shear the oil pump gear off the distributor shaft or whatever drove the oil pump.

I know that Pontiac engines in particular were infamous for having very low oil pressure at idle so I think you are OK. It could be a worn out oil pump, but I'll bet that engine did not have stellar oil pressure at idle when it was brand new. As long as it had decent oil pressure above idle you are most likely OK, you can't judge a 40 year old 350 Rocket by 21st century standards.

I would try to find a Vortec 350 and swap that in before I invested in your current motor. There are lots of GMT400 trucks with them that are overshadowed by the LS-powered GMT800s. You should be able to get a used Vortec carb intake somewhere.


HOLD UP on the Vortec 350 swap idea: This is a Olds 350- unless you were one of the few unfortunate souls that accidentally got the Chevy 350, the Olds 350 is a different engine. It is considered a "big block" and has more in common with the Olds 455 than the Chevy 350. The Chevy / GM 350 may not even bolt in due to motor mount or trans mounting hole differences (not sure though). There was a class action lawsuit at some point where Olds owners who thought they were getting a Olds Rocket 350 actually got some Chevy 350 instead, and GM failed to tell them about the swap. Class action suit, much hilarity ensued, owners won the lawsuit. If this car has some collector value then it might be worth just rebuilding the Olds 350. My overall point is to do your homework and do not assume any engine swap is a bolt on affair.


You are correct. Unfortunately the Canadian cars came with the Chevy 305 (after they switched to calling them all "corporate gm engines" or something to that effect because of the lawsuit you mention.

My friend and I switched a lot of stuff to put the olds 350 in (to make it right). It was worth it in the long run since the engine was free besides the cost of gaskets and a timing chain, water pump etc.

Back in the day I would never consider anything but the olds engine in my olds but nowadays I'm ready to do the ls swap for fuel economy, horsepower, etc.

 

[caprice_2nv]

Originally Posted by ka9mnx
I think your oil pressure is ok. LS swap is going to cost A LOT more than doing the bottom end. And take a lot more time. Stick with the 10w-30. M1 HM 10w-30 is a "thick" 30 at 100C (12.1) and has a nice HTHS (3.5)


The ls swap will be a long ways off. I'm doing it on the Caprice first to replace the 305, hopefully within the next few years. The Cutlass maybe in 10 years. I'm hoping it will be easier the second time. I also have a friend who already did one and wants to help.

I used to use "German Castrol" 0w30 a lot back when it was extremely popular. I could get it on sale for a reasonable price and it seemed to be a good balance of oil pressure and quiet. I remember that it was almost a 40w. I'll have to look at what the m1EP is.

 

[Red91]

I haven't used this personally, but I've read some really good things about Schaeffer's moly ep oil treatment. It's one of the few additives bitog seems to approve of. It's really thick from what I've read, and most use less than the recommended dose. It contains moly, antimony, zinc, boron and phosphorus. Either that or, since we're getting in to warm weather, why not try a good 20/50?

I know, I know, this may be the most anti bitog idea in this thread, but it's just my two cents.

 

[caprice_2nv]

Originally Posted by Red91
I haven't used this personally, but I've read some really good things about Schaeffer's moly ep oil treatment. It's one of the few additives bitog seems to approve of. It's really thick from what I've read, and most use less than the recommended dose. It contains moly, antimony, zinc, boron and phosphorus. Either that or, since we're getting in to warm weather, why not try a good 20/50?

I know, I know, this may be the most anti bitog idea in this thread, but it's just my two cents.


If I could get that locally quickly enough for my next oil change I would try it. I have over the years often used typical 5w30 Pennzoil platinum or whatever was on sale and spiked it with zinc additive which worked okay (back when my Paranoia about cam failure was still high) but now I've gotten away from using additives.

And as I said the engine just seems to sound "healthiest" on 5w30 or 10w30 (either conventional or synthetic apparently). I'm going with 10w30 because they usually have less vii and it's what the engine used to call for. 50w definitely brings up the pressure but it doesn't sound as good. I have almost literally had every common brand and weight of oil in this engine over the past 12 years, the only noticeable difference is the slight noise and change in oil pressure. It doesn't leak or burn much of anything considering what the standards were back then.

 

[ARCOgraphite]

Hydraulic lifter have a leak down rate - its probably out of range with the thick stuff. Plus too thick will just kill power with no benefit - unless you are trying to cover a rod bearing or two running at .005".+ And that you just have to attend to.

 

[addyguy]

M1 EP is good stuff. The 10W-30 should be a very stable oil, having very little, if any, VII in it.

If the engine is quiet and 'healthy' sounding on it, I'd use that.

Until you get a red oil light on, or heard a bottom-end knock, you should be good to go.

 

[DGXR]

My Corvette has run on 5w30 synthetic its whole life, 75,000 miles now. It has a slight lifter tick (or rocker, or some other minor thing) but otherwise runs awesome. I recently switched to 10w30 synthetic and the engine is super quiet now, especially on cold start. It is surprising that a 5-point thicker winter rating would make such a difference, all else being equal. Oil pressure is always excellent (SBC engines are known for good oil pressure).

 

[caprice_2nv]

Originally Posted by DGXR
My Corvette has run on 5w30 synthetic its whole life, 75,000 miles now. It has a slight lifter tick (or rocker, or some other minor thing) but otherwise runs awesome. I recently switched to 10w30 synthetic and the engine is super quiet now, especially on cold start. It is surprising that a 5-point thicker winter rating would make such a difference, all else being equal. Oil pressure is always excellent (SBC engines are known for good oil pressure).


That is another weird one. Mine doesn't seem to be effected by the "winter rating" at all. Just the hot rating. 5w30/10w30 both quiet, 10w40/15w50/0w40 all noisier.

I will probably stick with the 10w30 Mobil 1 and ignore the gauge unless it drops any lower. It sounds great and the oil stays nice looking.

Olds engines seem to have lower oil pressure than the Chevy's. My 78 Chevy k10 has lots of pressure until the sending unit goes bad. Never checked the Caprice but I'm assuming it's decent. It's harder to access the sending unit to install a gauge on a Chevy. The olds it's right up front.

 

[ARCOgraphite]

Originally Posted by DGXR
My Corvette has run on 5w30 synthetic its whole life, 75,000 miles now. It has a slight lifter tick (or rocker, or some other minor thing) but otherwise runs awesome. I recently switched to 10w30 synthetic and the engine is super quiet now, especially on cold start. It is surprising that a 5-point thicker winter rating would make such a difference, all else being equal. Oil pressure is always excellent (SBC engines are known for good oil pressure).


Note that Winter rating is not "5 points thicker" though it is a 10W and not a 5W and will have a higher(warmer) wax point which are all determined at well below freezing temps.

You may have stepped into an ACEA A3 oil from an ILSAC RC oil.

The RC have relatively high VM % and light base stocks for economy.

But sometimes you never know what works well till you step in it - sometimes by accident.

 

[Garak]

Originally Posted by Linctex
ALSO - - get rid of that worthless factory nylon cam gear (if it has one) while you have it all torn apart, too.

You're giving me nightmares of the past.

caprice_2nv: These engines always seemed to do quite well on ILSAC type 30s.

 

[caprice_2nv]

Follow up:

My friend brought over a nearly new, professional OTC oil pressure gauge from the shop he works at and we checked to get true readings. Hot idle in gear (500rpm) is 10psi. In park (about 600-650? my tach reads high so I'm estimating) it has 13psi. About 1800-1900rpm is 39-40 psi. Oil pressure also jumps a lot quicker with RPM than it did with the electric autometer gauge.

I'm no longer worried and will stick with 10w30.