20 /50 oil

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dvav

dvav

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just wondering if 20 /50 is over kill
I have a 340 with a high lift solid cam that I wind up as high as 7000 rpm
 
I am using 10w-30 in 360 that turns upwards of 7k. The engine was assembled back in 2006...and 5w-20 in another 360 that runs close to that rpm....

I used to run thick oil....but don't think it is necessary unless you have an oil pressure problem or wide bearing clearances.
 
I use 20w50 in my Mopars during the summer.

I don't like running 5wXX oils in my v-8 Mopars, seems too thin...
 
I used to use 70 in one of my 429's. I think it brought the fuel milage down a bit. It lasted as long as any other engine I ever had.
 
anyone use joe gibbs oil I was using royal purple 20/50 but was thinking about trying joe gibbs 15/50 full synthetic
 
50 weight oil is very heavy. just no need for it, IMO in anything like our cars.
 
I ran 15/50 in everything for ages, got a wild hair and tried some 10/40......OMG free horsepower, almost threatning to go 10/30 but at 360K miles??? maybe not.
 
I was thinking about lighter oil because I think my high vol oil pump sucks the pan so low that my pressure will flicker . I thought thinner oil might flow back to the pan better
 
Castrol and Quaker State 25W-60 is popular here in Baja California Sur. always warm or hot weather, never freezes. I used Castrol 20W-50 in my previous bracket racer (maximum clearances).
 
dvav said:
just wondering if 20 /50 is over kill
I have a 340 with a high lift solid cam that I wind up as high as 7000 rpm
Click to expand...

choose weight based on bearing clearances and oil temperature.
W weights are specified based on 'cold' temperatures, the other weights are specified on 'hot' temperatures. "hot" and "cold" are in quotes because they are SAE specifications, not what we normally call hot or cold when deciding to put on a jacket.

So if you're engine's oil temperatures run hot, like 280 F and it was built with fairly standard clearances, a 50 wt might be appropriate. But if runs cold, say like 190 F, then pressure in the pump will be high, but the relief valve will be open and much of the oil will get dumped back into the sump. At high rpm, that can be bad. For oil to support all the bearings and get to the top there needs to be enough volume as well as pressure.

Good information about SAE wts vs. viscosity and pour points on Richard Widman's Website.
In particular download his white paper on "Choosing engine oil for Corvairs", which also delves into other physical characteristics, explains the five basic types of motor oil, and a bit on additive packages.
Pdf in English from his hobby pages http://www.widman.biz/Corvair/English/Links/Links.html
or his business pages http://www.widman.biz/English/Selection/oil.html

A quick slick approximation of grading (weight) to viscosity are the tables on this page http://www.bobistheoilguy.com/viscosity-charts/

For more on the issue of blowing the oil out the relief valve, see "Haas on Oil" aka Oil 101.
http://ferrarichat.com/forum/faq.php?faq=haas_articles
Note when Haas mentions "track" he means road course - where an engine gets really heat soaked, not 1/4 mile drag strip. Also, if you reference the visocity tables for oil grades, you'll see where his "thickness" numbers come from.
 
Mattax said:
choose weight based on bearing clearances and oil temperature.
W weights are specified based on 'cold' temperatures, the other weights are specified on 'hot' temperatures. "hot" and "cold" are in quotes because they are SAE specifications, not what we normally call hot or cold when deciding to put on a jacket.

So if you're engine's oil temperatures run hot, like 280 F and it was built with fairly standard clearances, a 50 wt might be appropriate. But if runs cold, say like 190 F, then pressure in the pump will be high, but the relief valve will be open and much of the oil will get dumped back into the sump. At high rpm, that can be bad. For oil to support all the bearings and get to the top there needs to be enough volume as well as pressure.

Good information about SAE wts vs. viscosity and pour points on Richard Widman's Website.
In particular download his white paper on "Choosing engine oil for Corvairs", which also delves into other physical characteristics, explains the five basic types of motor oil, and a bit on additive packages.
Pdf in English from his hobby pages http://www.widman.biz/Corvair/English/Links/Links.html
or his business pages http://www.widman.biz/English/Selection/oil.html

A quick slick approximation of grading (weight) to viscosity are the tables on this page http://www.bobistheoilguy.com/viscosity-charts/

For more on the issue of blowing the oil out the relief valve, see "Haas on Oil" aka Oil 101.
http://ferrarichat.com/forum/faq.php?faq=haas_articles
Note when Haas mentions "track" he means road course - where an engine gets really heat soaked, not 1/4 mile drag strip. Also, if you reference the visocity tables for oil grades, you'll see where his "thickness" numbers come from.
Click to expand...

I think I`ll run 15w40 rotella and forget it. cheaper, available, works well enough. of course mine is a roller motor.----bob
 
340 main size 2.50" with Chrysler 3.48" stroke, 1994 Clevite Clevite mains : 1, 2, 4, 5 full groove : 3 modified to 3/4 groove, 11.5 : 1 , runs on any pump gas thanks to quench and comp 20-249-4 cam and a833 and 4.88 gears and moroso 7.5 quart pan and hp1 filter and hv pump and brad penn 10-30 and
 
when I built the motor a drag racer buddy suggested to run 20/ 50.i was also thinking it might be a little to thick to go through the small hole on the howards solid lifters I have
 
Mattax said:
choose weight based on bearing clearances and oil temperature.
W weights are specified based on 'cold' temperatures, the other weights are specified on 'hot' temperatures. "hot" and "cold" are in quotes because they are SAE specifications, not what we normally call hot or cold when deciding to put on a jacket.

So if you're engine's oil temperatures run hot, like 280 F and it was built with fairly standard clearances, a 50 wt might be appropriate. But if runs cold, say like 190 F, then pressure in the pump will be high, but the relief valve will be open and much of the oil will get dumped back into the sump. At high rpm, that can be bad. For oil to support all the bearings and get to the top there needs to be enough volume as well as pressure.

Good information about SAE wts vs. viscosity and pour points on Richard Widman's Website.
In particular download his white paper on "Choosing engine oil for Corvairs", which also delves into other physical characteristics, explains the five basic types of motor oil, and a bit on additive packages.
Pdf in English from his hobby pages http://www.widman.biz/Corvair/English/Links/Links.html
or his business pages http://www.widman.biz/English/Selection/oil.html

A quick slick approximation of grading (weight) to viscosity are the tables on this page http://www.bobistheoilguy.com/viscosity-charts/

For more on the issue of blowing the oil out the relief valve, see "Haas on Oil" aka Oil 101.
http://ferrarichat.com/forum/faq.php?faq=haas_articles
Note when Haas mentions "track" he means road course - where an engine gets really heat soaked, not 1/4 mile drag strip. Also, if you reference the visocity tables for oil grades, you'll see where his "thickness" numbers come from.
Click to expand...


^^ what he said...
 
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