Thickest 20w50

Messages
622
Location
42.4N 85.7W
Cold 20w-50! Seriously though, if you wanted something THICK, why not a 25w-60? I've never seen it, but the Australians here talk about oils this thick and thicker. Dave
 
Messages
2,794
Location
NM
Spritman has mentioned something like a 25W-70 oil in Australia....that's thick! [Eek!] As for the thickest 20W-50, just go to the respective oil websites and look for something that is 20cSt and higher @100*F
 
Messages
11,006
Location
Canberra ACT Australia
20.3 @ 100C? That's baby oil. Real auto's use 40W70. 33.7 cSt @ 100C, Cold Cranking viscosity cP @ -5C 12,693, VI 109, Flash 207C. Designed to "provide enhanced protection against wear, corrosion, oxidation, sludge under tough Australian conditions". Use in older oil burning engines, speedway and drag racing engines, or older large capacity engines operating under high temp/high load conditions such as towing in the outback"
 
Messages
1,759
Location
Elizabeth City NC
I think you are looking for the wrong thing. Most 20w-50 dino oils will be low 40 weight in a few thousand miles if not 30w. What you want is an oil that stay at it rating for 3000-6000 miles. Delo 400 starts as a high 40weight oil almost 50 weight and finished as a medium 40 weight after 5000 miles+. Unless you go synthetic no 50 weight dino oil will do this.
 
Messages
13,132
Location
By Detroit
quote:
Originally posted by TR3-2001SE: I think you are looking for the wrong thing. Most 20w-50 dino oils will be low 40 weight in a few thousand miles if not 30w.
Assuming they start with a 20w base oil I did not think there would be that much viscosity index improver added to get a 20W50. It's viscosity index is lower than even a 10w30, indicating that its viscosity changes less (from cold to hot) that a 10w30 does, and which leads me to believe it is a pretty stable oil, unless it is poorly manufactured.
 

Racerjk

Thread starter
Messages
1,199
Location
Arkansas
I have a truck with a fairly "hot" 350 in it. The reason I asked about the thick oil is that I have oil pressure that is too low for my tastes. It's been that way since the engine was built. Even with 20w50, the oil pressure is not much over 20-25 psi @ idle. I started out running 10w30, and the oil pressure was downright scary.
 
Messages
2,569
Location
College Dorm...
quote:
Originally posted by Racerjk: Even with 20w50, the oil pressure is not much over 20-25 psi @ idle.
Hot idle or cold idle? Is the engine just old and worn out? All internals "properly" installed? Thought of using a different oil pump? 20-25 at a hot idle though seems fine to me....
 

Racerjk

Thread starter
Messages
1,199
Location
Arkansas
Well, this engine has not run in a while due to valvetrain problems. I'm on my 3rd set of valve springs. The last time this happened, I got aggravated and parked the truck. I don't remember exactly what the PSI used to be. I think it even got below 20 psi @ idle. My Formula has a little over 20 psi at hot idle, and I remember now the psi on my truck being even lower than that. This engine had all new stuff put in it, and it only has 5 or 6,000 miles or so on it. It has TRW forged pistons, and the rings and bearings are Federal Mogul. The block was decked, squared and align-bored. Of course, it has a new oil pump also. Is there a difference in a high volume and high pressure oil pump?? The rule of thumb is 10 psi per 1000 rpm right??
 
Messages
636
Location
LA (Lower Alabama)
[QUOTE]What's the thickest 20w50 out there?[QUOTE] Mobil 1 V-Twin - SUS Viscosity @210F (tested) = 101.8 in a revcent VOA. Real high 50 weight. Pretty good add package too. Awfully expensive though.
 
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