Watch That Oil!!

[dkn1997]

Ok, so when i got my shortblock back from the machine many years ago, the guys says "run 20/50 in it."  So I do what he says.  This past year, with about 6 years and 3-4000 miles on the motor, I decide that it's got to be broken in by now and that this oil change I will go with sinthetic.  I put 10w40 in it and me no likey at all!!  if I get on it in 1st or 2nd and let off and let her "wind down" I can hear a bit of valve clatter.  Also, at idle, pressure would drop to 20psi, at cruise, would be around 40-50. 

So I got worried and just put 20/50 back in it and all is well. No noise, 40psi at idle, 60-70psi cruise.  I don't have the answer as to why except that maybe he assembled the motor with looser clearances and the upper end needs all of that pressure to keep the rockers/lifters oiled properly.  maybe it was the Fram filter I was running.  I put a valvoline filter on it this time.

Moral of the story: do what the man tells you. 

[Big Lebowski]

  Yep, I always use 20/50

[69charger2002]

same here. always 20/50

[The70RT]

Synthetic has the viscosity of water

[Charger_Fan]

Another 20/50 guy here, even with synthetic oil. Actually it's 15w50 in the synthetic stuff until winter, then I go lighter. Don't wanna strip any oil pump drives.

[NorwayCharger]

Synthetic has the viscosity of water

The viscosity is the same for synt/dino oil. 20w50 is 20w50..

[suntech]

Norwaycharger is right! Another thing is the climate you are living in. I would use 15-50 fully synthetic, and i would have run an oilcooler, through a thermostate. That would keep the oil flowing well on low temp, and cold starts, and keep the temp low enaugh to maintain oilpressure and proper lubing.
I run 5-40 fully synt on my GM Dually, with a 6,5 TD. It has 150 K miles on the meter. Runs smoother with that. Was thirsty the first 10 K miles ( started using this oil at app 30 K miles)
I change oil and filter every 7000 miles, and it is dropping only a quart!!

[pettybird]

running valvoline super blue 15w40 diesel oil per a conversation (and lecture later on the hot rod power tour in memphis) with herb mccandless.  there was also an article about running diesel oil in hot rod last year at this time, I believe.  they ran an article about the high rate of lifter failure in flat tappet motors, and talked to a number of sources.

new oils do not have moly and other things for flat tappet cam cars, and have reduced the additive packages to reduce emissions.  diesel oil is going the same way, but some still run old school formulas.  hot rod focuses on rotella by shell, but they've since changed formulas according to mr. mccandless. 

he was an awesome guy to talk to--it's one of his big preaching points.

[mikesbbody]

I agree with the guys, im a 20/50 man as well. 

[6670charger]

Never heard of 20-50 oil before now.  I've always used 10-40.  Is 20-50 that much better?

[71bee]

Never heard of 20-50 oil before now.  I've always used 10-40.  Is 20-50 that much better?

what he said. 20/50? WOW!    I run 15/40 in my Cummins diesel and thats some pretty thich chit!

I've always used 10W 40 for the 383 in the bee. 

[NYCMille]

I used to run 20-50w Valvoline Racing Conventional, just recently switched to 15-50w Mobil 1 Synthetic. The synthetic is MUCH thinner but seems to run cooler, especially on the race track and at prolonged RPMs of 3500-5500. I have another oil change coming up this week and am thinking of switching yet again to LUCAS Racing 20-50w Synthetic - anyone ever use this stuff or have an opinion on it. 

[NorwayCharger]

I used to run 20-50w Valvoline Racing Conventional, just recently switched to 15-50w Mobil 1 Synthetic. The synthetic is MUCH thinner but seems to run cooler, especially on the race track and at prolonged RPMs of 3500-5500. I have another oil change coming up this week and am thinking of switching yet again to LUCAS Racing 20-50w Synthetic - anyone ever use this stuff or have an opinion on it. 

Synthetic motor oils have been the object of numerous misconceptions, and ONE of them is that the synthetic oil is mush thinner.

In order for a lubricant to be classified in any SAE grade (10W-30, 10W-40, etc.) it has to meet certain guidelines with regard to viscosity ("thickness").

For example, it makes no difference whether it's 10W-40 petroleum or 10W-40 synthetic, at -25 degrees centigrade (-13F) and 100 degrees centigrade (212 degrees F) the oil has to maintain a standardized viscosity or it can't be rated a 10W-40.

[dkn1997]

I used to run 20-50w Valvoline Racing Conventional, just recently switched to 15-50w Mobil 1 Synthetic. The synthetic is MUCH thinner but seems to run cooler, especially on the race track and at prolonged RPMs of 3500-5500. I have another oil change coming up this week and am thinking of switching yet again to LUCAS Racing 20-50w Synthetic - anyone ever use this stuff or have an opinion on it. 

I did not know they even made 20/50 in synthetic.  that's what I get for going to the coram Autobarn for oil

Mike, where do you get that stuff?  online or at a speed shop?

[NorwayCharger]

http://store.summitracing.com/egnsearch.asp?N=700+400014+4294872948+115+4294872655

http://store.summitracing.com/egnsearch.asp?N=700+400236+115+4294872948

http://store.summitracing.com/egnsearch.asp?Ntt=royal+purple&N=700+4294925094+115+4294872948&Ntk=KeywordSearch


All of them good oil