NHRA Pro Stock Bearings

Originally Posted by RDY4WAR
Originally Posted by A_Harman
Pretty neat stuff!

What is the oil temperature, and what would you estimate the oil viscosity to be during the pass down the strip?


Oil temp is 100-140*F. The viscosity at that temp is most likely in the 10-15 cSt range.


I was just going to ask the OP the same thing. The viscosity at temperature is what matters, not the rated viscosity.
 
Originally Posted by ZeeOSix
Originally Posted by RDY4WAR
Originally Posted by A_Harman
Pretty neat stuff!

What is the oil temperature, and what would you estimate the oil viscosity to be during the pass down the strip?


Oil temp is 100-140*F. The viscosity at that temp is most likely in the 10-15 cSt range.


I was just going to ask the OP the same thing. The viscosity at temperature is what matters, not the rated viscosity.


Just to note... that's sump temp. They have a 10 qt capacity. Those engines turn 10,500 rpm with >15:1 compression making ~3 hp/ci. The amount of inertia and pressure still produces a lot of bearing heat. I'd imagine the bearing delta is 60-80°F over sump temp at the top end of the track.
 
Originally Posted by RDY4WAR
Originally Posted by ZeeOSix
Originally Posted by RDY4WAR
Originally Posted by A_Harman
Pretty neat stuff!

What is the oil temperature, and what would you estimate the oil viscosity to be during the pass down the strip?


Oil temp is 100-140*F. The viscosity at that temp is most likely in the 10-15 cSt range.


I was just going to ask the OP the same thing. The viscosity at temperature is what matters, not the rated viscosity.


Just to note... that's sump temp. They have a 10 qt capacity. Those engines turn 10,500 rpm with >15:1 compression making ~3 hp/ci. The amount of inertia and pressure still produces a lot of bearing heat. I'd imagine the bearing delta is 60-80°F over sump temp at the top end of the track.


Depends on how much oil flow is going through the bearings. 10 qts is a lot of oil which makes for a cool oil supply during the short run. In order to have the whole sump go through the engine one time in 4 seconds the oil flow rate would have to be 150 qts/min, or 37.5 GPM. Doubt the oil flow is that high through the engine.

And keep in mind that big bearings have lots of mass, which takes time to transfer and build up heat so they will start out relatively cool. The bearing mass is enough that I highly doubt the bearings themselves are going to heat up much in 4 seconds during the run as heat is generated and transferred to the bearings.

They have to run thin oil in this application, because the oil temps are not very high due to all these conditions. If a much thicker oil was used, they'd have to heat the sump to get the oil to the optimum viscosity for the run.
 
I'm a HUGE fan of Elite and Pro Stock. I have an all motor TopSportman TransAm, 604 BBC, 1170 hp on C15. I have GRP aluminum rods in my motor and expected to see aluminum rods in yours too? but obviously they aren't. Are they titanium? or Carrillo? What can you tell me about the rods you use? I would like to change my rods soon but I'm not sure what to go with? The upper rpm limit of my engine is 8000rpm.
Thanks
[Linked Image]
 
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NHRA Pro Stock rods are steel. So are the rockers. That's mostly due to the weight requirements by NHRA but also because steel allows you to get tighter on clearances. There's a few TS guys (MADCAP engines) running a similar oil to the Elite engines but in a 5w-30 grade.
 
Originally Posted by AJB0009
Does anyone know for sure what oil they run in a NASCAR race? Other end of the spectrum from this. 500 miles at 9,000 RPM's. 750-ish HP. 358 C.I.


If it had to be given an oil grade, it would be a heavy 0w-16 to a light 0w-20 (KV100 = ~7.5 cSt) that's a majority group III / PAO blend with some mPAO and POE to boost the flash point. At Daytona, the sump temps hover around 280*F with a 70-80*F temp rise through the bearings or 350-360*F at bearing exit. Zn and P are 800-1000 ppm, Mo is ~1600 ppm, B is ~200 ppm, and Ca is ~600 ppm. TBN = ~2.0.
 
Originally Posted by RDY4WAR
Originally Posted by AJB0009
Does anyone know for sure what oil they run in a NASCAR race? Other end of the spectrum from this. 500 miles at 9,000 RPM's. 750-ish HP. 358 C.I.


If it had to be given an oil grade, it would be a heavy 0w-16 to a light 0w-20 (KV100 = ~7.5 cSt) that's a majority group III / PAO blend with some mPAO and POE to boost the flash point. At Daytona, the sump temps hover around 280*F with a 70-80*F temp rise through the bearings or 350-360*F at bearing exit. Zn and P are 800-1000 ppm, Mo is ~1600 ppm, B is ~200 ppm, and Ca is ~600 ppm. TBN = ~2.0.

I was thinking that it had to be pretty thin, after watching it pour out of Ryan Newman's car after it flipped. It looked like water running out.
That says a lot about the quality of the lubricant that it can withstand that kind of heat and pressure for that long, being that thin.
Not really related, but maybe a little; I work in industrial maintenance. We use Mobil Glygoyle 220 and 460 in some gearboxes. It is a full synthetic oil made in The Netherlands, PAO. It is as clear as water, just like the stuff that came out of Ryan's car.
 
ProStock runs in the 6's
TFD/TFFC are in the 4's

1400hp has got to be on the low low side for a 8193cc motor

actually im kinda shocked that a pic showing the pistons (even if not the crowns) is displayed - slipper pistons taken from the f1/mx world
basically ringlands and a crown with antirock skirt and thats it - been in production bikes for 22+ years now
usually all of that is top secret hushhush blankets and screens over motors to keep prying eyes out
PS is a totally different world than TF where they will re-work the head next to the banner and you could reach over and touch it if you wanted.
PS teams usually dont let the spectators close enough to see anything
coatings are awesome but really only come into play once the hydro wedge of the oil isnt in play ... but then some coatings do otherthings as well
now coatings on the pin (as asked about) and skirts as well as rings them selves are fun
if you want fun with rods why settle for alum when Ti is so much more fun....ahhh but the spendy part comes in wfo

so what clearances and tolerances are used on the bearings and crank?
whats the end runout?
how close is the balance weight on all the piston/rod assemblys?
if the bearings last 21 passes...how long does the crank or rods or pistons last? rings?
and yes valve springs?
 
ProStock runs in the 6's
TFD/TFFC are in the 4's

1400hp has got to be on the low low side for a 8193cc motor

actually im kinda shocked that a pic showing the pistons (even if not the crowns) is displayed - slipper pistons taken from the f1/mx world
basically ringlands and a crown with antirock skirt and thats it - been in production bikes for 22+ years now
usually all of that is top secret hushhush blankets and screens over motors to keep prying eyes out
PS is a totally different world than TF where they will re-work the head next to the banner and you could reach over and touch it if you wanted.
PS teams usually dont let the spectators close enough to see anything
coatings are awesome but really only come into play once the hydro wedge of the oil isnt in play ... but then some coatings do otherthings as well
now coatings on the pin (as asked about) and skirts as well as rings them selves are fun
if you want fun with rods why settle for alum when Ti is so much more fun....ahhh but the spendy part comes in wfo

so what clearances and tolerances are used on the bearings and crank?
whats the end runout?
how close is the balance weight on all the piston/rod assemblys?
if the bearings last 21 passes...how long does the crank or rods or pistons last? rings?
and yes valve springs?
Lots to think about for sure. Yes or no? A short connecting rod will increase the VE potential of a PS engine.
 
above zeeosix said 4secs ... was just clarifying that PS does not run 4's but 6's (barely 6s when 1320)
and TF was 4s when it was 1320 not 1000

I'd like nothing more than for the current restrictions to end, and racing return to the full 1320. They've slowed the cars down drastically from what they are capable of. There are too many hand-wringers calling the shots.

I say remove the restrictions on the cars, and improve the tracks with short runoff, or remove them from the tour. Then we could see a 1/4 mile pass in the 3's at over 360 mph. I know, it's very unlikely to be allowed. But one can dream.
 
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