NHRA Pro Stock Bearings

[sunruh]

i like 660 and 1320
a 1000 seemed like a "pretty" number they picked out of nowhere that means nothing to nobody
had they made it 990 - or 3/16th or 330yds it at least would have some merit in relation to a mile

the only problem with going back to 1320 is not being close to the old records if they are all slowed down now.
you either have to freeze the records from the past and start new or risk them never being broken
people love to see attempts at records (viewership of olympics proves this)

im all in favor of safety ... with creativity being still allowed. nascar and its cookie cutters is a sleeperfest of rules

 

[userfriendly]

i like 660 and 1320
a 1000 seemed like a "pretty" number they picked out of nowhere that means nothing to nobody
had they made it 990 - or 3/16th or 330yds it at least would have some merit in relation to a mile

the only problem with going back to 1320 is not being close to the old records if they are all slowed down now.
you either have to freeze the records from the past and start new or risk them never being broken
people love to see attempts at records (viewership of olympics proves this)

im all in favor of safety ... with creativity being still allowed. nascar and its cookie cutters is a sleeperfest of rules

I doubt if the TF teams want 1,320 back. The insurance companies and track owners don't. Besides, the engines, magnetos, fuel system, spark plugs and tires are "all in" at 1,000 without going to taller gears and tires.
Don't be shocked if TF classes are shortened to 880 in the near future.

 

[sunruh]

They have seen 21 passes at 1400+ horsepower at 10,500 rpms. The oil used varied from a 0W3 to a 0W8.

how many passes can this 0Wx be used for at this level?

how much fuel dilution is in the oil at the end of 1 run?

 

[RDY4WAR]

Lots to think about for sure. Yes or no? A short connecting rod will increase the VE potential of a PS engine.

The rod length isn't important for the most part. When it comes to these engines, the stroke that's required and then the piston needed are chosen, and then they just throw in whatever length of rod connects the two.

When you're turning an engine at 10,500 rpm with >1.2" valve lift with rocker ratios in the 2.0-2.2:1 range, the amount of force exerted in the solid valvetrain is tremendous. Pushrod stiffness becomes a crucial issue to keeping the entire engine alive. The DRCE blocks have gradually gotten shorter over the years for this reason as it allows for shorter (and therefore stiffer) pushrods. It also shortens the intake runner length and decreases engine weight. The pushrod length is more critical than the connecting rod length.

 

[userfriendly]

The rod length isn't important for the most part. When it comes to these engines, the stroke that's required and then the piston needed are chosen, and then they just throw in whatever length of rod connects the two.

When you're turning an engine at 10,500 rpm with >1.2" valve lift with rocker ratios in the 2.0-2.2:1 range, the amount of force exerted in the solid valvetrain is tremendous. Pushrod stiffness becomes a crucial issue to keeping the entire engine alive. The DRCE blocks have gradually gotten shorter over the years for this reason as it allows for shorter (and therefore stiffer) pushrods. It also shortens the intake runner length and decreases engine weight. The pushrod length is more critical than the connecting rod length.

It was/is a hypothetical question. An engine with a given bore and stroke, everything else the same except connecting rod length.
Back in the day, Smokey Yunick was a long rod avocate. But he was mostly involved in restricted roundy-round and engines with stock type
cylinder heads.
A shorter con-rod will move the piston away from TDC sooner and dwell it longer ABDC, effectively increacing the duration of the intake stroke.
Yep, ps valvetrains take a beating, but so do tf, but in a different way. PS is with lift and rpm, TF with its instant launch rpm from an idle
and opening the exhaust valves against the high cylinder pressure of a late burning double based fuel. (Think of a double base gun powder. It takes heat to release the O2 to sustain the burn.)

 

[RazorsEdge]

Originally Posted by sloinker
Thanks for the info. Top treat? Not sure what that means exactly. I checked out your website. IIRC you are going to eventually add a store for your various products. I have two daily driver diesel vehicles that have DPF and urea injection. I run a one year 10k mile interval on them. They both are subject to -20F to -40F multi day cold soak conditions here in Wyoming in the winter. I have been using Ravenol and Red Line Euro for this reason figuring PAO/ester may be more forgiving in that environment. Any thoughts and do you sell a product that would be used in this style application. Thanks again for the transparency in your answers.


We are working on an online store at the moment. By top treat I am referring to the additional chemistry that needs to go in the oil because there would not be much of a chance to just put standard chemistry in that type of environment and expect it to work.

With respect to your climate and diesels we have good diesel product lines in the original robust CI4 plus family as well as current CK-4 chemistry that much like the Pro Stock oils we modify them. We start where many other companies do but say forget about the API license and then make the oils perform much better. We do make some PAO/Ester based diesel oils.

How's the progress going for the online store? I ask because it's not the easiest to find your oils online to purchase.

 

[02SE]

I doubt if the TF teams want 1,320 back.

Some of us do.

 

[userfriendly]

Some of us do.

Why? Just to see if a TFD can break into the 3's? I doubt it.
Do the math. A TFD leaves the traps at 340 mph, give or take. That is 500 feet per second. It will take another .640 to cover another 320 feet at that speed. Add that to Brittany's 3.623 = 4.263 seconds. Now let us assume 3.99@370mph trap.
340x340=115,600 x the vehicle weight.
370x370 =136,900 x the vehicle weight.
Without adding in wing generated down force and other parasitic losses, we are adding in another 18.4% of energy in .367 of a second to get into the 3's.

 

[02SE]

Why not?

Furthermore, you're basing your assumptions on a single known run, without knowing all that's involved.

It's a moot point anyway, unless the hand-wringers retire.

 

[userfriendly]

Top EV and other EV catagories will send the TF hillbillies to the gator huntin' n handfishing channels in the next 10 years.

 

[RDY4WAR]

It was/is a hypothetical question. An engine with a given bore and stroke, everything else the same except connecting rod length.
Back in the day, Smokey Yunick was a long rod avocate. But he was mostly involved in restricted roundy-round and engines with stock type
cylinder heads.
A shorter con-rod will move the piston away from TDC sooner and dwell it longer ABDC, effectively increacing the duration of the intake stroke.
Yep, ps valvetrains take a beating, but so do tf, but in a different way. PS is with lift and rpm, TF with its instant launch rpm from an idle
and opening the exhaust valves against the high cylinder pressure of a late burning double based fuel. (Think of a double base gun powder. It takes heat to release the O2 to sustain the burn.)

In my experience with that, the rod length isn't all that important. What you said is correct that with a shorter rod you get less dwell near TDC and more dwell near BDC. However, this effect is so minute that it's hardly relevant. We're talking thousandths of an inch difference in piston position across a wide spread of rod ratios. It is a factor, but it's way down near the bottom of the list of things to worry about. Smokey misunderstood what was really going on with his engines. The longer rods allowed for shorter, lighter pistons with more compact rings, shorter skirts, and shorter top ringland. All of this meant reduced reciprocating inertia, reduced friction, better piston stability, and improved ring seal. That's where the benefits come from. Either that or he did understand what was going on and saying "Put the longest rod in it" was his way of saying to run a shorter piston. Get the piston right for the application and then put in the length of rod that connects it to the crank. In the majority of cases, this means a longer rod for the shorter piston.

Note that you can go too short with the piston and run the risk of warp, which is catastrophic to ring seal.

 

[02SE]

Top EV and other EV catagories will send the TF hillbillies to the gator huntin' n handfishing channels in the next 10 years.

LOL

 

[wpod]

LOL

There isn't the noise with an EV that makes top fuel so awesome. EV sound like slot cars.

 

[A_Harman]

Why not?

Furthermore, you're basing your assumptions on a single known run, without knowing all that's involved.

It's a moot point anyway, unless the hand-wringers retire.

What are your thoughts on reducing TF and FC displacement limits to 410 cubic inches? I heard that was being considered maybe a year ago. If it allows them to go back to 1320 ft, would you make the trade-off?

 

[RDY4WAR]

What are your thoughts on reducing TF and FC displacement limits to 410 cubic inches? I heard that was being considered maybe a year ago. If it allows them to go back to 1320 ft, would you make the trade-off?

Easily achieved by allowing the same bore and deck height. Just reduce the stroke from 4.25" to 3.5". They could also enforce a rev limiter at 9000 rpm to help keep the top speeds in check.

 

[userfriendly]

Easily achieved by allowing the same bore and deck height. Just reduce the stroke from 4.25" to 3.5". They could also enforce a rev limiter at 9000 rpm to help keep the top speeds in check.

Fuel engines can't be rpm limited by dropping cylinders (spark). The fans are all at the starting line. Nobody watches the race at the far end of the track. It's boring down there. I'll bet that as soon as the entire field is running 340 mph, the finish line will be shortened another 120 feet to 880.

 

[02SE]

What are your thoughts on reducing TF and FC displacement limits to 410 cubic inches? I heard that was being considered maybe a year ago. If it allows them to go back to 1320 ft, would you make the trade-off?

As I've mentioned when you've asked me that in the past, there's no need. They've found a way to effectively keep the performance to an acceptable level*. If anyone comes up with any new ideas that boost the performance too much, they will quickly just put even more restrictive measures in place, as we've seen repeatedly in recent years.

No, I don't think they'll return to 1320 racing. There are too many tracks, Pomona in particular, that just don't have sufficient room to expand.

*What the NHRA and their insurance will tolerate...

 

[Lenny5160]

I think the mag and fuel pump restrictions that have been discussed in the past would make a lot more sense than a cubic inch reduction. My reasoning is that it would likely reduce expense to the teams to keep the cubes and just run them 'easier'. Making a smaller engine and pushing the envelope with them would make them slower, but not any cheaper which is the #1 issue with the fuel classes, IMO.

1000 foot racing made sense because there was already a timing block there, although they needed to add the speed trap for it. If they ever go any shorter, it would be to 660 (1/8 mile).

It'll be interesting to see what the Pro pits look like in 2021 with a lot of big names either not planning to return, or needing to find funding to keep their seat.

 

[thastinger]

Hello. I thought I would share what a set of bearings looked like from a NHRA 500" Pro Stock engine looked like when the Engine builder and the oil company are both hitting on all 8. These were run this year at Pomona and Phoenix. They have seen 21 passes at 1400+ horsepower at 10,500 rpms. The oil used varied from a 0W3 to a 0W8.

View attachment 22407

View attachment 22408

Carrillo rods and CP pistons?

 

[A_Harman]

I think the mag and fuel pump restrictions that have been discussed in the past would make a lot more sense than a cubic inch reduction. My reasoning is that it would likely reduce expense to the teams to keep the cubes and just run them 'easier'. Making a smaller engine and pushing the envelope with them would make them slower, but not any cheaper which is the #1 issue with the fuel classes, IMO.

1000 foot racing made sense because there was already a timing block there, although they needed to add the speed trap for it. If they ever go any shorter, it would be to 660 (1/8 mile).

It'll be interesting to see what the Pro pits look like in 2021 with a lot of big names either not planning to return, or needing to find funding to keep their seat.

NHRA paying $15k to win in Top Fuel is going to discourage competitors. All they can do is hope 2021 will be better.