yea the cup guys are smart its a whole nother world when you build a cup engine. i cant even imagine to build a f1 engine let alone a cup engine.

To expand just a bit on what logano20 has already said Cup teams don’t really use Honda or BMW bearings. The reference to theses is more in reference to the size of bearing being used. In Cup the minimum main journal size is 1.997 and the minimum for a rod journal is 1.847. Most Cup crankshafts today run 2.250 on the mains and rod journals around 1.888 to 1.850. There are some Cup crankshafts that are 2.000 on the mains, but the trend right now seems to be slightly bigger. For comparison all the Chevy LS series engines in passenger cars have 2.100 rod journals and 2.650 main journals. In Cup the bearings themselves are Clevite or Federal Mogul and are not any thinner than a passenger car bearing. They are required to be two piece just like your passenger car and they are made out of the same material; which is a copper-lead alloy layer on a steel back and electroplated with a white metal babbitt surface layer. I hope that helped answer the question.

chances are good you will find they are using a cl-77 a clevite bearing of some sort,if they can support an 8000 hp nitro engine i know they can handle a 500 hp piece of junk these boy's are using!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Unfortunately, a 3.5 second interval between crankshaft bearing changes won't work well during a 500 mile race.

auntysquat - 15 July 2009 10:24 AM

Unfortunately, a 3.5 second interval between crankshaft bearing changes won't work well during a 500 mile race.

The shrub thought maybe he's get by with far less than 500 miles this past weekend.

to support oil pressure,the crank and bearing only know the clearence at the given time,the tear downs in a nitro engine are not due to crank and bearing failure,piston burnout,and valvetrain failure are the main culprit's in failure's concerning their powerplant's,nice try guy's

the bearings you are talking about are babbit i don't think nascar uses babbit because its so soft.

1974nova - 15 July 2009 04:16 PM

to support oil pressure,the crank and bearing only know the clearence at the given time,the tear downs in a nitro engine are not due to crank and bearing failure,piston burnout,and valvetrain failure are the main culprit's in failure's concerning their powerplant's,nice try guy's

There is no need to be either obtuse or condescending here ... this is the technical board, not the baiting and biting at each other forum.

I did not suggest that crankshaft bearings are the main reason that nitro engines are torn down between rounds. The reality is that they're changed between rounds ... along with other inexpensive items and anything expensive that looks suspect.

There are a lot of people that frequent this board who are well informed on a variety of tech topics. If you want to discuss something, just assume you're talking to some people who are as intelligent as you are.

There is a lot of information available about horsepower and torque values for NASCAR Cup, Nationwide and Truck race engines. Your numbers are wrong. If you want to know where to look, send me a PM and I'll point you there.

auntysquat - 16 July 2009 02:02 AM

1974nova - 15 July 2009 04:16 PM

to support oil pressure,the crank and bearing only know the clearence at the given time,the tear downs in a nitro engine are not due to crank and bearing failure,piston burnout,and valvetrain failure are the main culprit's in failure's concerning their powerplant's,nice try guy's

There is no need to be either obtuse or condescending here ... this is the technical board, not the baiting and biting at each other forum.

I did not suggest that crankshaft bearings are the main reason that nitro engines are torn down between rounds. The reality is that they're changed between rounds ... along with other inexpensive items and anything expensive that looks suspect.

There are a lot of people that frequent this board who are well informed on a variety of tech topics. If you want to discuss something, just assume you're talking to some people who are as intelligent as you are.

There is a lot of information available about horsepower and torque values for NASCAR Cup, Nationwide and Truck race engines. Your numbers are wrong. If you want to know where to look, send me a PM and I'll point you there.

in no means was i trying to insult your'e intelegence,i'll not get into a contest of wit's,thank you.bob hughes aka 1974nova

Is there a spell-check option on these boards???