Reciprocating weight-component related

Steve Williams · 09-14-2012, 10:16 PM

The NHRA has posted weights on reciprocating engine components. If you build an engine using stock crank, rods and pistons and the weight is less than published weight for aftermarket pieces, is this legal? I have weighed stock pieces versus aftermarket pieces and the stock pieces always come up light when compared to aftermarket published numbers. Am I going to be legal or be a cheater? After all it is stock......

Richard Muhlenhardt · 09-15-2012, 08:00 PM

338 views and nobody gona say what there doing- hint nhra is only enforcing the total weight and nothing else

09-15-2012, 08:48 PM

They are looking for total weight, the component weights are a guide. When is the last time a piston and rod was weighed? I think those days are over. But as long as there is a rule, it keeps most, if not everyone honest.

Jeff Lee · 09-16-2012, 12:23 AM

Quote:

Originally Posted by Steve Williams

The NHRA has posted weights on reciprocating engine components. If you build an engine using stock crank, rods and pistons and the weight is less than published weight for aftermarket pieces, is this legal? I have weighed stock pieces versus aftermarket pieces and the stock pieces always come up light when compared to aftermarket published numbers. Am I going to be legal or be a cheater? After all it is stock......

I'm just making an assumption here. NHRA has made allowances for forged pistons that are up to .070" over stock bore. A forged piston, something like a TRW for example, will weigh more than a factory standard bore cast piston. NHRA may rightfully figure a majority of Stock racers are using forged and not factory issue pistons therefore the weight is on the assumption one is going to build an over-bored, forged piston engine???
And if you are light for some reason, there's nothing saying you can't add weight to your pistons. That'll give you something to talk about in the pits!

Steve Williams · 09-18-2012, 12:26 PM

Thanks for the replies. For a minute I thought that I may never get a reply. Nothing taboo about this subject as far as I know. A few Stock racers that I know carry a short block with them as a spare that is basically stock. I have asked this question to a few racers as well as an anonymous tech guy. Each person who answered had their own take on this. My guess is that if you are willing to take the risk with stock rods and pistons, that weight probably isn't the thing one should be worried about.

09-14-2012, 10:16 PM	#1
Steve Williams Member Join Date: Aug 2007 Location: Detroit, Michigan Posts: 352 Likes: 0 Liked 1 Time in 1 Post	Reciprocating weight-component related The NHRA has posted weights on reciprocating engine components. If you build an engine using stock crank, rods and pistons and the weight is less than published weight for aftermarket pieces, is this legal? I have weighed stock pieces versus aftermarket pieces and the stock pieces always come up light when compared to aftermarket published numbers. Am I going to be legal or be a cheater? After all it is stock......

09-15-2012, 08:00 PM	#2
Richard Muhlenhardt Junior Member Join Date: Mar 2009 Posts: 40 Likes: 0 Liked 1 Time in 1 Post	Re: Reciprocating weight-component related 338 views and nobody gona say what there doing- hint nhra is only enforcing the total weight and nothing else

09-15-2012, 08:48 PM	#3
Todd Hoven Guest Posts: n/a	Re: Reciprocating weight-component related They are looking for total weight, the component weights are a guide. When is the last time a piston and rod was weighed? I think those days are over. But as long as there is a rule, it keeps most, if not everyone honest.

09-18-2012, 12:26 PM	#5
Steve Williams Member Join Date: Aug 2007 Location: Detroit, Michigan Posts: 352 Likes: 0 Liked 1 Time in 1 Post	Re: Reciprocating weight-component related Thanks for the replies. For a minute I thought that I may never get a reply. Nothing taboo about this subject as far as I know. A few Stock racers that I know carry a short block with them as a spare that is basically stock. I have asked this question to a few racers as well as an anonymous tech guy. Each person who answered had their own take on this. My guess is that if you are willing to take the risk with stock rods and pistons, that weight probably isn't the thing one should be worried about.