rod weight ?

rod · 03-01-2015, 11:51 AM

I was checking my rods and I find one which is 4 grams lighter than the other 7. it is all at the big end. so how important is this?
thanks Rod in AZ

Mike Taylor 3601 · 03-01-2015, 01:06 PM

Depends on who you talk to, myself I balance everything I do+/-1/2 gram, a lot will tell you this is getting carried away, my theory is closer you get rods,pistons,pins, the better your balance will be on your crank.
Mike Taylor 3601

Roberte · 03-01-2015, 03:39 PM

I think that if you've paid for them to be balanced ,they'd have to
be going back. bob

BillK · 03-01-2015, 09:33 PM

Rod,

I typically try to make all of them the same. Most manufacturers of aftermarket rods and pistons say that if they are all within 2 grams they are ok, but it really only takes a few seconds more to make them the same so why not do it 100%

The only exception I make is with aftermarket "H" beam rods. I do not like grinding off any of the ribbing on the bottom of those rods. Sometimes you can take some weight off the sides but sometimes it is impossible to make them exactly the same.

That being said, are you having the crankshaft balanced ? All of the pistons and rods can be within a thousandth of a gram but that does not make a bit of difference if the crankshaft is not balanced to those weights.

Paul Precht · 03-01-2015, 10:29 PM

The motor will never notice it, if it bothers you though just have it corrected. Back in the early 70s when money was scarce for me I ran my BB Chryslers with unballanced parts and always turned them 7K in the lights, the motors ran as smooth as the ballanced ones.When I started working in a machine shop in the mid/late 70s I couldn't believe how out of ballance the stock BB Chyslers were. 4 grams is nothing to worry about IMO.

GTX JOHN · 03-02-2015, 03:18 AM

I agree with Paul.

carl hinkson · 03-02-2015, 11:12 PM

Quote:

Originally Posted by rod

I was checking my rods and I find one which is 4 grams lighter than the other 7. it is all at the big end. so how important is this?
thanks Rod in AZ

4 grams is alot for a set of rods, What rods are they ??

I seen alot of prebalanced assemblies where the pistons are still sealed in the box and the rods are still sealed in the plastic packages and guys run them all the time.

I see a lot of the GM circle track crate engines and those rods are all over the place and they run just fine lap after lap.

4 grams should not cause a problem.

rod · 03-04-2015, 08:30 PM

thanks for all the replies.
if 4 grams is OK, then I am in good shape. still it ticks me off.
Rod in AZ

03-01-2015, 11:51 AM	#1
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 314 Likes: 0 Liked 20 Times in 15 Posts	rod weight ? I was checking my rods and I find one which is 4 grams lighter than the other 7. it is all at the big end. so how important is this? thanks Rod in AZ

03-01-2015, 01:06 PM	#2
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,369 Likes: 348 Liked 292 Times in 101 Posts	Re: rod weight ? Depends on who you talk to, myself I balance everything I do+/-1/2 gram, a lot will tell you this is getting carried away, my theory is closer you get rods,pistons,pins, the better your balance will be on your crank. Mike Taylor 3601

03-01-2015, 03:39 PM	#3
Roberte Junior Member Join Date: Dec 2014 Posts: 68 Likes: 166 Liked 14 Times in 8 Posts	Re: rod weight ? I think that if you've paid for them to be balanced ,they'd have to be going back. bob

03-01-2015, 09:33 PM	#4
BillK Member Join Date: Nov 2005 Location: Waldorf Md Posts: 230 Likes: 12 Liked 30 Times in 17 Posts	Re: rod weight ? Rod, I typically try to make all of them the same. Most manufacturers of aftermarket rods and pistons say that if they are all within 2 grams they are ok, but it really only takes a few seconds more to make them the same so why not do it 100% The only exception I make is with aftermarket "H" beam rods. I do not like grinding off any of the ribbing on the bottom of those rods. Sometimes you can take some weight off the sides but sometimes it is impossible to make them exactly the same. That being said, are you having the crankshaft balanced ? All of the pistons and rods can be within a thousandth of a gram but that does not make a bit of difference if the crankshaft is not balanced to those weights. __________________ Bill Koustenis

03-01-2015, 10:29 PM	#5
Paul Precht Senior Member Join Date: Dec 2001 Location: Elysburg, Pa Posts: 730 Likes: 353 Liked 309 Times in 118 Posts	Re: rod weight ? The motor will never notice it, if it bothers you though just have it corrected. Back in the early 70s when money was scarce for me I ran my BB Chryslers with unballanced parts and always turned them 7K in the lights, the motors ran as smooth as the ballanced ones.When I started working in a machine shop in the mid/late 70s I couldn't believe how out of ballance the stock BB Chyslers were. 4 grams is nothing to worry about IMO.

03-02-2015, 03:18 AM	#6
GTX JOHN VIP Member Join Date: Jun 2009 Location: Boulder City, Nevada 89005 Posts: 2,730 Likes: 2,790 Liked 2,469 Times in 695 Posts	Re: rod weight ? I agree with Paul. __________________ John Irving 741 Stock 741 Super Stock

03-04-2015, 08:30 PM	#8
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 314 Likes: 0 Liked 20 Times in 15 Posts	Re: rod weight ? thanks for all the replies. if 4 grams is OK, then I am in good shape. still it ticks me off. Rod in AZ