Rod weights

[bugnut68]

Ok, I bought a set of rods used (Scat I beam, VW length, with 3/8 ARP bolts, stroker clearanced) at a swap meet last year.  Three of them good, one torched.  The box indicated they were Scat, but now I have my doubts.  The box indicated that these things weighed 391 on the big end and 195 on the little end, which would give a per rod weight of 586 grams each. 
I weighed each of these rods on the local UPS scale, and each of them weighed either 1.25 or 1.20 pounds, which is 566 or 544 grams, total.  I don't have a machine shop that measures rod weight end to end in this town (it's a small town), and I had a fairly lengthy conversation with Ron at Scat the other day. 
The only thing I can figure is these are some other brand of rods that were tossed into a Scat box for the swap meet, or some freak of nature.  Scat's rods weigh in at 600 grams and, as Ron said to me on the phone the other day, 40 grams is a lot of weight to shave off of a rod, so I'm trying to figure out what I've got, here.
Anybody have any weight figures for stroker rods (I beams, stock length) that I could compare notes with?
The box is dated July 2006, so I'm not sure where to go from here.
 I was hoping to find a rod of similar weight to complete the set rather than buy a whole new set, but if thats' what's necessary, so be it.

[Bruce]

Pic?

[Fasterbrit]

you are right about 40 grams being a lot of metal to take off. It is extremely unlikely that you have a matching set. Even an unbalanced set would not vary much more in weight than about 5-7 grams between the set. The next measurement should be height between the big end and wrist pin centers. I bet these will not correlate, either.

[bugnut68]

you are right about 40 grams being a lot of metal to take off. It is extremely unlikely that you have a matching set. Even an unbalanced set would not vary much more in weight than about 5-7 grams between the set. The next measurement should be height between the big end and wrist pin centers. I bet these will not correlate, either.

I just found a guy with a partial set of Empi rods (my favorite brand, lol) and he weighed them in.  Total weight on each correlate with my rods, about 1.25 pounds each.  Bruce, I'll try to get a pic when I can, maybe tonight and I'll upload them tomorrow at the office on a break.  I can say this much, they aren't stamped CB or Scat or anything else and don't have the "bump" that mark which side is up on stock rods.  The box, which is marked Scat, is dated 2006, so perhaps Scat had rods at this weight back then, but they sure don't now.

[bugnut68]

Pics...

[bugnut68]

Got a digital scale this weekend.... these rods weigh 570, 544 and 544 grams, each.  Nice, huh?  As a comparison, I have a set of stock, non-clearanced rods that weigh in at 623, 621, 621 and 621 grams total.  Guess I'll have those clearanced with new bolts installed.
I'm having words with Wally Schmidt this year if I make it to the Woodburn Bug Run. 

I guess the lesson is never buy performance parts used unless you really know the seller fairly well. 

[Bruce]

I have a set of stock, non-clearanced rods that weigh in at 623, 621, 621 and 621 grams total.  Guess I'll have those clearanced with new bolts installed.

You don't need to change the bolts.  Run them as is.

[nicolas]

I have a set of stock, non-clearanced rods that weigh in at 623, 621, 621 and 621 grams total.  Guess I'll have those clearanced with new bolts installed.

You don't need to change the bolts.  Run them as is.

so the stock bolts are as strong as the aftermarket ones? is that for most/all brands? i thought there really was a difference between stock and 'reworked' in quality and reliability...

[Bruce]

Stock un-modified rods are unbelievably STRONG!  Anyone that says otherwise is spreading a myth.  Reports of turbo engines with stock rods at 400hp exist.  Also revver motors going over 9k have survived with stock rods.

[TexasTom]

That may be so, but as one who has experienced the rath of a stock rod coming apart at 8600 rpm , my advice would be to change them often if you're going to run them under those types of conditions. The rod separated at the big end right where it meets the beam so it wasn't a failed bolt or nut. ... And just to clear the air, these were Berg prepped rods on a 78 stroker crank.

So what I'm saying is ... I was too bold to change them often enough as Berg recommends in the catalog and instructions.

[bugnut68]

That may be so, but as one who has experienced the rath of a stock rod coming apart at 8600 rpm , my advice would be to change them often if you're going to run them under those types of conditions. The rod separated at the big end right where it meets the beam so it wasn't a failed bolt or nut. ... And just to clear the air, these were Berg prepped rods on a 78 stroker crank.

So what I'm saying is ... I was too bold to change them often enough as Berg recommends in the catalog and instructions.

I think I"m safe, as there's no way my engine will be turning 8600 RPMS...;-)  It'll probably be done making power aroudn 6K, in all honesty.