Any real difference between factory 340 and 360 connecting rods?

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70aarcuda said:
Stock eliminator guys i know don't run stock rods
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back years ago, you had to run stock rods, period!!!! then the rules were changed for the chev boys, their powder cast rods broke easily, they whined and had aftermarket rods ok;d. then rest of us were allowed to use after market rods.
 
perfacar said:
back years ago, you had to run stock rods, period!!!! then the rules were changed for the chev boys, their powder cast rods broke easily, they whined and had aftermarket rods ok;d. then rest of us were allowed to use after market rods.
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There you go, from a guy who has been there and done that.
 
I did not know the bearings were date coded, here is what I found on a rod bearing:

8-85 X
.010
CB 481 P
Clevite 77

Here are a few dial caliper measurements I made if anyone is interested:

496 (340) rod
large end w/o bearing 2.2488" (cap not torqued down)
beam width .5413"
large end width .9275"
distance between bolts 3.561"

645 (360) rod
large end with bearing 2.114" (.010 undersize)
beam width .5039"
large end width .9259"
distance between bolts 3.566"
 
My experience with 'cheap' rods... bring 'em to a quality machine shop and, many times, they will have to rework them because the center to center length is off or the big end is too big or small. They might bolt in but they aren't usable right out of the box.

Speedmaster has a terrible reputation...

BTW... I'm looking for three bushed 340 rods to replace some damaged ones...
 
Wow...I have a set that has been running for 10 years now....and another set that has 7 years on them...and another set going on 4 years.....Got another set with 2 years running...and just put another set in a 360 that is on the engine stand..that is my experience. All are H beams except the 71 Duster has I beams that are not Scat I beams...

Out of the Box...into the fire...

Tell me about your experience...

TO EACH HIS OWN...LOL
 
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When my son and I were building an engine for his B-mod we spoke to two local engine shops... the answer was the same...bad luck with many out of the box import rods. Bad/inaccurate machining and/or the balance was off.

They had decent luck with Scat, K-1, Molnar or any that was machined in the US. Not so good with Eagle, Ohio Crank, ProCrap, Speedmaster, etc. One told us he wouldn't use Eagle rods in a lawnmower.

IIRC Speedmaster is the same outfit who used to be ProComp but changed their name due to the pee poor quality of their products. I hang around a site with many skilled engine builders from around the world... many would agree with what I've just said... some may not.

When all was said and done we chose to use GM LT1 powdered metal rods in his race engine since they were cheaper (bought 2 1/2 sets for $80.00... takeouts from a marine engine shop) and are very reliable in this application. I'd sooner use 30 year old Mopar rods in my DLM engine than any Chinese rod... but that's just me. I'll spend the $$$ for good rod bolts and expert machine work... for me new, shiney and cheap don't equate to quality.

I have a couple sets of used Cup rods for my next, next Mopar build. Cheaper and better than any Chi-Com rod out there... $125/set... originally $2800 or so new. My buddy in NC is a former engine guy from Rousch... he gave me the thumbs up when I bought these and he bought several sets for his future projects... a much better part and a much better buy.

Just remember... just because something LOOKS the same doesn't mean it is... look at Bruce Jenner.
 
70aarcuda said:
NO..they are stock mopar size, the .927 is reference to the width of the big end of the rod, not the pin size. There were selling for 187 dollars and I bought a few sets...

Pin End Bore Diameter (in): 0.984 in.
Big End Width (in): 0.927 in
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I`m probably the guy, in the past that posted about running the pin end , steel on steel w/ no bushing, full floater. I was building a 383 sbc, and I like full floating pins. The machinist that did the work on that block told me it would work, said he`s done it many times. So we tried it and no problems, was probly about 400-450 horse engine. It ran till I sold it ( low 11`s) and built a 406.
 
Krooser said:
When my son and I were building an engine for his B-mod we spoke to two local engine shops... the answer was the same...bad luck with many out of the box import rods. Bad/inaccurate machining and/or the balance was off.

They had decent luck with Scat, K-1, Molnar or any that was machined in the US. Not so good with Eagle, Ohio Crank, ProCrap, Speedmaster, etc. One told us he wouldn't use Eagle rods in a lawnmower.

IIRC Speedmaster is the same outfit who used to be ProComp but changed their name due to the pee poor quality of their products. I hang around a site with many skilled engine builders from around the world... many would agree with what I've just said... some may not.

When all was said and done we chose to use GM LT1 powdered metal rods in his race engine since they were cheaper (bought 2 1/2 sets for $80.00... takeouts from a marine engine shop) and are very reliable in this application. I'd sooner use 30 year old Mopar rods in my DLM engine than any Chinese rod... but that's just me. I'll spend the $$$ for good rod bolts and expert machine work... for me new, shiney and cheap don't equate to quality.

I have a couple sets of used Cup rods for my next, next Mopar build. Cheaper and better than any Chi-Com rod out there... $125/set... originally $2800 or so new. My buddy in NC is a former engine guy from Rousch... he gave me the thumbs up when I bought these and he bought several sets for his future projects... a much better part and a much better buy.

Just remember... just because something LOOKS the same doesn't mean it is... look at Bruce Jenner.
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Scat, K1, Moinar ...speedmaster...eagle and whoever are all probably made in the same foundry in china....Machine is Southern Cal...by Juan...instead on Wong.......

Nascar rods fit stock mopar cranks?,,,,that is got to be news....thought they were all using Honda 1.88 rod sizes...but as I said..I don't know **** from shinola....none of my rods have ever broken...can not say the same for stock rods...3 destroyed engines from stock rods...last one with arp bolts..magnafluxed ..shot peened polished...broke on there 5th pass....yeah...45 year old rods are better...LOL...
 
70aarcuda said:
Scat, K1, Moinar ...speedmaster...eagle and whoever are all probably made in the same foundry in china....Machine is Southern Cal...by Juan...instead on Wong.......

Nascar rods fit stock mopar cranks?,,,,that is got to be news....thought they were all using Honda 1.88 rod sizes...but as I said..I don't know **** from shinola....none of my rods have ever broken...can not say the same for stock rods...3 destroyed engines from stock rods...last one with arp bolts..magnafluxed ..shot peened polished...broke on there 5th pass....yeah...45 year old rods are better...LOL...
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Some people get pissed because the buy new rods and then have to fit the pin bores and hone the big ends.


If I was KING, every rod sold would be required to be pin fitted and honed to final size so cheap asses would have to have their stuff done correctly.
 
70aarcuda said:
Scat, K1, Moinar ...speedmaster...eagle and whoever are all probably made in the same foundry in china....
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People would be scared when they knew how much is made in China. A lot of the toolings in the automotive industry are made in China... because it is cheaper.
They are still made to the same specs as in the US... because of strict QUALITY CONTROL. Not all Wongs are stupid and cheap-***, and car makers have their own people down there to look after the quality. That's the world of today.
 
Not criticizing at all, but all of this rod comparison by experience has only so much validity. How high you rev it AND how long, as well as piston weights and power levels, are all variables that rarely get mentioned when the 'this rod broke' or 'these rods are good' is brought up. One shop may do only unlimited circle track stuff going 8k rpm all the time on pavement; that is gonna be a lot harder than other uses.
 
70aarcuda said:
Scat, K1, Moinar ...speedmaster...eagle and whoever are all probably made in the same foundry in china....Machine is Southern Cal...by Juan...instead on Wong.......

Nascar rods fit stock mopar cranks?,,,,that is got to be news....thought they were all using Honda 1.88 rod sizes...but as I said..I don't know **** from shinola....none of my rods have ever broken...can not say the same for stock rods...3 destroyed engines from stock rods...last one with arp bolts..magnafluxed ..shot peened polished...broke on there 5th pass....yeah...45 year old rods are better...LOL...
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Never said Mopar made rods to fit the Honda rod size but resizing a crank to that spec is about the same $$$ as it takes to grind a crank to a .030 undersize.

I'm redoing a small block 383 that had one rod seize on the journal and became a weapon of mass destruction... not the rods fault but the driver who felt the bearing start to seize but kept his foot in it because he was passing for the win...

I always use custom pistons so having them built to the smaller pin size and longer 6.250 length doesn't cost any more either. Plus these rods are much lighter than stock or most I-beam or H-beam cheapo rods so that's a bonus.

Did I mention they are cheaper than the Chi-Com rods? And the country that produces them (Austria) doesn't consider you and I the enemy of the state and have nuclear missiles pointed at us.

I didn't think this thread would tun into a wiener measuring contest but I guess it has...
 
All i did was pointed out an inexpensive alternative to redoing stock rods about 50 post ago. It's your money spend it as you see fit.
 
All I'm saying is any part... rod, head assembly, crank... needs to be inspected, measured and, perhaps, modified to insure everything is correct before it's used in a high performance application.

You can pull anything out of a box, bolt it in and it may work in your application... what's the old saying?... good, cheap or fast... pick any two? I don't make enough money to gamble on a race engine.

Not everything needs the same treatment... right now I'm doing a partial rebuild on my wife's 4.0 Grand Cherokee. All that fancy talk goes out the window when working on a $1200.00, 148,000 mile daily driver... one new piston, new rod bearings (mains are fine), lap the valves and install new seals and bolt it together. $300.00 in parts and my labor is all I want to invest...
 
Funny how this started with someone asking to id a floating rod, and 3/4's of the thread is about what rods are good or bad.
 
Valkman said:
Funny how this started with someone asking to id a floating rod, and 3/4's of the thread is about what rods are good or bad.
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Why does that surprise you??? Standard OP around here to go off topic....................
 
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