Has anyone bought/used forged conrods from aliexpress? https://m.aliexpress.com/wholesale/A15 ... .html?keywords=A15-conrod

Not sure if they're worth it and what size I'd need for my rebuild

I haven't but have been told that if you get the standard rods shot peened they will handle a lot of punishment.

Where would I go to get that done to them? does it work harden them?

I was under the impression the standard con rods are forged.

Shot peening introduces compression stress at the material surface and effectively increases the resistance to fatigue crack formation. That means you can stress them more (i.e. increase RPM) before running into fatigue issues. Forced induction has less of an impact on rods than rpm does.

They are apparently! Nissan replied and confirmed.. As did David!

So where would I get my stock ones shot peened?

Ask your local engine machine shop... they will point you where you need to go
While your at it..get the rods smoothed/polished so the oil slips off them
And fit ARP rod bolts

I prefer H beam standard rods to I beam rods... heres why
Oil gathers in this area as the rod rotates
Believe it or not this amount of oil can unbalance the rod and reduce the ability to rev
Yes its negligible... but some of us care about such things.

Oh.. and the Maxspeeding rods weigh 500g each

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Thanks very much! Good to know!

I'll have a chat once the engine is back

stock rods are fine but rallytwit had stockies shot peened and
his engines saw constant 8000rpm and more as I recall.
If you can get the H beams for 300usd with arp rod bolts then
that is worth it as well vs treating rods and as pointed out
at 500grams probably 30 grams lighter each.

H beams are more efficient with material and hence lighter for the same strength. Any weight saved is less stress on everything at the same rpm. Reciprocating mass is the main source of stress in a piston motor.

D actually I don't have them shot peened; I run stock rods, the only thing I have the machine shop do is balance the rods and pistons and that was only for the forged pistons. I also use the stock rod bolts (I use new Nissan many becuase I have/had about 10 sets)

On the A15 I keep it to 8000 but it does briefly see 8100 in 4th at the end of the fastest straight on my home track. I'm on season 5 with this motor. Granted the motor is making all of a 100whp. It's going on the dyno tomorrow so I'll finally know the exact number.

On the A12 with flat top pistons I regularly revved the poor motor to 8600 rpm. During one of the Alfa Datsun challenge weekends I was chasing a GTV hard and revved the motor to 9100 several times. Again no issue with the rods but the rings on the other hand were toast after about 10 hours of running.

For my next motor I planned to finish the rods per the Nissan prep manual; it calls for relieving the sharp edge were the rod bolts seat on the rods and polishing ridge/seam on rods. See DatsunCherry.CH for the manual.

Unless I were doing a big power turbo motor I people simply use the stock rods.