Hey guys,

Is the purpose of the small oil hole in the big end of a conrod play a vital part in lubrication?
I have two different sets of conrods for the build.One from ts block other from nismo.
Just doing some research on engine build and trying to find out why the nismo conrod and their bearings dont have that hole?Or did they use another mechanism to compensate for it?

cheers

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The hole sprays oil onto the thrust side of the cylinder wall as the corresponding hole in the BE bearing passes over the crankpin oil gallery. Primary purpose is to reduce piston scuffing if the engine is heavily loaded when cold. Also helps lubricate gudgeon pin etc.
No need for this on competition engine - unless you want to hammer it dead cold.

The shinny rod looks like a std rod that has been prepped. Lightened and probably balanced. Looks to have the little end bushed for floating piston pins. The other rod looks beefier and stronger though. What's the weight difference?

Topics move so fast in this forum i didnt even notice i got a response to my query.

thanks ddiesel for the info mate.Very much appreciated.So as long as i warm up the engine, the nismo conrods will do fine i guess.I know other type of engines have mechanism that squirt oil.didnt know why nismo conrods didnt have said hole.

benny,
Yeh ur right.they are normal rods that have been lightened,balanced,oil holes modified and also been polished.seller said they had been wpc treated but not sure.il try and get them on a scale by weekend,latest end of next week and post up the weights.

ive got a nismo 240z book and they advise lightening of the nismo conrods?
so will most likely end up lightening the nismo rods and keeping them as spares for a rebuild down the line..

cheers

So i weighed all the conrods..

Weight of the prepped conrods complete (with connecting rod bolts and nuts with no bearings) are 448grams each.
I will try and also weigh the modified crankshaft and tomei pistons that came with these rods as a set and all had been balanced.

Weight of the nismo conrods (each with only one nismo connecting rod bolt.so missing the other rod bolt and nuts and no bearings) are 488grams each.
Will be interesting to see their weight after they get prepped as has been recommended in a nismo 240z book.

will post pics tomorrow.