installing 3400 rods

[Alxsmt]

so i gotta stupid question... its been so long since i took it apart i cant rember which way the rods go and i dont wanna tear into my other 3400 if i dont have to..

so does the little flat tab go facing the water pump or the tranny?

[WrathOfSocrus]

The little tab above the bearing appears to face towards the trans. The bottom of the bearing cap is flat on the back (trans side) and beveled towards the front. The stock pistons have arrows pointing towards the front of the engine, at least on a gen2, 3100, and 3500 they do. The 3500 rods seem to have different distinguishing marks machined into the connecting rod. Hope that helps!

[Alxsmt]

eh well sorta but not enough for me to be sure... im just gonna take my othere engine apart to be positive

i dont have stock pistons on it, and there not directional

[WrathOfSocrus]

LOL alrighty then!

EDIT - OK here are a few pics of the pistons I have.



From left to right we have 3500, 3100, and 2.8 pistons. If you look closely there are arrows on the pistons pointing towards the front of the engine (pulley side).



Here is the transmission side of the rods. Notice the little half round tabs in the middle of the rod just above the bearing on the 2.8 and 3100 rods. Also the 3500 rod has tabs on either side that extend to the edges of the rod.



And here is the side facing the pulleys. Notice no tabs on the 2.8 and 3100. Also the 3500 rod has tabs that don't go all the way to the edge like trans side does.



And finally the bearing caps. we have the 2.8 and 3100 starting from the left with a beveled edge towards the pulleys. The 3500 has no distinguishing marks on the outside of the cap. It has interlocking grooves that differ from one side to the other to make it easier to identify which way the cap goes on.
It only fits one way!

My engine with the original rotating assembly is in a crate under a pile of other engines/parts so I can't dig that up at the moment. I have seen this question asked before and I figured it would be a good idea to get some pics up with an explanation of the orientation of the rods. If any of the senior members can confirm or deny this, or have something to add, that would be great!

[Alxsmt]

ok thats clears it up, thats what i was thinking but didnt wanna risk it. i was just about to go pull my pan too

good info on the other rods too

thanks man

[3400-95-Modified]

Are you sure your pistons are not directional? Stock 3100 and 3400 rods are offset .030 from center of the piston for torque reasons... I would double check your order sheet from JE to make sure they are directly centered center pins.

[WrathOfSocrus]

ok thats clears it up, thats what i was thinking but didnt wanna risk it. i was just about to go pull my pan too

good info on the other rods too

thanks man

I figured pictures would help verify the parts. I would have gone and pulled the pan without pictures myself. I just figured I could save you the trouble. I have a 2.8 and 3500 laying around the garage and I can't afford to do what I want with my car just yet. So I always try to get up and take pictures anytime I can.

Plus I spent over $200 on that camera and for the moment nothing is going on with my car, so i have no other need to take pictures. I gotta make use of it somehow!

[Alxsmt]

the machine shop that mounted and ballanced them said there not directional. they had all the specs in the box too. i will check tommorrow to be positive

well it was a great use of a camera, they were invented for automotive reasons i swear! lol

thanks

[pocket-rocket]

the machine shop that mounted and ballanced them said there not directional. they had all the specs in the box too. i will check tommorrow to be positive

well it was a great use of a camera, they were invented for automotive reasons i swear! lol

thanks

I've had mine for around 5 years now. So far about 9/10 pics if not more are for car stuff