Hot Rods Help! SCAT Connecting Rod Orientation

Hey Hambsters

I've run into a bit of confusion when assembling the SCAT rods and pistons in my 283 small block chevy.

I'm looking at these rods and have noticed that half of the rods have been installed with the numbers facing forward (in relation to the F on the piston) and half with the numbers facing back(see photo #1).

The big end bearings are slightly offset, with more of the bearing on the side with the writing (see photo #2).

I don't know what to make of all this. I thought that numbers (and dot) on all rods had to face forward. But am I wrong? Have half of these rods been installed backwards? I have looked online for clear answers but have not found any. I don't have the manual for these rods either as the machine shop would have thrown it out. Any advice is greatly appreciated.

Thanks in advance

 

Numbers mean nothing to the relationship of the rod install. The bearing tangs go to the outside, toward the pan rail, when the piston rod assembly is installed

 

Towards the pan rail? I’m confused, as there is a pan rail on both sides


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He is referring to the "oil pan rail." Yes it is located on both sides of the engine block.

 

I’m missing something. Whether the rods are installed one way, or another, they will, for half of the stroke face outward, to one of the sides of the oil pan rail...

 

Right bank, left bank
Tangs toward pan rail on corresponding side.

 

Orientation remains the same when installed correctly on the crankshaft. Every second rod journal faces in the opposite direction (180 degrees) on each crankshaft journal. The narrower sides on the rod journal face each other, the wider part of the journals face outwards towards the crankshaft journal. All they do is go up and down in the cylinder bore as the crankshaft rotates. Just remember to have the bearing tangs on each rod journal on L&R cylinder banks facing towards the outside (Oil pan rails where it bolts to engine block) when installing the piston rod assembly in the engine.

http://www.hotrod.com/articles/51578-small-block-chevy-assemble/
http://garage.grumpysperformance.co...g-and-installing-connecting-rods-pistons.247/

 

Ahh I got it. So the shallower sides of the rods face one another on the journal and the tangs face to the oil rail on the same side that the cylinder is in. So a cylinder that’s on the drivers side will have the tang also facing the drivers side thanks guys!

 

Must have been that right side of the road, left side of the road thing.

Ben

 

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If you put the bearings in the rods, no Pistons, and put the rods on the crank, just one set will do, with the champher to the center you will see why it's wrong. They won't turn ez like when they are correct. Doing it wrong intentually sometimes is the best way to learn.

 

That is because they are not lefts and rights when they are made. They go tangs in.

The big end bearing is offset for rod angle, if they are made correctly the offset with loosen up your lower end a little bit. That's free torque.

 

When the bearing inserts are installed in the rods they are offset in one direction.
http://www.grumpysperformance.com/bearingshelloffset.jpg

http://www.grumpysperformance.com/bearingoffset2.jpg

If the rods are made correctly the offset and the large chamfer machined in the rod should both be toward the radius at the edge of the journal, when the rods are installed correctly.

 

May be say away from cam. Not as confusing as rails