ImBatman

Ok let me preface this by saying it has been a very long time since I put together a motor. :crazy: I have 5 of the 8 pistons installed in my 454 block. Everything seems fine but I was reading an assembly manual and I may have made a mistake. The crank is brand new as well as the pistons. The rods are origional to the block except one that had to be replaced. I bought the motor already disassembled so I don't know what rods went in what bores.
1. Does it matter which rod goes on which journal? Oh please say no :eek: :crazy:
2. How tight are the rods supposed to be against each other on the journal.
3. The rod caps when installed should have the 2 bearing tangs on the same side and the half moon on each bearing should fit together to form a circle correct?
thanks for the help.

Michel B

I can't help you on the rods, but you should go out to your local auto parts store and pick up a hanes manual, all the specs you need are in there...Good luck, have fun!!!!!!!!!!!!!

Pete79L82

1. Does it matter which rod goes on which journal? Oh please say no :eek: :crazy: It does not matter what rods go on what journals but it can matter which way the rods are on the pistons
2. How tight are the rods supposed to be against each other on the journal. Generally .020 side clearence on the rods will be about right.
3. The rod caps when installed should have the 2 bearing tangs on the same side and the half moon on each bearing should fit together to form a circle correct? Yes, the two tang should align with each other. To make sure the rods are on the pistons the correct way the tangs on rods 1 -3 -5 -7 should be on the drivers side of the block and the tangs on the rods 2 -4 -6 -8 should be on the passanger side of the block. Meaning that on each crank journal one rod will have the tangs pointed right and the other rod will have the tangs pointed left. This will asure that the bearings will match up with the radius on the crank.

ImBatman

Thanks Pete.

I still feel like a moron on these issues. You would think a computer engineer could figure this crap out. :banghead: Please bare with me while I throw a couple more questions out there.

1. I am running Speed Pro Hyper dome pistons. The stamping for the part # and size should always be to the top towards the lifter valley so that if you look at them you are reading the #'s right side up correct?

2. Not sure I understand your point on the tangs and the direction that they are pointing :confused:
To dummy this up for me. :D If I am standing at the rear of the block looking forward. I hold up a piston. If I have it positioned right. (assuming I am correct in question #1) if the tangs are on the left side of the rod then it goes on the drivers side. If they are on the right side then the rod\piston goes to the passenger side. That made my head hurt :cry Is this correct?

3. Lastly a guy on the Chevy Talk forum said that there is a right and left side to the big ends of the rods. The smooth side goes to the inside of the journal against the other rod journal and the chamfered side goes out towards the counter weght. Ok I looked at my rods which are OEM GM 3/8 rods and they are no different on one side than they are on the other. :smash: :confused:


I feel like a real boob on this! :bb Thanks for the patience and help.
Wade

Fevre

On you first questions no you do not go on being able to read the part number you go by the little notch that is on the outter edge of the piston, it should point toward the front of the block, if I am not mistaken one bank of pistons you will be able to read the part number while other side is upside down.

Check to see if you piston's have them like this, see the little notch toward the top of the pic:

ImBatman

Thanks Fevre. Should all Pistons have this sort of dot or whatever on them to indicate which way the piston goes in? Looks like to be safe I need to go back and remove the ones I have installed and start over. Better safe than sorry.

Can anybody else lend anymore info on my delima being kind to my demonstrated ignorance of course. :D

Anybody have there bottom ends built with dome stype pistons that can take some pics of the left and right banks?

Thanks
Wade

Fevre

I am not sure on the BB but for my small block there is that notch on the hyp pistons I have and the stock cast pistons that are in my LM1 short block. As far as the rods I believe one side of the rod is machined to face the other rod on that journal and the opposite side is meant to face the crank.

norvalwilhelm

Rods have a generous radius on one side and a more flat surface on the other side, The radius must face the crank and the flat surface to the inside. Turn a rod around and the corner of the bearing will bite into the radius of the crank. Once installed each rod and pair of rods must have movement to the side, slide the rod back and forth on the journal to be sure it is free.
BlackRat you are scaring me. :lol:

ImBatman

Thanks Norval. I am scaring myself. :eek: I'll get get there. If nothing else I will snap a ton of pics tonight and ask for help. :D


Thanks
Wade

ImBatman

Norval,
I removed all of the rods form the block and separated them again by the stampings on the rod caps. there are no dots, arrows, notches that I can see on the pistons. Also I thoutoughly examined the rod faces and both sides are machined smooth with no radius. Can you help me with this? The domes go towards the exhaust or outside area of the block and the notches go towards the cam or inside of the block correct. I don't have a set of heads so I have nothing to reference. As far as the rods I do not see any decearnable difference to tell which side would face the outside against the crank and which would face the inside against the other rod.

Thanks
Wade

Jughead

Here's a pick of my pistons installed. I think they're TRW'2 2349. The valve relief must be installed lifter valley side of the head. Sorry Wade, I can't help with the rods since I used the stock numbered connecting rods.








[Modified by Jughead, 6:03 PM 3/25/2004]

ImBatman

Thanks Jughead. Did your pistons have a notch or dot to go by like some have asked? Also what about your rods? Was there a radius side and a flat side? I took some pics of mine and I am getting ready to post them. It does look like on one side of the big end face the rod bearing is recessed in farther than the other. Is this the side that is supposed to face outword toward the crank counter weight?

i know I am probably making this harder than it actually is. Just want to make sure I am doing it right. :banghead:

Thanks Wade

MotorHead

I know that I wanted to build my motor myself, the engine builder who machined my block would put the bottom end ( short block ) together for 150 bucks. It is pocket change compared to what I spent on the motor so far but I want to do it because I enjoy it, it has nothing to do with money.

I also bought all the mics, bore gauges, dial gauges you need for doing the job.
I bought a brand new crank and Clevite 77 standard bearings and after measuring the crank, main bore housings with and without bearing a couple of hundred times I had to go out and get new set of Clevite 77 bearings that were 1 thou oversize.

There are very important measurements that need to be made like main and rod oil clearances, piston to wall and ring end gap just to name a few.

If you have not made these measurement please do so or better yet spend 100 bucks and get the short block assembled by a pro you probably have a lot invested in the motor and I would not want to see you disappointed :D

ImBatman

For the first 2 pics is this the notch referred to that should point towards the front of the block?




These next 4 show the sides of the rod are machined flat.





However, note that the picture below shows the bearing recessed further inside the cap. Is this the side that goes outward to the counter weight side?






Thanks
Wade

Jughead

I don't remember there being a dot or indentation on the pistons. I figured the pistons could go in only one way, that being with the valve relief at the top on each side. I may be mistaken but I think when the pistons were installed the numbers on the pistons were upside down! :eek:





Here's one of the few pictures I have of the rod/piston together.



Don't feel to bad if you need to remove them, I had to remove 4 of mine just to re-check the ring gap position and settle my mind. Ain't this fun? :lol:



[Modified by Jughead, 7:26 PM 3/25/2004]

norvalwilhelm

When the bearing is inserted in the rod and in the cap it sits off to one side. The bearing sits this way to clear the radius on the crank. You will notice the bearing sits closer on the other side. This is the side where the 2 rods sit together. The offset bearing side sits towards the crank radius.
In your pictures you can see the bearings offset.
All cranks are ground with a radius on each of the journals. The bearings need to be offset to keep from digging into this radius.
Some reground cranks don't put this radius back causing a stress riser.
Hope this help Black Rat


[Modified by norvalwilhelm, 7:50 PM 3/25/2004]

norvalwilhelm

However, note that the picture below shows the bearing recessed further inside the cap. Is this the side that goes outward to the counter weight side?

Yes

ImBatman

Thanks for all the help guys! the pistons are finally in :hurray: I did have them upside down the first time. :banghead: It was hard to picture how the head mates against the block when you don't have the heads yet and I have never used dome pistons only 4 valve relief flat tops. :smash:

Now the only thing I have to worry about is the # 4 piston. It made a little funny sound when it finally released through the ring compressor and into the bore :eek: I am sure that is nothing but like Jughead said I may need to remove it to double to settle my nerves. And oh yes Jughead this has just been a barrel of monkeys. :D :thumbs:

Thanks again for all the help. After I torque everything down tomorrow evening I will snap some pics.

:cheers:
Wade

LemansBlue68

Hopefully you at least stamped the rods and caps uniquely so that the caps and their mating rods do not get mixed up?? My 427 had each rod and cap stamped 1 thru 8 from the factory. Don't know if they've done this through later years or not. Mixing rods and caps is a big boo-boo since they are machined together as a matched pair.

ImBatman

They were already disassembled when I bought them. Some were marked and some were not. However I had new rod bolts installed and the big in resized so I am sure that the right caps are with the right rod now. thanks for the input.

Wade