sbc help

[luxeryvic]

we were takin apart a 77 305 but i forgot to mark the con rods of which cylinder they came out of, is there a way to figure out how to put them back in the right place, we tried guessing a few times but when we trqued them everythin siezed up tight???

[mcmalloy]

you will have to get it line boared at a machine shop

[777stickman]

Originally Posted by luxeryvic

we were takin apart a 77 305 but i forgot to mark the con rods of which cylinder they came out of, is there a way to figure out how to put them back in the right place, we tried guessing a few times but when we trqued them everythin siezed up tight???

Never seen anybody cause themselves as much trouble as you do (except for maybe me). It's called the learning process.

The reason for stamping the rods and caps is to make sure they not only go back in the same hole (not a real big deal) but that the same cap goes on the same rod (a real big deal).

So, it sounds like you've got a rod or 4 in backwards or the bearings are not correct or the wrong cap on the wrong rod or??? I can just picture your next ? "How do I know backwards from forwards"? Each piston top should have a dot, arrow or notch. This indicator should be pointing to the front of the motor.

If I had a motor going together I'd send you a pic of what the rods should look like when installed correctly, but it's been so long ago I can't remember.

Good luck to you while you are learning.

[silicon212]

Like 777 said above, if you intermixed the caps with different rods, it's off to the machine shop. You will have to get them all resized.

Rods only mount in one direction. It doesn't matter if 2 goes into 6 or if 3 goes into 1 as long as the caps are properly oriented. If you look at the rod sideways, you will note that the rod bolts are slightly offset from front to back. There is a 'tang' on the side with the greater offset - this tang is oriented so that it's always near a crank counterweight and never in the center of two rods. The sides with less offset are oriented back-to-back.

If you put a cap on backwards, that's an instant and thorough bind and if you force the crank, you will break something.

This is what I love about the newer technology powdered, cracked rods. It is impossible to mix up caps on them, or install them in any other way except correctly.

Again, if you mixed up any rods with caps from other rods, have ALL of them resized, and since you're going to do that, have the machine shop install new bolts on them.

[luxeryvic]

looks like its off to the machine shop then lol yeah im 18 and this was the first engine i pulle apart , turned out the block needed boring so we went with another runnin engine anyways

[silicon212]

Originally Posted by luxeryvic

looks like its off to the machine shop then lol yeah im 18 and this was the first engine i pulle apart , turned out the block needed boring so we went with another runnin engine anyways

The 18 year old thing doesn't work with me, but then I also have an INTJ personality plus I was doing this stuff when I was 10, so ...

But yes, everyone learns by trying - it is the best 'school' that can ever be found. I am all self taught on this, so if I could do it ... anyone could!

I've biffed a few in my time, too.