main cap bearing grooves

[capriceowns]

Im assembling my 350 4 bolt. and the groove in the block and on the main cap were the bearing fits into on one side.

when putting the caps on, does it matter if the groove from the cap is on the same side as the one on the block?

[Blue Bowtie]

Groove? As in oil groove? If you orient the shells according to the tangs, there is only one correct way. And they are frequently marked:



If you are using half-grooved mains, the inner oil grooves are installed in the upper halves of the mains:



The mounting tangs determine the orientation, and any numbering would determine the positions.

Generally, the bearing locating tangs are installed opposite each other, so the shoulder of the mating bearing acts as a "stop" of sorts to prevent bearing slippage and spinning. The caps should have been stamped and match-marked for position and orientation before disassembly. If they aren't, you'll need to bolt them down and either check saddle alignment with a ground/polished test bar or possibly align hone them to be sure they are straight.

[capriceowns]

im not talking about the oil grooves. theres a groove in the actually block and the cap and theres a lip on the bearing that fits in there.

one side is more indented then the other, i was wondering if there installed opposite or not.

I think you anwered it in thre bottom of your post, but idk what tangs are, lol.

I had the block align honed aleready, and i numbered them for which one goes were, but didnt look at the groove thats cut into each of them

the groove im talking about is by the topmost main bolt you showed there with the bearings in it.

[silicon212]

Look at the left bearing shell on the first of Blue Bowtie's pictures. Notice that tab in the center, more or less, of the foreground of the bearing? Those are called 'tangs' and they MUST both be on the same side, opposing eachother. If you put a main cap on backwards, expect that bearing to last as long as it takes to start the engine, no more.

[capriceowns]

Originally Posted by silicon212

Look at the left bearing shell on the first of Blue Bowtie's pictures. Notice that tab in the center, more or less, of the foreground of the bearing? Those are called 'tangs' and they MUST both be on the same side, opposing eachother. If you put a main cap on backwards, expect that bearing to last as long as it takes to start the engine, no more.

So the main bearings(the ones in the middle not the 2 end ones) have those two, but arent in the middle like the pic of BB. those have to be on the same side?

Did i read it right?

I guess what i was asking before was the tangs. didnt know they were called that.

So the tangs on the block anc cap must be on the same side on top of eachother in a way?

[silicon212]

Yes. If you look closely at the caps, all except for the rear cap (for obvious reasons) have an arrow on them. This arrow points toward the front of the engine.

If you put the caps on backwards, the bores will not be in alignment and will take out your crank and all affected bearings in very short order - the failure will occur well before a flat tappet cam achieves a good break in, and very well could occur just cranking the engine over even before it starts.

[capriceowns]

Originally Posted by silicon212

Yes. If you look closely at the caps, all except for the rear cap (for obvious reasons) have an arrow on them. This arrow points toward the front of the engine.

If you put the caps on backwards, the bores will not be in alignment and will take out your crank and all affected bearings in very short order - the failure will occur well before a flat tappet cam achieves a good break in, and very well could occur just cranking the engine over even before it starts.

I feel dumb now, lol. There are arrows on the caps. I had them right to, i suprised my self.

Thanks for the help guys

I got one more question on my pistons, theres a little punch on one of the sides on top. Does that mark go to the fron of the engine or rear?

[silicon212]

Take your connecting rod and put the cap on, both ways (do this out of the engine, on the bench). When installed one way, you will notice that everything is perfectly aligned. If you install it the other way, you will notice that the rod and cap are offset. This is because the bolts are offset - so that the cap will only fit one way. Some rods are stamped and some are not. I always mark the rods with a stamp of the cylinder they are from, both cap and rod. Don't mix up the caps - the caps MUST be reinstalled on the rods from whence they came - if they get mixed, the rods must be honed and the proper oversize bearings used in order to obtain proper bearing crush.

The edge of the rod that's closer to the studs are to be matched in the middle, the edges that are further from the studs are to be oriented toward their counterweights at all times. The pistons themselves have a mark on them - could be an arrow, notch or indentation, that points to the front of the engine. 4 of the rods will be installed on the pistons in reverse of the other 4.

I apologize if this isn't making any sense to you, I am in the midst of a migraine attack and I can't think too clearly right now.

I would strongly suggest that you obtain a good manual that details engine building before continuing further. This is not a knock on your skill in any way, but it is pretty obvious that this is your first build. The internal parts must be assembled in a specific way if the engine is to live beyond initial fireup. You have to be certain of how the parts are installed.

[capriceowns]

Originally Posted by silicon212

Take your connecting rod and put the cap on, both ways (do this out of the engine, on the bench). When installed one way, you will notice that everything is perfectly aligned. If you install it the other way, you will notice that the rod and cap are offset. This is because the bolts are offset - so that the cap will only fit one way. Some rods are stamped and some are not. I always mark the rods with a stamp of the cylinder they are from, both cap and rod. Don't mix up the caps - the caps MUST be reinstalled on the rods from whence they came - if they get mixed, the rods must be honed and the proper oversize bearings used in order to obtain proper bearing crush.

The edge of the rod that's closer to the studs are to be matched in the middle, the edges that are further from the studs are to be oriented toward their counterweights at all times. The pistons themselves have a mark on them - could be an arrow, notch or indentation, that points to the front of the engine. 4 of the rods will be installed on the pistons in reverse of the other 4.

I apologize if this isn't making any sense to you, I am in the midst of a migraine attack and I can't think too clearly right now.

I would strongly suggest that you obtain a good manual that details engine building before continuing further. This is not a knock on your skill in any way, but it is pretty obvious that this is your first build. The internal parts must be assembled in a specific way if the engine is to live beyond initial fireup. You have to be certain of how the parts are installed.

I got what your saying silicon. I had my pistons pressed on reconditioned rods and matched so those are good now. I numbered the caps/rods as to which one they came from. So i dont forget like I did with my main caps and had to get a align hone, lol.

So all the indentions on my pistons must face the front of the block?

I bought a book before I had my block its called "building a SBC for the street" it was a good book, but it lacks in area like how the main caps went on etc. im thinking of finding a more detailed one.