I wanted to know if it is absolutly neccasary to do an align bore on a block that has just been resleeved?

See my problem is that when I was taking apart my block I threw all of the crank supports away, thinking that if I sold it, someone else can use theres when reassembling the block. The gentleman that I was going to sell my b18a block to this weekend, told me that if you throw away the main caps then the block is trash, you cant use it.

My buddy that was with me told me differant and said that you can use any main caps from any b18a on any other b18a block. Also that if you are going to resleeve a block (which this one HAS to be resleeved) it is absolutly neccesary to do an align bore on it.

I dont know who to believe. I posted this here because alot of the guys in this forum are very smart, and would be able to give me a for sure answer.

So to sum this up.

Can you use the main caps (or crank supports) from one b18a on another?
Is it neccesary to do an align bore on a block (that has just been resleeved) when assembling it?
Is my block really trash now?

Thanks alot for eveyones help.

Jamison

 

You need to do an align bore so you're pistons and bore will match. I'm not sure about using different main caps though. Who knows, you may get lucky. You could have a machine shop try to make some but I dont know.

 

ok cool, thanks. any other people know more info?

 

Yes, after you align bore it
It could be necessary, depending if it was out of align
I wouldn't take your block, even if it was free

My question to you is why would you ever throw something like main caps away? Did you throw the main bearing bolts away also?

 

Honestly I didnt relize that they were that important, and you couldnt use some from another block. I threw everything away except the crank and block. Well it looks like the block is going in the trash now anyway. I guess I have just learned not to throw anything away. Thanks alot for the help.

 

Um, NO....

 

Can someone explain what an "align bore" is?

 

it makes kool furniture

 

Tony, that one made me giggle too...lol

 

well, is not...align bore doesn't serve the purpose of matching the bore size with the piston's diameter, regular boring can do that....all you need is the piston diameter size and skirt to wall clearance spec

one way to check bore for misalign to to insert a bar a shade smaller (very very tiny..) than the indicated bore size and see if the bar turn easily, it basically repair a problem of inconsistent bore along the cylinder walls....

stan

 

An align bore (i always thought it was called a "line bore", but i could be wrong) is boring the main bearing journals to make sure everything is straight. You can no longer use the honda color and bearing codes if this is done. I personally have not run into a block yet that has needed it after sleeving, but i'm not saying that none need it. Simple to check though. It's just a matter of checking the bearing clearances on the mains. This always has to be done if you are using the main caps from another motor. The bore is done with the main caps installed and you cannot mix them up.


[Modified by tony1, 12:57 AM 1/20/2003]

 

maybe this will help: https://honda-tech.com/zerothread?id=218565

 

I have had to do an Align bore? with every GE sleeve job. I think it is nothing but trouble on a honda because if the block was beat to **** and it is twisted or the saddles are beat you will run have to take out alot of aluminum to get it straight and it will move the crank up in the block, then pistons will probably stick out of the deck a couple thou. bad news from there
I know from my customers experience

 

Old school name is align bore but I actually saw a machine shop's price list that said line bore on it.

 

So, after the align bore, what bearings should I use?

 

You need spec your bearings to what clearance that you specifically run in your engine.

 

if you give the machinist your crank and a set of bearings, he can set the clearance
for you. So if you give him green bearings, then when he is done, you use
all green.

 

So then, and pardon the stupidity of my post but I want to make sure I completley understand this, a line bore has nothing to do with the cylinder bores correct? After all is the main bearing journals you are boring even. Tha being said, why/how does a sleeve job affect the main journals?

 

correct, it's just to make sure all the main caps are aligned.

 

I think in his head he was just thinking about boring the cylinders, and just got them mixed up or something.

 

I was aleways under the impression that "line boring" is what you do to the cylinder walls not the mains. "Align boring" is what is done to the mains- you make sure the main caps are "aligned"

 

Well at least I'm not the only one that was confused on this topic. I went and asked a machinist last week about it.

 

"if you give the machinist your crank and a set of bearings, he can set the clearance
for you. So if you give him green bearings, then when he is done, you use
all green."

Ahh... So I should take my bearing in with my block when getting honing done?


[Modified by VWkila, 10:25 PM 1/29/2003]

 

ok if you havnt figured it out yet
you SHOULD have your main caps align bored with your block, every block is different from every main, just like every bearing is different. if your selling the block i would put the sleeves on and not align the block. the sleeves have nothing to do with the aligning process. you may need your deck plained if the sleeves stick up tho.

aligning the crank insures the pistions are moving up and down straight and smooth if the alignment is too off your rods may snap and there goes all your work

as for bearings it depends on how they align the bore. they could make the bore larger by just drilling the hole bigger to straighten it in which case you will need larger bearings to fit the crank, or if they grind the top of the caps and bottoms of the rods then make the bore the oem size you can keep the oem bearing size but then your piston will sit lower. which can be fixed by a good decking job (shaving the deck)

if im wrong on anything here someone please let me know so im not handing out false info.

 

This thread is 8 years old.