Strokeing Vs Boreing

[Lyle_Style]

Hey guys, im not sure if this makes sence
But what is the difference between boreing out a motor and strokeing it?

when doing it is there any power difference, strength, cost... etc etc

[McChook]

Stroke = distance the crankshaft moves the piston in a downwards direction - ie 77mm
Bore = diameter of the piston across the top of the crown ie 77.5mm

Increasing either in size or distanace movied will increase capacity

Increasing stroke requires you to change crankshafts to increase the movement ratio - ie B20b Crank in a B16a will increase stroke (as will a B18c crank in a B16 etc)

Increasing bore requires you to increase piston size, and eventually, increase the size of the holes the pistons move in - this is when you infact, "bore" the block out to make room for those larger pistons.

Now - price - well, slipping in a another B series crank into a B16 is pretty cheap, provided you can find a crank. There is also some tolerance by honda to go .5mm oversized in the pistons, after that, go boring.

In the end either option is only really worthwhile if you are going all out

[Lyle_Style]

is one more safe then the other?

[Lyle_Style]

and is any particulary better for performance or boosting?

[wynode]

They are quite different IMO and the whole argument of bore vs stroke comes into it (do a search there was a long dicussion on it).

So you'd have to look at things like the loss of revebility if you plan on stroking. On the other hand, when you look at boring one of the weakenesses is the cylinder walls (in which case you have to sleeve).

But how much more capacity would you want? An extra 200cc? Anything more than 200cc and I think you'd be looking at spending a lot of $$ to make the motor reliable in the long run.

[2ds]

well given that he is talking about going turbo i don't think the loss of revability would be so bad but weakening the cylinder walls could be....

-2ds

[pgclee]

Nothing is safe unless big buck were in...but when big buck were in, not to say it will be safe...
so..nothing is safe...hahaha...but if you do it rite...then your engine may last longer..

[EK9]

sorry if i'm hijacking the thread, but i wanna ask the same question in regards to the B16B ie CTR motor... i've heard that the block of the b16b is a b18 block, not b16 like other civics... is this tru? and if so would just changing the crankshaft to a b18 increase the capacity to 1.8 (keeping this very question very simple) ???

pgclee did u stroke/bore ur ctr motor? i know u've done quite sum work to it...

[SiR JDM]

From wat ive read/been told, the b16s and b18s have the same/similar block with different internals, ie, Crank, Pistons, Rods, etc etc..

I think boring is esential to increase capacity, thats what this guy told me last week.. hes a mechanic? :S

[wynode]

You can also stroke to increase capacity Sir JDM

[SiR JDM]

Oh yea, of course... = ]

I should have phrased it differently.
Talking to my mechanic he said even if i change the crank, rods and pistons, boring is still esential to increase displacement, ie - installing ITR or TODA etc internals alone will not increase displacement... .but hes not the main mechanic so i dont fully trust him, he dind't have much conviction in what he was saying to me