FATBOYeg6

im not sure if this is a stupid question, but here it goes. will an engine make more torque from an increase in the stroke, than an increase in bore? i ask this because i have a b16, and i want to increase the displacement. i want to keep the 1.74:1 r/s ratio though, so i intend to bore it out. will it give me less torque then if i was to get a stroker kit? thanks for any help.

red91sit

Stroking it will lower your redline and give you more power

Boring it will give you more power with no bad parts except weaker cylinder walls if you don't get it sleeved

You'll make the same amount more power either way because the displacement will go up the same amount if you bore/stroke it that way. The only difference would be a few horses from the valve shrouding being opened up with boring and not with stroking.

FATBOYeg6

ok good. i do plan on getting it sleeved. thanks for the input.

dmotoguy

it makes a difference if you have a bigger stroke/smaller bore or a smaller stroke/bigger bore. it depends on what you are looking for. do you want a street motor with lots of grunt down low but doesnt want to rev to 8k whatever.. or do you want a motor that doesnt hit as hard down low but pulls strong in the higher rpms.. its all a balance. there is no right way to build a motor, everyone has their own theory.

FATBOYeg6

i guess what i am asking is would it be a waste of money to bore and sleeve a street b16 to 1.8 liters?

dmotoguy

yes, just get a b18 block

JDMorgan

do a lil of each. im doin b17 with 25 over itr pistons and it will still be just under 1.7L but it will rev nice and have no cracking problems with stock sleeves.

Fkned

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ninefivehatch &raquo;</TD></TR><TR><TD CLASS="quote">i guess what i am asking is would it be a waste of money to bore and sleeve a street b16 to 1.8 liters?</TD></TR></TABLE>

Yes if all you want is 1.8L then either buy a b18b and make a lsvtec.Use your b16 block,put in a ls crank and get custom rods.Don't worry so much about your r/s% your building a street car not a race car.

LeGeND4LiFe

"Stroking it will lower your redline and give you more power"

What are the downsides to this?

So what is better, making more power down low and having a lower redline, or making less down low, and having a higher redline?

Thanks

Lsos

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LeGeND4LiFe &raquo;</TD></TR><TR><TD CLASS="quote">"Stroking it will lower your redline and give you more power"

What are the downsides to this?

So what is better, making more power down low and having a lower redline, or making less down low, and having a higher redline?

Thanks</TD></TR></TABLE>

The downside is the lower redline. What is better? Depends who you ask. Most Americans will say power down low. I say higher redline and power up high. It's all preference....

Mikey3000

increasing stroke will give you more torque than if you increased bore. torque is a product of radius and force. in this case, the radius is equal to 1/2 the value of the stroke. i dont see how a bigger bore would increase torque very much.

Lsos

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mikey3000 &raquo;</TD></TR><TR><TD CLASS="quote">increasing stroke will give you more torque than if you increased bore. torque is a product of radius and force. in this case, the radius is equal to 1/2 the value of the stroke. i dont see how a bigger bore would increase torque very much.</TD></TR></TABLE>

A bigger bore means there is a larger area for combustion pressure to act on, resulting in more force.

93hatchin

so do you lose revability in boring a cylinder out at all?. im thinkin since you are needing more a/f it might take a bit longer to fill the chamber and the wieght of the piston? just wondering. thanks!

Smeeg Heed

if you increase the stroke then that increases the distance the piston has to travel, and the maximum speed it's going to be travelling at, which both increase friction which is why you have to lower the redline (I think... lol)

lowering the redline lowers your horsepower potential slightly because horsepower = (torque*rpm)/5252. so the same amount of torque at higher rpms will give you more horsepower - how do you think F1s make 800+ horsepower off a 3.0L NA engine?

Long story short, might cost more but I would bore it.

nickzed20

just to clear something up...

having a 1.8L undersquare engine is by no means the same thing as having a 1.8L oversquare engine. A few people said its the same thing, since its the same displacement. Do a search, and you will find out the benifits of both. A few guys are giving some good info here.

Fkned

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nickzed20 &raquo;</TD></TR><TR><TD CLASS="quote">just to clear something up...

having a 1.8L undersquare engine is by no means the same thing as having a 1.8L oversquare engine. A few people said its the same thing, since its the same displacement. Do a search, and you will find out the benifits of both. A few guys are giving some good info here.</TD></TR></TABLE>

Very true,I didn't mean it that way sorry.I'm assuming it's a street car so my suggestion was to go the most sensible route.Why spend $1000 on sleeves when you can get more street usable power from stroking the motor.Spend the $'s on custom rods and save a few hundred $'s.Chances are you'll enjoy the extra tq alot more then the top end gain.I like big bore for race stuff,I just don't think the price is justified for most street rides.

nickzed20

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fkned &raquo;</TD></TR><TR><TD CLASS="quote">

Very true,I didn't mean it that way sorry.I'm assuming it's a street car so my suggestion was to go the most sensible route.Why spend $1000 on sleeves when you can get more street usable power from stroking the motor.Spend the $'s on custom rods and save a few hundred $'s.Chances are you'll enjoy the extra tq alot more then the top end gain.I like big bore for race stuff,I just don't think the price is justified for most street rides. </TD></TR></TABLE>

yea definately, i wasnt really talking about you though. I completely agree with what your saying, and I think that it all depends. There are advantages to both, and depending on the application, or the type of racing you are doing, different powerbands are required.