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Discussion Starter · #1 ·
wadzii22...

see if you agree with me on this...

power from storking will not give the same HP increases as say boring would(considering same displacement and combustion area)... because of the load on the cylinders walls... The force would greater, thus causing more friction, drag, etc.( i can not think of the right word), which would casue the motor to work harder and put more stress on the motor...As opposed to boring where the force is the same on the cylinder walls but gains it power from a bigger combustion area...

Would you agree? and anybody can jump in here.. :)

also wadzii22 it is good to have you hear, you seem very knowledgeble...
 

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If you stroke i.e. Mr. lsvtec, you run into the R/S ratio thing, and/or valve clearance. When you bore, the cylinder wall integrity is comprimised, but valve clearance and revebility potental remain the same, example: raising rev limit and aggressive advance on stock 1st gen b16 to 8k without worring about snapped rods or bent valves. Though with a thin cylinder wall from the overboring may cause vibrations of a raised rev limit and may induce cracking/warpage. The best setup to me for street would be a little extra stroke, a little advance, and a little extra bore. I should have pics of my Ls/vtec up soon. Its .25 over ,USDM ITR pistons, 8k rev limit, 3-angle valve job on stock ports with stainless valves, and bronze valve guides.
 

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Discussion Starter · #5 ·
ryanplayjoint said:
If you stroke i.e. Mr. lsvtec, you run into the R/S ratio thing, and/or valve clearance. When you bore, the cylinder wall integrity is comprimised, but valve clearance and revebility potental remain the same, example: raising rev limit and aggressive advance on stock 1st gen b16 to 8k without worring about snapped rods or bent valves. Though with a thin cylinder wall from the overboring may cause vibrations of a raised rev limit and may induce cracking/warpage. The best setup to me for street would be a little extra stroke, a little advance, and a little extra bore. I should have pics of my Ls/vtec up soon. Its .25 over ,USDM ITR pistons, 8k rev limit, 3-angle valve job on stock ports with stainless valves, and bronze valve guides.
This is not ture if you sleeve your block... you can 4.5mm bigger then your stock bore with sleeving and be perfectly fine....

If you need more power then that, then you resote to stroking, but to storke that big you need a deck plate and also to resleeve your block...I am not debating which is the best way to go on the street(I already have my thoughts on that and it was discussed in another thread)...
 

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true you get more side loading, but if built properly then there wont be any significant losses from the extra loading.

that is unless you go and do some crazy shit like put a 95mm stroke in a b16 block.. hell i dont even know if that would fit but im sure you'd break some stuff and make crap for power.

with the new piston skirt designs on the market today increased friction is a non issue. i dont have any numbers to back it up but im willing to bet that with some good lightweight strutted pistons you will have less friction inside a b18c with a 95mm stroke than you would in a stock piston'd b16b (those have aorund a 1.85r/s ratio)

as for the stock rod/rod bolt issue.. imo thats a non issue as well. we have well over 35k miles on our b20vtec. bone stock bottom end, never been apart and reved to 8500 rpms making 185hp every day.. and we give it hell.

from my experience boring tends to make gains from idle to redline. stroking will make more in the mid range, and if you go far enough it will lower the peak of the power b/c of the piston acceleration and cam profiles. a longer stroke means a lower rod ratio which means the piston will dwell at tdc and bdc longer and accelerate alot faster, this requires different cam timing, cam profiles and ign timing.

one example of an engine i helped put together was a gsr motor, stock bore with a eagle 95mm stroker, mild head work, 10:1 compression and s2s2 cams. these cams responded really well with the lower rod ratio of the engine and the increased piston speeds. with only a vafc to tune with and turning the distributor to adjust timing we had around 195hp at the revlimiter.. 7800 i think?? with proper tuning that would have been a 220hp engine. it was stroked 7mm.. making it a 2.0 liter.. when was the last time you saw a 10:1 b20vtec make that kind of power...

also keep in mind that a 2mm overbore will increase displacement more than a 2mm stroke will. so naturally you will gain more with boring than you will with stroking assuming you go the same ammount.

sorry bout the book yall... its 230am and i aitn got shit to do :D
 

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ryanplayjoint said:
i was speaking in terms of keeping the motor reletivly "stock". Without having to sleeve or install a block gaurd or something to that affect.
stroking a stock sleeved motor isnt the best idea.... you could put the money into sleeving and going with a bigger bore and you would have a much more reliable engine... rember K.I.S.S. keep it stock stupid.. :)
 

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Stroking seems to produce a lot more torque than over-boring does, on the other side of the coin, if not properly performed then one runs into the issue of higher pistons speeds and a significantly reduced redline, which prevents most honda engines from taking full advantage of the above average airflows that the OEM heads provide.
 

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stroking in itself dosnt reduce redline... the revability of the engine depends on the head, the induction and how well its put together. i have done a few 95mm stroke gsr's that made power to 8500-9000 rpms with mild cams and good headwork.
 

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Wadzii22 said:
stroking in itself dosnt reduce redline... the revability of the engine depends on the head, the induction and how well its put together. i have done a few 95mm stroke gsr's that made power to 8500-9000 rpms with mild cams and good headwork.
Interesting insight. I'll have to look into my theory more and revise it. Thank you for shedding some light into things for everyone, myself included.
 

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Discussion Starter · #13 ·
Wadzii22 said:
stroking in itself dosnt reduce redline... the revability of the engine depends on the head, the induction and how well its put together. i have done a few 95mm stroke gsr's that made power to 8500-9000 rpms with mild cams and good headwork.
yes...this is true...but in general, it takes alot more care and effort to storke a motor and keep a high redline, then it does if you over bore a car....
 

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TodaTeg said:
yes...this is true...but in general, it takes alot more care and effort to storke a motor and keep a high redline, then it does if you over bore a car....
just to give a little factoid here why do you think that the NSX has the same stroke as the B16a but a larger bore? makes better power at higher rpm just my thoughts
 

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capn said:
just to give a little factoid here why do you think that the NSX has the same stroke as the B16a but a larger bore? makes better power at higher rpm just my thoughts

thats called squaring.......well kinda
 

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temp03 said:
thats called squaring.......well kinda
well squaring is when the bore is the same as the stroke correct?

if so the NSX would not be square beacase it has a 77mm stroke and a 93 mm bore i believe, if thats not right someone please correct me
 

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they did that with the nsx b/c honda likes to make their race motors have a long ass rod. take the s2000 and the b16b. both those engines have something like a 1.8 rod ratio. i would assume they did the same thing with the nsx. they had to keep the stroke short so the engine isnt too big. all those engines are designed for racing where the engine has to retain the stock demensions. having a short stroke and a long ass rod makes the engines last longer when you are pushing massive ammounts of power near max rpms for extended periods of time.
 

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Wadzii22 said:
they did that with the nsx b/c honda likes to make their race motors have a long ass rod. take the s2000 and the b16b. both those engines have something like a 1.8 rod ratio. i would assume they did the same thing with the nsx. they had to keep the stroke short so the engine isnt too big. all those engines are designed for racing where the engine has to retain the stock demensions. having a short stroke and a long ass rod makes the engines last longer when you are pushing massive ammounts of power near max rpms for extended periods of time.

exactly, long rod engines w/ a short stroke allow the piston to dwell at TDC longer, therfore making a more efficient combustion cycle which in turn will make more power
 

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temp03 said:
exactly, long rod engines w/ a short stroke allow the piston to dwell at TDC longer, therfore making a more efficient combustion cycle which in turn will make more power
nope, it has nuthing to do with making power, its all about longevity.... specially in an all out road racing engine
 
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