wherezmytofu
03-13-2002, 08:07 PM
let get it right pplz! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/cool.gif" border="0" valign="absmiddle" alt=':cool:'>
now here's a few givens:
1. displacement (cc's) is the volume in the cylinders that means only the volume in the block!
2. compression ratio is truely measured by the cc's in the combustion chamber,that means if i got 8.5 compression ratio pistons (calibrated for my engine of course) and i milled the cylinder head then the compression will be much higher then 8.5 since the height of the combustion chamber is shortend, thats why geting a thinner/thicker head gasket is a cheap and effective way to gain/lose compression.
3. rod ratio is based on connections rod lenght divided by crankshaft stroke.
4. rod length is measured from the center of the wrist pin to the rod journal.
5. crankshaft stroke is the measurement from teh center of the main journal of a crankshaft to the center of the rod journal on the crankshaft.
now back on topic.....
boring: is the term used meaning honeing out the cylinder walls increassing the diamater of each cylinder. volume is gained by the increase of the radius, v = (squ(R)Pi)h.
stroking: is the term meaning changing the crank and connection rods to a higher lenght (for front is obviously measured from the center) the longer crank and connection rods push/pull the piston higher and lower then stock hieghts/depts. volume is gained by the increase of the hight, v = (squ( R )Pi)h . wilder stroker kits will require the block to be reworked, because the connection rod get wider as it connect to the crank, the high lenght is not normal and this "fat" part may hit the block, that is why the holes must to widen....the normal clearance issue. this is the differance between a "drop-in" stroker kit and a "race/pro" stroker kit.....there r other names....but drop in always mean non clearance issue with stock block.
now here's a quote of an mr. x:
"Just because the piston goes further down into the bore doesn't mean it goes higher up too. The goal of stroking is to bring the piston down further on the 1st and 3rd stroke without making it go any higher on the 2nd and 4th. Piston to valve clearances are already tight as it is. If stroking actually brought the piston closer to the valves, they would hit."
when i read this i get the impression mr. x has never seen a crank in real life, here is a picture of a stroker kit.
http://www.crower.com/cat/import/honda/images/kit.jpg
*the connection rod and crank are solid objects, with a fixed connection, they do not change lenght, thats why going up and going down are the same lenght, so if it went 2mm down extra it will go 2mm up extra!
*notice that the crank is perfectly symetrical, so even tho 1st and 4rth are active when 2nd and 3rd are down, they are all the same lenght, if this wasnt true then at ideal the engine would be as smooth as falling down mount everest...if the forces werent balanced you would have a push, weaker push effect, making the car ever ever jaggy.
*this was an error or mine the valves have very little to do
with it
main problems:
boring: thinner cylinder walls, this is a big issue with allumium blocks, cast iron blocks really dont have this problem, seein that right after the iron sleeves...it iron again.
*that is why when you bore your sleeves, on alluminum blocks, it is a smart choose 2 get aftermarker sleeves. godzilla, dart and other companies make high quality sleeves with and with out cooling holes(a whole differnt issue) they have gareenties like 85mm max 40psi, this will insure you that you havent bored the walls to thin.
strokeing: stroking adds a great deal of stress to the block, this is from the rod ratio and the compression ratio increase. the when the crank is inlarged the angle that the connections rods come in at out are greatly changed picture a wheel with a stick going thru a whole, when the rod is longer it comes in at a more tilted angle, this extra pressure is why f1 engines destrock the block, and the main reason why bore > stroke = high reving enigne, for a safe high reving engine you want everthing working smoothly, but with a londer stroke the connection rods come at a very large angle, the smaller the better, this makes the rotation transfer force in a harmful way. normaly stroker kits will at 3-9 degrees safely on a stock block. now the second problem is the compression ratio gain, because the rod goes higher into the combusion chamber, the compression is increase, heres a real life example of the compression gain.
850csi engine
source = http://membres.lycos.fr/clube31/850csi.php
5576 cc v12
9.8 compression ratio
80mm X 86mm (stroke X bore)
from the dealer that car needs 91 octane (premium)
HARTGE makes a stroker kit for the car it makes a 5.6 liter => 6 liter... this is a v-12 so the cc gain is spread out between 12 cylinders, dont get the idea u can get .4 litter safly out our i-4s...
source = http://membres.lycos.fr/clube31/hartge.php
5992 cc v12
10.5 compression ratio
86mm X 86mm (stroke X bore)
Super Plus unleaded (98 octane)
why the hell does a 10.5 compression ratio engine need 98 octane?...wtf?....
well you see the 10.5 is the pistons that the stroker kits comes with, they didnt add the compression increase of the 6mm lose in the combusion chamber. with would make the compression in teh 13-14 range...one needs 2 know the original demenions to find out the lose, which i dont have.
*only one company RS sports have actually found an effective way to fix both the rod ratio degree increase problem and the bump in compression ratio problem to bad they are only mass making it for the b-series honda block <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/dozingoff.gif" border="0" valign="absmiddle" alt=':zzz:'>, anyway it is called a deck plate, the idea behind a deck plate is it is a plate that is welded onto your block that is the exact lenght of the increaced in mm upword, lets so the crank moved an extra 5mm upword, then the deck plate will be exactly 5mm thick, this changes the rod ratio and combusion chamber volume back to stock!
ok if you have read this far you should either have a really really bad headache or in a comma....can i have your car?...if u have one? just node your head <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>
now here's a few givens:
1. displacement (cc's) is the volume in the cylinders that means only the volume in the block!
2. compression ratio is truely measured by the cc's in the combustion chamber,that means if i got 8.5 compression ratio pistons (calibrated for my engine of course) and i milled the cylinder head then the compression will be much higher then 8.5 since the height of the combustion chamber is shortend, thats why geting a thinner/thicker head gasket is a cheap and effective way to gain/lose compression.
3. rod ratio is based on connections rod lenght divided by crankshaft stroke.
4. rod length is measured from the center of the wrist pin to the rod journal.
5. crankshaft stroke is the measurement from teh center of the main journal of a crankshaft to the center of the rod journal on the crankshaft.
now back on topic.....
boring: is the term used meaning honeing out the cylinder walls increassing the diamater of each cylinder. volume is gained by the increase of the radius, v = (squ(R)Pi)h.
stroking: is the term meaning changing the crank and connection rods to a higher lenght (for front is obviously measured from the center) the longer crank and connection rods push/pull the piston higher and lower then stock hieghts/depts. volume is gained by the increase of the hight, v = (squ( R )Pi)h . wilder stroker kits will require the block to be reworked, because the connection rod get wider as it connect to the crank, the high lenght is not normal and this "fat" part may hit the block, that is why the holes must to widen....the normal clearance issue. this is the differance between a "drop-in" stroker kit and a "race/pro" stroker kit.....there r other names....but drop in always mean non clearance issue with stock block.
now here's a quote of an mr. x:
"Just because the piston goes further down into the bore doesn't mean it goes higher up too. The goal of stroking is to bring the piston down further on the 1st and 3rd stroke without making it go any higher on the 2nd and 4th. Piston to valve clearances are already tight as it is. If stroking actually brought the piston closer to the valves, they would hit."
when i read this i get the impression mr. x has never seen a crank in real life, here is a picture of a stroker kit.
http://www.crower.com/cat/import/honda/images/kit.jpg
*the connection rod and crank are solid objects, with a fixed connection, they do not change lenght, thats why going up and going down are the same lenght, so if it went 2mm down extra it will go 2mm up extra!
*notice that the crank is perfectly symetrical, so even tho 1st and 4rth are active when 2nd and 3rd are down, they are all the same lenght, if this wasnt true then at ideal the engine would be as smooth as falling down mount everest...if the forces werent balanced you would have a push, weaker push effect, making the car ever ever jaggy.
*this was an error or mine the valves have very little to do
with it
main problems:
boring: thinner cylinder walls, this is a big issue with allumium blocks, cast iron blocks really dont have this problem, seein that right after the iron sleeves...it iron again.
*that is why when you bore your sleeves, on alluminum blocks, it is a smart choose 2 get aftermarker sleeves. godzilla, dart and other companies make high quality sleeves with and with out cooling holes(a whole differnt issue) they have gareenties like 85mm max 40psi, this will insure you that you havent bored the walls to thin.
strokeing: stroking adds a great deal of stress to the block, this is from the rod ratio and the compression ratio increase. the when the crank is inlarged the angle that the connections rods come in at out are greatly changed picture a wheel with a stick going thru a whole, when the rod is longer it comes in at a more tilted angle, this extra pressure is why f1 engines destrock the block, and the main reason why bore > stroke = high reving enigne, for a safe high reving engine you want everthing working smoothly, but with a londer stroke the connection rods come at a very large angle, the smaller the better, this makes the rotation transfer force in a harmful way. normaly stroker kits will at 3-9 degrees safely on a stock block. now the second problem is the compression ratio gain, because the rod goes higher into the combusion chamber, the compression is increase, heres a real life example of the compression gain.
850csi engine
source = http://membres.lycos.fr/clube31/850csi.php
5576 cc v12
9.8 compression ratio
80mm X 86mm (stroke X bore)
from the dealer that car needs 91 octane (premium)
HARTGE makes a stroker kit for the car it makes a 5.6 liter => 6 liter... this is a v-12 so the cc gain is spread out between 12 cylinders, dont get the idea u can get .4 litter safly out our i-4s...
source = http://membres.lycos.fr/clube31/hartge.php
5992 cc v12
10.5 compression ratio
86mm X 86mm (stroke X bore)
Super Plus unleaded (98 octane)
why the hell does a 10.5 compression ratio engine need 98 octane?...wtf?....
well you see the 10.5 is the pistons that the stroker kits comes with, they didnt add the compression increase of the 6mm lose in the combusion chamber. with would make the compression in teh 13-14 range...one needs 2 know the original demenions to find out the lose, which i dont have.
*only one company RS sports have actually found an effective way to fix both the rod ratio degree increase problem and the bump in compression ratio problem to bad they are only mass making it for the b-series honda block <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/dozingoff.gif" border="0" valign="absmiddle" alt=':zzz:'>, anyway it is called a deck plate, the idea behind a deck plate is it is a plate that is welded onto your block that is the exact lenght of the increaced in mm upword, lets so the crank moved an extra 5mm upword, then the deck plate will be exactly 5mm thick, this changes the rod ratio and combusion chamber volume back to stock!
ok if you have read this far you should either have a really really bad headache or in a comma....can i have your car?...if u have one? just node your head <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>