Engine Theory, Build, Etc Discussion.

WhiteAccord

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OK OK my turn....

So I have K20 pistons and rods...And I got the compression ratio of 9:5:1...

Ok added... GT3*R....at about 17psi.... or so...

Is there any harm here?
 
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pyaarawala

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you mean, xx.xx : 1

higher number = higher compression, higher cylinder pressure before ignition
lower number = opposite

ex: 6.0:1 the volume of the combustion chamber at BDC is 6x the volume at TDC, etc...

What do BDC and TDC stand for? So in our i4 cars, the volume of the combustion chamber at BDC is 9x the volume of the combusion chamber at TDC?
 

BadgerType

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What do BDC and TDC stand for? So in our i4 cars, the volume of the combustion chamber at BDC is 9x the volume of the combusion chamber at TDC?

Top dead center

bottom dead center <<< never heard of it refered to as tht though :confused:



xci: i knew some of the answers, but i dont know if they were correct
 

xci.ed6

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OK OK my turn....

So I have K20 pistons and rods...And I got the compression ratio of 9:5:1...

Ok added... GT3*R....at about 17psi.... or so...

Is there any harm here?

not an answerable question. Torque is the best way to estimate the structural limit of the engine, boost is not even an option.

If it blows there is harm, if it holds yay for you. Tune it well and it will last much longer.
 

pyaarawala

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So the stroke is when the air/fuel mixture is compressed, meaning when the connecting rod moves the piston upwards in the cylinder. Since this is compression, for N/A you want this process to be longer (high compression), and for F/I, you want this process to be shorter (low compression), right? And stroker kits one of the ways to change the stroke right?

I know this is a n00b question but what is boring and sleeving and what does that achieve? Let's say for example I want to build my motor for an N/A build, what am I looking to bore/sleeve to? (in case of numbers)
 

BlkCurrantKord

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So the stroke is when the air/fuel mixture is compressed, meaning when the connecting rod moves the piston upwards in the cylinder. Since this is compression, for N/A you want this process to be longer (high compression), and for F/I, you want this process to be shorter (low compression), right? And stroker kits one of the ways to change the stroke right?

I know this is a n00b question but what is boring and sleeving and what does that achieve? Let's say for example I want to build my motor for an N/A build, what am I looking to bore/sleeve to? (in case of numbers)


The compression stroke is when the piston is moved up in the cylinder towards the head/combustion chamber. Compression is just that, the piston is compressing the mixture of fuel/air in the combustion chamber, then when its ignited it pushes the piston back down the cylinder (Exhaust stroke). Higher compression means that there is less room in the combustion chamber for air/fuel to ignite. This is why high compression pistons have a dome or peak to them. Turbo or low compression pistons are usually dished or recessed to allow more air/fuel, usually from boosted applications b/c your flowing more air into the motor.

You could use a stroker kit to change the stroke, you could also swap in a crank with larger or smaller stroke to it. However, by changing the stroke you're also changing how far up and down the piston/rod has to travel. Then you start coming into things like rod length, location of the pin on the piston, and rod/stroke ratio, and ultimately your compression ratio. Everything is related, you change one, you have to compensate for the others.

Boring is enlarging the cylinder walls or sleeves. Ex: Stock F23 bore is 86mm, stock H22 bore is 87mm, if you overbored the stock cylinders by 1mm you could run H22 pistons and really raise the compression ratio.

Sleeving is replacing the stock cylinders with ones that are made of a stronger material than the stock units. Ex: H22/23's, K20/24's, and the F22/20C all have FRM sleeves which only allow for cast pistons to be run in them, in order to run forged aftermarket pistons, you have to resleeve these motors other wise the expanding of the forged pistons will eat up the stock sleeves in these motors. Sleeving is also a choice for when you want to overbore but can't safely do it on the stock sleeves. Meaning that at some point you can only bore out the stock cylinders so much before you run the risk of running the cylinder walls too thin.

If you're referring to that N/A build I posted, you don't have to bore or sleeve to anything. You could overbore or run stronger/thicker sleeves but its not necessary for an N/A build like that. Boring would increase the displacement and torque.
 
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euroking99

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lets startoff with my car, 1999 Accord ex coupe 5spd 4cyl

ive been looking around and have come up with a pretty good hybrid, but looking for some help on the entire construction.not sure if im missing something or if it is all compatible. also, not sure if i will be keeping the a/c, but will keep power steering since it will be DD

f23a1 block
aem pulley kit
f23a1 water pump
h22 water pump gear
lightened and micropolished crank
k20a2 rods and pistons
arp h23 headstuds
f20b head w/ PnP
f20b stock cams (same as prelude type-s/accord euro-r)?
kms valvetrain
f20b lsd tranny
exedy stage 2 clutch
fidanza lightweight flywheel
mfactory 4.64 fd (4.4 fd?)
msd sparkplug wires, distributor, blaster 2 coil
obdII-obdI conversion harness
phearable h22 obdI ecu
hondata s200 (maybe s300?)
5th gen accord fluidyne radiator
optima battery relocated in trunk
accord euro-r cluster
rc 440cc injectors
walbro 255lph fuel pump
aem fuel rail and adj. fuel pressure regulator
all tuned on 91 octane (i hope)

not sure:
prelude axles
what timing belt to use
what motor oil to use
what tranny oil to use
what header,catalytic converter,exhaust to use

LMK if im missing anything. All input is greatly appreciated, especially if u got experience with an N/A build
 
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