big engine mod?, bigger displacment Options

[playr158]

ok my friend has a 1.8t jetta and then she mod'd the hell outta it.
my biggest interest is the engine bore from a 1.8 to around a 2.5 which is really sweet and FAST. she used a .018 overbore
which is sweet. i wanna know if i can bore my 7afe at .018 or .02 i really want the .02 but the .018 or .019 is nice too! so can i do it? what will i need, and about houw much?

[OOBE]

Kid, you need to do some SWEET research before posting high-schoolish things like this. In other words, learn the SWEET facts of what the hell is a .02, .018 or .019 overbore, how it's done and why it's done.

[Supersprynt]

[Kwanza26]

[FallenHero]

yea, there is seriously no room to boar a 7a. I learned that by looking at the pic of the burned up piston posted by 97sccelica...

[Digndoug]

The dude, that is selling the gt-4 on e-bay and the white 96 st, did his, so its now a 2.0 heres the link it shows what internals he did, and there is no freggin way she bored a 1.8 to a 2.5 thats bs My Webpage

[boosted_K2]

.2 overbore is huge. my car is only overbored .02 with JE forged 9:1 comp pistons, i still have the stock stroke and stock cam duration and stock timing.


boreing out a motor isnt really a "mod", its something you do when rebuilding/building a motor. if the pistons have seized up but you still want to use the block, you need to bore it over to recondition the cylinder walls. and the only time you would overbore a motor that much is if you are changing timing, stroke, compressions, duration etc... you dont just overbore a motor that much and just call it a day.

[97sccelica]

i doubt she got that much more displacement out of the engine, the 1.8t engine block is nearly the same size as a 7a block.

2.0l, yea, its possible, but to go from 1.8 to 2.5 the stroke would need to be changed, among other things.

and even if you did manage to get your engine to 2.5 liters, doesnt mean its going to make all that much more power. the power is made in the head, the power is maintained in the tuning.

This post has been edited by 97sccelica: Jan 22, 2004 - 6:19 PM

[boosted_K2]

he said she bored it over by .018", that is a resurfacing, not a full overbore. im interested to see what "modded the hell outa it" entails.

[OOBE]

The kid doesn't know what he's talking about. You don't increase the displacement of the engine by boring out the cylinders...you STROKE it

[macavely]

ok what he is talking about is done when the cylinder is damaged and you can one take off so much before you weaken the block. he might have been talking about getting a stroker kit..

you get more into your engine up and down not left to right..

[boosted_K2]

displacement can be increased left to right as well as up and down displacement is a 3 dimensional figure, so changine either dimension will change the overall displacement.

[Supersprynt]

For the newbies: stroke (up and down) bore (left and right).

[Element23]

BRINGING THIS POST BACK! haha. anyway. im not very familiar with bore and stroke so dont bag my knowledge. but wouldnt increasing the bore increase horsepower, since there is a greater vacuum during the intake stroke created in the cylinder, bringing in more air and fuel, allowing for a larger more powerful explosion? i know that sounds a little intuitive, and it might be a misconception, so feel free to clear it up with more mechanical knowledge. Also, increasing the bore weakens the engine based on what it is bored to, but by how much would it be weakened from about a 1/5th of a liter bore?

[Supersprynt]

Yeah u'll get more power...thats why ppl do it.

[playr158]

haha damn this is old, well just to let everyone know she was full of it her car is bullshizzo, but anyways i DO how ever race dirtbikes. when i raced an 80cc back in middle school i needed more umf to get me goin so i BORED it out. sorry no strokin it but DAMN there was a very big difference in HP instead of just pullin off the line..i stood it up and took off about twice as fast...i think i went fron 80cc to around 95cc or so... as for a car i'm not sure how much you'll feel in the change but you defenitly feel more torque out of it but you'll get a pretty penny bill to do it....also if you wanna do this i suggest a port and polish on your head to help with the flow