Hey guys, so I know hardly anything about cars, but I'm curious about boring and stroking. From what I can gather, boring is increasing the size of the cylinders and piston. Stroking is modifying the crankshaft to give it better throw. If this is the case, my question is:

Can you both bore and stroke an engine or is that impossible?

Another dumb question:

When boring the engine, do you expand your existing cylinders or is their a way to install brand new cylinders at a suitable size?

Thanks in advance.

 

You can bore and stroke an engine to a certain extent.

Depending on the engine,theres a (steel usully) cast sleeve that acts as the cylinder wall. But none of the ford v6 have that type of setup. Some hondas do.

 

But boring requires sending the block to a specialist to have done. Its something a normal person wouldnt want to fo at home with little knoledge of it.

 

And if your refering to a mustang 3.8 motor,you can stroke it to a 4.2. With a kit,or with using a used 4.2 from an f150.

 

And there is no dumb question if not knowing the correct answer could cause you to loose lots of monney of lots of frustration and stress.

 

my motor is bored and stroked, Yes its possible and many people do it. It is fairly easy to do on our 3.8's

 

So if I'm running a 3.9, can I bore the engine to a 4.5 or is that too much?

 

well the usual stroker crankshaft that most people use is a F150 4.2L crankshaft. Anything other than that and you are looking at custom crank= big $$$.
Then I bored the walls after that, .030" more and it rounds up to a 4.3L I know you can bore it more, possibly .060"-.090" and that would be around a 4.4 but I have never herd of a 4.5. I thing that is too much. Im not even sure there is enough room inbetween the cylinders to bore out to a 4.5 They need to have enough room to not raise the cylinder temp between each other.

 

its posible to bore/stroke to 4.5..but I wouldnt recommend it. Your cylinder walls would be like paper thin. It would run hot as hell til it blew up. You would loose all block strength.

If your looking for big power,stroke it to 4.3 with a forged kit from supersix motorsports. Choose a good supercharger/turbo kit with a water/meth kit and start turning up the boost..alot safer then ataining 4.5l. Plus a higher hp number.

 

I know,i looked onto doing a 4.6l v6 when I started tooling around with my mustang. Would be cool as hell,but not practical.