stroker numbers for +4mm

[billyboy]

I was looking at the HOT RODS Crank and Rod combo's (first off any good or bad I would like to hear it) second, what do the numbers break down too for the stroker cranks???

+4mm stroke with a 400 bore= 4??
+4mm stroke with a 416 bore= 4??

[davetheslave]

Here is a formula to calculate cc's:

bore x bore x .7854 x stroke (cm) x # of cylinders

[Wheelie]

416 bore with a +4mm crank is a 440.

[billyboy]

Curious then, what is the use of stroking a motor, when you can get there by piston size? I know there has got to be an advantage here? I am just not seeing it...

Wiseco 440 kit?

or

Stroked rod and crank combo with 416 piston kit?

[billyboy]

What numbers can you expect with a stroker with a 440 kit in it?

[Wheelie]

Most strokers require the use of a custom piston. Either a piston with the wrist pin relocated, or a piston with the skirt modified to clear the throws of the crank.

Strokers are more $$ than a big bore, but, IMO will make more power per CC than a big bore. Also, when a 400ex is highly modified a HD rod is a good idea--this is something that can be taken care of while the crank is being modified/buying a new crankshaft.

It's a more expensive way to go, but worth every penny.

[billyboy]

I lost a nice 426 a few years ago. The rod broke literally mm's from the wrist pin, and when it did. It took everything out. So I dont even care if it has a stock bore on the rebuild it will have a new hot rod, rod and crank in it.

[Wheelie]

Are wondering about HP numbers? Which kit? 440/452/460/483?

My 440 with stock carb has no problem keeping up with and beating the newer 450's.

[GOTFEAR]

We just put in a 4m strocker kit came with a strocker piston (shorter) coms to 460cc an big valves man this thing is fast on bottom all the way to the limitter but blown head gaskets a few times so we instaled over size studs. man did i say that this thing is fast. im going flat tracking soon and see how this thing runs with other strocker trx450s man they are fixing to have a bad day.

[billyboy]

Yeah, obviously the more work you do the more HP its going to make. I have a great port and polished head already. Someone I was talking to yesterday planted the idea of maybe having it flow tested, just to make it a little better. It already has a web cam and the HD rockers in it. I am going to get the kibble whites and springs for it as well.
But I think with what I was told yesterday, I dont have much choice with what I purchased. The +4mm stroker from Hot Rods and the piston kit they sell is basically (440 or 89mm) and so the complete deal is going to be a 460.

These are the numbers I was really looking for. Just what displacement cylinders are equal to the +4 stroker.

[GOTFEAR]

Well flowing your head is ok but a good engin builder has a good recipe already and dont need to flow. I have built a few dozen of drag bike motors and realy got good on the porting for all diferent styles of drag racing so i started atv racing and did what i have ben doing for years and aplyed it to atvs man the things are fast good luck!