Even just the basic mods like air intake and header/muffler, will really bring the Z400 to life!

Just an HRC kit, will do wonders for he 450R.

 

If you look at my list I was bias to two strokes.But if I were to make this the 10 most modable motors I would make it this:



10.cannondale 440
9.kawasaki v-twins 650,700,750
8.Any 450 sport racing engine
7.Quadzilla 500
6.polaris 400
5.400ex
4.660 raptor
3.ds 650
2.banshee
1.250r

On an off note was the 660 raptor motor originated from a motorcycle engine ?

 

Indeed it did, I know you could get one in Japan. The raptor 250 motor is also from a bike.

Infact everything on your list except for the, Polaris and the kawi v twins, came from a bike.

 

wait wait wait....how is the banshee cheap to mod out?
a set of toomeys is 600!
you can get a scrammy 400 pipe for like 300-350

so thats 250-300 to work with right there.

 

No 4 stroke will see the difference in performance like a (Any) 2 stroke.

Pipe , jet and mod the breather on a 400ex and a 400 Polaris and see who gets there bang for there buck.

Heck, it takes a 450cc 4 stroke with a 200cc advantage to make it fair to race with the 250 2 strokes in motocross.

 

Heck, it takes a 450cc 4 stroke with a 200cc advantage to make it fair to race with the 250 2 strokes in motocross.</end quote></div>

really? i would've guessed up to a 350 but a 450 wow

 

The 2 stroke 125cc Motocross race the 250 4 stroke motocross. Without the displacement advantage rules no racer would buy a 4 stroke motocross.

 

<div class="FTQUOTE"><begin quote>Originally posted by: TLC

No 4 stroke will see the difference in performance like a (Any) 2 stroke.



Pipe , jet and mod the breather on a 400ex and a 400 Polaris and see who gets there bang for there buck.



Heck, it takes a 450cc 4 stroke with a 200cc advantage to make it fair to race with the 250 2 strokes in motocross.</end quote></div>

The Polaris 2-stroke 400 is only a 378cc with 38 HP, but a stage 1 kit gets you about 15 more horses. With a 440 big-bore kit you can double the stock HP.

 

I would go bigger bore simply for more torque and depending what I was going to put it in possibly a v-twin motor. You get twice the aoumt of bore capabilty and alot more torque.

 

<div class="FTQUOTE"><begin quote>Originally posted by: scrambler400enoge

Ok maybe 100 is pushing it but with an aaen performance stage 5 kit with the 440 big bore has been dynoed at 75 hp which is pretty good IMO.</end quote></div>

No its not, AAEN is a moderate builder and very reputable but Olav Aaen isnt the only one. Like ANY 2 stroke its all in the ports. Stroke is easier CC on any motor. The 400 motor is not much different then the 250r's and 500 Zilla's all single cylinder 2 strokes. Few different quarks here and there is all. But the general basis is no different. Best way to describe it is a single cylinder detuned snowmobile engine under 400cc.

<div class="FTQUOTE"><begin quote>Originally posted by: redmoon85

and that will run you about $2100 plus race porting.......



Spend that on a banshee, 250r, or even 400ex or z400 and you've got yourself and full blown race quad. That's not an automatic.</end quote></div>


You can not compare any bang for the buck to a 2 stroke period. You cant compare a 40-45 hp 4 stroke motor to a 100+hp 2 stroke motor for the money. Last time I checked the fastest shee's are tripple cylinder snowmobile motors running jackshafts and yes a CVT tranny... you spend $2100 on any 450 or 400 Naturally Aspirated 4 stroke compare to any 2 strokes mentioned and lets go gladly drag race. I will assure you, you'll be bringing a spitball straw to a cannon fight. A 700 +cc 4 stroke would be more of a comparison.