What is a stroker kit?

[johniboi702]

Ive been hearing about these stroker kits and i would like to know what they are. Also, i need to take my clutch and oil slinger off. any suggestions on how to hold the engine still while i take off the nuts????​

 

[sean01]

stroker kits are a kit that increases the stroke in an engine to give bigger CC's (simple way of putting it)
there are many way to stroke and engine
offset conrod pins
crank out of compatible bigger engine.
custom CNC crank

as for the taking the nuts off. the easiest way is to use a rattle gun and the proper castle nut tool..

 

[corey58]

most the times strokers kits aint worth it! splitting the whole motor, sending the crank away to be split and swapped over then balance then re assembled! a lotta other mod that you can do to go faster first,

Ill be doing this to my Daytona cos our class in 160cc and don't wanta give away 10cc, but 99% of people wouldn't bother.

 

[Dabomb]

heres one for ya, if you increase the stroke do you lower the compression of the cylinder?

 

[Barnesd09]

Ill be doing this to my Daytona cos our class in 160cc and don't wanta give away 10cc, but 99% of people wouldn't bother.

If your going to be riding motard, putting the storker kit will actually slow you down belive it or not, as I have been humming and harring about whether to get a 150 or 160, it appears the fastest guys in Vic have the 150 as the shorter stroke actually allows the engine to rev up much faster, giving better acceleration and engine braking, but the power is alot snappier/violent than the 160.

This isn;t with a stock engine though, it has a rotor kit the size of a 20c piece, big valve head and high comp piston.

Its the differnce of about half a second a lap at Warrnambool I've been lead to believe when ridden by the correct rider.

If your a hack like me, the 160 would be better as the power band is alot broader and isn't so snappy and engine braking isn't over the top and I'm probably not going to be able to extract the maximum from eveything from the bike and engine.

 

[grnman]

i cant help thinking Barnesd09, by running a 150 in a 160 class, is a disadvantage, there is 10cc less fuel air mixture going into the cylinder every forth stroke.

so if the average motard engine rev's at lets say 7,000rpm over the course of a race that means ......7,000rpm x 10cc = 70,000cc divided by 2 because its a 4 stroke = 35,000cc of air/fuel per minute.

Now if a race is 10min then that = 35,000cc x 10min = 350,000cc of air/fuel mixture that all the competitors have used as horse power over a 150cc engine to a 160cc.

im going to go a 160cc.

P.S just trying to think of the physics side of things dave. those vic guys are quick either way.
ill need a 160 to attempt to keep up. hehe

 

[topguntravis]

oooo post what a stroker kit is in the miniriders dictionary..link is in my signiture

 

[johniboi702]

thanks guys

 

[Barnesd09]

Yeah Dave you are right, us hacks will need all the CC's we can get as the other guys really are damn quick. Even if you put them on an 88 I'm sure they could beat the average guy on 160.

 

[Cactus Jack]

heres one for ya, if you increase the stroke do you lower the compression of the cylinder?

In short ... the answer is that increasing the stroke also increases the compression ... A piston in a cylinder works exactly the same as a plunger in a syringe ... the further you pull it back ... the more cc's it draws in ... then those extra cc's get compressed into the same sized combustion chamber ... so the compression ratio goes up ...

 

[grnman]

can it be generalized that a larger stroke = more torque.
and a larger bore means more HP?

so for motard racing, would it be better to gain 10cc by increasing the bore, rather than increasing the stroke to gain 10cc?

by going from 150 to 160 stroke wise, does the peak power at 10,000rpm stay the same and the area below the line on a dyno chart get bigger. i think you guys know what i mean by that. l mean peak 10,000 rpm stays the same, but 6,000 , 8,000 get bumped up abit?

where on the other hand, does going from 150 to 160 bore wise, lift that top end 10,000 rpm hp figure?

 

[wogtaz ryder]

That is how i have always thought about it . makes sense to me.

Im liking your questions grnman . getting some good info from them.

 

[grnman]

thanks man, hopefully one day ill have all those green reputation box's you have.

 

[XR160R]

its when it strokes you

 

[grnman]

so if what i've said is correct, wouldn't it be no disadvantage to go that extra stroke?

i mean your still getting the same top end HP, but you get more 6,500 rpm HP or so for free when you come out of the corners.

if the down side is the engine doesn't 'spin' up as fast. carn't you do other things like rotor kit and your spin up prob is better. still free HP.

if the engine doesn't spin up as fast, does that make a difference to lap times even if your generating more power? how does rpm make it faster?
i mean if your doing 10,000rpm with 15 HP or 7,000 rpm with 15 HP how is that different?

 

[Dabomb]

power = torque x rpm

 

[grnman]

yes i remember you saying that Dabomb it was useful to know

but.................

if the torque and rpm has been used to already calculate power.
you still would have more power at 6,500 rpm because this is where the stroker 160 would generate more torque.

(Where are you catus?)
need clarification from someone
who actually know what
they are taking about.

 

[grnman]

tell me this doesn't spin up.

YouTube - monstermotoUK's Channel

i think the specs on these are 57mm bore and 62mm stroke.

 

[sean01]

man it sounds like its pinging its head off when it brings it to a roll then nails it