Engine mod

There seems to be more and more members appearing that are racing the ZXR400 so i've created a special section just for you to show off results, discuss meets etc etc.

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patlangan
Posts: 16
Joined: Thu Mar 12, 2009 11:16 pm
My Bike: tomos moped

Re: Engine mod

Post by patlangan »

same weight as an aprilla rs 250! very impressive
luckyeddie
Posts: 19
Joined: Fri Oct 03, 2008 5:45 pm
My Bike: zxr400

Re: Engine mod

Post by luckyeddie »

I have already done this. Tried to upload a picture but its too big. Anyone wants to see it can send me your EMail address.
luckyeddie
Posts: 19
Joined: Fri Oct 03, 2008 5:45 pm
My Bike: zxr400

Re: Engine mod

Post by luckyeddie »

Saved over 6kg with this mod & others. On the engine alone.
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jake
zxr400 oc member
zxr400 oc member
Posts: 1016
Joined: Mon Oct 02, 2006 10:03 pm
My Bike: tomos moped
Location: wirral

Re: Engine mod

Post by jake »

it would be appreciated very very much by me and others if you could upload them onto photobucket and paste the img code onto a thread here!
cheers
luckyeddie
Posts: 19
Joined: Fri Oct 03, 2008 5:45 pm
My Bike: zxr400

Re: Engine mod

Post by luckyeddie »

Ok done that. Apologies for the picture quality but it was taken with a mobile phone.Heres the thread.
http://s679.photobucket.com/albums/vv152/1luckyeddie/
neil_cb125t
Posts: 43
Joined: Wed Jan 16, 2008 10:20 pm

Re: Engine mod

Post by neil_cb125t »

you get NO power gain from removing the flywheel - i did it an re dynoed it - O diff. but when you ride / rev it it spins up really quick. it was impossible to get off the start line fast thou.

the plate thing is done over here ( nZ ) crank gets chopped off at that end - these guys are getting over 90 Hp at the wheel - but will be the most modded Z ever 444cc and all the bits.
xlr8_07
Posts: 50
Joined: Fri Feb 27, 2009 8:30 pm
My Bike: zxr400 h1
Location: Wanganui, New Zealand

Re: Engine mod

Post by xlr8_07 »

hey again neil, i have to say i dunno if i agree, when i wacked that l1 motor in my bike and took it for a play the other day ( pre sp cams ) i noticed a huge diffrence in 1st and second gear after i took the flywheel and starter and stator off, and thats with my small amout of exp on the bike, and also the weight gain its self must almost warrent it, i have 5 keilos of more crap in the shed now lol and after seeing what i did to that other 400 on the streights ( admitidly my bike is prob alot lighter thanks to bradens efforts - but then he was a smaller guy then our soild asses lol ) i must have gained something, also would help with less enertia to get off the crank on down shifts thus letting you change down later and harder ??? - just a theory ?


ps for neil can you text me bills number i need to get these axle pinch bolts back to him hahaha confuddled ,

Brendon
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noelb
Posts: 61
Joined: Tue Oct 16, 2007 1:02 pm
My Bike: ZXR4H , H'Berg , BMW R12S
Location: Oirelannnnddd!, D'middle'o'

Re: Engine mod

Post by noelb »

As I understand it, removal of inertia from the crank may or may not show an increase in horsepower, depending on how its measured. If measured on an inertia dyno, an increase may show as it will allow the engine to accelerate the drum a wee bit faster. Power is definetly wasted in accelerating the extra mass on the crank. That power has to go somewhere. If a brake dyno is used then it may not show up at all as the torque the engine produces will be unaffected. (torque is totally dependant on combustion pressure and stroke)

I hope this is correct, its what makes sense to me anyhow :smt001 . I have a stripped flywheel (still has the starter gear) but haven't used it yet. If the whole flywheel is removed then a turned down bolt with an O-ring needs to be made up to block off the oiling hole for the starter gear or there's gonna be no pressure - I've heard of this happening and its gotta be embarrassing!

Noel B.
xlr8_07
Posts: 50
Joined: Fri Feb 27, 2009 8:30 pm
My Bike: zxr400 h1
Location: Wanganui, New Zealand

Re: Engine mod

Post by xlr8_07 »

we have no need for a starter so we just make a coller that is 3mm thick alloy and use locktite retaining fluid with a press fit to seal the lubrication hole up
neil_cb125t
Posts: 43
Joined: Wed Jan 16, 2008 10:20 pm

Re: Engine mod

Post by neil_cb125t »

a brass frost plug works great too!!
Yeah it will pull better but thats not extra power - just depends what your after - i had all my bits balanced so she spins up great and has torque.........
i don't run a starter system thou - that weight i dont need.
xlr8_07
Posts: 50
Joined: Fri Feb 27, 2009 8:30 pm
My Bike: zxr400 h1
Location: Wanganui, New Zealand

Re: Engine mod

Post by xlr8_07 »

as far as the weight goes i wacked a post in "free for all" to find out what other people are weighing in at
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