Dialling in SP Cams

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.

Moderator: Moderators

User avatar
mick41zxr
zxr400 oc member
zxr400 oc member
Posts: 170
Joined: Wed Jan 14, 2009 4:07 am
My Bike: ZXR400sp

Re: Dialling in SP Cams

Post by mick41zxr »

Yeah, then you can run a smaller main jet. Has the effect of leaning out midrange. Found dynojet needles to be a bit toad. There are four types of oem needle they are marked n77c through to n77s. Found the r's work best.
User avatar
mick41zxr
zxr400 oc member
zxr400 oc member
Posts: 170
Joined: Wed Jan 14, 2009 4:07 am
My Bike: ZXR400sp

Re: Dialling in SP Cams

Post by mick41zxr »

To be honest if you can find yourself with a good set of flat slides with race kit fitted. Like night & day, you will never touch cv's again.
shaggy69
Posts: 63
Joined: Sat Jun 18, 2011 8:10 pm
My Bike: ZXR 400 Racebike

Re: Dialling in SP Cams

Post by shaggy69 »

Hammy,

I had one engine that I built that, even though timed to the marks on the cams, locked solid when turned over by hand. Turns out the exhaust cam sprocket had spun on the cam, probably following a valve/piston interface earlier in its life lol. Point is, all these parts are up to 24 years old and all sorts of hands have been upon them. And we still expect them to do 15,000 rpm all weekend? Mental eh? Lol
shaggy69
Posts: 63
Joined: Sat Jun 18, 2011 8:10 pm
My Bike: ZXR 400 Racebike

Re: Dialling in SP Cams

Post by shaggy69 »

Mick,

I've been running blocked correctors and 107.5 keihin mains in my engine which, up till now is standard plus ramair. I pulled dynojet needles as they screwed mix up at every setting. Ill need to check which needles I have, although have loads of carbs to scavenge :)
Rad
Posts: 4
Joined: Sat Jan 04, 2014 10:40 pm
My Bike: Zx6

Re: Dialling in SP Cams

Post by Rad »

Interesting thread. Just trying to work out how to time sp cams up myself.
Going back to an earlier post regarding cam markings on standard cams pointing away from each other at tdc. If they are pointing together it would mean that the engine would still run fine but when you had no1 on tdc on the compression stroke it would now be no4 on the compression stroke instead? I may be talking utter bo##ox though.
Post Reply