Advice/Pearls of wisdom on situation

**T.W.R** · 23rd December 2005, 20:14

Some of you may or may not know the current situation of my ZXR

well currently i'm basically doing a ground up rebuild of the old girl due to an unscheduled mishap a few months back, and due to finances etc its a slow but steady program which has suited me due to other obligations.

so far i've completed doing the frame work ( repaint,bushes,bearings,seals, etc), re-plumbed the wiring loom, ditched the engine subframe, ditched the bulbous rear guard/plate mount, rebuilt the brake calipers etc.

the engine work has been bit by bit, new Kawasaki race clutch-kit and other minor goodies.

but heres where the problem starts: now to start with i knew that J1 model cams & carbs had been fitted ( which was sweet, gave it more berries which is always good) but i had plans to get work done on the head ( machined etc ) but now having had the head away at the shop it turns out that its a H2 head.
when i took the head off i found that a competition gasket was in place ( a paper thin metal job ) which meant the compression was above std & thought about milling a couple of thou off the head & fitting a standard gasket to keep the compression roughly the same ( because i thought it was an H1 head )

Now this is the question: H1 std comp is 11.3:1, H2 std comp is 11.6:1 so should i save milling the head & fit the std gasket to keep the compression at 11.6 or mill it fit another competition gasket & send the compression into the mid 12s ( roughly 12.5:1) ? what do you think people?

as it was prior to the work being done I usually ran it mostly on race fuel anyhow

( due to a friendly local servo ) but it went like a cut cat ( still winding up at 240kmh pulling only 9200rpm which is what these old girls a supposed to do at 10500rpm

)

**R1madness** · 26th December 2005, 07:50

The paper thin gasket is probibly the middle section of the STD genuine gasket.

It was (is) a comon trick to split the gasket into its 3 parts. Discard the 2 outer skins and repaint the center part with silver 1500deg VHT. Instant raise in compression. The problem is that you should now slot your cam sprockets as the cam timing will be slightly retarded.

Re your compression ratios did you measure them or are ya just going by the book?
The reason i ask is that the ratio may be different using H1 pistons with the H2 head as i seem to remember they had different pistons (maybe the H2 had deeper valve cutaways but maybe it was only the ring lands that were different). A quick call to your local dealer parts man will confirm or deny this.

Just repaint the gasket you have. Let it dry completely and reuse it with confidence.
Hey what hp you getting? I had a very fast J1 and it made 124hp at the rear wheel. Had 40mm flat slides, race ignition unit, cams, titanium valves, light crank, close ratio gearbox, slipper clutch and lots of genuine Kawa race kit parts, all the shit.
Where did you get your engine from? it may be my old race one.

If i can make you one recomendation it would be to REPLACE THE AUTOMATIC CAM CHAIN ADJUSTER with a manual one. The std auto ones crap out and back off on high rev downchanges. Messy.
good luck
Ian

**T.W.R** · 26th December 2005, 09:08

Originally Posted by R1madness

The paper thin gasket is probibly the middle section of the STD genuine gasket.

It was (is) a comon trick to split the gasket into its 3 parts. Discard the 2 outer skins and repaint the center part with silver 1500deg VHT. Instant raise in compression. The problem is that you should now slot your cam sprockets as the cam timing will be slightly retarded.

Re your compression ratios did you measure them or are ya just going by the book?
The reason i ask is that the ratio may be different using H1 pistons with the H2 head as i seem to remember they had different pistons (maybe the H2 had deeper valve cutaways but maybe it was only the ring lands that were different). A quick call to your local dealer parts man will confirm or deny this.

Just repaint the gasket you have. Let it dry completely and reuse it with confidence.
Hey what hp you getting? I had a very fast J1 and it made 124hp at the rear wheel. Had 40mm flat slides, race ignition unit, cams, titanium valves, light crank, close ratio gearbox, slipper clutch and lots of genuine Kawa race kit parts, all the shit.
Where did you get your engine from? it may be my old race one.

If i can make you one recomendation it would be to REPLACE THE AUTOMATIC CAM CHAIN ADJUSTER with a manual one. The std auto ones crap out and back off on high rev downchanges. Messy.
good luck
Ian

cheers Ian,

yeah its ultra thin job (haven't measured it) i'd put it around the .25mm going by eye where as the STD 1 looks roughly 1.5mm thick, so theres a hell of a difference. basically its the thinest H/gasket i've seen.

the Cams, i had been thinking about that, i'd heard retarding inlet 4deg & advancing exhaust 6deg increases things dramatically. but wasn't to sure whether or not it would be worth it seeing that they're J1 cams which have considerably more lift & duration compared to the H1 anyhow.

not sure about the pistons whether their H1 or H2 haven't got anything to make a visual comparison too, but they do have a fairly high crown & the valve cutaways are reasonably deep. the local Kawasaki dealer i wouldn't trust to tighten a loose bolt let alone quote parts details

the Comp ratio figures are quotes from liturature i've sourced on the bikes, and the possible raise is a rough guesstimate/stab in the dark

Not 100% sure on what Hp is ( i know std their supposed to 91hp at the wheel) i have run it against another H1 and it did get left behind from 180ish, so i suspecting its putting out a few more than stock. i'm going to do the final tune up on it by dyno so will get figures then. I'm not to sure on its past, the bloke i brought it from was a fella i've known for years & avid petrol head, he'd brought the bike from down south. & since having it i have heard some stories of it past, it may have raced going on bits n pieces on the bike ( the sump plug has been drilled, some of the basic wiring has been disturbed in places that shouldn't be touched unless being removed etc.

ha don't talk about camchain adjusters

the culprit that caused the unscheduled rebuild

cheers
Bill

**Brian d marge** · 26th December 2005, 17:46

Hey there

look i have access to performance trends dyno ( very good at planning the go faster it )

If you can tell me the plan ..ie where you want to make power off throttle , mid range top end , this program can tell you ... Then you can go about getting the bits more effectively
Such as the current enquiry ...The more info that u can supply the better the results ,
cam lift per deg etc ?

Anyway i can only ask ,

Stephen

**T.W.R** · 26th December 2005, 21:07

Thanks Stephen,

I'm not trying to be a tight bastard but due to limited funds & also considering the age of the ZXR i've got tread carefully with what i do to it.

if it was a couple of years old & i had the funds to do it, i'd be going full steam ahead into hot-rodding the engine which would be quite nice

but sensibility endures so have to take each step into consideration.

from what i have been able to gather in relation to the cams & other bits that have been done it seems at some stage whoever had the bike previously 2 or 3 owners ago compiled the parts to pretty much what was the factory racekit specs for the H1 when they were new.
comparing it to another H1 i've ridden it has a beefy punch at 6500 & again 8000 through to around 10000; were the other 1 was quite linear in comparison. and i'll admit that i haven't actually wound it right out to see what full noise is, but having had it indicating what magazine testers say was top wack 245kmh 1000+rpm lower down the revs has kept me happy, also the gearing hasn't been changed its running 16/46 which is stock.

**Stevo** · 27th December 2005, 00:02

Originally Posted by T.W.R

as it was prior to the work being done I usually ran it mostly on race fuel anyhow

( due to a friendly local servo ) but it went like a cut cat ( still winding up at 240kmh pulling only 9200rpm which is what these old girls a supposed to do at 10500rpm

)

I hate to break it to you but it doesn't matter what fuel you use or what sort of carbs you have etc. If you are doing 240 kph then your engine will be doing 9200 rpm. The RPM is the rotation speed of the crank and the KPH the speed of the bike. Everything in between is constant ie the gearbox ratios and the sprocket ratios.

**RiderInBlack** · 27th December 2005, 06:06

Originally Posted by Stevo

I hate to break it to you but it doesn't matter what fuel you use or what sort of carbs you have etc. If you are doing 240 kph then your engine will be doing 9200 rpm. The RPM is the rotation speed of the crank and the KPH the speed of the bike. Everything in between is constant ie the gearbox ratios and the sprocket ratios.

Too True. Then it's down to if your speedo reads from the wheel or the gearbox.

**T.W.R** · 27th December 2005, 06:49

Originally Posted by RiderInBlack

Too True. Then it's down to if your speedo reads from the wheel or the gearbox.

i know that and understand the laws of wheel driven speedos but as i said i'm not 100% sure on the history of whats been done internally & as i've been finding out there a few things that aren't what they should be for a stock ZXR so, going on stock sprocket ratios 16/46 & stock tyre sizes 120/70-17 theres been an alteration internally on the gearbox ratios either on the driveshaft or main shaft. the driveshaft ratios are the most obvious ones to have been changed and from the performance changes compared to stock the changes have been one tooth increase across the whole cluster & possibly two teeth on sprockets 4 - 6, somewhere in the region of a 30-35kmh change.

the quote i put up was just diplay the difference between what i have & what a stock ZXR does, as tests on the bike when new stated that in top it would pull 245kmh @ 10500rpm & the engine would run out of puff considerably beyond those revs, now in comparison what i have is is pulling the same speed but at 9200rpm 1300rpm below & its pulling strongly as in the speedo is climbing only slightly slower than the rev counter. given this & the way it produces power in zones lower down the revs theres no linear build up that the H1 was known for, it has far more punch when it comes on cam & having run it against another ZXR ( same year & with less kms) it easily left that bike behind at over 180kmh in the same style that 1000-1100cc sportsbike would.

**Stevo** · 27th December 2005, 07:11

Fair enough then. Just thought it sounded like you thought the fuel was enabling your engine to rev lower. My apologies

**T.W.R** · 27th December 2005, 07:29

Originally Posted by Stevo

Fair enough then. Just thought it sounded like you thought the fuel was enabling your engine to rev lower. My apologies

oh please! nah but running it on the race fuel does make it run a lot better than on 96oct , response is a lot crisper &

nothing looks as good as a nice off-white/grey exhaust pipe

**Lou Girardin** · 28th December 2005, 08:24

Originally Posted by T.W.R

( still winding up at 240kmh pulling only 9200rpm which is what these old girls a supposed to do at 10500rpm

)

speedo error.

**T.W.R** · 28th December 2005, 08:30

Originally Posted by Lou Girardin

speedo error.

don't think so lou ! even got a ticket from the boys in blue to back up how accurate the speedo is

read through the rest of the thread instead of just picking one small section

**R1madness** · 28th December 2005, 09:43

Sounds to me like its got a close ratio gearbox in it.
Bloody cam chain tensioners. Its not only Kawasdakis that are having that problem. I know of 4 GSXR1000K3s that have suffered the same fate. Oops.

**R1madness** · 28th December 2005, 10:07

Also here is a few comments about "RACE FUEL" in New Zealand.
THERE ISN"T ANY. What the petrol companys sell as race fuel is actually derated avgas. It can only sit for a limited time before it on longer meets the rating for avgas (110 octane i think) so they sell it as RACE GAS 100 octane. Avgas is made for high altitude (low oxygen) consistant rev motors. Sure it can reduce KNOCK or PINKING in a motor but that is because it burns slower and is harder to ignight. This is fine for things that rev less than 10000rpm but as the revs rise the flame spread can not keep up. The higher it goes the worse it gets.
Try a 50/50 mix of 91 and 96. It will give the same results as the avgas without the slow flame spread.
Regards
Ian

**RiderInBlack** · 28th December 2005, 19:59

Originally Posted by R1madness

Sounds to me like its got a close ratio gearbox in it.
Bloody cam chain tensioners. Its not only Kawasdakis that are having that problem. I know of 4 GSXR1000K3s that have suffered the same fate. Oops.

And The CBR1000F's. Why didn't they just put gear driven cams in them like they had with the VFR750