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zx-4 engine - any issues?
Posted: Tue Sep 09, 2008 1:10 pm
by markzxr400l3
I have just aquired a zx-4 (1988) engine and have spliced the head/cams/etc on top of my zxr400l3 cylinders. does anyone know if this will work or if there will be any issues/loss of power/oil route probs etc?
I have electrical gremlins as well, will post seperately, or I would fire it up myself to see.
Any help is appreciated.
Re: zx-4 engine - any issues?
Posted: Tue Sep 09, 2008 1:52 pm
by masterofinsanity
zimms probably the best person to answer this question.
Re: zx-4 engine - any issues?
Posted: Wed Sep 10, 2008 9:38 am
by deviant
AFAIK (and this is largely info from zimm) there's no difference in the top ends, apart from the ZX4 has slightly different cam profiles. They may even be 'better' than the ZXR-L ones, depending on what you want.
Should be no problems, but I'll let zimm fill in the details.
Re: zx-4 engine - any issues?
Posted: Thu Sep 11, 2008 11:39 am
by zimm
yeh, it'll work ..
well, it should work

Re: zx-4 engine - any issues?
Posted: Sat Sep 13, 2008 3:24 am
by Vard66
Good details, zimm.
Re: zx-4 engine - any issues?
Posted: Sat Sep 13, 2008 3:37 am
by zimm
what do you want ? an in depth explanation of exactly why it should work ? he's already built it which precludes any obvious component mismatch, i've built several, zx-4's, H's and L's and see no reason why it shouldnt work, the gaskets are even the same across the board...
ok, the zx4 uses smaller carbs, but so do many L imports, and i've got the larger (32mm) carbs on a zx4, so thats not an issue*.. as long as carbs and inlet stubs come from the same bike you should be fine, i never noticed any difference in the shape of the inlet port itself.. cams.. yeh, supposedly better than L .. a dead ringer for SP but without the adjustable sprockets, but i couldnt swear to it.... valve sizes are the same afaik, but i've never measured them.
if its a roadbike why not use the whole zx-4 engine ? the gearbox is nicer and has more evenly spaced ratio's, and the clutch isnt as rattly (non KBATL) if you really want an oil cooler fit a zxr sump to it. but please do throw away the zx4 camchain tensioner, out the window, up the street, in the bin, up the cat.. just not in an engine, they are toad and were replaced by a better design for a reason, they're better.
k ?
lol
*does need/want diff needles to carburate cleanly compared to my H though, despite now having an H airbox, but it's got a completely different exhaust
Re: zx-4 engine - any issues?
Posted: Sat Sep 13, 2008 3:43 am
by Vard66
*shrugs*
I don't want anything, I'm normally only here to contribute sarcasm here and there...
Re: zx-4 engine - any issues?
Posted: Sat Sep 13, 2008 3:58 am
by zimm
Vard66 wrote:*shrugs*
I don't want anything, I'm normally only here to contribute sarcasm here and there...
fair enough.. im drunk and about to pass out ..
wtf you always awake for at stupid o'clock anyway ?
Re: zx-4 engine - any issues?
Posted: Sat Sep 13, 2008 11:44 pm
by Vard66
Dunno. Insomnia setting in again, I guess.
I am what's known as a 'slow sleeper'. Basically, it's one of the lower cases of insomnia.
Where normal people take between 4 and 20 mins to drop off, slow sleepers take anywhere between 1 and 4 hours.
Even if I got to bed at half nine, I usually won't be tired till 2ish.
Re: zx-4 engine - any issues?
Posted: Sun Sep 14, 2008 12:20 am
by zimm
lol,
a very honest answer to a rather flippant question
im same mate, only way i go to sleep before 2am is if i've already been awake more than 24 hours,
Re: zx-4 engine - any issues?
Posted: Thu Sep 25, 2008 8:24 am
by markzxr400l3
Zimm (and everyone)
Thanks! The reason for not fitting the bottom end is that it has sat on a wet garage floor for at least two years. When I compression tested the the inner pair were a fair bit down and when the head came off the top of piston 2 (or 3) is rusty. Not an expert but I took this as not a GOOD sign
I am going to try to make a spare engine with the 2nd rate parts just so I can keep on running if the main engine goes T1ts up. The engine is in and it feels fine (prepares to be shot down) a bit slow compared to my VFR 750 but above 10k it really sings, just takes a week to get there.
Nice tip about the Camchain tensioner and when I rebuild the spare engine I'll replace it. Thanks.
Vard, I get like that sometimes (insomnia), does it come and go depending on what youre doing (i.e. lifestyle) or do you get it all the time?
Re: zx-4 engine - any issues?
Posted: Thu Sep 25, 2008 3:32 pm
by Vard66
Not seemingly, but it dos show hints of being possibly stress related.
And if such is the case, I'm guessing my previous shitty, rushed, overworked and underpaid job kicked it back off, and my recent change of job, coupled with having to learn all this shiznit *gestures at 'Wine for Dummies' book, open at page 102* is what's to blame currently.
Clutching at straws a bit there though.
Re: zx-4 engine - any issues?
Posted: Sun Sep 28, 2008 2:17 pm
by markzxr400l3
They reckon sleep deprivation is one of the worst ailments possible, affects so much of what we do.
Anyway, fecking bike is still not playing ball. Fork stanchion and leg will NOT seperate!! fork 1 came out with a sleeve over the spring and was fine, new seals, all good. This tw@t come out with the sleeve still in the gold stanchion, I wonder if thats related? I am going to find my biggest hammer and have at it industrial strength. This was last job before MOT as well!!!
Death or Glory awaits!
M
Re: zx-4 engine - any issues?
Posted: Sun Sep 28, 2008 2:30 pm
by markzxr400l3
Death awaited,
Anyone got a right hand fork for sale?
M
Re: zx-4 engine - any issues?
Posted: Mon Sep 29, 2008 3:05 am
by Vard66
D'ya know, I didn't see the word 'fork' in that post then.
I read it and just sat frowning to myself going 'now what the feck?'