Just got back from Sicily where we were running the supercharged engine for the 1st time on a circuit.
Friday's testing was very encouraging with a whole day of running without any problems at all and the engine sounding and feeling very very good.
Saturday morning warmup was not so good as after about three laps the engine dropped an exhaust valve and made a mess!! I will take some photos of the damage and post them later on.
I am assuming that the OE valves are 2 piece and cannot take the heat build up that the engine gets on a circuit. Obviously you guys that drag race will probably never encounter this problem because you are never at WOT for this sort of duration continueously going up and down the gears lap after lap.
On the other hand I am happy to say that with water injection, 10.3:1 compression ratio, 8PSI boost, no intercooler, 109 octane Sunoco fuel & stock ignition timing once we had the head off after the damage the mixture colour on the pistons looked very good and there were absolutely no signs of detonation at all.
Can anyone suggest valve replacements for this kind of application?
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John Bul Racing. Malta.
posted May 03, 2010 01:43 PM
Im not sure about compatibility, but the ZX12R can use the oem inconel exhaust valves out of one of the kawaski jet skis(one of the supercharged ones). do zx12r and zx14 valves interchange?
might also want to look into getting bronze seats installed in the head
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posted May 03, 2010 02:43 PM
From your last video that thing is spinning up something fierce and your bouncing off the limiter like crazy. Time to get a propper head done to match the power it's now putting out.
posted May 03, 2010 06:28 PM
Edited By: smokinZX14 on 4 May 2010 02:31
johnbull with 8 psi boost and banging the limiter you are asking for problems or dropped valves ..That 8 pounds makes the factory springs very weak .. Lets say they are 35 psi on seat ... Now add 8 pounds of boost , Now you have 28 on seat ...Bang the limiiter with 28 on seat and you got problems ..I think Adams offers a spring that is 65 on seat , that should take care of the problem ..
Even with good springs you better stay off the limiter ...
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Smokin Performance Cycles..
Tampa Bay , FL .. Brocks Performance Dealer ..
Gen 2 ZX14R Best ET 8.43 , Best MPH 164.95
quote:johnbull with 8 psi boost and banging the limiter you are asking for problems or dropped valves ..That 8 pounds makes the factory springs very weak .. Lets say they are 35 psi on seat ... Now add 8 pounds of boost , Now you have 28 on seat ...Bang the limiiter with 28 on seat and you got problems ..I think Adams offers a spring that is 65 on seat , that should take care of the problem ..
Even with good springs you better stay off the limiter ...
Thanks for that Smokin, what you said makes a lot of sense and now I see exactly what you mean. So you dont think that it dropped a valve due to too much heat build up in the chambers????
Have contacted KPMI about valves, springs, retainers etc and they have everything in stock for the zx14. Has anyone had any experience with these products? Are they known to be reliable parts?
posted May 04, 2010 04:06 AM
I run Kibble springs in both my ZRX motors. One with stock valves and the other with Ferrea stainless valves. No problems. Your at a point where you will have to do a once a year tear down to keep everything in spec and reliable. Especially the valves and springs.
quote:johnbull with 8 psi boost and banging the limiter you are asking for problems or dropped valves ..That 8 pounds makes the factory springs very weak .. Lets say they are 35 psi on seat ... Now add 8 pounds of boost , Now you have 28 on seat ...Bang the limiiter with 28 on seat and you got problems ..I think Adams offers a spring that is 65 on seat , that should take care of the problem ..
Even with good springs you better stay off the limiter ...
Coming to think of it, whilst I understand that the boost could work against the springs on the inlet side, the boost pressure shouldnt make a difference on the exhaust valves sinse it is supercharged, correct??
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John Bul Racing. Malta.
posted May 18, 2010 11:52 AM
Heres a couple of pics of the damage the engine suffered last time out. Luckily the broken valve wedged itself in the piston right away before it good bang around and damage the bore.
posted May 18, 2010 10:02 PM
I see coppercote on that head.
One very reputable performance engine builder near me, in business for over 30 years told me to use hylomar, and stay away from coppercote.
He says his head gasket issues went away when he stopped using coppercote.
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natural selection.....
destiny will overcome intervention.
Some are not worthy of the effort.
posted May 18, 2010 11:04 PM
Hi Johnbull,
Sounds great and you seem to have more than enough power with the spinning wheels.
How fast are your times with that particular vid compared to the other racers and what engines are they using?
Any others using the ZX14 engine. I'd guess that a few gixer engines would be used, or not?
quote:Coming to think of it, whilst I understand that the boost could work against the springs on the inlet side, the boost pressure shouldnt make a difference on the exhaust valves sinse it is supercharged, correct??
Negative. All the forced induction tuners I've talked to agree that you need stiffer intake and exhaust springs: apparently the extra pressure in the cylinder tends to hammer the exhaust valve as it closes, causing it to bounce or "float". N/A cylinder evacuation events normally relieve all the pressure before the exaust valve closes: not so on a forced induction setup at full boost.
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'06 zx14
Muzzy M10/M14
PCIII w/ Muzzy map
Flies out K&N in!
bits n pieces...
quote:Hi Johnbull,
Sounds great and you seem to have more than enough power with the spinning wheels.
How fast are your times with that particular vid compared to the other racers and what engines are they using?
Any others using the ZX14 engine. I'd guess that a few gixer engines would be used, or not?
In that particular event I placed 2nd overall just 0.2 off first place despite the mess round the last corner going down one gear to many!! The car thats doing most of the winning overall at the moment is running a highly tuned fuel injected cosworth 2000cc engine. There is my old single seater which runs a N/A zx14 motor, some R1 engined cars, some gixxer 1000's & quite a few Busa engined cars.
We're racing again this weekend with stock internals for now so we'll try and keep off the limiter but straight after this event the motor will be stripped down and rebuilt with all the new bits.
Sticks_N_Stones, thanks for that info aswell.
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John Bul Racing. Malta.
posted May 23, 2010 12:34 PM
Just back from a great weekend of racing and I'm glad to tell you all that we finally got our first overall win today with the supercharged ZX14 motor setup. The car was really flying and the engine sounding great.
Thanks for everyones input here on ZX14.com
Will post vids and pics soon.
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John Bul Racing. Malta.
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posted March 30, 2010 10:03 AM
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