lymon

actually it has nothing to do with any valve...as far as I know there isn't a valve in the block or head, only 2 (small) oil jets in the oilpassages to the head, but these are there to regulate the oilflow/pressure to the heads and if they get blocked for some reason you'll have far more serious problems. There is a small checkvalve inside each lifter, to keep the oil inside the lifter, but this valve normally isn't the problem either. The actual problem is caused by a problem in the design of the lifters themselves: inside the lifters is a small round plate between the lifterbody and the housing (left in the picture) This plate has a small groove that is fed with oil through 2 VERY tiny pinhead holes on the far ends of the groove to create a thin layer of oil between the inside top of the lifter and the plate to prevent the ticking sound: The problem is, it's very easy for one or both of these tiny holes to get blocked and the result is that the groove will no longer fill up with enough oil and this will cause the ticking sound. In the worst case, the groove wears out because of the lack of oil and this causes the lifter to tick allways. -Eric

>> http://www.alternativeauto.com/waterbox/wb_archives/boostapump.html Yes, heard some good stories about these as well...also when used on Zeds. But as you point out when running on the edge of the pump's capacity in most cases requires other modifications first or you will run into other issues first. The fuel supply and return lines need to be upgraded/replaced to at least 10mm diameter, a high flow fuelfilter needs to be used and the stock fuelrail hasn't got the best design for maximum flow either. a simple trick to see if your pump/lines/filter are capable of flowing enough fuel for 550+ hp is by running a line straight from the fuelfilter into an empty 5ltr jerrycan, turn ignition on and see if the pump is able to fill it with at least 3.5 ltr of fuel in 1 minute.

if there's a modelnumber on the calipers: http://www.brembo.com/CatalogoHPGT/Templates/SearchHPGT.aspx?NRMODE=Published&NRORIGINALURL=%2fENG%2fPerformance%2fGranTurismoCatalogue%2fCatalogoHPGT%2ehtm%3fsearchCode%3d1B1%2e9002A%26idBU%3d1&NRNODEGUID=%7b97CFEBDC-74B5-481D-95E0-024644BC51FA%7d&NRCACHEHINT=NoModifyGuest (select "search by code") this might help as well: http://www.brembo.com/NR/rdonlyres/2D8F1381-5297-4C1A-A985-ECB61E7E9A97/0/PartnumberHPGT.pdf other method might be to identify them using the productcode on the brakepads (if the calipers still have the pads)

for a 6 cylinder engine running standard fuelpressure (3bar), injector size multiplied by 0.9 roughly translates directly to maximal achievable power at the wheels so: stock inj. (370cc) --> approx. 330hp, 555cc -> approx. 500 hp if you increase fuelpressure, the max. flow and achievable power increases. Increasing fuel pressure to 4bar results in a flow increase of roughly 20%. so, 370cc@4bar -> approx. 400cc, 555cc@4bar -> approx. 600cc note1: increasing fuelpressure requires remapping of the chip note2: when running 555's at 4bar fp you will run at the edge of the fuelpump's capacity once the injectors are running on full dutycycle.

Also, as an addition to Mark's comments: the stock fuel pump won't be able to flow over 3600cc/min, (divided by 6 : 600cc per cylinder)...so a single stock pump will not be able to flow enough fuel for 800cc injectors running on max. dutycycle.

if you mean replacing the lifters, then yes..it can be done with the engine in the car. but needs removal of a lot of things (plenum, rocker covers, cambelt, camshafts)

Your problem is most likely caused by worn steering rack bushings.

you can make the stock 5 speed box a close® ratio by installing a NA diff/subfr. or a 4.1 ratio drive gear in the current diff (http://www.leadergears.com/site/content.php?content.5). One of the better modifications for the Zed imo.

here's someone that actually did the conversion: http://www.twinturbo.net/net/viewmsg.aspx?forum=general&msg_id=1393957 magic words: "nothing fits, absolutely nothing, we could have used a caterpillar tranny"

stick with the recommended plugs: PFR6B-11B Nissan partnr. 22401-40P66 problem with most iridium plugs for the Zed (the right one being the PFR6B-11B plug): and for example, this is a socalled 300ZX iridium plug in a TT head: There are iridium spark plugs especially made for the VG30DETT available in Japan, but they are VERY rare and I very much doubt sparkplugs.co.uk has these (in stock.)

tried different sparkplugs ? > would car missfire that badly with one coil not working The car should still run and idle ok with one coil not working, be it a little lumpy If it doesn't idle, there's probably something else wrong other things you can try: pull the widest plug from the PTU and check resistance of the wires. from the top of my head, the middle thick wire (black) on every coil plugs runs to a single pin on the wide PTU connector (-) and the other pins all run to an individual coil plug (+) the wires from the other/smaller PTU connector run straight to the ECU.

checked injector connectors as well ? (especially the one of the failing cylinder)

>> No I meant is it in that location Yes, fuelpump controller is located at the same position (near LH rear wheel arch) for both 2+2 and 2+0

PTU (power transistor) is probably on it's way out

jwt700's are GT28RS turbos with 0.80 AR turbine housings: very laggy on our engines...better alternative would be the Garrett GT28RS with 0.64 AR turbine housing. The GT28RS turbos are hard to fit and require quite a few modifications, but Zeds that have the 0.64 AR versions fitted seem to break all the records lately. (Greg Dupree's car from SpecialtyZ being a good example) The TD05's have proven to work very well on Zeds (even on engines with stock internals) and are fairly plug and play. There have been numerous reports of cracking Greddy manifolds (the ones that come with the TD05 kit), but apart from that not much that can go wrong with this turbo kit. Even though the technology used in these turbos is somewhat ancient, the TD05's are still going strong against all their new ballbearing competitors.

remove stopper and carfully turn the needle 360 degrees counterclockwise. then keep turning it counterclockwise and slowly pull off the needle.

>> twin intake without maf sensors(converting temp and pressure to voltage data),eprom swap on main ecu + unichip piggyback. Are you using a HKS VPC ? If so, has the VPC been programmed for 550CC injectors ? >> My new tuner says he would have favored standard 370cc injectors supplemented with 2 injectors ,one before each throttle body to avoid this problem. VERY bad idea when using systems like this the 2 cylinders on the back of the engine (5+6) are running extremely lean and you'll most likely have another meltdown. -Eric

the only reliable and cheap"ish" injector upgrade is by using 440CC 's from a subaru WRX (GC8, EJ20G/K). only problem is, they come in sets of 4, so you'll need 2 sets and have 2 spare injectors ;) -Eric

DTA-motorsport (http://DTA-motorsport.com or http://DTA-motorsport.co.uk) can source headers for the LHD NA's. -Eric

just a small warning: Nissan moved to the new style injectors + fuel rail on NA's at a earlier stage (somewhere around late '92), so if you have a '93 or later NA, most TT injectors are not going to fit. Easiest to tell if you have new style injectors is by looking at the injector connectors, if these are oval shaped you have the new model, square shaped is the old model.

the "3 mad scientists trying to do a burnout in a 300" feature :D http://www.mytwinturbo.com/video/300zx_topgearburnout.wmv

If all camshafts have seized, it could have been caused by an extreme case of overheating (heads have warped far beyond specifications) Though I've seen this before on a car that had one seized camshaft and it was caused by oil-starvation, because an oil channel under the camshaft was completely blocked.

maybe he disconnected the pipe because there was/is a leak in one of the small vacuum tanks or in the clutch booster. ...or he just preffered a more heavy/firm clutch feel

There are 2 temps sensors: a main sensor (yellow connector) which is used by the ECU...this one is very important and I suggest you don't splice into this one. The other one (smaller black connector) is used for the dash temp gauge and you could try to splice into this one or just disconnect the connector and use the sensor for your aftermarket gauge. -Eric

if you want to keep the steeringwheel, you'll need to get a hub adapter that allows you to keep HICAS (eg. a DAIKEI hub adapter) Also make sure you still have the HICAS steering angle sensor ! (usually this one is removed and binned when installing a non HICAS enabled hub adapter) http://300zx-twinturbo.com/cgi-bin/manual.cgi?list=st&dir=&config=&refresh=&direction=forward&scale=0&cycle=off&slide=58&design=default&total=98 -Eric