it's done through their valves tho, i don't know the details but the cams are on a little ramp and i think the entire camshaft moves so the lift changes depending on where on the ramp they sit...
Originally posted by James it's done through their valves tho, i don't know the details but the cams are on a little ramp and i think the entire camshaft moves so the lift changes depending on where on the ramp they sit...
You mean for the valvetronic right? I think that is how it works.
vtc, oil pressure controlled advance in intake cam which kicks in at about 1500rpm's, this meaning the vtc solenoid is on up to about 6500, then cuts off, returning it to somewhat idle or in retard, i monitored this with my'98 and with Nissan Consult scan tool, it helps us at take off, but on the long run, it kinda slows us down, so i shift before it shuts off, taking full advantage of the advance.
vanos, also oil pressure and with a solenoid, like ours, it too is just an on/off system, also kicks in at the same range and cuts off in the same area, found on earlier versions of the 6-cylinders.
dual vanos, found both on the intake and exhaust cams, this however is not an on/off, it receives (the solenoids) a pulse width modulated signal from the dme, expanding the effective range and producing an infinitely variable advance or retard, what ever is needed for clean emissions and more power.
m5-dual vanos, same principle but works on a 100bar pressure system, quicker response and also wider range.
valvetronic, no camshafts, electric solenoids control valve opening and duration, also with pulse-width modulated signals.
I had been trying to diagnose my 97 GA16DE.
All of the sudden it started to make noises like if it was a diesel.
I did the timing chains and hydraulic tensioners and guides.
I still have that annoying noise. The Valve adjustment was then my other theory...and all the valves were in spec.
So the noise comes from the area where that extra lump on the intake cam. I wonder if that VCT system on the intake cam could just rattle like a diesel....noise... or the solenoid is not opening the passage and then the adjustment is offf ...I am out of ideas,....HELP!!!!
We should all be glad we have VTC on our GA16DEs; have you ever driven an Euro- or Jap-spec GA16DE without it? Lag, lag, lag. Especially on the first generation ('91-'94), after about 3500 rpms it seems like there is just nothing left to give from the powerplant. Unfortunately, Nissan never designed NEO-VVL for the GA16DE, since they cut the engine from production in 2000 here in the United States and almost everywhere else.
FYI, ALL GA16DE'S HAVE VTC AND JDM SPEC MOTORS ACTUALLY PULL HARDER THAN THE U.S. SPEC MOTOR. NOT TO MENTION EURO SPECS, THEY ARE WAY UP THERE TO TAKE ADVANTAGE OF HIGHER SPEED LIMITS
Last edited by Sunny16 : Mar 20th, 2008 at 11:11 AM.
Actually, they don't. The VTC-equipped GA16DE produces 120 hp (85 kW) @ 6400 rpms while the European-spec non-VTC GA16DE produces 102 hp (76 kW) @ 6400 rpms. That right there should tell you not all GA16DE comes with VTC. As well, the GA16DNE (DOHC TBFI) also does not have VTC, and produces 105 hp (78 kW) @ 6400 rpms. I might also mention the GA16i (SOHC TBFI), GA16DS (DOHC Carb), and GA16E (SOHC MPFI) all do not have VTC.
P.S. I've lived in the United Kingdom where we get Euro-spec Nissan models, and I've driven GA16DEs that do not have VTC. The UK and most of Europe have stricter air emissions than the United States, and because of it, their passenger cars are much more tuned down. I can say the GA13DE cams are supposed to scream in the GA16DE, but I have no real confirmation of that, so don't try it at home! The aftermarket overseas for the GA16DE is about as limited as it is here in the United States, especially since more GA-series engines were sold here than anywhere else in the world, most likely even Japan! Think about how many Sentras there on on the streets from 1991-1999?
GA16 I, DS, DNE ARE NOT GA16DE, DIFFERENT CODE AND THE STRICT EMISSION VERSION IS LIMITED, BTW OUR NISSAN SENTRA (SUNNY FROM JAPAN) GA16DE ALL HAVE VTC AND WHEREAS THE U.S. REV LIMIT IS 6.9K, MY GA16DE REVS ALL THE WAY TO 7.5K STOCK AND DOES HAVE MOST OF IT'S PUNCH FROM 3,500 RPM ALL THE WAY TO 6,600, SO I'M NOT SURE WHAT JDM SPEC GA16DE U'VE DRIVEN.
P.S. 93 NISSAN SUNNY, SO IT'S THE OLDER VERSION GA16DE (SILVER TOP) - 110 HP, (BLACK TOP) OR 95-99 GA16DE 120 HP
Last edited by Sunny16 : Mar 20th, 2008 at 01:31 PM.
Congratulations, you're Sunny has a GA16DE with VTC, woohoo! However, not all GA16DEs have VTC, that is all I am saying. The GA16DE non-VTC I drove was in a B13 Sunny overseas in the United Kingdom minus VTC and just about every accessory you can think of; basically it was a steering wheel and a gear lever. I think there might have even been a radio.
Linear Mode
