Water Pump

Discussion in 'Technical' started by TWIN TERROR, Oct 18, 2015.

  1. TWIN TERROR

    TWIN TERROR Well-Known Member

    Hi all,
    Is there any difference between a N/A and T/T water pump?. Quality wise would you use a Gates water pump or only Nissan Genuine?. Anyone know the Nissan T/T part number so if I go that way I know I am getting the correct part.
    Cheers
    Dave
     
  2. scottyoz1962

    scottyoz1962 Active Member

    Take note of #16

    ENGINE
    1. The cylinder block castings and main caps are the same. They both have oil squirters that direct oil towards the underside of the piston, but they point at different angles. The oil squirters on the TT direct oil straight into an off center hole on the underside of the TT piston, which leads to a hollow area inside the top of the TT piston. The NA squirters direct the oil towards the middle of the underside of the piston, which has no passages inside.
    They blocks have all of the same oil passages. Two passages are plugged with a bolt on the NA block (one on each outside face that feed the turbos on a TT). The TT block has two oil passages plugged inside where the oil filter bracket mounts. The NA has two small check valves in this location. They are plugged in the TT providing more pressure so that the oil will go through the lines to the oil cooler, which returns back to the oil pan. There are check valves on the inside of the TT oil filter bracket where the oil filter screws on, but none on the NA. The purpose of these check valves is if the oil filter somehow becomes clogged or collapses that oil will still circulate.
    2. The crankshaft is the same.
    3. Connecting rods ARE the same!! (Same Nissan part #)
    4. Piston rings, and Crankshaft (main) bearings are the same. The rod bearings are the same size but the TT?s are a different alloy (kelmet).
    5. Of course the pistons are different because of lower compression ratio in the TT, 8.5:1 in respect to 10.5:1 on the NA. The internal structure of the pistons is also different, the TT have a hollow ring inside the top that fills with oil for better cooling and a thicker dome towards the center. Oil pumps are different. They mount the same and are the same internally except for the spring for the pressure valve in the TT one is tighter so it produces more needed pressure to circulate oil to the turbos and cooler. You can actually just change the spring
    to the tighter one.
    The 94+ NA oil pumps and the replacement NA oil pumps from Nissan are different internally to the older ones and the TT?s. They have internal gears with larger rounded teeth.
    6. Oil filter bracket on a TT is different (longer) because it has an outlet that accommodates the hose going to the oil cooler. There is a spring loaded valve in the bracket that will not let the oil circulate to the cooler unless there is sufficient pressure. And then there are the spring loaded ball check valves that let oil bypass the oil filter if there is a problem, these are in the block on an NA. Oil filters are all the same.
    7. Cams, lifters, locks, retainers, and valve springs ARE the same (90-93)(same Nissan Part #) The Auto TT has different intake cams (lower lift) but the intake cams on the 5 speed TT, NA, and auto NA are the same. The different intake cams in the auto TT along with the slightly smaller exhaust housings on the turbos results in 20 less HP in the auto TT (it was detuned to
    help the transmission last longer). All the exhaust cams are the same. The 94-95 cams were different than the 90-93 but just like the earlier ones they are all the same except for the intake cams on the auto TT. The 96 cams were ALL the same.
    8. The valves are all the same size. But the exhaust valves on a TT are made from a stronger alloy (iconel)
    9. The heads are different between NA and TT. The castings are almost the same but not quite. The intake runners are of a different design in the turbo heads. The castings offer a more open port for the TT. We have used them interchangeably before without any problems, just probably results in the loss of some power, when using NA heads on a TT. It is significant enough that it would take extensive porting to get NA heads up to TT specs. We use different spark plugs on the NA and TT but we see them used
    backwards and every way in between a lot. The TT ones we use are NGK PFR6B-11B which are slightly longer that the NA PFR6G-11. The longer plug is ?colder? which helps with preventing detonation at higher boost levels.
    10. The oil pan is different because the TT one has 2 tubes protruding on the sides where the oil return hoses for the turbos mount and another one for the hose returning from the oil cooler.
    11. The turbo engine obviously has a few different
    accessories and systems to accommodate the turbos. The exhaust manifolds on the TT are much shorter than the NA ones, which go all the way down and tie into the exhaust section including the catalytic converters. The turbos are oil lubricated and water cooled. So there are oil and water, supply and return lines everywhere on a TT motor.
    12. The throttle bodies are the same size but the passenger side one is different on a TT simply because one of the water lines
    attached to the bottom of it has a junction in it to feed water to one turbo.
    But we usually do away with all that nonsense with the water lines under the plenum running to the TB?s in our warm climate. We just run water to and from the metal hoses on the back of the motor going to and from the heater core. Nissan added all the water lines under the plenum going through the TB?s to warm
    the intake air charge in cold climates. I think they designed it for the NA and just didn?t change it for the TT. You do not need this on a TT. You intercool your air to cool it down after it leaves the turbo, why try to heat it back up. Remove all the nonsense under the plenum. It makes life much easier.
    13. The upper and lower intake manifolds (plenums) are the same TT and NA 90-92. Newer ones are different from the earlier ones. They made the change to the new style injectors, lower plenum, and the intake port on the heads in 93 for the NA but
    not till 95 on the TT. So lower plenum and heads would be different on 93 -94 NA and TT?s. The upper plenums changed just a small bit in 94 when the angle that the flange of one of the EGR tubes bolts on to the plenum rotated about 30 degrees. Just enough stuff to make interchanges a pain.
    14. Motor mounts are the same, but I have a secret on that. I guess I?ll let it out if you?ve read this far although I have made some money because of it. The convertible motor
    mounts are the same but substantially cheaper for some reason. Motor mounts are broken into almost every time we pull a motor, so we go through lot of them and
    have saved $.
    15. Head gaskets have a different part # but appear to be the
    same we use all TT ones because they are cheaper also (another secret).
    16. Water pump, PCV valves, exhaust gaskets, intake gaskets, plenum gaskets, valve cover gaskets, seals, Timing belt, thermostat all the same.
     
  3. TWIN TERROR

    TWIN TERROR Well-Known Member

    Thanks for that. Interesting reading.
    Dave
     
  4. Sanouske

    Sanouske Retired Moderator

    On my zeds engines, I personally try and always replace mine with genuine nissan pumps, but that being said ive used the aftermarket type thats branded with the company name that supposedly makes oem nissan pumps (cant recall it atm, its a 3 letter brand.. NS something. Cant recall) and they've worked fine. Its one of those bitch jobs to have to do twice due to a cheap pump failure...
     
  5. Sanouske

    Sanouske Retired Moderator

    NPW. Thats the brand.
     

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