NA conversion to TT

[cmutchler]

ENGINE
1. The blocks 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 a 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 ones just 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 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.

I came across this post in the sticky thread at the top of the forum and I am hoping to get some clarification. I am planning a complete rebuild, literally tearing everything in the car apart and building it out to be exactly what I want in a 300ZX. The donor car itself looks like it is going to be a 1992 NA 300ZX.

As far as the holes go for the NA engine versus the holes for the TT engine, would a machine shop be able to plug/unplug the correct holes since the paragraph makes it seem like all the holes for both versions are present regardless of the model? I would think that would be possible, but this is my first time rebuilding an engine from the ground up.

Thanks in advance.

[NolimitZ32]

As far as I remember the only difference is the coolant and oil passages for the turbos. Everything else is the same on both blocks. The coolant comes from one of the hardpipes in the back of the block and the oil passages will be plugged with threaded plugs on the NA so its a matter of taking them out with a wrench and installing the lines.

[t.mcginley.jr]

As far as I remember the only difference is the coolant and oil passages for the turbos. Everything else is the same on both blocks. The coolant comes from one of the hardpipes in the back of the block and the oil passages will be plugged with threaded plugs on the NA so its a matter of taking them out with a wrench and installing the lines.

This. There are threaded plugs in the NA block that you can just take out and put in the correct TT fittings. The hardest part with be getting the oil check valves out of the NA block where the oil filter tree goes. Once they are out (supposedly you can drill them out), you need to plug them with something. Engine builders like EP Racing tap the hole and plug it with one of those square pipe plugs. They also sell these:

http://www.conceptzperformance.com/Cart ... 194.82.254

Anyway, you just plug the holes up on your NA block and install a TT oil filter tree with the check valves already in it. I would lube them up before install and make sure they work first. Used TT filter trees can be had for $30-50

[cmutchler]

Thank you both very much! I am trying to get everything ironed out before I start spending loads of cash on the rebuild, mostly because I want to avoid any gotchas halfway through the project.

[NolimitZ32]

What exactly are you trying to do? is it going to be an OEM build?