Canadian Posted May 10, 2014 Share Posted May 10, 2014 Hey guys, so I am in the process of gathering maintenance parts for my engine swap for my 2001 with vq35de. For those that dont know I am putting in a used engine, the used engine is from a japanese rhd model qx4/pathfinder.I just noticed they have different intake manifolds. If youve taken off your vq35 intake manifolds off before, youll know there are "power valve" butterflies (6 of them) in a row right under the UPPER intake manifold, but also if you take off the upper and middle intake manifold, there is a bottom manifold. Well that bottom manifold is different on my JDM engine compared to my factory USA engine.The old engine has butterflies built into the lowest intake manifold aswell, and a "plunger" on the front of the manifold that ties into those butterflies and must open them based on vacuum?? Well the JDM manifold has no butterflies and no plunger. Heres a pic of the plunger and you can see the butterflies. The vacuum line you see connects to the picture below this (red line)Right now I have the jdm version still bolted to the engine, I am hoping I can use it and it wont make any difference, really would just like to know it isnt going to cause any driveability issues. The only issue I see is the vacuum source that ran from the "plunger" that tied all the bottom butterflies, the vacuum line runs to the back of the "black box". Would I just cap that line. This pic shows where the vac line would come from the bottom manifold, and plug into the back of the unit.Do you guys think it would be any problem using the version without the bottom butterflies? im not quite sure why they are needed Link to comment Share on other sites More sharing options...
silverton Posted May 10, 2014 Share Posted May 10, 2014 Use your original manifolds and you won't have a problem. Link to comment Share on other sites More sharing options...
fleurys Posted May 10, 2014 Share Posted May 10, 2014 I recall that only the auto trans had the butterfly intake... Your replacement engine must be coming from a manual trans equipped truck... Link to comment Share on other sites More sharing options...
Canadian Posted May 10, 2014 Author Share Posted May 10, 2014 Id prefer to use the JDM version with no butterfly, as I have already replaced the gaskets on the intake manifold, valve covers, loc tited the power valves before I noticed there was no plunger on the jdm engine compared to the US engine and the motor is pretty much ready to drop in aside from a few coolant hoses. Im just wanting to see if it would make a drivability issue? Link to comment Share on other sites More sharing options...
keelhaul Posted May 11, 2014 Share Posted May 11, 2014 (edited) I recall that only the auto trans had the butterfly intake... Your replacement engine must be coming from a manual trans equipped truck... Fleurys is correct. Another difference would be where the flywheel bolts on to the engine. Manual tranny has a pilot bushing while an auto has a pilot converter. I just realized you said you locktited the powervalves. It must be and auto engine then. The lower butterflies are swirl control valves. Further than that, I have no idea. Good luck Edited May 11, 2014 by keelhaul Link to comment Share on other sites More sharing options...
Canadian Posted May 11, 2014 Author Share Posted May 11, 2014 Im curious what specifically you mean on the flywheel, I planned on using the flywheel from my original engine, will it not bolt up? Link to comment Share on other sites More sharing options...
Canadian Posted May 11, 2014 Author Share Posted May 11, 2014 Do you guys think the car would somehow know the bottom butterflies werent there? I mean there isnt any wiring that goes to the bottom intake, those bottom most valves are run by a vacuum line (the one I posted)Since the engine I bought is a manual trans version, and that seems to be one of the main differences from the auto (I will be running the stock auto ecu) Link to comment Share on other sites More sharing options...
keelhaul Posted May 11, 2014 Share Posted May 11, 2014 I think that if you have the upper butterfly valves(power valves) that you said you locktited, then you in fact have the auto engine. I cannot explain the missing swirl control valves(lower butterflies). Manual tranny engines have a pilot bushing for the input shaft of the transmission. I am not sure what the auto tranny engines have or if they easily swap. Link to comment Share on other sites More sharing options...
Canadian Posted May 11, 2014 Author Share Posted May 11, 2014 I was just comparing the 2 flywheels from both engines and I dont see any differences, and both crankshaft ends look exactly the same, scared me there for a sec lol Link to comment Share on other sites More sharing options...
silverton Posted May 11, 2014 Share Posted May 11, 2014 Your ECU is going to be expecting those butterfly valves. without them you will most likely have driveability issues. Link to comment Share on other sites More sharing options...
Canadian Posted May 11, 2014 Author Share Posted May 11, 2014 I think I may leave it as is for the time being and install the engine and let it start up. Heck for all I know this engine might have a problem, it is used with an unknown history for that matter (although it looks spotless for leaks, and the internals were near factory clean) I will keep the other intake on hand, really dreading having to clean off its mating surfaces, and the piece in general, if I do end up having to install it, because it is caked dirty Link to comment Share on other sites More sharing options...
Leo98 Posted May 14, 2014 Share Posted May 14, 2014 Hey Canuck, I found this interesting. http://www.nissanpathfinders.net/forum/topic/18310-vq35-power-valve-riddle-w-answer/ Link to comment Share on other sites More sharing options...
Leo98 Posted May 14, 2014 Share Posted May 14, 2014 How i read it, you are going to need those butterflies for your A/T to work properly. If i have been following along correctly. The jdm engine is RHd and manual transmission setup, your old enigine was LHd with automatic transmission. That is why the jdm engine doesn't have the butterflies and your old one did. Unfortunately you are going to have to tear down and install them. Link to comment Share on other sites More sharing options...
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