The VG33E information thread

Maybe the time is right, i've seen quite a few vg33 threads popping up in the past few months. How about we get this going?

The official unofficial VG33E information.

This was created to solve the problem of little information and many myths regarding the SOHC VG33E. As many are still unaware of all the differences this motor has compared to other variations in the VG engine line up, this thread and following post will build on the growing knowledge of understanding differences and modifying the VG33E. The following is to my current knowledge, over time I hope the forum members and moderators can both add to, and help keep this in order while simple to read.


To start lets cover the models and years this engine was avaliable in. In some vehicles the 3.3L was an option.
In the USDM vehicles:
'96-'00 Nissan Pathfinder
'97-'00 infinity QX4
'99-'04 Nissan Frontier, '01-'04 supercharged avaliable
'99-'02 Nissan Quest & Mercury villager
'00-'04 Nissan Xterra, '01-'04 supercharged avaliable

Visually the VG33E besides a few components is idential to a VG30E. There are mostly minor location differences of components, routing of lines, and electronic components that visually set the VG33E apart, though these minor differences can be worked around by using parts from other VG's.






Basic information, intake manifold down to the heads:

Getting a little more in depth lets talk about the intake and fuel related pieces, the VG33E uses the upper intake manifold found on earlier pathfinders and quest that used the VG30E. The lower intake manifold is similar to the VG30E's as well being able to use most of the 3.0's upper intake manifolds, the coolant neck found on the 3.3's lower intake houses two sensors though it is similar to some of the 3.0's does not function as a filling location like some 3.0 designs, but it shares the same flange design and bolt pattern so it is able to use many variations. The fuel system is similar to the later +'87 3.0's using side feed injectors, though the seals are of larger diameter and different design. The injector design found on the 3.3's are junk and impossible to find high flow rate injectors for, you might as well junk them. (NOTE: the VG33ER injectors are rated around 320cc, which is a little step up from the 260cc found on VG30ET making them useful, this requires use of the 3.3 lower intake manifold.) The locations to bolt the fuel injectors down is much lower on the 3.3's lower intake manifold, other differences are the 3.3's intake manifold lacks a coolant temp gauge sensor and coolant tube on the rear passenger side some of the 3.0's used, the rear coolant tube has different routing than most 3.0's, again the flange and bolt pattern is similar to the 3.0's so swapping tubes is simple. Port diameters (~36mm) are similar as well as head to manifold coolant passages, and will line up with any VG30 head casting. Worth noting is the thermostat housing is angled slightly differently, while using the same diameter thermostat as 3.0 housings.

The heads specific to the 3.3 are known by casting reference "OWO". Visually they are very similar to the 3.0's head using 13 head bolts, the main difference being the 10mm exhaust studs. The exhaust studs can easily be rearranged to suit your header choice using a TORX socket.

Internally they share parts with the 3.0 specifically the rockers, lifters, lifter guide, valve and valve spring locks, retainers, valve stem diameter, height, and ultimately - layout. The 3.3's valves can be identified by their casting "EF-3". The valve stem diameters, guide diameters, and seat angles are the same between the 3.3 and 3.0. Both the intake and exhaust ports have a much smoother casting than the 3.0's V52, 21V, and 85E heads. Head bolt locations, water passages, and oil galleys are similar though there are slight differences in the water passages they will not interfere with swapping 3.3/3.0 heads to ether block though I would advise against 85E or 21V heads onto a 3.3 block due to the water passage being close to the combustion chamber more so than the V52. A major difference is in the camshaft found in the 3.3, the 240/244 .354"/.354" cam is good for low end grunt but not that great for high RPM power. The 3.3's camshaft is commonly swapped out for 3.0's camshafts for better high RPM performance, aftermarket 3.0 cams will also work. Another difference that is very important to note is the camshaft sprockets, the 3.3's sprockets use a round tooth style compared to the 3.0's more squared tooth style, the matching crank gear must be used.





Basic information, bottom end and rotating assembly:

Lets start with the engine block. Again the 3.3's block can be identified by an "OWO" casting on the front driver side. Many of the locations to bolt up engine brackets, and accessory brackets are predrilled and tapped making the use of other 3.0 pieces an easy affair. The block to bell housing pattern is also the same as 3.0's making many transmissions available. What makes the 3.3 a 3.3 is the bore of 91.5mm, the stroke length is shared with the 3.0 at 83mm. The pistons are cast like other VG's having a compression ratio of 8.9 (non-SC) and 8.4 (SC):1 they also have the OWO imprint along with valve reliefs and a slight bowl to the center. The connecting rods, again stamped with "OWO" are similar to a 3.0's the difference being the notches at the bottom. The 3.3 rods are also similar to the later 3.0's floating wrist pins found in the "W" series engines.

The crankshaft is cast sharing the same main and connecting rod journal sizing system as the 3.0's. The crankshaft also shares the six bolt flywheel pattern found on 3.0's making many quality clutches available. The major difference between the 3.3's and 3.0's crankshaft is the snout, the 3.3's has a larger diameter and must be used with the matching 3.3 oil pump and pulley. The 3.3's oil pump also is the mounting location for the oil filter and oil pressure sensor, the pumps pickup is also closer to the center line and has a taller mounting location than 3.0's pick up location this may require modifying the oil pan per-application. A common discussion is drilling the block for an oil feed location when adding a turbo, the motor I picked up from a '96 Pathfinder did not require any drilling as it only has a plug. The oil filter location was rumored to not clear when mounted in a Z31, my set up with a 1" antiswaybar, z31parts.com poly engine mounts, and intact power steering lines clears with plenty of room for a larger filter.

Accessories:

The 3.3's crankshaft pulley is delicate, and prone to chipping/cracking use caution when removing and handling.

The 3.3's pulley is special, it has a 32mm center bore, and has variations in belt style and routing per-model. Early pulleys use a rib-rib-V, late pulleys use rib-rib-rib belt routing. The easiest way to over come this issue is to keep or aquire the associated brackets and accessories that come with the engine, though this may interfere with simple intake and intercooler pipe routing on those who choose to use turbochargers. There is also the option to swap in a 3.0 crank and use the 3.0 pulley and accessories this also involves using the 3.0 oil pump and using the Quest style 3.0's oil pump that side mounts the oil filter like the 3.3's, or simply using the 3.0's oil filter stud from other variations to relocate the filter. That's the most of my knowledge concerning this topic, personally I'm still unfamiliar with mix matching brackets and pulleys, as I've previously sourced a setup from a Frontier.



There is much more information and examples yet to be shared, the basic information posted is a start in the right direction to document the knowledge in an effort to centralize it. If you would like to add information your self please keep it organized and easy to read.

If you're planning to swap a VG33E in place of a VG30E the swap is pretty straight forward as long as you keep an eye on the subtle differences and an open mind to solve simple problems. There are many others out there that know much more about this engine than myself, I am looking forward to any additional information, corrections, or pictures.



I will be back to edit this I'm sure!