nissan pathfinder engine 

Project Pathfinder Part 10, How to Build the Nissan VG30E

We are getting quite excited as Project Pathfinders motor is now up and running. We are out to show that a solid and reliable naturally aspirated VG30E can be just as strong or stronger in the power department as the VG33R supercharged motor in the Frontiers with vastly superior fuel economy.  We also want to show that we can get the pulling power of a small V8 out of the VG. Last month we covered some tricks that Dan Paramore of DPR used to make our heads flow.  This month we will dive into the shortblock of our super Pathfinder.

To read about our VG30E headwork click here!

Perhaps the hottest combo for older vehicles like ours equipped with the VG30 is using the block from the bigger bored VG33.  This is especially good for a post 87 engines with the better cylinder heads although the VG33 heads feature 10 mm exhaust manifold studs, which is good as the older engines 8mm studs, are very prone towards breakage. The donor motor for Project Pathfinder was pulled from some poor bastards rolled and very totaled Xterra with only 1800 miles on the odometer.

When the heads were sent to DPR, we stripped down the shortblock and deburred it internally to remove casting sand and stress riser causing flash from the interior of the block. After this prep we obtained a set of pistons from a first generation Infiniti Q45 (1990-1994) VH45DE engine.  These pistons give 3.4 liters of displacement and the flat top dome gives a compression ratio to 9.6:1, up from the stock 9:1 of the dished standard piston.  The piston feature low friction coating on the skirts to boot and are cheap.

Q45 Piston Nissan Pathfinder
This close up shows the additional notches cut in the top of the Q45 piston to clear the VG’s valves. Any automotive machine shop can do this easily and cheaply.
Q45 Piston Nissan Pathfinder
The black stuff on the skirt of the Q45 piston is a Teflon like anti friction coating, very similar to Swain coating and other similar products.  Nissan applies this at the factory.


chrome rings nissan pathfinder
Here is the Q45 piston when compared to the dished lower compression stock piston.  The Q pistons are 1mm bigger to give a new displacement of 3.4 liters.
45 Piston Nisan Pathfinder
Nissan rings need a smooth surface.  This is a 600-grit plateau finished bore; it is as smooth as glass.  Don’t let an old school machine shop talk you into getting a rough bore.  Nissans have chrome rings that require a smooth bore.

The Q piston domes must be slightly modified with notches for valve clearance. We had a local machine shop duplicate the VG’s valve notches on the Q pistons. The piston pin diameter for these pistons is 0.866” up from the VG33E’s 0.822”.  This happens to be the same size as the 300ZX’s VG30DE rods so these rods can be used or the stock rods can be easily and cheaply rebushed for the larger pin.  The VG30DE rods are stronger so it is advantageous to use them although the stock E rods are definitely not weak. 

VG30DE or DETT rods are easy to find as many Twin Turbo Z owners have upgraded to racing rods.  The advantages of the DE and DETT rods are stronger bolts, which are torqued to 43-48 ft/lbs vs 28-33 for the E rods and a bigger piston pin and more beef in the big end of the rod. We happened to have the rods and crank from a VG30DETT lying around so we used them.  The stronger crank and rods from the twin turbo Z are not really necessary since the stock parts are beefy as well but since we had them, we might as well use them.

After this cleanup, we bored the VG33 block to 93 mm using a torque plate to assure that the bores would stay round when a cylinder head was bolted on. We fine honed the cylinder walls to a 600-grit finish and plateau hone the surface to make it even smoother.  The Plateau honing speeds break in, reduces friction, gives the parts a longer life and reduces oil consumption.

If you are thinking of building a similar motor to ours, since there are many variations of oil pump, crank snout, balancer and drive pulley on these motors, you are probably best off installing the crank, balancer, oil pump, oil pan and water pump from your vehicle into the VG33 engine. Fortunately all of the bolt bosses for the accessory drives and motor mounts are exactly the same Between the VG30 and the VG33.  This saves time and money for the big bore conversion. 

If you are putting early VG heads on the VG33 block there are a few things you have to consider. In 1987 the coolant flow through the heads was modified to improve cooling. If you have the earlier heads, it’s easy to incorporate these changes by simply laying a 1987 and later head gasket on the head deck to locate where holes should be drilled for the additional coolant flow. 

If you put a VG33 block on VG30 heads the water passages between the head and block have a slight misalignment.  Simply lay the VG33 head gasket on the VG30 heads and scribe where the passages are misaligned.  You can then grind away the scribed areas with a die grinder or dremel tool to fix the water flow.  The misalignment is slight and you will only literally have to grind away about 1/8” of material to get the passages to match.

VG33 head gasket and VG30 head for nissan pathfinder
This is where the mismatch of the style pre 87 old head to new block is.
VG33 head gasket, VG30 head, nissan pathfinder
This is the mismatch of the water passages between the VG33 and VG30 is, simply slightly grind the hole so the block holes match up.











pre '87 head gasket for nissan pathfinder
To fit a pre 87 head on a new block, you must drill the two holes so more cooling water can flow.

Next we polished the stress risers off of the cranks parting line and the rod beams and had the parts shotpeened.  This is not entirely necessary as the stock parts are really strong, but since we were in there, shotpeening and polishing are cheap insurance items.  After this work, the crank, rods and pistons were sent out to be balanced. After balancing, we micropolished the cranks journals.

We thoroughly cleaned our block with Motul Moto Wash, a great clean due to its anti rust properties, If you have ever prepped an engine before, you know how it’s a struggle to keep the barely new machined iron surfaces of the bore from rusting and Moto Wash works like no other here. We used a Summit Racing engine cleaning brush set to clean all the passages in the block.  It’s amazing how much crap ends up in there!  After blow-drying off the engine with compressed air, we used Motul Contact Cleaner to clean the bores perfectly.  It’s amazing how much grit and slurry from machining gets caught in the bores as well.

We assembled our engine using genuine Nissan bearings to the tighter end of the stock clearances.  We also used the oil pump from a VG30ET motor for its 25% larger capacity.  Our Dan Paramore heads were bolted in place with our Nissan Motorsports cams and we were ready to rock.

We have been taking it easy while breaking in our motor but its apparent that we have plenty of power for once.  Now there is enough acceleration to push you back in the seat and the increase in low-end torque is really noticeable.  It’s possible to even break our big off road tires loose sometimes, even with our limited slip diff.  We think that this motor is probably great for everything from off-roading to towing.

The motor even had enough power to edge out a ricey GS Integra after it was obnoxiously tailgating us.  The Integra driver looked amazed when he could not pass a SUV with raised suspension and big tires. When the SUV edged away he looked even more surprised.

We have noticed a few things that we have to do; our motor now slightly detonates on cheap 87-octane gas that we used to feed it due to the higher compression.  We will probably do a multimap ECU so we can take advantage of 91-octane fuel and still run around on crappy 87 when we have to.  Our tranny now shifts sluggishly and slips from all the new found power as well.  We have to do some research on what to do about that as well. If any readers have suggestions for what to do with the tranny, please contact us with your suggestions.

We are really happy with our motor setup.  It might make our old warhorse actually pleasant to tow with. Stay tuned, in the next editions of Project Pathfinder, we tackle the steering issues, which are coming up again fixing them once and for all and make vast improvements on the brakes.


DPR Racing


Summit Racing

Nissan Motorsports

Bookmark and Share
Thursday, February 18, 2010 11:03 AM
hows it going..... i new to the site and i dont know where 2 post to get ahold of the owner of project pathfinder, actuallly i found project pathfinder looking for my own ideas...... i have a lot of questions if u dont mind on the overall process and costs..... i have a 93 pathy 3.slow 4x4 se and want to redue just about everything....... prob start with a fresh motor, more power..... like wat i read, but not sure who to actually take the short block 2........ any help starting out would be awesome.
Mike Kojima
Mike Kojimalink
Thursday, March 11, 2010 8:00 PM
I'll sell you Project Pathfinder. It is for sale.
Friday, March 12, 2010 3:58 AM
How much are you selling it for?
Mike Kojima
Mike Kojimalink
Friday, March 12, 2010 4:25 AM
PM me!
Thursday, March 25, 2010 12:48 PM
I really enjoy that you guys put so much effort into Project Pathfinder, aka cars that aren't the most sporting or exciting.... it's inspiring, especially since the vehicles I own aren't sports cars or sporty (though I like to imagine my late 90s Civic sedan is).

So consider me selfishly hoping you guys didn't sell Project Pathfinder. =) But good deal for whoever bought it.
Monday, October 25, 2010 10:53 AM
Does anybody know what year the Xterra was that they used in project pathfinder? Does the year matters to much because I want to do the same thing to my 88 pathy?
Tuesday, October 26, 2010 7:19 PM
To whom it my concern,

I would like to find out the engine spec of Project Pathfinder. I know the Pathfinder that was used was a 1993. What I don’t know is what year the donor Xterra engine was. If that is the only year that can be used, if they used the same transmission from the Pathfinder, what bell housing was used and what if any parts from my 1988 Pathfinder can be used? I wanted to do the same modifications to my Pathfinder and before I start buying parts and or engines I would like to have a better understanding of what I need. My personal email address is osoberan@yahoo.com.

Thank you,

Saturday, December 11, 2010 5:29 PM
I joined this forum initially only to congratulate you on truly awesome work you guys did on this pathfinder. So, did it finally sold? Seems like there were not to many people that wanted to copy this project and actually managed to complete it. Once I am done with my honda, I will give it a serious thought.
Monday, January 02, 2012 9:50 AM
Recently i had to open my engine to replace the head gaskets. Given that the heads were off i also sent them to be cutted just a little. I want to put a better radiator to keep to engine cool. Can you please recommed me a good radiator that also fits without any modification?
Tuesday, September 10, 2013 1:53 AM
I have a year 2000 pathfinder SE, and my car needs some serious help. I have a custom cold air intake and exhaust. I also took off one of my resonators. My car does have more power, and I am not mechanically inclined at all. From reading your forum I am under the impression that I can do what you did by getting the new pistons from a first gen Q45, having a shop machine copy the valve notches on the new pistons, and have my motor bored out 93mm? Sorry if I am annoying, but I'm just asking. Any response is greatly appreciated.
Sunday, September 15, 2013 7:49 AM
I joined because I too liked what I read about the big bore pathfinder. Here is my son and I's project. 88 Pathfinder bad VG30 already disassembled, spun rod bearing #3 due to blown head gasket very slow leak! Very clean combustion chamber on # 3 finally knocked the rod bearing out. So anyway the 3.0 crank is not going to be usable. My first question is since I don't happen the have a VG30DE or DETT crank and rods laying about! can I use the VG33 crank with the VG30 oil pump if I machine down the drive area on the 3.3 to the 3.0 size? Now I know that you now have the seal issue to deal with, instead of machining the rest of the snout down to the 3.0 specs could I instead open up the inside diameter to the VG30 oil pump to the VG33 seal outside diameter size? Now we are down to the harmonic balancer. I have seen on another website where a person made a hub to fit the VG30 crank and was wondering if that coulg be duplicated for the VG33 crank and still be able to use all of the VG30 accessories? I know thats a lot of questioning right off the bat, so thank you in advance for your research.
Thursday, November 07, 2013 7:01 PM
I came across this 2000 Pathfinder SE 4x4 totally accident and rust free. I was just going to to a mild restore when i heard that the bore was out of tolerance! So when I researched on how far i could safely bore this 3.3 I was informed of building the vg34! I have decided to build this motor and try to sell this truck restored all new or rebuilt parts with this 250 hp 3.4 beast for 7500 Everything working. Message me if interested all reciepts and pictures will be kept and docimented
Monday, February 17, 2014 8:22 PM
looks like you guys found the last set of q45 pistons on the planet... lol love the article shame i cant locate the parts to do this myself im dying to get more power out of my xterra great work!
Wednesday, August 05, 2015 3:19 PM
@Mike Kojima where is your shop located? I just took over my father's 1989 pathfinder he's had since buying it brand new in 1989. I want to fix it up exactly how you did yours. If you can let me know how much I'll need for such a project?
Thursday, November 26, 2015 3:01 PM
Would you be able to post a complete parts list?
Friday, November 27, 2015 12:50 AM
What is the HP and torque ratings after the build?
Tuesday, December 01, 2015 6:13 AM
It seems pointless to ask, but you specifically mention pre 87 heads... If post 87 heads are used are there any mods that need to be done?
Post Comment Login or register to post a comment.

MotoIQ Proudly Presents Our Partners:

© 2018 MotoIQ.com