Installing the VG 30 in a 510
By Michael Spreadbury
Thinking about an engine swap? Tired of seeing L16-18-20B’s every time that you open a 510 hood? Want to have a reliable, powerful 510? Consider the VG30, Nissan’s 3.0 liter V6 engine.
There have been many requests for an article about installing the Nissan VG30 V6 engine into a 510. I have done this conversion, and have been very pleased with the results (see photos of Michael’s VG30 installation). In this multi-part article, I will review what I did to successfully install the VG30 into my 510.
But first, some background information about the engine. The VG30 was introduced in 1984 in the new 300ZX. Reviewers raved about the V6’s power, torque, and smoothness. In normally aspirated form, (which I installed), in stock trim makes 165hp and 175ft-lbs of torque @ 4000rpm. In turbo form, it makes 200hp and 227ft-lbs of torque at 3600rpm. Another advantage of this engine is that it is very lightweight. When it was introduced, Nissan engineers boasted that it was the lightest three liter V6 in the world.
Another advantage to the VG30 is that it is a very common engine. Nissan has used the VG30 in the 200SX, 300ZX, Maxima, truck, Pathfinder, and the Quest minivan. The version of VG30 that I choose was the fuel injected 300ZX engine. I choose this engine because it creates the most horsepower in stock form, and it is quite common. The 200SX V6 is also a popular choice, but they are harder to find since they were only made for two years, 1987-1988. The front wheel drive versions could also be made to work, but would require a different intake plenum, exhaust manifold, and oil pan.
I choose the VG30 because I wanted a massive power gain without relying on a turbo or higher compression. I have had several `built’ L20B’s, with carbs, flat top pistons, SSS heads, etc., but could never get the horsepower that I yearned for without building a very expensive engine. How much does it cost to build a 175hp L series engine these days?
With early 300ZX’s becoming quite common in wrecking yards, I decided to do some investigating to check prices for the whole setup. I found that the VG30 is not in very high demand as a used engine. This is true for several reasons. Most people think that the only place a 300ZX V6 can go is in another 300ZX. Unlike a L series engine from a 510, 610, 710 etc. the VG30 engine is not `swappable’. Most 300ZX owners take really good care of their vehicles, maintain the engine, and do not blow them up very often.
Another advantage of using this engine is the fuel injection system. I never liked playing with carbs, setting chokes etc. With fuel injection, you get in the car in the morning, start the engine, and you get a perfect idle at 1200rpm. Once it warms up, the idle drops to 900rpm. No messing with a choke cable, burning too rich or too lean, just a perfect running car, from idle to redline.
A myth about the Nissan V6 is that “its too heavy!” Lets compare some 510 vehicle weights. A stock L16, 4 speed, 2 door 510 weighs 2078lbs. A friends L20B, Z 5 speed, 2 door 510 weighs 2270 lbs. My 1970 2 door with the stock VG30 and 5 speed weighs 2210 lbs.
Another reason that I choose the VG30 is that I wanted to keep Nissan power under the hood. I have heard all kinds of wonderful claims about Mazda rotaries, but I wanted to keep my Datsun a Nissan. What you get with the VG30 is is a reliable (at least 200k) engine that will produce good horsepower, (with an open exhaust, and a K&N intake, I would guess around 180hp), has great torque, require a tuneup every 30,000 miles, and gets great gas mileage. Last year I got 27mpg driving home from Mt. Shasta, better than all the other 510’s in our convoy.
Installing the VG30 is NOT like swapping a L18, L20B etc, into your 510. It requires some fabrication skills, money and patience. This swap is not for everybody, but it is another alternative to the L series engine.
In the next article, I will describe local costs of the VG30 engine/transmission and what to pull when getting your V6 from the car.
Last time I talked about the advantages and disadvantages of using the VG30 V-6 engine in your 510. I will now discuss buying the engine and transmission and what other parts you will need from your donor car. Again, I used the 1984-89 VG30 from the 300ZX, and this is what I will cover, however these guidelines will work for any of the VG30 equipped vehicles.
First, start calling around your local wrecking yards, or locate someone parting out a 300ZX. Get an idea of how much the engine, transmission, ECU, and other electrical components will be. The amounts will vary from yard to yard, but will give you an idea of what the local market is going for.
Once you have established a general price, look at some of the donor cars. Ideally you want a car that still has the engine and transmission still in it. Check the externals on the outside of the engine, check to see if it is complete, with no major oil leaks. The VG30 is a very tight engine, and oil leaks are uncommon, so be wary of a wet engine. Also check to see if the injectors are leaking gasoline in the intake manifold. One of the few weaknesses of this engine is deteriorating injector seals at the manifold when they get older. Check to see how many miles the engine has. Again, these engines are very reliable and can go 200,000 miles without a rebuild, but obviously try to find one with low mileage.
When you have found a suitable power train, and have negotiated a fair price, it is almost time to pull the engine. But before attacking the car with wrenches and wire cutters, do a little more research. Find out what year the donor car is and go visit the local Nissan dealership. Go to the service department (try to visit them at a slow time) and ask if you can see a shop manual for the year and model of your donor car.
In the back of the manual there is a section that covers the wiring harnesses and the major electrical component locations, (Section EL). Politely ask if you can photocopy the pages that show the engine compartment wiring harness. The EFI system has a its own wiring harness that connects to the ECU. You will also want to copy the engine harness page as well, as you will need some of those components. Study the component locations, and take the photocopies with you when you pull the engine. Workshop manuals by HAYNES also contain this information and can usually be found at most used bookstores. The part number for a the HAYNES manual is 1173.
Whenever possible, I try to pull the engine and transmission with the wrecking yard employees. Most yards around here do not mind and will sometimes give you a break in the price. I also do this so I can see how everything fits together, and to make sure that nothing gets cut or removed incorrectly.
To remove the engine and transmission follow the normal steps. Bring along a cardboard box, masking tape, and a pen to mark components as you pull them out. Keep all the hardware, it is useful for reattaching components in your car and makes for a cleaner installation.
Unhook the engine compartment wiring harness from the alternator, oil pressure sender, starter, etc. There is NO need to cut any wires! On the EFI harness, DO NOT disconnect the connectors from the engine. I found that it is much easier to disconnect the harness from the ECU, which is located in the kick panel on the passenger side of the car.
Now, this is the ONLY time that you should cut any wires. There are 12 wires that connect to the ECU from the under the dash and the rear harness. Follow them about a foot down and cut them, this way you will have enough wire to rewire them later. Feed the EFI wiring loom through the firewall and lay in on top of the engine.
These are the things that you can leave in the donor car. The cruise control unit, air conditioning components, power steering pump and lines, radiator (its too tall for the 510), drive line (we will reuse the 510 unit), and the exhaust pipe.
Now that you have pulled the engine and transmission, be sure that you take these components; ECU, motor mounts, wiring harnesses, air flow meter, ignition coil, intake plumbing (before the plenum), all hardware, all relays and fusible links, (we won’t use most of them but grab them anyway.) Also grab the fuel pump relay, and wiring that is located behind the quarter panel on the passenger side of the car.
Next time we will clean the engine up and install it in the car!
Now that we have our engine and transmission home, it is time to clean and inspect it before diving into the project. Get a pad of paper to start making lists of what needs to be done. This project seems overwhelming at first, but if you make a list and do ONE project at a time, the task becomes much easier.
Remove the engine from the transmission and mount the engine on a engine stand. This is an easier way to get at everything. If you do not have an engine stand, use an old tire to set the engine into to keep it upright. Clean the engine with your favorite degreaser. Be careful to keep the degreaser and water from the electrical components, as they could get damaged. Working with a clean engine and transmission is much nicer than a grimy unit.
It is now time to strip some of the parts that we will either not use, or that are going to be changed. Remove the motor mounts from the engine. Remove the bracket on the right side of the engine that holds the alternator (and used to hold the A/C, PS, pumps). Also remove the exhaust manifolds and crossover pipe from the back of the engine. We are going to use different exhaust manifolds so they will clear the steering box. On the transmission, remove the crossmember, as you will need to modify the existing 510 mount.
Remove all components in your 510 engine compartment. Leave the steering box and linkage, and the front crossmember. I also suggest removing the front fenders and hood, so you will not damage them during the install. It is much easier to work in a stripped engine compartment, than working around all the other components. This is also a great time to remove the battery tray and move the battery to the trunk for better weight distribution. You should also remove the existing 510 engine compartment harness. Clean the engine compartment and all components.
Before installing the engine in the car, remove the front crossmember and cut off the existing motor mounts. Cut the crossmember flush so you have a wide flat surface to fabricate to. Reinstall the front crossmember. Using an engine hoist place the engine and transmission into the 510 engine compartment. Rest the oil pan on a 3/4″ piece of wood on top of the crossmember to provide enough clearance. Slide the engine as far back in the engine bay as possible.
This is where some of you will have to improvise. I converted my car to rack and pinion steering when I did my conversion so I did not have to mess with the steering box and linkage. You many want to remove the cross rod assembly to clear the existing oil pan. Once the engine is mounted you can mark where the steering rod will need to cross below the oil pan and be able to build a new oil pan as necessary. 300ZX oil pans are rear sump (like a stock 510) but do not have the clearance to clear the steering rod. 200SX oil pans are a rear sump and will clear the steering linkage, but a new front crossmember and sway bar will need to be constructed to clear the oil pan.
This is where people who are using the 200SX VG30 are going to have an advantage, as their intake plenum does not hang as far back as the 300ZX version does so they can get their engine back an additional 2″ without firewall modifications. What ever version you use, it will still sit farther back than any stock L series engine will, so handling will not be affected.
Once you have the engine slid as far back as possible, note your clearances. I did a little firewall “massaging” and was able to gain an additional 1/4″ without doing any cutting. You will want the intake to just clear the firewall and wiper motor. Measure both sides of the engine to ensure that it is centered in the car. The other factor that you must consider when installing the engine in you car is the bottom of the bell housing on the transmission. The overall height of the engine will be decided by the bottom of the bell housing. Sight along the bottom of the engine crossmember and make sure that the bellhousing is not lower than the front crossmember. You want the engine as low as possible, but not lower than the front crossmember. To decide the correct angle of the intake plenum, use an angle indicator on top of the intake plenum and measure the angle. On a 300ZX engine the plenum should be at about 6 degrees. Raise or lower the back of the transmission to get the correct angle. You will need to modify the hole in the transmission tunnel to clear the transmission shifter. Be sure that your brake lines are clear before cutting the transmission tunnel. Use your hand to make sure that you are not touching any of the body or transmission tunnel with the engine or transmission. Finally, carefully test fit the hood on the car to make sure that you do not have the engine mounted too high. I believe that I have about 1 1/4″ of clearance.
Ignore the fact that the oil pan sticks down too low, you will need to modify the existing one to raise it above the front crossmember for ground clearance. Mark the sides where the bottom should be, I believe that I took one inch out of mine. The pan should be modified to make up for the missing capacity.
Once you have the engine exactly where you want it, and you have triple checked your measurements and clearances, it is time to make motor mounts. First, find an appropriate piece of metal that is about the same thickness as the original mount. The first part to building the motor mounts is to do make the plate that mounts to the block. Make that plate the same size as the original leaving enough room to mount another another plate for the sides. On the left side of the engine the clearance between the oil filter and the motor mount is tight, so be sure to leave enough room to get the oil filter on and off.
Next, build the plate that the FACTORY VG30 rubber insulator will mount to the crossmember. The rubber insulators that Nissan used on the VG30 engines are liquid filled to absorb vibration and to shear in case of an accident. If your insulators are broken or are seeping a fluid replace them! The VG30 is a VERY smooth engine and does not move much, so clearances with the body can be very tight. But I HIGHLY recommend using the factory insulators. Yes they are expensive, but they are designed for this engine, and you will have a VERY sooth engine with no vibrations if you use them. The rubber insulator has threaded studs that come out each side, and a small dimple to ensure that they are installed the correct way. I recommend building a mount that the threaded stud can slide into, and can be tightend from underneath the 510 crossmember. You will need to cut a hole in the crossmember to get to the bottom stud. After the rubber insulator is mounted to the crossmember, build the plate that attaches to the top of the insulator. Again the insulator has a threaded stud that will fit through the hole in your plate with a dimple to ensure that it is seated. Be sure that your plate has enough clearance to clear the nut for when you want to attach it.
Now that you have the plate for the engine and top of the motor mount made and attached, use a piece of cardboard to figure out the piece that will need to fill the gap. Take your time and make the piece fit exactly, also check that it will work the same way on each side. This is a backup to make sure that you have the engine square in the vehicle. Trace out your pattern on your metal and cut and grind until it fits. Test fit the piece on both sides to check for its fit and once you are satisfied that it will work, tack it with your welder. Be sure to do lots of small tacks to make sure that it will not come apart when you take it out for its final welding. Remove the motor mounts from each side and make gussets for both sides of the mounts for additional strength. Weld all gaps and reinstall on the engine.
To build the transmission mount, use the factory 300ZX insulator rubber, and cut off just the pieces that are necessary to mount the rubber to the transmission itself. Then cut off the ears of the 510 transmission mount and attach them back in the car. Again using cardboard for patterns, fill the gaps with new steel. I used a section of large pipe (approx 4″ in dia) to get the curved angle to clear the exhaust that would be alongside the transmission. Be sure that your new mount does not interfere with the speedometer mount.
Now that we have the engine and transmission mounted in the car, it is time to start the seemingly endless list of details. I will start at the front and work towards the rear for what I did on my car.
Radiator: The 300ZX has its water outlets on the same side unlike most cars. I considered a VW rabbit radiator since they are designed this way, but thought that its capacity would be too small. I used a Chevy S10 3 row, crossflow, radiator with custom tanks. It keeps the engine very cool and I have not had any problems with this setup. It fits the stock 510 opening perfectly and looks OEM. I installed a temp sensor in the tank of the radiator to turn on a slim electric fan that is mounted behind the front grill, to cool it when it gets hot. The setup works perfectly.
Stock fan and clutch: Remove the stock fan and clutch assembly, they are no longer needed because of the electric fan, and the water pump pulley reattaches with the old hardware. This makes for a much nicer looking engine compartment.
Timing Belt: Nissan uses a rubber timing belt that MUST be changed every 60,000 miles. If this timing belt brakes, you will bend at least 2 valves and maybe all 12. Since you do not know when your belt was last changed, do it now. It is cheap insurance. I also recommend changing the tensioner at the same time. While you have it apart, change the thermostat as well.
Exhaust manifolds: I used the 87-88 200X exhaust manifolds. These allow you to move the engine farther back in the engine compartment. I also highly recommend changing ALL exhaust studs out of the heads, as these seem to be a weak point of the VG30. If you change to the 200SX manifolds and are using the 300ZX plenum, also get the stainless breather tube from the 200SX that connects from the exhaust manifolds to the EGR valve.
Intake Tubing: I used a K&N air filter which eliminates the factory air box and gains some horsepower. The filter that I used connects directly to the air flow meter, but there are many kits out there that use an adapter to fit over the air flow meter. I shortened the intake tubing, which is made of grey plastic,) a few inches to fit in the 510 engine compartment and it keeps for a clean factory look.
Alternator: I used the turbo 300ZX alternator bracket which moves the alternator to the passenger side of the car (like a stock 510.) This eliminates the large bracket that the stock car comes with, and makes the engine compartment look much cleaner.
Radiator overflow bottle: I used a Mazda 626 radiator overflow bottle which is mounted to the passenger side of the car. This bottle combines the windshield fluid bottle as well and fits the contours of the 510 inner fender perfectly.
Battery tray: I removed the battery tray using a spot weld drill, to provide more room and to make the engine compartment look cleaner. I also removed the bracket that held the 510 windshield washer bottle, since it was no longer being used.
Throttle Cable: The 300ZX uses a throttle cable, so I found one that was the perfect length from a 1980 200SX.
Driveline: Have your stock 510 driveline shortened to fit the 300ZX transmission. The splines on the end are the same.
Exhaust: There are lots of ways to go here, I used 2 inch pipe from each exhaust manifold which then join together behind the transmission using a Flowmaster collector. The rest of the exhaust is 2.5″ mandrel bent tubing which goes through the modified rear crossmember and then to a Flowmaster muffler. The Flowmaster is quite loud however, I would recommend another brand, perhaps a Borla next time. It sure has a banshee wail to it at WOT though! I also installed the O2 sensor in the collector, which is farther back than stock, but seems to work fine.
Oil Pan: As noted before you will need to modify as necessary. Be sure that it does not stick down lower than the front crossmember, and to make up any displacement that you remove.
Remember, this is a big project, but if you take your time, and make lots of lists, it becomes one small project at a time. I am not claiming that this is the only way to do this install, but this is what worked for me. I am also at the advantage that we in Oregon do not need to have smog checks (yet). I think that my car would pass most smog inspections as it is mostly stock and is running all emission devices except the cat.
Again, any questions or comments can be sent to me directly at [email protected]