3RZ vs 5VZ F/I Application

Looking for some advice on my next build...I'm currently looking to move from a 2nd gen back to a 1st gen. The purpose of the truck is 90% for hunting trips. Some local, lots of traveling from state to state. It needs to be able to reliably go long distances and handle bad terrain once it gets there. The plan is for mid travel, extended travel rear, and skinny 35s. Whichever I go with, the truck will be getting forced induction. I'll be doing all the work unless machine work is required if I buy one that's ready for a rebuild.
The #1 priority is long term reliability. Sure, N/A is ideal for that but having some extra power in some scenarios is worth the extra investment.
Current options:
5VZ with the new Magnusson 1320
3RZ with an LCE high boost supercharger
3RZ with a turbo, if that's better.

I've had a couple of 5VZs, including one with the TRD supercharger. They were brilliantly reliable and I really like the engines overall. The 3RZ is a consideration for simplicity of maintenance and build. Everything being on one head sure is nice when it comes time for maintenance and repair.
My only experience with a 3RZ was a stock N/A truck my buddy had in high school. He was incredibly hard on that motor but it never skipped a beat.
I'm open to advice from those who have experience putting F/I systems on both motors. Especially turbo vs a supercharger on the 3RZ, and how well the stock ECU keeps up. I'm looking for 220+HP, if that seems reasonable.

 

I'm in to see the comments here, I can't weigh in much to what you're after specifically since I went with turbo for my 5VZ... but maybe @Reh5108 or @Digiratus are willing to weigh in for ya.

 

I guess I'd be open to a turbo on the V6 as well. My perception is that the supercharger is more reliable without oil and coolant lines running to a turbo...but I don't have any experience one way or the other.
I'm sure there will be plenty of interesting comments...
But if it helps avoid those, a lot of what I'm hoping to learn is what to expect from an F/I 3RZ. I liked my supercharged 5VZ, although it needed a little more fuel. I'll be doing an aftermarket pump and injectors if I go that route again.

 

It needed more fuel and more timing and an ECU that would not counteract that. As long as you are running the stock ECU any FI setup will be lacking in fuel and timing. And your options for injectors are severely restricted by the ECU as well.

 

From that I understand that an aftermarket ECU is mandatory then, that seems to be the conclusion most people come to. Piggyback or stand alone? It sounds like Haltech is the go to for these trucks from the research I've done so far.

 

The supercharger is great for low-end torque for truck-like driving. It's also stupid simple and reliable as long as you keep a spare belt. A standalone like a haltech is mandatory though. It will never run right without it. The only other idea would be an ls swap for reliability and power.

 

I'd consider the parts availability as well. Junkyard 5vz's seem more plentiful and as a result more affordable than 3rz's. So if you manage to blow the motor, you can source a replacement for less going the 5vz route.

Doubtful you blow either to be honest, but just a thought. Junkyard 3rz's go for like $2.5-3k, while $1500 will get you a decent 5vz.

 

My main objection buying a 3RZ to turbo charge is if you've already decided an unmodified 5VZ isn't powerful enough, why would you consider buying an engine that will put you at an even greater disadvantage? All the people who think about turbo charging a 3RZ (as far as 4runners go) are people who bought a 4runner with one and thought "Fuck this thing is slow, too late now, maybe I can mitigate it".

True, the reliability is greater (assuming the valves adjustments are done) on the 3RZ. But it's simply because it has less parts. I can't imagine the turbo would make the valve adjustments much easier. It's not such a big difference in reliability that I'd let it affect my decision. The price of 3rz is more expensive too.

At 74 mph the I4 is at 3k RPM. It's not a quiet highway engine, something a turbo can't fix. The W59 transmission on the 3rz isn't as robust as the R150 found on the 5VZ, it's reliable but your gonna find its limit long before the R150. It'll handle 220 hp just fine though.

 

I wonder why that is. Are the 3RZs failing more? The oiling system isn’t as robust as the 5VZ, so I’m not sure I agree they’re more reliable like @Pyral said. They also seem to have more head gasket/overheating issues, perhaps cause of the EGR and longer head. Nobody ever adjusts the valves either except for Toyota nerds cause it’s a PITA, and most people don’t even know what valves are. You rarely hear about the 3.4 valves going out of adjustment.

 

I think it's just an uncommon engine. Basically no 4runners have the the 2.7, and the Tacoma and T100 had 2 other engines to choose from. The 2TR that succeeded it is bomb proof and fixed all the valve and oiling deficiencies (if there were any), yet it's still a pricey engine to buy.

I disagree about the oiling system being worse than the 5vz. Toyota still uses the 3RZ block on the 2TR-FE, so if there was something worth upgrading it would be the head. And they did, they added oil squirters over the cams, but that's not something the 5vz had either. The 3rz looks very similar under the cover to a legendary 1FZ (minus 2 cylinders), and it has more oil capacity than a 5vz despite being smaller.

The engine is tolerant of heat, I've seen people run them without coolant and overheat it yet get away with it. I've driven mine loaded up hill on the highway in 102 heat, and I wouldn't know looking at the temp gauge. Stationary they can get warmer than usual on very hot days, if that's a concern install an auxiliary electric fan.

I'm not a fan of the EGR. The Japanese engines didn't have it and were fine without it. But, I've never seen someone have problems with it. The top thread about EGR delete wasn't the result of it failing, it was just something they wanted to do. If it fails, delete it, if you have smog . EGRs can be trouble, like on the 2nd gen Prius, but it's super rare on the 3RZ from what I've seen.

 

Yea not sure. They may cost more just because more 5vz's were produced. I too am skeptical of the 3rz being more reliable than the 5vz claim.

 

This is the sort of information I'm looking for. The availability of parts/engines is worth considering. It's part of the reason I want to go back to a 1st gen. The 5VZ is definitely more available, but there are some decent priced 3RZ around.
I'd also have to 4wd swap a 3RZ truck because I want a double cab...that's another consideration. Especially since people with the 4 cylinder 2wd trucks seem to think they're worth as much as the 6 cylinder 4wd

 

All the more reason to just go with the 5vz. I'm biased, but there's no denying that the 5vz is an absolute tank.

 

The following is what I have to say about a 3rz that has likely had a very small headgasket leak for the last 5 years prior to it having a turbo on it. Still working on the rebuild so I'm anxious to see what a healthy engine feels like.

I don't have any experience with a blower but after running my turbo for a few years without an intercooler and then adding one, it makes a noticeable difference. You can't intercool the supercharger unless you do a lot of custom fab work and sandwich one in between the blower and head. I personally would not waste my time with a SC.

The best tank of fuel I ever got with the turbo was 22mpg. Before my headgasket/head totally shit the bed on me I was avg 15mpg. My rig weight around 5500lbs, 33" tires and 4.88 gears.

The torque only 5psi puts out is pretty impressive. 3350rpm seems to be around it's peak and it'll pull hills doing 80 in 5th on the highway all day long. I was just barely pulling hills on a buddys 5vz with a very similar build at 4psi and not intercooled.

The place where it struggles most is the very bottom end and I think this progressively got worse for me with my diminishing head. Again, excited to see what things feel like with a fresh head. Trying to crawl through technical trails with steep hills doesn't work. I'd often just climb things with the starter because it offered considerably more control. The turbo I have does start to build boost when under very high load and low rpm, I'll see positive pressure when it stalls out and it does help to keep it chugging through sometimes. I really don't see a blower making much difference here either but again no experience with one.

If you are going to 35s there is no question about getting 5.29 gears, if you want control in technical stuff. Ideally a crawlbox if it's in your budget. Some of the areas I hunt have some technical stuff but generally not too bad.

I would not be concerned with either engines reliability. If you don't check valve lash a minimum after 100k you are asking for issues. Every 3rz, 5vz or 2uz I've checked needed some adjusting. Its not a very difficult job to do just a bit overwhelming if you have not done it. 4 cylinders has less to go wrong and a timing chain that is lifetime.

If you are willing to put MLS gasket, headstuds, bigger injectors, and stand alone, you should be able to make 300hp pretty easy.

I prefer my turbo 3rz 5 spd to my T100 with 5vz and auto. I feel the 3rz pulled my 3500lb boat better than the 5vz. The T definitely stops better however.

 

I hope you don’t mind me quoting you here from another thread in response to the discussion above.

In addition the balance shaft oiling issue, the 5VZ also has a dedicated oil cooler, which the 3RZ lacks iirc. As far as I can see, they both have an oil capacity of approximately 6 quarts.

 

That's the only difference between the 4runner and the Tacoma 3rz. The 4runner 3rz has an oil cooler, the Tacoma doesn't.