Anybody ever swap 3.4 to 2.7? (serious question)

[HawaiianKong]

My daily-driver Runner has 225k and has started to sputter and hesitate under load. It could use some new plugs, coils, and probably fuel injectors and I'm sure it'll be fine.

But that got me wondering - when something catastrophic goes with the engine, I've considered replacing it with the 2.7, keeping in mind that past 4-cylinder cars I've owned have been an absolute breeze to maintain and repair compared to the 3.4.

I know it's going backwards. I know it'll be slower (but considering how tired my engine is now, maybe not so much). It doesn't seem like it'd be a difficult swap (I've done a KA to SR20 swap before). I'd still keep my 5-speed. I'd also be open to turbocharging down the road when my Runner achieves second-car status.

But has anybody actually done this? Or...what are cost/labor of maintenance and repairs like versus the V6? Is it totally laughably slower?

 

[dogtail]

I dont think it would make sense at all, your mileage is still relatively low for that motor. Just maintain it.

 

[spartacus]

why do you think you need fuel injectors, plugs wires tuneup I understand you'll have to do maintenance on a 2.7 as well. if you neglect any motor it will deteriorate no matter how reliable the engine.

 

[tvpierce]

Have you cleaned your MAF Sensor?

 

[gamefreakgc]

The 2.7L is comparable in power to the 3.0L 3VZ-E. Ever driven a 2nd Gen 4Runner with the 3.slow? Yeah, it sucks.

If it's just a commuter car and you don't live near any hills then I suppose you could. It's a rather gutless engine though so rule out any significant towing capacity either.

If you're looking for a project build with a turbo then sure, it'd be fun to drive then. However a lot of people talk about putting a turbo on a 4Runner but there's not a whole lot of aftermarket turbo support so it ends up being more work than anticipated so very few have actually done it. Tacomas yes, 4Runners no. The 2RZs are similar to the 3RZ's but are not identical.

The only real difference between maintenance with the 3.4 and the 2.7 is a timing chain vs timing belt, which only has to be done every 100,000 miles or so anyway.

 

[HawaiianKong]

The 2.7L is comparable in power to the 3.0L 3VZ-E. Ever driven a 2nd Gen 4Runner with the 3.slow? Yeah, it sucks.

If it's just a commuter car and you don't live near any hills then I suppose you could. It's a rather gutless engine though so rule out any significant towing capacity either.

If you're looking for a project build with a turbo then sure, it'd be fun to drive then. However a lot of people talk about putting a turbo on a 4Runner but there's not a whole lot of aftermarket turbo support so it ends up being more work than anticipated so very few have actually done it. Tacomas yes, 4Runners no. The 2RZs are similar to the 3RZ's but are not identical.

The only real difference between maintenance with the 3.4 and the 2.7 is a timing chain vs timing belt, which only has to be done every 100,000 miles or so anyway.

The timing chain is definitely a bonus but if that's all it offers, then yeah I'll take your advice and stay away.

Have you cleaned your MAF Sensor?

That's actually a good call - hadn't even thought about that. I installed a new OEM fuel filter a few months ago and throttle under load improved...but that's definitely an easy maintenance item. Thanks!

 

[phattyduck]

I'm not sure why you think the 3.4 is difficult to maintain? The only annoyance I have found so far is the oil filter likes to spill lots of oil when removed... Maybe the starter is a bit annoying (if 4WD) but other than that, it is all straightforward.

Also, 'easy to maintain' and 'aftermarket turbo kit' don't go together at all. Keep the 3.4, put some minor work into it (clean MAF, change spark plugs with CORRECT plugs, etc.) and you'll be happy as a clam. If you want more power, it is a supercharger away.

-Charlie

 

[CircuitCircus]

I'd still keep my 5-speed.

The 2.7 uses a W59, you have a R150F which won't bolt up. If you swapped the engine you would also need to swap the transmission. The 2.7s came with lower axle ratios so you'd probably have to swap those out as well

 

[ChildrenOfBodom]

How many of the above commenters have owned both?

Drive a 4th or 5th gen 4.0, or any other V6 put out in the last 15 years, and then tell me a 5VZ isn't slow, too. We're not going very fast with 3rd gens. Cindy in her CR-V or Linda in her Accord will wipe the ground with a 3rd gen. I'm sure you're well aware of this for even considering the swap.

I currently own both. 3.4 is great, but I don't favor it. It's strong, but I've rebuilt so many of these at the shop I worked at, I know for a fact that they crack/warp heads and have weaker rods than the 3RZ. I don't feel very comfortable with high RPM or forced induction with the 5VZ.

My 2.7 4R is by no means stock, it has 4.56's and 285/70/17's, 250lbs in armor, 5 speed manual, 4WD, and it's supercharged. Original gear ratio was 3.91, up to 4.56 made a world of difference. Locked at 65, it'll give you 25mpg highway. I drive it hard, redlining and boosting daily. It is surprisingly well matched to the other 4Runner, faster by only a hair.

On stock gears, tires, motor, etc, it's not glacier slow as the biased 5VZ owners would have you think.

Some of the shit I've put the 3RZ through:

- My teenage years (27 and I've still got it!), 142k-241k. I used only Mobil 1 5W-30, 5-7k intervals.

- Supercharged at 190k until current (241k), full 2.5 exhaust, headers included.

- Towed a 2500lb 1987 4Runner 30 miles (Fullerton to Newport, then Mission Viejo)

- Towing a 2400lb 1989 Ford probe GT 120 miles (Palmdale to OC)

- Redlining for several miles up 241S at 5PSI of boost, while towing a 2500lb 88 Toyota 4x4 full of stuff, on a tow dolly. (Lake Arrowhead to OC)

- Towing a 3500lb wrecked 3rd gen 80 miles (LA to OC)

- Towing a 3500lb Supra turbo 130 miles (Palm springs to OC)

- Towing a 2800lb Supra 60 miles (Glendora to OC)


Let's not forget this gen 4R has a lower towing capacity than the newer gens. It's a whole different ball game towing something significant. Who the hell buys a 3rd gen 4Runner to tow something significant?

My 3RZ is running original EVERYTHING except some seals and the valves have been adjusted. Radiator has been replaced also. I've replaced just about everything on this truck at least once - everything instead of the motor, LOL...

 

[ChildrenOfBodom]

The 2.7 uses a W59, you have a R150F which won't bolt up. If you swapped the engine you would also need to swap the transmission. The 2.7s came with lower axle ratios so you'd probably have to swap those out as well

For what it's worth, I have an R150F bolted to my 3RZ. It takes an R155 bell and a little shortening of the input shaft to do it.

 

[phattyduck]

How many of the above commenters have owned both?

Very few have... but - the real question is this - having owned both, would you ever swap a 5VZ truck to a 3RZ? It isn't just a bolt-in and go operation... (wiring, crossmembers, mounts, etc.)

BTW, I wouldn't say that the 3RZ is a bad motor or anything. It also isn't that far down on hp/tq from the 5VZ. I just say that there is no reason to go through the hassle of swapping TO it if you already have a 5VZ in the engine bay.

-Charlie

 

[96RedRunner]

This swap would be alot of work for just a 3RZ, but I would do it if I was buidling a 3RZ. May/June 2017 4WDToyotaOwner had article on All-Pro's 83 Truggy build Dyno'd 500 HP interesting article. Dug into it, 3RZ is a good platform to build on. A streetable/reliable 300 HP is do-able budget wise, 5 speed trans, along with a couple box's, twin sticks, I'm forgetting something I know.
But yea I'd do it. :naughty:

 

[Red October]

I daily drive a 3RZ 5speed 4runner, 285s, 4.56 gears, and armor, the works. I love it. But I'm very used to under-powered trucks. My brother has a 5VZ in his 4runner, and I really feel that my 4 banger can hold its own against the 6. I'm also in the process of building a mild naturally aspirated 3RZ to put in my truck.

That being said, I think that swapping "down" to a 4 cylinder engine would be more involved than it might look on the surface. IMHO the 4 cylinder is a more build-able platform. Check out Paradise Racing, and LCEngineering, they have built anything you can think of from mild to ridiculous on the 3RZ platform.

The 3RZ has its share of know issues to keep in mind. Routine valve maintenance is a must, and its kind of a pain. If you don't keep the valves adjusted properly you can burn exhaust valves pretty easily. Earlier motors with cast exhaust manifolds were prone to cracking the manifold, and that could also lead to exhaust valve problems. 3RZs are equipped with dual balance shafts that can possibly ruin a block if a bearing fails. I cant really think of anything else super noteworthy. And these failures are pretty rare. I think that either engine will run reliably for a very long time if properly maintained.

If you want to do something crazy and build a gnarly boost monster, the 3RZ is gonna have the advantage. If you are just wanting a reliable, dependable, and good everyday performer, the factory installed 6 cylinder you already have is probably the best choice.

 

[ChildrenOfBodom]

Very few have... but - the real question is this - having owned both, would you ever swap a 5VZ truck to a 3RZ? It isn't just a bolt-in and go operation... (wiring, crossmembers, mounts, etc.)

BTW, I wouldn't say that the 3RZ is a bad motor or anything. It also isn't that far down on hp/tq from the 5VZ. I just say that there is no reason to go through the hassle of swapping TO it if you already have a 5VZ in the engine bay.

-Charlie

Agreed, I wouldn't swap either motor with one another. There's enough work involved in that swap to consider other motors.

A little pricey, but how about a 2JZGTE 450hp twin turbo 4Runner :zoom:

 

[phattyduck]

A little pricey, but how about a 2JZGTE 450hp twin turbo 4Runner :zoom:

I keep going back and forth between that and a 2UZ... Both have their benefits. :reddance:

-Charlie

 

[Scramble]

The 2.7L is comparable in power to the 3.0L 3VZ-E. Ever driven a 2nd Gen 4Runner with the 3.slow? Yeah, it sucks.

If it's just a commuter car and you don't live near any hills then I suppose you could. It's a rather gutless engine though so rule out any significant towing capacity either.

If you're looking for a project build with a turbo then sure, it'd be fun to drive then. However a lot of people talk about putting a turbo on a 4Runner but there's not a whole lot of aftermarket turbo support so it ends up being more work than anticipated so very few have actually done it. Tacomas yes, 4Runners no. The 2RZs are similar to the 3RZ's but are not identical.

The only real difference between maintenance with the 3.4 and the 2.7 is a timing chain vs timing belt, which only has to be done every 100,000 miles or so anyway.

Gutless? Have you ever drivin' one with a manual. I'll race any 5VZ on this board.

 

[sleepydad]

Gutless? Have you ever drivin' one with a manual. I'll race any 5VZ on this board.

challenge accepted.

 

[Red October]

Agreed, I wouldn't swap either motor with one another. There's enough work involved in that swap to consider other motors.

A little pricey, but how about a 2JZGTE 450hp twin turbo 4Runner :zoom:

I agree with this. If you are gonna go to the trouble and expense of swapping a motor do something a little out of control!

 

[snow junky]

My 3rz on 37s has plenty of power but I wouldn’t bother swapping a 3.4 to a 2.7 because the 3.4 needed maintenance.........


Sent from my iPhone using Tapatalk

 

[T4R2014]

Gutless? Have you ever drivin' one with a manual. I'll race any 5VZ on this board.

A 5VZ with 3.73 gears and 225/75/15s? Bring it on. I timed like 8.5 to 60 and it pulls to 100 easily.

I think OP just likes wasting time. There’s three different UZ engines you can choose from and the 2JZ. If you’re gonna swap and cut and wire and yada yada yada then you’d might as well get some power out of it. A 5VZ is like 700 bucks from a JDM distributor. Throw a supercharger on it and it’s the safest and most proven power you can get on a stock 3rd gen.