Is Toyota V35A-FTS Engine Reliable? Well..It's Not That Simple

the first GX was called GX470 because it had a 4.7L

engine

. The second generation was gx460 because it had a 4.6L

engine

. Now we have the latest generation GX 550 but it only has a 3.4L engine. So , why was it called 550 to my surprise? no one really knew, so I asked the chief engineer what the 550 means, because it can make the right amount of power and torque that a typical 5.5L VNA would make H. Guess how good that might sound? impressive, most Toyota fans will probably take it the WR way, aren't we overreacting a smaller engine? So in this video we'll delve into Toyota's new twin-turbo V6

v35a

FTS, how does it achieve incredibly high torque from such a small package, and more importantly, how?

Do you maintain Toyota reliability or do you and make sure you follow to the end where I interviewed the Alexa technician who actually had to replace some of these motors? OK lets start. The V35a FTS was first introduced in the 2018 Lexus LS and then made its way to the Lan Cruiser 300 series, Tundra Sequoia and the LX600, the GX550 having the lowest maximum horsepower. I thought it was just a different fit, but according to koi, the chief engineer, it was actually because we are using smaller turbochargers in the GX and this time the LX stands as a flagship, the M GX represents our true all-rounder within the Lexus hardcore model, but our peak torque is still 650, so it's the same as the L, so no yeah, 479 lb-ft of torque was up 46%. increase over the V8 in the gx460, but to really put it into context, 479 is more torque than the 4L per Turbo V8 of the Defender 5L Supercharged V8 and the Jeep Wrangler 392s 6.4L Hemi V8, so it's crazy a Toyota's 3.4L V6 can make so much torque, so much torque that the chassis squirms coming off the line.

Most Toyota fans prefer the old school naturally aspirated engine. Reliability is something we'll look at later, but a practical reason is good, predictable low-end torque - there's no turbo to spool up. above so that there are no lags, however, this Twi turbo V6 not only has a higher maximum torque, but also achieves it at lower RPM and so that our users, GX owners, can enjoy off-roading to the fullest potential that we really focus on. Low-end response and drivability, but if we compare the spec sheets of the old and new GX, the displacement per cylinder was almost identical, but a big difference was the bore and stroke.

The old engine has a large bore short stroke, which is more square, while the new one has a small long stroke, so it is below the square four compared to the stroke, it has always been a hot topic among the car enthusiasts. The general wisdom is that a squarer motor can achieve higher peak power, while an UND Square motor has better low-speed torque. It lines up perfectly with the

v35a

, which is much inferior. I thought this must be it. I cracked the code, so I brought this up during our interview and hoped to impress the chief engineer, but that wasn't the only contributing factor.

Well, first you. The lean angle between the V8 and the V6 is different so we need to find the most optimal lean angle and of course we are comparing a na engine with a twin turbo V6 engine so it is different so we see it like a total engine and then we try it. to find the best bore stroke for that particular unit, that power unit, so the bore stroke is not really the primary stroke, it's one factor within a multitude of factors that you know contribute to that, okay , I really love this part of our conversation.

Because that line of thinking probably represents many car enthusiasts, we tend to cling to an oversimplified idea, but as Koji pointed out, Bor and the stroke were just one part of a much bigger picture, so yeah, I didn't fix the code, but they did. say good question, very good question, by the way, you're probably impressed by how technical our translator was. Well, he's not a regular translator. This is Toshi Hayama, he was the former host of many car shows and built many cars and in fact he was the technical advisor for Fast and Furious toky drift wow, you can read the brochure, the Lexus GX was my first vehicle.

If you want to see me interview more people like Koji and Toshi, you can help, just watch this video until the end and hit the like button when automakers see more people enjoying my content, they will invite me to more events and I appreciate your support, okay, let's talk about reliability, when the main attraction of old school Toyotas was their engine, they generally produce a very modest output relative to their displacement, in other words, modest specific power and specific torque, this equates to less wear and therefore reliability, but now it seems that we are doing the opposite, so I express this concern to the chief engineer, so it should not change because we have developed these new engines. with the same QDR durability standards to the standards we already set, okay, that's good to know, but of course they'll say we lost 25% of the engine displacement, but we're pushing 16% more power and 46% more torque, how does this not equal more wear, so I pry them a little harder to make the motor, the smaller motor, work harder?

There is a general instant, so our combustion efficiency also increases and so on. Until now we had to burn more, but now we can create more power with less combustion, which causes less stress and fatigue. That's very interesting, okay, what I was missing is the combustion efficiency, but how does it work? We have a limited amount of time, so just until 1:30 was fine. Thank you. Unfortunately I had to end our interview, but luckily I found a document on the Society of Automotive Engineers specifically regarding the development of v35a FTS. Keep this in mind. It wasn't marketing material.

I actually had to pay $37 just to get access because it was a proper scientific article. You know, I'm something of a scientist too. In this SAE post I found exactly where we left off and this is what I learned last. The goal of all internal combustion engines is greater thermal efficiency, which means collecting more mechanical work with the same amount of fuel. However, there is an inherent trade-off between thermal efficiency and specific power or horsepower per liter of displacement, as this graph from the document shows. There are a lot of conventional engines from different manufacturers and we can clearly see an inverse relationship, so if we want to produce more power with less displacement, we are increasing the specific power with conventional technology.

This engine tends to have worse thermal efficiency, so we need to burn a lot. more fuel and most of it is simply converted to heat, all of that leads to more wear, so our concern about high performance from a small engine has scientific roots if we assume the technology remains the same, but in this case it doesn't. It's the same as a part. of the dynamic Force engine family, Toyota overcame that disadvantage by using what they called high-speed combustion, which is essentially the co-dimension of combustion efficiency with which this V6 biturbo achieves high thermal efficiency and high specific power at the same time, We can now create more power with less combustion, which causes less stress and fatigue, therefore not overloading in the same way as a conventional wood engine.

So how exactly do we get high speed combustion? If you look online you will find these cool animations showing the optimized intake P angle and geometry to promote camber flow, but the problem is that these marketing materials make you think that's it, but in this document, the port Intake adjustment wasn't really a standalone thing, but there are many other changes to the fundamentals of the engine that are needed. in fact even high speed combustion is just a primary concept, there are many other things mentioned in this document that I didn't even mention, in other words if you just machine the intake port geometry on the old V, that alone will do it . doesn't give you high speed combustion, the intake port was just one part of a much bigger picture.

H sounds familiar, it was like my discussion about drilling and acceleration with the chief engineer, it is one factor within a multitude of factors that you contribute to that, okay, the general theme Here things are not that

simple

, but the Most of us don't know what we don't know, so before posting emotional comments about new engines, I encourage you to first spend $37, read the newspaper, and gain more knowledge. I'll link it in the video description. Well, so far everything sounds great, but that was all research and development, what happens in real life? And this is where things got interesting.

This is my friend Chris, Wills a l Cruiser 200 series and has been a technician for Alexus. for 20 years a few months ago he sent me this message lx600 which has the same v35a came for a problem with the main bearing the main bearings are what keep the crankshaft in place when the main bearings wear out prematurely the crankshaft which keeps all the torque starts to rattle violently, there are also reports of the same problem on the 3rd generation Tundra, so I interviewed Chris to get more information, so I think we are suffering from the same things.

We've seen at least one with a major problem. on the LX 00 mhm and the ls 460, not the ls 600, we have also seen a problem with the main bearing. What surprises me was in 2018 when they first released the LS 500. Chris already worked on a main bearing issue. Yeah, it probably had about 20,000 miles on it, okay, and yeah, exactly the same bearing, exactly the same bearing, but that block that we replaced that car is still in service to this day and we still service that thing with regularity, so, oh, that's a local guy for you. Okay yeah let's keep our fingers crossed it's still good, it's a big project once you tear it all up and stuff like that, the vehicle that had the bearing problem were like hard drivers or something, you know, I don't HE.

I mean, the car had very low miles on it, the car had so few miles on it that it was almost like it was still like a new car at the time, but how the customer drove it before, yeah, we don't know, okay, CU. I see some Internet, uh. Comments say a bearing wears out because, oh, because you get so much power from a smaller engine, you wouldn't have that problem with a V8. I mean, that's a very loaded comment, because I don't know, yeah. So the bearing sees more load, it sees more torque, but sure, but I mean, you can be so technical about it, like, how big is the surface of the bearing compared to the protrusion, how much force are you seeing and at what? ?

RPM and things like that are correct, correct, so it's not a blank state, we can just say yes, this causes rolling, yes, no, it's not really black and white, because from the evidence I can find that the bearing is reinforced on some To my surprise, the old V8 actually used resin bearing liners. Basically we had sliding steel over plastic, but in the new engine all the bearing liners. they switched to metal and Toyota was very clear about the intent, yes it says a layer of metal is used on the inner surface of the connecting rod bearing, just like the crank bearing, it is all metal to support the high load and high speed driving, which occurs due to the use of a turbocharger, so they are actively, yes, they want you to know that in addition to the liner, the main bearing caps were also updated, says caps of Cast iron crankshaft embedded in AL casting, so it is the crankshaft covers that hold the main bearing.

It's a crankshaft cover. Yes, on the old V8, each main bearing has a separate crank cover. It is made of cast aluminum and is held on with six bolts, which is called Sixbolt Main compared to the new one. The engine combines the four crankshaft covers into one large structure. Toyota calls it a frame. The individual crankshaft covers are now made of iron and are embedded within this frame. The design intent was to increase rigidity and robustness, hence, in theory, the new main bearings. They are supposed to be better, but somehow we seem to have more failures in this specific part and there is no official explanation why the bearing is like this.

No, okay, no, we just replaced the long block and

well

, we just replaced the short block. and hope nothing else was damaged and continue from there, okay, it's a case by case scenario, it's not likeif it was okay, this is a problem, this is what we are going to do to fix it, since we don't have the strength stats. This bearing issue was perhaps a bit exaggerated, but here's some anecdotal perspective for you. Chris had worked at Lexus for 20 years. Of all the vehicles that came into his dealership, he had only seen two major problems with the bearings and both were v35a FTS and just before.

He was about to post the first version of this video. I got another message from Chris. He just suffered his third main bearing failure right now, April 2024. This is still a developing story, but does this mean we should forget about all the good things? Of course, we learned before that not only like the discussion about Bor and Stroke and high speed combustion, bearing failure is probably not that

simple

, there are many mechanisms that we simply don't know about. I hope Toyota can give us some official explanation that makes me feel a lot better, if I learn something new I'll definitely keep you posted.

Thanks for watching. See you at the next one.