Here's the break down: The V6 vs V8 info center

[techno]

The Toyota spec sheet I have for the 2008 model has different engine output figures for both engines compared to what you show in the 1st post. A suggestion, if you are going to show specs, it might be worth breaking them down by year model, since they changed several times over the years.

 

[94toy22re]

The weaker rods on the 2uz of motors are only in the vechiles built in the USA, the Tundra and Sequoia. The japenese built landcruiser, 4runner and gx470 have stronger rods.

 

[m85476585]

The Toyota spec sheet I have for the 2008 model has different engine output figures for both engines compared to what you show in the 1st post. A suggestion, if you are going to show specs, it might be worth breaking them down by year model, since they changed several times over the years.

Some of the changes are just a change in how they measure it, but I think the actual power changed between some model years, too.

JA has a great website with history and specs for each model year.
Toyota 4Runner History 2003

 

[flipflopnfly]

[MENTION=142445]flipflopnfly[/MENTION]

Thanks for the chart, it's interesting to see; odd that the 1GR-FE dips in the middle there, I'm assuming from VVTi..

I think that's a pretty accurate chart of torque curves, there may be others that have slight differences. I posted that chart because it shows the 4.0, the 4.7, the Lexus 3.5, and the 3.5 that is in the new Tacoma.

4.0 vs 4.7, people often say "Well, the dual-VVTi 4.0 has the same HP as the 4.7". But that's not the entire story. HP = torque x RPM / 5252

When the 4.7 is busting out 290 torque at 2000RPM that is only 110HP. When the 4.7 is busting out 320 torque at 3400RPM, that is only 207HP. The 4.7's peak HP comes (of course) at a higher RPM, roughly around 5000RPM. The 4.7's lowend torque also explains the small difference in MPG despite the heavier iron block engine and fulltime 4WD. Less skinny pedal needed to get the vehicle up to desired speed.

The 4.0 is a great engine, but it will be in a lower gear at higher RPM to pull the same load up the same hill at the same speed. That difference is what counts for me.

That may not count much for many folks considering the 4.7 should have a $700 (what it cost me for parts & labor at a Toyota dealer) belt change every 90k miles and considering the 4.0 is an adequate tow engine.

Towing with a 4.0 one should put an auxilliary transmission cooler on it if it wasn't a factory option (it was an option along with a Class IV hitch).

I believe both V6 and V8 had a factory 130A alternator, which is a good thing to have. And I believe both are prewired for a trailer brake controller.

 

[flipflopnfly]

Some of the changes are just a change in how they measure it, but I think the actual power changed between some model years, too.

JA has a great website with history and specs for each model year.
Toyota 4Runner History 2003

Yeah, from 2005-2006 there was a revision of SAE HP and torque measurements meant to eliminate manufacturer's claims for HP and torque and put them on an equal level.

SIDE NOTE: The Tundra 4.7 has a bit better specs for the same model years. I believe that is because of different exhaust headers. The Tundra has a wider engine bay, I think they put in different exhaust headers.

2005 Tundra 4.7l 282HP@5400RPM, 325 torque@3400RPM
2005 4Runner 4.7l 270HP@5400RPM, 330 torque@3400RPM

2006 Tundra 4.7l 271HP@5400RPM, 313 torque@3400RPM.
2006 4Runner 4.7l 260HP@5400RPM, 306 torque@3400RPM.

SIDE NOTE II: Before anybody asks, the torque curves 4.0 vs 4.7 remain the same with the SAE measurement revisions.

 

[DirtDawg]

The weaker rods on the 2uz of motors are only in the vechiles built in the USA, the Tundra and Sequoia. The japenese built landcruiser, 4runner and gx470 have stronger rods.

From most everything I have researched, this is not true. Several threads on IH8MUD about this and here is a specific article from lextreme: 2UZ-FE Connecting Rods Forged or Cast?

 

[BlackWorksInc]

The weaker rods on the 2uz of motors are only in the vechiles built in the USA, the Tundra and Sequoia. The japenese built landcruiser, 4runner and gx470 have stronger rods.

That's debatable at best. As far as I can tell from trying to get a solid answer on this, all the 2UZ-FE are sinter-forged rods. This... rumor (can't say it's true, but can't say it's not) started mainly because the only 2UZ-FE vehicles to get the superchargers in the US (as far as I know that's mainly where most of them were installed/operated) were on Sequoia and Tundra; Those on LC and 4Runner had to be adapted to fit and as far as I remember were never offered with "Fit Kits" sold by Toyota. This left an extremely small number outside of the Tundra/Sequoia equipped with superchargers, thus the majority of the failures noticed and recorded by Toyota were from the "officially approved" vehicles equipped with them. Thus a suspicion from somewhere began that since the 4Runner & LC are made in Japan that the issue is with crap US rods (which were the main failure point in boosted 2UZ-FE units.)

As of this post I have not seen anything definitively indicating that there were anything but sinter forged connecting rods used in the 2UZ-FE in all units produced. Nor have I seen anything indicating that the two rods were significantly different in design, shape, and/or metallurgy (though part numbers may have been different due to originating supplier). So at best, the rods in all 2UZ-FE were never really designed for boosted applications (as you can easily see by finding the famous connecting rod comparison from 1UZ to 3UR rods). That compounded by people running improper fuel rating (you'd be surprised how many people ran regular instead of Premium, the stories I've heard from fellow techs and an FTS or two were entertaining about the mistreatment of some of those vehicles), user error (droppin' burnout all the time, ect.), and tuning issues from the factory resulted in failures. It was a combination of things, but the engine being mainly designed for NA was a big factor.

So at best I'd say, it's possible a US/Non-Japanese supplier had a slightly "weaker" rod than the Japanese supplier; but it seems more that it's a case of coincidence being attributed as fact.

 

[rcebowl]

Thanks for putting this together. This is the first I've seen as the chain having a life of 200k. What do people normally do then? Just let it wear? Change it?

there's no real service interval but its when it should be checked. I'll update it tomorrow. it's a little harder to update since it's a picture

 

[97hb]

Thanks for putting this together. This is the first I've seen as the chain having a life of 200k. What do people normally do then? Just let it wear? Change it?

Keep letting it ride!!!! Will post a thread when mine breaks or when my head gasket goes. Still waiting and saving.

 

[DZNUTS]

As for the price of the replacement exhaust manifold on the v8, employee discount/repair shop price for the OE manifold is $430 per side


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[rcebowl]

that's labor? or parts and labor?

 

[flipflopnfly]

That's debatable at best. As far as I can tell from trying to get a solid answer on this, all the 2UZ-FE are sinter-forged rods. This... rumor (can't say it's true, but can't say it's not) started mainly because the only 2UZ-FE vehicles to get the superchargers in the US (as far as I know that's mainly where most of them were installed/operated) were on Sequoia and Tundra; Those on LC and 4Runner had to be adapted to fit and as far as I remember were never offered with "Fit Kits" sold by Toyota. This left an extremely small number outside of the Tundra/Sequoia equipped with superchargers, thus the majority of the failures noticed and recorded by Toyota were from the "officially approved" vehicles equipped with them. Thus a suspicion from somewhere began that since the 4Runner & LC are made in Japan that the issue is with crap US rods (which were the main failure point in boosted 2UZ-FE units.)

As of this post I have not seen anything definitively indicating that there were anything but sinter forged connecting rods used in the 2UZ-FE in all units produced. Nor have I seen anything indicating that the two rods were significantly different in design, shape, and/or metallurgy (though part numbers may have been different due to originating supplier). So at best, the rods in all 2UZ-FE were never really designed for boosted applications (as you can easily see by finding the famous connecting rod comparison from 1UZ to 3UR rods). That compounded by people running improper fuel rating (you'd be surprised how many people ran regular instead of Premium, the stories I've heard from fellow techs and an FTS or two were entertaining about the mistreatment of some of those vehicles), user error (droppin' burnout all the time, ect.), and tuning issues from the factory resulted in failures. It was a combination of things, but the engine being mainly designed for NA was a big factor.
So at best I'd say, it's possible a US/Non-Japanese supplier had a slightly "weaker" rod than the Japanese supplier; but it seems more that it's a case of coincidence being attributed as fact.

Correct, and correct again. All conn rods are sintered and forged, and here is a link to the comparison picture of conn rods in the various flavors of the "UZ" V8 from 1986-2006. Toyota Tundra Rods, Sequoia Rods, 4 Runner rods, 4runner rods, GS400 rods, SC400 rods, Lexus engine code

As can be seen the conn rod in the original 1UZ-FE used in the Lexus GS400 was much beefier.

And here's a link to a discussion about "cast vs forged" in Japan-produced vs US produced where it's confirmed all Toyota connecting rods are sintered and forged. http://www.lextreme.com/forums/inde...ecting-rods-forged-or-cast.14121/#post-119553

I doubt any engine ever produced has cast connecting rods.

Not every 4.7l supercharger owner broke a rod, URD still has a kit available.

 

[BlackWorksInc]

...
Not every 4.7l supercharger owner broke a rod, URD still has a kit available.

From what I understand, it came down to people using different pulleys, trying to get a bit more power from the factory tune, ect. Those that didn't do that were usually running wrong fuel causing detonation and/or overworking the engine a bit too much. That being said from what I understand there was a good section of legitimate concerns that stemmed just from the engine not really being meant to handle boost.

Thanks for the links.

 

[iBison]

there's no real service interval but its when it should be checked. I'll update it tomorrow. it's a little harder to update since it's a picture

Mine was good at 170k when we did the head gaskets.

 

[NJck22]

Thank you for this post, so informative

 

[DZNUTS]

The 03 & 04 v8s has 4 speed transmissions. Toyota switch to 5 speed trannys beginning with the 05 MY

 

[Montego Murph]

The 03 & 04 v8s has 4 speed transmissions. Toyota switch to 5 speed trannys beginning with the 05 MY

DZ,
Going to politely disagree with you there... I own an early (#2308) 2003 V8 and it has a 5 speed.

 

[JpAdct]

The 03 & 04 v8s has 4 speed transmissions. Toyota switch to 5 speed trannys beginning with the 05 MY

I believe that pattern was only true to on the 6cyl models.


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[Inv4drZm]

The 03 & 04 v8s has 4 speed transmissions. Toyota switch to 5 speed trannys beginning with the 05 MY

DZ,
Going to politely disagree with you there... I own an early (#2308) 2003 V8 and it has a 5 speed.

The 03-04 V6's had a 4 speed I think. Then swapped over to the 5 speed in 05. V8's always had the 5 speed from what I just read.

Toyota 4Runner History 2005

 

[Shank2015]

Good info, been looking into getting a 4th gen and think I want a v6 but if the right v8 deal came along....