2UZ-FE Connecting Rods forged or cast?

[agaisin]

I'm new to this forum but wanted to put the question to bed - many here seem to have first hand experience so figured this was a good place to post.

Word on the web is that 2UZ-FE engines made out of USA (GX, 4Runner, Tundra, Sequoia) had cast connecting rods but that the 2UZFE engines out of Japan (LX470 and Land Cruisers) had forged rods.

Along with that goes the assertions that LXs and LCs could handle the TRD Supercharger without replacing the connecting rods, and the only reason TRD took the Supercharger kit off the market was due to the other (cast) connecting rods that couldn't handle the boost.

Here's the actual 'evidence' I can find:
1)
I have confirmed from Toyota's TIS/Techinfo site where they post design information that the LX/LCs 2UZ-FE has forged connecting rods. Same design document in TIS for Tundras on the 2UZ-FE does not say it anything about forged or cast for the connecting rods.

2) The (replacement) part numbers for the connecting rod assembly on LC/LX and Tundras are the same part number.

So based on the info above, I would conclude that:
1) either all have forged
2) all have cast (and the TIS document is wrong), or
3) from the factory Tundra/Sequoia etc have cast and LX/LC have forged, but the replacement part is always forged.

Anyone here know the truth?

This thread got me questioning: http://forum.ih8mud.com/100-series-cruisers/491573-2uz-fe-diffrences.html

 

[cribbj]

Welcome to Lextreme.

All UZ, the 2JZ-GTE, and probably most other Toyota engines have "powdered" forged rods. This is a process whereby powdered metal is subjected to intense pressure and heat, and is "forged" into shape (Toyota makes reference to this in the TIS when they refer to the rods as "sintered and forged").

The waste material is minimal, and the strength and failure characteristics of rods made in this way are well known. By adjusting the powder recipe, the manufacturer can make a rod as weak or as strong as needed.

Predictably, the strongest UZ rods were in the earliest 1UZ's. The engine was brand new and unproven, so Toyota overengineered and overbuilt it. Later on, as the engine proved itself, the fat was trimmed out, and one area Toyota trimmed was the cross section of the rods.

The 2UZ truck engine, which was only supposed to make torque, and not rev any higher than 6000 or so, got the weakest rods of all. If I were going to do a hotrod project with a 2UZ, the rods would be one of the first things to go. Either put in early 1UZ rods, or Lextreme's rods, or Argo's from Oz (in order of increasing cost and strength).

 

[agaisin]

Welcome to Lextreme.

All UZ, the 2JZ-GTE, and probably most other Toyota engines have "powdered" forged rods. This is a process whereby powdered metal is subjected to intense pressure and heat, and is "forged" into shape (Toyota makes reference to this in the TIS when they refer to the rods as "sintered and forged").

The waste material is minimal, and the strength and failure characteristics of rods made in this way are well known. By adjusting the powder recipe, the manufacturer can make a rod as weak or as strong as needed.

Predictably, the strongest UZ rods were in the earliest 1UZ's. The engine was brand new and unproven, so Toyota overengineered and overbuilt it. Later on, as the engine proved itself, the fat was trimmed out, and one area Toyota trimmed was the cross section of the rods.

The 2UZ truck engine, which was only supposed to make torque, and not rev any higher than 6000 or so, got the weakest rods of all. If I were going to do a hotrod project with a 2UZ, the rods would be one of the first things to go. Either put in early 1UZ rods, or Lextreme's rods, or Argo's from Oz (in order of increasing cost and strength).

cribbj - thanks for the quick response. Is there an official source for what you stated above?

 

[spf_lexus]

http://www.lextreme.com/Toyota-Lexus-Rods.html

Pictures of rods from all years.

 

[agaisin]

http://www.lextreme.com/Toyota-Lexus-Rods.html

Pictures of rods from all years.

Cool - I've seen that, but it doesn't indicate whether the 2uz-fe ones are forged or cast (not sure if that's something that can be confirmed visually?), and it doesn't compare 2UZ-FE rods from different models against each other. It just compares rods from various flavors of 1UZ, 2UZ, 3UZ against Lextreme's rods.

I was wondering if there was official Toyota or TIS info that confirms cribbj's statements. If I'm trying to settle a debate in cyberspace it's all he said she said until there's either an official source or physical evidence (if someone visually compares rods from a 2uz out of tundra to landcruiser's rod for example)

 

[Lextreme II]

Dont let the word forged fool you. They are very weak.

 

[cribbj]

Here is the technical description for the 1/2/3UZ rods, taken straight from the Lexus/Toyota TIS.

The key to understanding that these are powder forged rods is the term "sintered and forged." Look this term up, or ask a metallurgical engineer what it means. The same terminology is used in the TIS for the 2JZ-GTE engine, and any other standard production Toyota engine I've ever referenced.

 

[4U2QUIK]

The ISO definition of the term Sintering reads:

“The thermal treatment of a powder or compact at a temperature below the melting point of the main constituent, for the purpose of increasing its strength by bonding together of the particles.”

eagle rods are sintered also. Another product that's sintered also is carbide inserts for machine tool cutters on cnc machines. It's a very common process in oem manufacturing.

 

[JustenGT8]

John is on the money mate....just find an image of a broken one for all the confirmation of the composition you'll need

 

[4U2QUIK]

yep! too true.