Another Toyota V6 question

[jsharp]

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Originally posted by RussellA:

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Doesn't the 3.4L use belt drive OHC's, whereas the 2.7L I-4 uses chains?

Come to think of it...does the Sienna really use gears to drive the cams?

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I have the service manual for the 3.0 L in the 99 Avalon. A timing pulley is attached to the front of the exhaust cams only. There are meshing gears at the back of each cam. This allows the turn of the exhaust cam to turn the intake cam. This is really independant of the timing chain or belt.

I believe JohnBrowning had a picture in a thread on this site showing that the synchromesh gears have been moved external (away from heat) and to the front if I remember in the new engines like new 4cyl the 3.4 L V6

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Nope. There are internal cam gears on the truck engines. The external timing belt runs the exhaust cam, the intake cam is run from a gear that meshes with a gear on the exhaust cam.

The 3.0L used in the trucks is the same engine family as the more modern 3.4L and I'm sure it's done the same way even on the new 4.0L engines.

[ August 19, 2003, 12:03 PM: Message edited by: jsharp ]