Inside the Vtec (Please Dont shoot me.. hehe)

[sw20r]

Ala! I present

I took this pic today and found it pretty interesting the way the actuators work on honduh motors. Has anybody got pics of how Toyota VVT/VVTL-i works?



It would also be interesting putting in vtec killer cams.. i asume you'd have to remove those lobeswitch kinda things in the head.

dont kill me! I just find it interesting thats all

[Nim]

You can get cams that have a larger lump on the secondary lobe. But the tuning is a nightmare apparently.

Race builders usualy disable the VTEC, 'cuz it's just a pain in the arse to re-tune, especialy as you don't normaly need the low end torque that the normal cam provides on a track. In that case, they just make the two outside lobes lumpier, and take off/disable the VTEC controll unit so that VTEC never engages.

VVT works totaly differently. It only adjusts timing advance.

VVTL-i is very similar to VTEC, but from what I've seen, the rocker design looks more robust (trust Toyota) and it also has VVT attached to the cam gears.

One of the things I find interesting is that they don't use the lash adjusters/rockers to make the head a narrow angle... but that might have something to do with valve and port size.

Bill has some stuff on his site about it:
http://www.billzilla.org/vvtvtec.htm

[sam-131]

wtf i have all ways wondered what they look in side all i can say is it's very strange

[Nim]

It's just a set of lash adjusters designed to have 3 cam lobes per 2 valves, rather than the usualy 2. The center free floating lash adjuster locks into the other part of the lash adjuster.