Enter your username:
Do you want to login or register?
  • Forgot your password?

    Login / Register



    Results 1 to 4 of 4

    Thread: VVT strokers?

    1. #1
      Join Date
      Oct 2010
      Location
      SLC
      Posts
      571

      VVT strokers?

      Anyone here running stroker with VVT. Seems like deleting it is the popular thing to do, but why wouldn't you want the advantage of better torque and mpg down low.

      Zach

      1970 Mach 1 build - Half-Breed (pro-touring.com)


    2. #2
      Join Date
      Nov 2018
      Posts
      568
      Country Flag: United States
      https://www.motortrend.com/how-to/18...n-iv-v-engine/

      "This amount of authority also presents a problem. The factory system is carefully designed in conjunction with the stock cam to prevent piston-to-valve (P-V) contact. This isnít difficult with the short duration and conservative lift numbers of the factory camshafts. But in a performance situation, weíve all seen that even slight increases in cam duration can have a very positive effect on peak power."

      Cam manufacturers don't want to be liable for your engine, and most folks building high performance engines are doing it for the WOT power and don't care as much for cruising power.

      But, I'm with you on this - I'd prefer a VVT engine to a straight cam engine. But better than that, I'd prefer an electric valve engine where the ECM directly controls lift and duration of the valves. Imagine an engine that runs the best cam profile for WOT throttle, changing "cams" at every RPM level, and runs the best profile for cruising efficiency. I'd love an engine that pulls 50MPG or better while cruising, and does 8 second quarter miles.

      https://www.hotcars.com/science-behi...amless-engine/
      2021 Durango R/T
      2008 Colorado beater
      2003 Dakota project-o-mobile

    3. #3
      Join Date
      Nov 2010
      Location
      Ventura County CA
      Posts
      549
      Country Flag: United States
      I have an LY6 370ci where I've retained VVT using a Texas Speed cam (VVT2) and Comp Cams phasor limiter to prevent P-V interference. I used flat top pistons with small valve reliefs and I checked clearance using clay with the phasor locked full advance and full retard - plenty of room. With a stroker the pistons are usually dished a little, so more than likely you would have plenty of valve clearance using a phaser limiter, but of course you should check. Being able to vary the cam timing helps flatten the torque curve a bit to maximize area under the curve. On the other hand there are fewer grinds available on a VVT core and there are costs and complexities with the phasor and phasor limiter. I have had no issues over the last 7 years with my VVT system running up to about 6,000rpm and I am very happy with how broad my torque curve is.
      Clint - '70 Nova "restomod" cruiser & autocross family car

    4. #4
      Join Date
      Apr 2001
      Location
      The City of Fountains
      Posts
      15,973
      Country Flag: United States
      Quote Originally Posted by Zachalanche View Post
      Anyone here running stroker with VVT. Seems like deleting it is the popular thing to do, but why wouldn't you want the advantage of better torque and mpg down low.
      While it seems like a good idea to retain VVT, the fact is that a higher compression stroker with a mild cam will make more torque than you could ever put to the ground. With such an engine, tuning becomes an issue with the stock ECU, so then you would be considering an aftermarket ECU, like a Holley system, and Holley does not support VVT on the Gen3/4 engines.

      Andrew
      1970 GTO Version 3.0
      1967 Cougar build
      GM High-Tech Performance feature
      My YouTube Channel Please Subscribe!
      Instagram @projectgattago
      Dr. EFI
      I deliver what EFI promises.
      Remote Holley EFI tuning.
      Please get in touch if I can be of service.

      "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her