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theczechone last won the day on September 30 2016

theczechone had the most liked content!

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About theczechone

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    South Lyon, MI

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  1. theczechone

    New Valves?

    are oem valves still available from Nissan? What happened with your SI valves?
  2. theczechone

    New Valves?

    FWIW i spoke with Dave Rebello and he seemed to think that the valves would be fine as long as used with bronze guides. Great guy, I've only bought a cam kit from him and he has been super helpful with every step along the way.
  3. theczechone

    New Valves?

    Interesting, I did source bronze guides. Perhaps i should check what the proper clearance needs to be. The factory guides were bronze and the factory valves were stainless so there is no change of material so i would assume same clearance is expected. I will take some measurements on the valves when they get here and compare to the stock ones.
  4. theczechone

    New Valves?

    @HuD 91gt i'm getting new guides installed , i will provide the valves to the machine shop so they should be able to size the guides after the installation to the new valves. Is the stem diameter on SI valves larger than stock? Any issues with valve seals?
  5. theczechone

    New Valves?

    Ended up ordering from SI Valves. New stainless valves available in 44 or 46 for intake and 35 or 38 for exhaust. I went with a stock size, and they were 10.50 a piece! for a shipped priced below 140 for the set!
  6. theczechone

    New Valves?

    So i am rebuilding an N42 head with some mild porting, it will also get a street cam which needs new springs(outers only). I'm installing new seats and guides, should i also spring for new valves? Or can i just get the used OEM ones cleaned and inspected? Do the Z valves experience a lot of keeper groove wear? If i choose the replace route, what are good manufacturers? I see ferrea offers some nice valves but the price is high ($420 on their website, $330 on ebay) Datsun Spirit Offers their set for $230 which seems fair... and then we have the ITM and DNJ valves that are questionable for $8/piece for a total of $96 from RockAuto.... Is there someone else?
  7. theczechone

    240Z ITB Install

    DSI uses Jenvey throttle bodies that can be sourced here : https://foxinjection.com/collections/dcoe-throttle-bodies-91mm-long/products/thpxxi-th-body-45-50mm-pair there are also different versions other than 50mm
  8. theczechone

    280 duration cam 0.480" lift vs 0.540" lift

    You can generate them with DesktopDyno it's a simple math based program but it can show trends. It's not perfect but you can learn a lot about the effects of changing components on your engine.
  9. theczechone

    280 duration cam 0.480" lift vs 0.540" lift

    I would need more info than just two points and at what vacuum pressure were these flowed. would also need more cam info to define the profile. need to know crank rotation for exhaust and intake valve events. This is the flow numbers i have found and i am using
  10. theczechone

    280 duration cam 0.480" lift vs 0.540" lift

    If you have some port flow numbers for stock and ported heads I’ll gladly update my plots. But this is the numbers I was able to find. keep in mind that larger cam will make less torque but peak will happen at higher engine speed therefore generating higher horsepower. Big cams benefit from high compression ratios, 10.5 is relatively low. So unless you’re changing other components the net benefit of a larger cam is low and kills drivability.
  11. theczechone

    280 duration cam 0.480" lift vs 0.540" lift

    Talk with Dave if you are thinking of going with his cams, he's quite helpful. As far 540 or 480 lift the difference will be negligible unless you have done quite a bit of porting. And it's a small gain for a lot of added complexity. I just got the 480 cam because i am doing an amateur port job and just learning as i go, plus less than $500 for cam regrind, lash pads, springs, and rockers resurfaced... tough to beat that. BTW this is plotted on 87mm bore 79mm stroke L28 with 10.5 static CR n42 stock flow n42 ported flow
  12. theczechone

    WTB Shifter

    I have a few available, these would be oem 240z units. I think all of mine are series 2 style with the S shape. I can check the threads on the ones i have.
  13. theczechone

    WTB CAM core

    Thanks guys. Have one to send to Dave.
  14. theczechone

    Don Potter Racing Cam?

    Ha thats what im using. Should have no issues I’m running it on windows 10
  15. theczechone

    WTB CAM core

    Looking for a good cam core to send to rebello for re-grind. Must be in fairly decent shape with not too much pitting.