Shorten exhaust cam. | Page 3 | FerrariChat

Shorten exhaust cam.

Discussion in '308/328' started by TommyA, Jan 25, 2021.

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  1. Ferrari Tech

    Ferrari Tech Formula 3

    Mar 5, 2010
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    Wade Williams
    My bad, I should have read it all. How about an aluminum insert with an o-ring around the outside and button head screws holding it in?
     
  2. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Tommy A
    I'm entertaining all option right now. If I go with a new cam from Cat cams, their end is plugged and don't have the annoying pump drive. Maybe build a cover just like the other side and get it done and over with.
     
  3. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Scott, Mark,
    What a PITA to make something to measure valve travel :( nevertheless current cam lift is 7.57mm. Valve travel is at 13.2mm. I spoke with Cat cams and he advised me that besides the 3 profiles advertised they have many more if I choose to go a different route and the cost will still be at $1,500 or provide my own cam profile and he will make them. Scott per your research the 402 is to close to call (risking it) and this is not the way I want to go. It can be done but I just want to drop in the cams and button up the engine. Any suggestions on the cam profile?
     
  4. TommyA

    TommyA Formula Junior

    Oct 7, 2002
    549
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    Tommy A
    Derek, how are the cam ends from Cat? Are they solid or plugs at the ends? Can you post some images? Just trying to think ahead for my cam trigger set-up.
     
  5. smg2

    smg2 F1 World Champ
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    Really comes down to what the build is.. what have you done?
     
  6. TommyA

    TommyA Formula Junior

    Oct 7, 2002
    549
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    Tommy A
    Scott, block and heads are all stock. The heads have new SS exhaust valves new guides seals and seat with stock springs. EFI, MAF, COP, 68mm TB etc.
     
  7. smg2

    smg2 F1 World Champ
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    CR?
    TB... Is this twm style or single with stock plenum?
    Valves, stock size?
     
  8. mk e

    mk e F1 World Champ

    Oct 31, 2003
    12,899
    The twilight zone
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    I think Something closer to the WEB cam numbers would make you happier....its the 291/283 on the Cat spec that concerns me a little, long seat to seat numbers are not great for low end performance. I think it will be ok but would be much better with high CR and I didn't read you had that? You MAF my not like it much either....an MAF is normally not used on a performance engine, for street its normally speed-density or MAP load sensing but its easy to switch if you have problems so really the CR not being high enough to give good low-end is the main concern.

    If everything it stock inside the engine (stock or stockish CR), maybe give the Web specs to Cat, tell them specifically you want to limit the seat to seat and see what they come back with?
     
  9. derekw

    derekw Formula 3
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    Sep 7, 2010
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    Derek W
    From what I remember the cams were plugged except the one for the distributor drive. I had to use the splined drive plug from my old cam— press it in, tap in the pin and peen both sides.

    I bumped up my CR to 10.5:1 and agree that a milder cam would suit standard internals.
     
  10. TommyA

    TommyA Formula Junior

    Oct 7, 2002
    549
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    Tommy A
    Valves are all stock. I'm using single 68mm TB on the stock plenum. I had to enlarge the plenum to 70mm to have a smooth airflow. I can increase the TB to 70mm but I have to increase also the plenum to 72mm and I already shaved enough to get to that point. I don't want to weaken it. It's really hard to get a tool in there to measure the thickness. The bottom section of the TB has a hump that is not very thick.
     
  11. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    I was thinking of asking them to plug all cam since no distributor will be used and then threat my Cam trigger wheel and use it as a plug as well?
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  12. smg2

    smg2 F1 World Champ
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    Got it...
    What do you have for CR?

    Here's a data point, for the 2v engines, stock rebuild, only changes being upping the CR to 10.5:1 and efi, I've gotten solid 30/30 hp/tq increases... Dyno run. That's with the crappy CIS cams. The two big changes that help are increased CR and efi, next up is cam profile. Head work also really helps but that requires dialing in valves, cam, etc...
     
  13. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Tommy A
    These are very interesting numbers. Do you feel that I need to increase the TB to 70mm or 68mm is adequate?
     
  14. mk e

    mk e F1 World Champ

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    That cam trigger looks filament printed? If so what is it printed from that will handle the engine heat?
     
  15. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Mark, that's only a 3D print for fitment before I send the file to the shop.. Good catch though ;)
     
  16. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Tommy A
    Do Cat cams have the index mark for alignment?
     
  17. derekw

    derekw Formula 3
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    Sorry, I don’t recall seeing a timing notch but ask them directly— they can probably add them if they don’t already. They probably assume that people using these will dial them in more accurately than a notch will typically allow.
     
  18. mk e

    mk e F1 World Champ

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    I stamped my cams after installing and dialing them in where I wanted them the first time to make repeats much faster. With the engine all assembled if there are no marks at all even installing the cams without marks is a bit risky......if it turns out there are no marks I would probably try to line each up with its OEM counterpart and put a sharpie or dye mark as close to oem as I could get to have the best chance possible of getting them installed in a happy place to start dialing in.
     
  19. GordonC

    GordonC F1 Rookie
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    Aug 28, 2005
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    Gordon
    I was more wondering if the filament material would be able to trigger a cam sensor?! ;) There are filaments made available recently that can handle higher temps, a few nylon types that will go to around 170C before any effects.

    Gordon
     
  20. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Does anyone see it as a problem drilling an M6 hole on the 2 nipples on the front cover, next to the alternator mount to attach the mount for my crank trigger sensor?
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  21. smg2

    smg2 F1 World Champ
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    Nope, no problem. Those bosses were used for the other variant of alternator bracket m8 threading. Obviously don't go to far into them, should have an easy 15mm depth, more then enough for what you want to do.
    Keep in mind this though... Alternators are electrically 'noisey' and can cause signal issues with crank sensors. It's why the sensors are usually on the other side of the block, bank 1-4.
    That said, I have run them mounted where you're looking, but I also ran them with a shielded sleeve.
     
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  22. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Well I'm using the harness that came with the M800 and the wire for the sensor does have a shielded sleeve, so I guess I will be ok? Worse case scenario I could also add a noise filter. Looking around that area this is the best spot that I could find unless I mount it on the timing cover...?? :(
     
  23. mk e

    mk e F1 World Champ

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    I THINK the M800 has built in settings to help filter the signal should it be needed, but I suspect it will be just fine and wouldn't hesitate to do what you're plotting.
     
  24. smg2

    smg2 F1 World Champ
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    Should be good then. Shielded cables really help. And if he software has filter capabilities then it's easy to tune out any noise.
     
  25. TommyA

    TommyA Formula Junior

    Oct 7, 2002
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    Tommy A
    Ok this is where I stand with the cams... Do to extremely long wait at Cat Cams to make them (at least 10 weeks) I will have to do a regrind with Web cams so back on the drawing board with the end covers. On the intake cam that I will install the trigger wheel, do I have to clone the rear seal mount? Many have done it but nobody documented it.. My fear if I don't clone it is oil will get in the housing and possibly splash all over the trigger wheel and sensor??
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