Jump to content
SAU Community

Analyze my CAM specs?

Predator1

By Predator1,
in Engines & Forced Induction

 Share

Recommended Posts

Predator1 Rising Star

Predator1

Posted
Posted

Hi Guys,

I have a new CNC'd 26 head with the Kelfords catalogue thrown in it, good for 12+rpm.

Flow specs:

   

.450"    Intake -295cfm    Exhaust 214cfm

Now my cam specs seem a bit wild/weird? Anyone have experience with  the Kelfords split type cams?

My specs are: Intake 278mm @ 10.8mm Exhaust - 286mm - 10.80mm

Any ideas what it would be like paired with a 3.2 and a 9180?

Link to comment
https://www.sau.com.au/forums/topic/481440-analyze-my-cam-specs/
Share on other sites
GTSBoy Grand Master

GTSBoy

Posted
Posted

The duration total or at 0.050"/1.25mm? Reason I ask is that that duration and that lift do not appear on Kelford's RB26 page. But nevermind, because I guess the specs are at the same lift as other Kelford cams, which is advertised duration at 0.35mm. So your 1mm lift durations will be ~242-245°. Moderately chunky!

in which case, they will probably be great. You will benefit from a big cam on a big engine. Your flowbench numbers have ~72% of the intake flow on the exhaust, so, maybe just maybe the split duration is not all that required. But I don;t think it will hurt anything.

Predator1 Rising Star

Predator1

Posted
  • Author
Posted
23 hours ago, GTSBoy said:

The duration total or at 0.050"/1.25mm? Reason I ask is that that duration and that lift do not appear on Kelford's RB26 page. But nevermind, because I guess the specs are at the same lift as other Kelford cams, which is advertised duration at 0.35mm. So your 1mm lift durations will be ~242-245°. Moderately chunky!

in which case, they will probably be great. You will benefit from a big cam on a big engine. Your flowbench numbers have ~72% of the intake flow on the exhaust, so, maybe just maybe the split duration is not all that required. But I don;t think it will hurt anything.

Thoughts? I've attached the specs sheet.

cams.jpg

GTSBoy Grand Master

GTSBoy

Posted
Posted

So, the X is their custom code. That means that someone ordered those cams to those specs, or Kelfords were asked to come up with cam specs to suit engine parameters given to them.

That spec sheet is interesting in that it differs from many of Kelford's off the shelf cam sheets in what lifts are used to spec durations. Nevertheless, it is pretty close to the 1mm lift territory I came up with, so I still think it will go well.

Predator1 Rising Star

Predator1

Posted
  • Author
Posted
12 minutes ago, GTSBoy said:

So, the X is their custom code. That means that someone ordered those cams to those specs, or Kelfords were asked to come up with cam specs to suit engine parameters given to them.

That spec sheet is interesting in that it differs from many of Kelford's off the shelf cam sheets in what lifts are used to spec durations. Nevertheless, it is pretty close to the 1mm lift territory I came up with, so I still think it will go well.

Yep, sounds right.. I had my head CNC'd as well, so thats probably what it is. I just dont want a super aggressive lumpy idle and bunny hop with my triple plate in slow speeds.

GTSBoy Grand Master

GTSBoy

Posted
Posted

272+ degree cams will definitely have a choppy idle, but I've not seen what they're like on a ported 26 head on a really big capacity bottom end. The big capacity should help.

I've driven 290° cams on a 2JZ and it idled like a motorbike (buzzy, changeable revs, clutch chatter like a bitch from the twin plate) but it was not struggle to get it moving and it was only soft below 2000rpm (IIRC).

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Hendasto
      Lets play a game - What is causing my oil consumption?

      By Hendasto · Posted

      Hopefully it ends up being something manageable, like a hone, rather than a full bore—it would be a huge relief if it’s not as bad as it looks. Hang in there; these setbacks are annoying, but it sounds like you’re handling it as smartly as possible.
    • Hendasto
      Are RBs worth building reliability wise

      By Hendasto · Posted

      At the end of the day, it’s all about understanding the odds and being comfortable with the potential cost, whether it’s horsepower on a build or chips on a roulette table. And I have to say, the Laine example made me laugh—some people really do embrace that carefree, “roll and see” attitude!
    • Songo
      New kid on the block

      By Songo · Posted

      Thanks MBS206, i got that PDF but got abit overhelm with all the connections and tracing of wires. I wasn't expecting to plug the dash harness anywhere. i was just going to use my electronics jumper wires to plug into the right pins like ECU power, ecu ground, ignition trigger etc... I do have a few ratchet straps locking it down tight. Fire extinguisher ready and only a small amount of fuel at a time, enough to submerge the pump.
    • Songo
      New kid on the block

      By Songo · Posted

      Thanks GTSBoy, i will do abit more digging. I am missing a blue relay near the ECU connector... so i will chase that up in the next few days as well  
    • MBS206
      New kid on the block

      By MBS206 · Posted

      https://yariksteel.ru/manual/R33/Skyline_R33_elektroprovodka.pdf   Page 18 should be what you want for the Dash Cluster wiring. Though, you don't need the dash plugged in to get the motor running. What you want is power as how GTSBoy said. You need to power the ECU. Find in the above link the ECU pin outs (Verify them before just connecting them up from things written on the internet). Find anything needing power, give it power, find anything needing ground, give it ground. Then give the starter motor power through a big cable, and bridge the solenoid on the starter straight to power too.  ECU will be on, and when you give the starter power, it'll spin the starter motor, and it should start. I also hope you have a proper stand, and not just the engine sitting on some wood. You will want it bolted down properly.
×
×
  • Create New...