Sniper 2 Initial Inputs

[Bengeman]

Looking for some advice on the initial inputs for the Sniper wizard. I used Holley's standard inputs on the previous version of this engine and it seemed to "learn" pretty quick (before I lost a cam lobe), But I figure you guys might be able to get me closer to start out with.

Inputs needed
Camshaft type-
Idle RPM-
Timing @ Idle, WOT, and Cruise and cranking-
AFR @ Idle, WOT and Cruise-

EFI- Sniper 2 with Hyperspark

Engine-
447 (.040 over with 4.25 stroke)
Performer RPM intake, stock
Trickflow 175 Heads, stock
10.1 CR
Hyd. roller
Cam is from Brent- I don't know how much info he wants published on this??
Long tube headers

Any other advice related to this is appreciated, This forum has been super helpful during the build. Thanks

[My427stang]

Camshaft type- Street/strip
Idle RPM- Start at 850 RPM, up or down to taste
Timing @ Idle, WOT, and Cruise and cranking- Idle, 15, WOT, 34 (maybe 36, depends on exact cam design, early ICL, smaller lobe stay 34, bigger lobe, later ICL go 38), Cruise 38 (might be able to raise cruise once you get to know behavior)
AFR @ Idle, WOT and Cruise- Idle 14.0, WOT 12.7, Cruise 13.8   (WOT is a little fat but safe, Cruise is also little fat, you can pull back if it doesn't buck)

If tuning from the handheld, just let it rip, see how it does.  However, if you have laptop access, look close at the instructions with the distributor, it tells you different setup procedures (custom settings not just picking the distributor, although I cannot remember if that is Hypersprak or Dualsync). 

Also be sure to not only set the Hyperspark up, but also verify TDC on the balancer mechanically and then use the handheld to make sure the computer sees the same.  There is an offset adjustment if you need it.

Also, just verifying that you put a steel gear on it, Hyperspark distributors as I recall come with an iron gear, Dual Syncs come with steel.

[Bengeman]

Seems like the Holley defaults are pretty close.

I sent the Hyperspark back to MSD for a new steel gear.

I am aware of checking the actual timing VS the command timing so I think that's covered.

The other posts said that the chamber design with the Trickflows allows less timing, at 34* that is pretty close to what Holley's default is.

What's your opinion of paying for a few hours of Laptop tuning from someone with experience? Is it worth it for an engine that I'm not needing to get every last horse out of?

[My427stang]

Someone sharp on a laptop can drive up drivability and add some tweaks, decel fuel shut off, change the shape of the timing curve, etc.  I don't think you'd see a gain for peak power, more for street behavior.  In the end, depends on the cost, but simply flogging it on a dyno probably not worth it.

I don't usually see peak HP and ground strap marks in the right place at 34 with 10:1 and a Trick Flow, although it is close.  At 11:1 generally closer and usually a colder plug.  You are close, but I usually see 35-36 vs 40 for a big sloppy factory chamber.

[Bengeman]

I'm fired up and "learning" now.

The base timing table is pretty abrupt, does anyone have a timing table for a 445 with Trickflow heads, 

And not EFI related but, I got that fired up and no leaks so I took it out(no hood) and once I got to about 3-3500 I got a bunch of smoke. I got out and seen the dipstick had blown up and oil had sprayed out. I had 2 small PCV valves on the valve covers when this was a 390 and never had an issue. Would that added stroke increase the crankcase pressure or once the rings seat, will the case pressure go down. 

I got 2 free flowing breathers for today's test run but I hear that its better to have at least 1 side pulling some vacuum thru a PCV.

[My427stang]

I generally put a TFS head at 35-36 depending on compression.  Then I find a linear curve is not the best at WOT, I generally bring it in faster starting until about 2000 and then smooth it.  Be sure you checked your setup using the hand helpd though, there uis an offset if commanded timing doesn't match the light

If you are blowing out a dipstick, a breathers will help, you just may get a little mist.  However, I would ask what you are using for a PCV and breather now?  I had one come in with a fixed orifice PCV (no rattle just a little hole) that doesn't do so well on a big incher.  An old school PCV can work well, although the breathers are a get out of jail free if it's simple crankcase pressure.

Although a stroker in theory will have slightly more blowby due to stroke, you should not have that little ring seal, nor should you need a significant break in.  If it's huffing hard, need to see if you broke or damaged a ring or even popped a head gasket.

I recently had a 347 on the dyno that the repop breather was misdrilled, won't ever miss that again, it pushed the dipstick up at WOT, but didn't after we fixed it

Worst case, it's easy to damage a 1 mm ring if you used a standard ring compressor too.  They won't break, but you can bend them without trying hard without a tapered compressor

[Bengeman]

I had some GM PCV valve that used a 5/16" hose in both valve covers. I went as small as I could just for optics but after posting, I went out and just blew thru those valves and they are much more restrictive that the breather is. I got a new breather that fits my grommet and put it on the driver's side and put the tiny PCV back in the passenger side and just got back from a run.  4000 rpm and no oil spray.  I am getting some smoke out of the breather at idle, that normal?

[My427stang]

Well, it depends, if you are seeing pressure, not really.  If you are seeing a little oil spray or off-gassing, especially when cold or damp, likely OK.

Some things to think about, the PCV only works when there is vacuum present.  So a 5/16 line is likely plenty if the PCV flows enough.  When you hit WOT, at zero vacuum the breather does more work. 

If you have a blowby issue, neither will fix it.  A couple questions

- Where is the PCV vacuum sourced from? Plenum, runner or base of Sniper?
- Can you take a pic of the smoke from the breather, if yes, do it with the PCV hooked up, then without.