Whats next for more N/A power?

[BlackNDecker]

Why then does the cobra jet cam with its huge duration similar to the comp cams not need the phase limiters? is there some special thing with those grinds that gives more piston to valve clearance?

I'm not sure...but if I had to guess I'd say that either the CJ's pistons have deeper valve pockets or that cam lobe lift (more so than duration) is what actually moves the valve closer to the piston....I'm guessing the NA CJ has the right combination of the two for proper clearance...

 

[Highway Star]

Why then does the cobra jet cam with its huge duration similar to the comp cams not need the phase limiters? is there some special thing with those grinds that gives more piston to valve clearance?

Check out the specs on both. I bet you the cobra jet cams have less lift.

Also, from the crane cam website. Just a reminder that high compression pistons will require a custom cam grind.


The compression ratio of the engine is one of three key factors in determining the engine's cylinder pressure. The other two are the duration of the camshaft (at .050" lifter rise) and the position of the cam in the engine (advanced or retarded). The result of how these three factors interact with one another is the amount of cylinder pressure the engine will generate. (This is usually expressed as the "cranking pressure" that can be measured with a gauge installed in the spark plug hole.)

It is important to be sure that the engine's compression ratio matches the recommended ratio for the cam you are selecting. Too little compression ratio (or too much duration) will cause the cylinder pressure to drop. This will lower the power output of the engine.

With too much compression ratio (or too little duration) the cylinder pressure will be too high, causing pre-ignition and detonation. This condition could severely damage engine components.

 

[Konaboss302]

As far as the CJ cams go... the CJ cars are built/tuned by Ford, I would imagine they are a little better at locking in the VCT than most aftermarket tuners... could it be possible that they're good aggressive cams and that Ford just has a little bit more "tuning mojo" to put into it keeping them in line?

 

[BlackNDecker]

As far as the CJ cams go... the CJ cars are built/tuned by Ford, I would imagine they are a little better at locking in the VCT than most aftermarket tuners... could it be possible that they're good aggressive cams and that Ford just has a little bit more "tuning mojo" to put into it keeping them in line?

I agree that Ford has more "tuning mojo" but tuning will only offer limited protection from p2v contact....it certainly won't help with a 5-2 or 4-1 mis-shift. You have to clay the motor to be certain that clearances are safe, otherwise you have to put in a "hard stop" like a phaser lock (i.e. a pin to prevent cam advancement past a certain degree).

Also, I believe the NA 2012 CJ is 5.1 liters (slight overbore)...correct? So the pistons would certainly have deeper valve pockets to prevent p2v contact if this was an issue with the 302R exhaust cams.

 

[Rebel302]

I agree that Ford has more "tuning mojo" but tuning will only offer limited protection from p2v contact....it certainly won't help with a 5-2 or 4-1 mis-shift. You have to clay the motor to be certain that clearances are safe, otherwise you have to put in a "hard stop" like a phaser lock (i.e. a pin to prevent cam advancement past a certain degree).

Also, I believe the NA 2012 CJ is 5.1 liters (slight overbore)...correct? So the pistons would certainly have deeper valve pockets to prevent p2v contact if this was an issue with the 302R exhaust cams.

Seems as though we all had a slight misconception here...

:read:"The spring is typically designed so that at max lift there is not a lot of room for the coils to surge up and down. The base spring (Coyote) was designed for 12mm lift, and there is only another millimeter before it goes completely solid, which wouldn't have worked, so we lowered the solid height on the spring so we could get to the 13mm lift and still have a half a millimeter of clearance before it went fully solid. So in addition to the higher load, we had to take out some coils." ---quote from Kevin Shinners from the RR team

That being said, that explains why the Comp cams(which were designed for the Coyote to begin with and have 12.5mm of lift) need limiters while the Boss upgrade cams/Cobra Jet (which have 13mm of lift) do not when installed on a Boss. I'm sure if someone took the time to do the clay check on the comp cams in the Boss, you probably wouldn't need the limiters technically. But when reading the article I posted before about the Comp cams, they were designed with the limiters and not having to upgrade the springs in the Coyote in mind.
It has nothing to do with "deeper valve pockets" as the 302R didn't have an issue with p2v clearance. It's the same motor with a 12qt oil sump and a few other ancillary differences.

We all said we read the articles....but did we really? :dw:

 

[BlackNDecker]

Great info....thanks for sharing!


Just found this....Here is a nice package to fill in the midrange with those stage 3 cams:
SEMA 2012: Wiseco/K1 Show off Cage Pistons, 351 Coyote Stroker Kit | StangTV

 

[twistedneck]

I think the Ford Racing Engineers were on a compressed timeline when they were trying to improve the flow of the Boss 302 cylinder head for the Cobra Jet. I imagine at some point, we will have better flowing heads but I will want to see flow bench results....because it is relatively easy to increase high lift flow at the expense of low lift...but this would be unacceptable.

Also, I think that the CJ intake and 302R cams will shift the power curve to the right, necessitating either more displacement or higher compression to shift the curve back to the left. I bet this is why Ford Racing increased the displacment on the NA cobra jet.

After talking with Michael at L&M he did confirm the Cobra jet cams are still on the small side compared to what's possible with stock GT/Boss piston to valve clearance and minor tv-vct liming say 30 degrees max.. but lift is limited to 13mm due to head architecture. So there is room for a bigger beastly cam on duration and on some centerline changes.

Your point about the compressed timelines makes sense so does the extra compression, its also interesting that Ford added the extra bore even though valve un-shrouding is not an issue in the boss combustion chamber and is not helped by bigger bore. However, I heard the only reason the 290 degree BEXH exhaust cams were taken out of the Boss 302 original program was due to emissions.. it made more power across the board with 290 exhaust.

 

[BlackNDecker]

Also, I believe the Boss 302R cams require long tube headers to see maximal gains...maybe that accounts for the emission issues?

 

[Boss 327]

Great info....thanks for sharing!


Just found this....Here is a nice package to fill in the midrange with those stage 3 cams:
SEMA 2012: Wiseco/K1 Show off Cage Pistons, 351 Coyote Stroker Kit | StangTV

Damn! Now that's a piston.

 

[BlackNDecker]

Damn! Now that's a piston.

Unfortunately that stroker kit is around $10,000....but dayum it would be bad-ass to have a Boss 351:rockon:

 

[txstroker]

Yes this is something I cant wrap my head around getting a big cam while you gane top end power you loose all your low end and you got only 2000 to 1000 rpm to play with. I don't cruse around at 7000 rpm all day.

 

[twistedneck]

Yes this is something I cant wrap my head around getting a big cam while you gane top end power you loose all your low end and you got only 2000 to 1000 rpm to play with. I don't cruse around at 7000 rpm all day.

You don't lose all the low end, just some at 2500-4000 zone has less. There is so much more everywhere else its well worth it.

 

[2013Boss302]

http://www.stangtv.com/tech-stories/engine/maximizing-boss-302-horsepower-ford-racing/


This is the article that StangTV did for my CJ install

 

[twistedneck]

http://www.stangtv.com/tech-stories/engine/maximizing-boss-302-horsepower-ford-racing/


This is the article that StangTV did for my CJ install

Great write up! I have the same setup and my car also showed that small flat spot around 6500 rpm, must be a function of the CJ intake.

Another note, i thought all along that the CJ BINT / BEXH cams were hollow like the stock boss cams but i was wrong, they are billet.. ah well.

My ride made 489/413 on a Mustang Dyno @7400. It made more spinning higher i saw 493 but that didn't record and i was worried about the engine. I use stock GT rods and pistons. the reason i made a bit more power is down to E85 and more timing i think.

 

[GrabberOrange]

So what everyone here agrees on is that the 2012 and 2013 Boss 302 Mustang does NOT require cam phaser limiters for any stage of comp cams. Its just a straight up swap and a tune. Nothing else.

Correct?

 

[OrangeCompete]

http://www.stangtv.com/tech-stories/engine/maximizing-boss-302-horsepower-ford-racing/


This is the article that StangTV did for my CJ install

Very cool build and excellent description, must have cost some serious coin!

 

[na svt]

I'm not sure...but if I had to guess I'd say that either the CJ's pistons have deeper valve pockets or that cam lobe lift (more so than duration) is what actually moves the valve closer to the piston....I'm guessing the NA CJ has the right combination of the two for proper clearance...

The intake lobe center and duration of the lobe determine PTV, NOT THE VALVE LIFT.

 

[na svt]

Also, I believe the Boss 302R cams require long tube headers to see maximal gains...maybe that accounts for the emission issues?

Any cams, even the stockers, gain power when combined with long tubes. The 302R cams are not that much longer in duration than even the GT cams; lift matters little.