New guy ? about cam swap and idle characteristics

4.6_02_Black_GT said:

Indinia,

Seem cams are on everyone's mind lately we are all running out of bolts on to add. Anyway I too am swapping cam soon. I have narrowed down my choice. Heres a little info, I have found. Hopefully this will set up on the path.

Your Stang is 02 like mine so we have both have PI heads(Comp makes PI and NPI cams Romeo engines). Some dyno runs have shown cams can provide 20-25 HP to our motors. Some a little more(have seen 30hp quoted..but I question that high a number) based on intake and exhaust mods. 20 seems a fair expectation. Both company cams are roughly $500 plus $180 for springs. Wheter or not you need tune seems to be based on preference. The cam swap will give you greater power in the range that is stated on the cam card. Typcially cams are going to help you out above the 1800-2000 rpm range and up, with the stiffer springs and better breathing at high rpm you can possibly push you motor up a few hundred rpms as well and gain some power up high.

Lots of people on Stang Net are favoring the Comp cam xe270(me too ). The Stage 2 VT cams seem to have a big following over on Modular Depot. They have good reviews there as well.

The only drawback to concern you should be the cam swap is straight forward but requires attention to detail to avoid f@@#$$ your timing up, that would be bad(4 more hours to pull the timing cover and reset it). The valve springs will take a day to install and requires patience(keepers are slippy and small). You will need a few speciality tools you might not have a cool little valve spring compressor($50) and cylinder leak down tester($80) and possibly and timing chain locking tool(or a spare set of hands). .

Some people have had some clearance issues with aftermarket heads and aftermarket flat-top pistons. Some people have complained that the Stage 2 Comp grind caused some piston to valve contact even with stock pistons and heads(do a search for details) It is a fact the Comp Stage 2 is really really aggressive and is very close to the maximum duration for our stock setup. Notice how the VT Stage is has slight less duration on int/exh and havent seen anyone with proven ptv contact yet.

That being said I'm still leaning toward the Comp x270 cam. There are as many people with the 270 grind that have NO problems as people with issues. I have seen no dyno comparisoin between the Stage 2 VT and Comp Stage 2. So there no hard facts as to which one would make the most power. But they will both be close in power. Stage 1...are just not worth the effort to use if you keeping the engine in the car. Stage 2 is the way to go... You pick a company either would should make you happy. You might also check out Crowder and SeanHyland they make cams too.

hope this helps

Comp Cam
Stage 1 xe262 226/230 @.050 with .550 lift (1400-5400 rpm)
Stage 2 xe270 234/238 @.050 with .550 lift (1800-5800 rpm)

VT Engines
Stage 1 N/A 224/226 @ .050 (total lift no stated) (rpm not given)
Stage 2 N/A 225/235@ .050 (total lift no stated) (rpm not given)

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96SOHC said:

Just to add to the VT cam specs: Stage 1 lift is 540/550 with a C/L of 110. Stage 2 lift is 560/575 with a C/L of 108. Not sure of the RPM ranges for either.

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VTEngines said:

RPM range also depends on what the head flow is. On a stock head, the rpm range will be 3000-6500...about 500rpn higher with the Stage 2's. I just posted some Stage 1 results with stock heads over on Modular depot. They gained 33rwhp peak to peak and about 50rwhp at 6000rpm. Stage 2's will see similar results with stock heads...but really shine with some addition head airflow.

Hope this helps....

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