Camshaft duration C&C

[robftw]

I'm looking to get my camshaft reground locally and i've come up with two possible grinds that will suit my needs.

I primarily drive this car on the street, and take it to the strip every weekend. I'm looking for something that would wake the car up from about 2000 to 6500 Rpm These are the two grinds i've been looking at, and i'd like some opinions / input on them.

1) Lift(In/Ex): .460/.460. And the Duration is (In/Ex): 274/274

2) Lift(In/Ex): .460/.460. And the Duration is (In/Ex): 274/280

And a 3rd option which i'm not so sure about is this one,

Lift(In/Ex): .460/.460. And the Duration is (In/Ex): 270/280 MSA sells this grind and i guess the car really bogs down until 3000rpm

The car has an L28 in it with an MSA thermal coated header and exhaust system, emissions removed with a P90Turbo head.

I'm really leaning towards number 2

Edited July 18, 2011 by robftw

[LeonV]

If those are your choices, there won't be much of a difference between them. The MSA one may come on at slightly higher rpm. Number one and two are almost identical, with #2 probably shifting the powerband up a tiny amount.

Why do you limit yourself at .460" lift, valve springs?

[robftw]

Yes because of budget reasons i want to keep the lift at .460, unless i can reach .480 without any troubles. I haven't found any information on the web about stock springs an .480 cam lift

EDIT: Just called the machine shop, they can resurface my rockers for 4$ each. instead of buying new ones

I'll get new springs and grind it to .480 lift

Edited July 18, 2011 by robftw

[LeonV]

While we're on this topic, increasing lift will not hinder performance. The only detriment to increasing lift is higher valvetrain acceleration, which in turn increases valvetrain stress and affects stability.

The lesson being: go as high lift as your hardware safely allows.

[robftw]

Thats what im mostly worried about.

The cam shop just called me back and suggested this grind:

.460/.460. And the Duration is (In/Ex): 270/280

that would allow me to keep my stock springs, and possibly lash pads. Which would actually work out great because my valvetrain was just rebuilt and all of these parts are new.. this cam "should" pull hard from 2400-6600 which is right where i want it to be

[LeonV]

I would recommend putting the car on a dyno before and after to see what it actually gets you. It would be nice data to have.

How much is the shop charging for the cam regrind?

[robftw]

$150 for the grind $4 per rocker

I'll see what i can do dyno wise, the pulls are rather expensive here

[LeonV]

Around here dyno testing/tuning runs about $90-$100 per hour, and I consider it money well spent!

If I were going for a regrind, I would just send the cam to Isky (they have a ton of experience with Z cams), resurface rockers, get some matching valve springs, lash pads and be on my way. My point about the dyno is, what sort of "bang for your buck" will you be getting with the mild cam change? If I decided to change cams, I'd want something more. Call Isky and talk to Ron, maybe you'll change your mind.

Otherwise, you can try the local place, or just drive your car the way it is.