Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Cat cams

Oh man, I need to hang around the CEG more often then I used to! I just commited to buying a set of SVT cams for the 3L, doh!

What do you mean no valve timing points... Havent heard of centerlines or valve seperation angels have we... <smacks forehead...

Further more on the power shift. That is a very accurate depictation of what will happen with their biggest cam. That doesnt nessasarily mean the peak will go up 30-35 percent but out in the 7300 area you could see that much..

http://www.focaljet.com/ubbthreads/showflat.php?Cat=&Board=UBB2&Number=803159&page=0&view=collapsed&sb=5&o=&fpart=1

Look at this post I done on the 2.0 Liter zetec.. this is what i mean.. Look for my graphing approx half way down.

2394002
&#9658;
INTAKE EXHAUST


clearance [cl] 0.00mm 0.00mm
duration [0.1mm+cl] 257° 257°
duration [1.0mm+cl] 216° 216°
valve lift [cl=0] 10.20mm 10.20mm REQUIRED PARTS
cam lift 5.00mm 5.00mm
peak angle 112° 112° followers: O.E.M.
timing [1.0mm+cl] -4/40° 40/-4° retainers: O.E.M.
lift at TDC [cl=0] 0.70mm 0.70mm

And what do you think that is... just because the cam is not dual pattern doesnt mean anything. Most v8`s run single pattern cams.. Call a 454 peaky all you want..

Im really getting sick of some peoples attitudes in this place. With this whole my opinion is correct and your doesnt matter. Why dont people open there ears and try to help others instead of being so destructive... We are here to help each other after all... right?

Here is the graphing. Here you go.

Its on their website click the the grind number out to left and it presents a cam card... I just dont see where you people are getting this 1 valve opening for an extra 8 degree`s is going to COMPLETELY change the curve of an engines output. Your talking mayby 4 or 5 hundreths of an inch of additional lift. This might account for 3 to 4 ft lbs of torque in the top end at the expense of the same amount at the bottem. Cams are cams. You cant have top bottem and middle unless you have a system that changes ramp rates lift and duration.

Just made me angry when someone came out and got on their soap box and said that these cams would only make the engine drivable in the 4800-7000 range when the the cat stage 2`s put down more power then the stock from 3500 north and are only down by mayby 10 ft lbs of torque by 2000 rpms.

I could careless what these engines make at 2000 rpms no one normally drives an engine in that range anyways. I ran a cam equivalent to the cr3 intake and exhaust cam in a zetec with a short runner intake manifold and that car still pulled very well from 3000 up.

Being one of the very few Duratec drivers out there that had hot cams, I can tell you that lots of duration doesn't kill the bottom end as much as you think.

If my memory serves me right they were 280deg and very little over stock lift. Since these cams were made by SVO a while back, it was very hush hush at the time. Before you even think about it don't IM me for specs because I don't have em. You can try Chris Rienke, he might be able to give you a little more info on them.

Click here to see my dynos

I just wonder how aggressive those ramps are, the ones I had had a pretty high rate and made a decent amount of bottom end.

Like 35-40 percent greater valve accel then stock. 10.00 mm lift at max compared to 7.6 or so at less seat duration. (257@ .1 mm cam) Itd make a great turbo cam but those ramps are really aggresive. Seats might not like it much, but from a performance side of the house I dont see how you could go wrong with these cams they just breath so much deaper then stock.

Yeowza!

Anyone out there looking to buy a good set SVT cams?

Well for starters the lift is not much over stock.

Stock "theoretical" valve lift is ~9.80mm (vs 10.15 to 10.70)


Also you still DO NOT have the valve points. Intake/exhaust open & close. While you have the duration of each cam you can not nail down the rpm range and curve size without knowing WHEN it's actually happening.

Stock duration
Intake Primary: 244
Intake Secondary: 250
Exhaust: 260

SVT duration
Intake Primary: 250
Intake Secondary: 258
Exhaust: 262


For instance the SVT cams have more duration then stock, but NONE of the valve timing points are the same. It's not X extra duration from a set point or even in the middle of an equal number of degrees from each point.

Valve timing is everything! Every point plays a large part. How close to TDC it opens, how late after BDC it closes, etc, etc and vice-versa for the exhaust cam.

Using just a generic duration is very inaccurate.
So is your thinking about comparing a single cammed pushrod 2 valve engine to a DOHC 4 valve engine. The changes on a DOHC engine would be much more drastic in effect.