page 14 http://www.avl-schrick.com/dat/MK/Sc...202011%20E.pdf

 

Thanks Nick.............do you know of anyone that installed one of the cams listed and were they satisfied? Any idea of power gains?

 

I will look into this for you!

 

in for info

 

I have flow numbers for stock and ported head . so if you can get me lift and duration #s for these cams it would be great . thank you

 

If you check the link I posted above the data is there on page 14

 

Anyone know the duration of stock cams ?

 

higher duration cams will .................

 

Porsche's 997tt engine already has "Variocam Plus", Porsches own version of VVT or VCT (variable camshaft lift) which provides optimum power across the entire rev spectrum. Has anyone actually seen the physical change between the 2 cams ie:modified vs unmodified to explain the differences? It would be interesting to see what has been done. There are benefits of altering lift where performance is the goal on engines which do not have this VCT technology but there is always a trade off in the rev/power ranges as mert as pointed out in his account, where power is swayed more to either side depending upon where it is required. I guess with the increased lift duration (which i thought would be controlled by VCT anyway) which they say is good for racing and beneficial only at high rpm, but what about down low and midrange? How does it affect the VCT and what are the trade off's? I note the OP was enquiring the differences so i am wondering why he is questioning his mod? Is it the case the difference can't be felt from how the engine was prior too this mod? Or is it the case other things were also done to the engine at the same time so now it's hard to pinpoint exactly where the gains actually came from?

 

The camshafts that Nick mentioned, found on this link are made by Schrick.

The specs are below and we typically see 25 to 30 hp & torque in the mid and top rpm range with our programs.

Inlet Cams:
Cam lift (Valve Lift) I/E (mm) = 11.0 mm
Duration°/Peak Timing = 288°/105--135°
Valve Lift at TDC I/E (mm) = 0.4-2.4mm

Outlet Cams:
Cam lift (Valve Lift) I/E (mm) = 11.0 mm
Duration°/Peak Timing = 292°/110°
Valve Lift at TDC I/E (mm) = 3.4mm

Thanks,
Rhonda

 

Hmm nice!!!

I may have to slap some of those babies in my engine too

What will the stock motor rev to with the cams installed?

 

So is there any decrease in the low end? Or does VCT take care of that leaving it the same or, does it add a little extra on the lower end. Looking at it, it's quite an expensive mod for the hp gained especially when you add the cost of parts (cams, bearings gaskets labour and other expert machining work such as porting. Or is porting not an essential component enabling the cams to achieve the claimed gains with these cams? Mert pointed out there is quite a delicate balance required in the porting procedure so everything flows/operates in harmony.

 

Your rpm is limited by the hydraulic dual stage lifters after installing a set of upgraded cams.Usually about 7800 is tops.I know they start to come apart after 8000 rpm.The next step is solid lifters.

 

Maybe if it is not just as simple as replacing the stock cams then it is best to do them when the engine is rebuilt I guess.


Let's see what Rhonda has to say!

 

IMO it is a complete waste of time and money to do cams unless you are doing major head work and a complete rebuild......been there done that