Q4/Integrale cam lift

[corriedw]

Can one of you please tell me what the lift and duration on a std Q4/Integrale cam is?

I have noticed that the boost on these cars are very high when compared the amount of power made. With a smaller turbo(T2.8 Garret) stuck on a std TS at 0.5 bar boost delivers more than 220 whp at 1200m above sea level.

The theory for hydraulics say a pump make flow and a valve or restriction in the system cause pressure. When running an engine the flow through the induction pipes, throttle, intake manifold and the valves will create this pressure. From a std TS I do not see large differences, what cause the boost pressure to be higher on a Q4?

[Steve Webb]

Hi Corrie,

these are the standard durations:

Intake
opens before TDC 8*
Closes after BDC 35*
duration 223*

Exhaust
opens before BDC 30*
closes after TDC 0*
duration 210*

The in the workshop manual it states that the minimum lift should be:

Intake 8.6mm
Exhaust 7.5mm

Hope that helps a little.

[Evodelta]

Can one of you please tell me what the lift and duration on a std Q4/Integrale cam is?

I have noticed that the boost on these cars are very high when compared the amount of power made. With a smaller turbo(T2.8 Garret) stuck on a std TS at 0.5 bar boost delivers more than 220 whp at 1200m above sea level.

The theory for hydraulics say a pump make flow and a valve or restriction in the system cause pressure. When running an engine the flow through the induction pipes, throttle, intake manifold and the valves will create this pressure. From a std TS I do not see large differences, what cause the boost pressure to be higher on a Q4?

What is the CR on a std TS? 10:1? A lot more than 8:1 on the Lampredi, that's why you make more power on less gauge pressure.
Cylinder pressures will be similar....

[corriedw]

What is the CR on a std TS? 10:1? A lot more than 8:1 on the Lampredi, that's why you make more power on less gauge pressure.
Cylinder pressures will be similar....

I agree with your reasoning. But according to the figures the Q4 should be better. To get everybody understanding: Assuming correct A/F ratios, the higher the pressure in combustion chamber is, the bigger the combustion pressure will be during burning of the fuel.

Simple comparison: Absolute pressure(Ambient press. + Boost press.) X Compression ratio = combustion chamber pressure (lets do this in pound/sq inch)
On the Q4: (15 + 15) X 8 = 240
Squadra: (15 + 18) X 8 = 264
TS @ 0.5b: (15 + 7.5) X 10 = 225

With low compression/high boost the flow from the turbo is larger and normally more effective. Also larger turbos running slower have lower supply temperature making them more effective. But in real life we found better figures from the High compression/low boost engines. This is not competition applications.

The TS cam is much similar with a little overlap and a 9.3mm lift

I do not quite understand the logic? Does the Q4 and Lancia intake manifolds not flow well? What do I miss?

[corriedw]

Hi Corrie,
these are the standard durations:
Intake duration 223*
Exhaust duration 210*
The in the workshop manual it states that the minimum lift should be:
Intake 8.6mm
Exhaust 7.5mm
Hope that helps a little.

It does help, Thank you Steve

[corriedw]

Steve, you do not have the spesification for the cams, in the NA Lancia, that use the same 16v engine as in the Q4. Which Lancia would that be.

Are they also prone to wear as in the Alfa TS. How available are these cams 2nd hand and new and at what prices.