camshaftsbp
Differences
This shows you the differences between two versions of the page.
Both sides previous revisionPrevious revisionNext revision | Previous revisionLast revisionBoth sides next revision | ||
camshaftsbp [2022/01/02 16:35] – [Quotes] imakeyoufast | camshaftsbp [2022/01/02 22:55] – [Camshaft Theory BP] imakeyoufast | ||
---|---|---|---|
Line 1: | Line 1: | ||
====== Camshaft Theory BP ====== | ====== Camshaft Theory BP ====== | ||
+ | We had never too much lift ([[https:// | ||
+ | - DBilas | ||
+ | |||
+ | **IVC, IC intake valve closes (at)** | ||
+ | |||
+ | * The significant value to estimate the target power rpm of the camshaft | ||
+ | * Later IVC -> More time to overcome the pressure differential, | ||
+ | * Too late IVC -> Cylinder pressure > Manifold pressure, loss of power (but efficiency gain through better expansion (reverse Flow Atkinson Cycle [[https:// | ||
+ | |||
+ | **OL, O/L overlap (OL duration = IVO + EVC)** | ||
+ | |||
+ | * Overlap can be used to evacuate the remaining intert gas out of the cylinder | ||
+ | * Free Flow Exaust -> Inertia of the exhaust gas helps via scavenging effect | ||
+ | * Positive Pressure Intake -> Inertia of the intake charge pushes the remaining inert gas out | ||
+ | |||
+ | If air or intake charge is pushed into the exhaust, NOx / HC emission increase. Also precious charge is wasted, resulting in higher BSFC. | ||
+ | |||
+ | **EVO exhaust valve opens (at)** | ||
+ | |||
+ | * Too early -> Gas goes through the exhaust valve and doesn' | ||
===== Rotrex Specific ===== | ===== Rotrex Specific ===== | ||
==== Consultation with Jeff David, who developed a Rotrex specific Camshaft for Honda K22 ==== | ==== Consultation with Jeff David, who developed a Rotrex specific Camshaft for Honda K22 ==== | ||
+ | |||
+ | **Preparation** | ||
In my experience it's a combination package. For the bolt on's like inlet manifold, TB, exhaust headers and exhaust system use what a good/ | In my experience it's a combination package. For the bolt on's like inlet manifold, TB, exhaust headers and exhaust system use what a good/ | ||
Line 24: | Line 46: | ||
* Free Flow Catless: 4 PSI Backpressure ([[https:// | * Free Flow Catless: 4 PSI Backpressure ([[https:// | ||
* Metal Cat, 2,5" Exhaust, Resonator and Magnaflow Muffler: 5-5.5 PSI @ 10 PSI MAP @ Redline, | * Metal Cat, 2,5" Exhaust, Resonator and Magnaflow Muffler: 5-5.5 PSI @ 10 PSI MAP @ Redline, | ||
+ | |||
+ | **Blow Through / High Overlap** | ||
As it's important to trap the fuel/air on the valve overlap, higher lift and longer duration NA cams tend to loose power due to blow through. | As it's important to trap the fuel/air on the valve overlap, higher lift and longer duration NA cams tend to loose power due to blow through. | ||
Line 34: | Line 58: | ||
So I would try the mildest inlet cam you can find, hopefully with more lift than stock. And a stage 2 exhaust cam as a starting point. Fit a venier exhaust cam gear to advance it's centre line. Position based on dyno tuning but 6 degs advanced is a starting point depending on the duration. | So I would try the mildest inlet cam you can find, hopefully with more lift than stock. And a stage 2 exhaust cam as a starting point. Fit a venier exhaust cam gear to advance it's centre line. Position based on dyno tuning but 6 degs advanced is a starting point depending on the duration. | ||
+ | |||
+ | |||
---- | ---- |
camshaftsbp.txt · Last modified: 2022/01/03 09:41 by imakeyoufast