Opel Club Finland (OCF)

Terve!

Pari venttiiliä solmussa joten aloin purkaa kantta eilen.

Nytkun on kansi kädessä niin kannattaako samalla tehdä jotain pikkuvirityksiä?

Ajattelin että laittais xe nokat ja samalla kattoo kanavat läpi valuvirheistä jne..
Ja paljonko ne xe nokat vaikuttaa menoon jos ei muita muutoksia oo tehty?
Z20LET kannentiiviste laitetaan luultavasti myös..

Onko muuta mitä kannattais samalla tehdä?

Onko kellään GM osanumeroa nokista? Pitäis vaan varmistaa ettei siellä jo ole noita XE nokkia..

Jos laittaa XE nokat niin pitäisi ymmärtääkseni laittaa imunokka hampaan myöhempään niin saa parhaat tulokset?

http://www.max-boost.co.uk/max-boost/cy ... C20LET.htm

(stock LET)

IN: 7/64, i.e. duration 251

EX: 50/20 i.e. duration 250, overlap 27 degrees


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(XE inlet retarded by a tooth)

IN: -3/78, i.e. duration 255

EX: 50/20 i.e. duration 250, overlap 17 degrees

The XE inlet cam has a bit more duration, and more importantly 1mm more lift (9.5mm instead of 8.5mm).

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Setting 2 (or even better XE inlet retarded by 5 - 8 degrees) has the following cumulative advantages:

There is better filling of the cylinders as the intake cycle now lasts a bit longer and lift is 1mm higher (more area under the curve)
There is less overlap, reducing reversion at high revs. This addresses a serious limitation of the stock KKK16 exhaust setup The graph below is from the racing version of the LET and it, too, was plagued by reversion from 4500rpm upwards. Typically this feels like the engine runs out of breath - with this mod it feels more free-revving.
The intake valves are kept open for longer during the compression stroke, 14 degrees in the extreme setting 2. This reduces the dynamic compression ratio, something quite useful for engines running high boost while keeping the stock CR. It's a good way of slightly decompressing the engine without affecting the squish band. The compression test figures (dry) were stock: 12.0, 12.0, 11.8, 11.9. With inlet cam setting2:10.4, 10.9, 10.2, 10.8. So from an average of 11.9bar it came down to 10.6 This is like fitting lower-compression pistons!
A by-product of less overlap is smoother idling. It purrs like a pussycat and the servo is happy too.