16 replies to this topic

[siztenboots]

Looking at alternative options to changing the inlet for the x20 with half tooth adjustment From the catalogue can't see anything for the z20let , just one cam for the VXR z20leh

[Duncan VXR]

Be interesting to see the outcome of this as I will prob change my cam to something as the head is off. CS do one via Klassen but not cheap! Suspect Regal inlet cam is just the x20 inet cam but more expensive lol. Not looked into full options myself yet

[cheeky_chops]

been reading up on this - the x20xev inlet and exhaust cams are the same so 1 head = 2 inlet cams for Z20LET

There is some confusion if they do work on the Z20 but they def work on the C20LET and they have the same cams as z20.

info:

http://www.astraowne...;highlight=cams

http://www.vauxhall-...ght, cams.html

Got to get my cambelt done so be rude not to if it works!

[MEAGY]

Excuse my ignorence but what are the advantages of a venier pully other that its lighter?

[siztenboots]

Excuse my ignorence but what are the advantages of a venier pully other that its lighter?

allows very accurate and small timing adjustments to the cam

[techieboy]

Excuse my ignorence but what are the advantages of a venier pully other that its lighter?

More finite adjustment to the cam timing. Instead of advancing/retarding it with the OEM pulleys which might mean a 3 degrees or more (depending on how many teeth on the pulley) you can adjust it in much smaller increments. Or, something along those lines.

[MEAGY]

Excuse my ignorence but what are the advantages of a venier pully other that its lighter?

More finite adjustment to the cam timing. Instead of advancing/retarding it with the OEM pulleys which might mean a 3 degrees or more (depending on how many teeth on the pulley) you can adjust it in much smaller increments. Or, something along those lines.

But how does that suit the teeth on the belt? If it has more/smaller teeth than how does it match with the belt?

[techieboy]

Same number of teeth as on the OEM pulley but it's in two pieces so that the outer part (with the teeth) can be rotated separately to the inner part, which is fixed to the camshafts. Once the desired timing is set, the two parts are tightened up and bingo.

Edited by techieboy, 05 February 2009 - 12:50 PM.

[MEAGY]

Cheers techy! Well the setup seems quite straight forward so i may give it a go!

[Duncan VXR]

Need to sit down and have a look at the specs to understand what I am going to change to but options so far seem to be;

Stick with std VXR z20LEH cams - anyone know the spec of this cam? I do also assume the z20let and z20leh are the same cams??

Change to c20xe inlet cam and adj pulley - from looking at the links Paul put up the cam there is a statement that the x20xev inlet cam has 1mm more lift and roughly 20deg less duration than the standard z20let cam.

Regal inlet cam - The regal inlet cam has less lift than the x20vex cam but has the same duration as the standard z20let cam. (I was wrong on my last statement then, they are different lol)

Piper VXR cam change - details on the site - http://www.pipercams...rCamFrames.html

Courtenay Sport do a full set of cams via Stephan Klasen http://www.klasen-mo...;products_id=68
These cams where specially developed by us during long tests. They give a wide revrange up to 7500rpm and constant maximum power from 5500-7500rpm where with the standart cams the maximum power drops at 5500rpm. Especially the for turbos very important exhaustcam gives a good response for the turbo and less exhaustgas in the cylinder when new fresh air comes in. These cams are machined from blanks on a modern CNC-camgrinding machine and have a lift of 10.6mm. They can be fitted on standart camsettings, but you should use adjustable camgears if the cylinderhead was machined on the gasketside. With big Garrett-applications we measured 70HP more at 7000rpm compared to standard cams!!!


vmax also do a set again no data - http://www.vmax.de/

Guess the issue may be if I am going to start to really rev the engine its not just the cam change then is it also worth doing some head work while it's off? (Z20LEH engine) sure the turbo is still the biggest restriction and yes the new one will flow a little better and take the abuse longer but its not a big GT turbo and still have the bog manifold lol

If only lots of money and time were available

[MEAGY]

Might see what deal piper come up with on the cam & pulley!

[Duncan VXR]

Might see what deal piper come up with on the cam & pulley!

Cost may also play its part (does most times lol) but def interested if cheap enough drop us a pm when you have details

[Exmantaa]

On higher boosts the exhaust timing becomes very important on a LET engine! (backflow of gas in cilinder) Somewhere I have a graph from a Stephan Klasen exhaust cam in a C20LET. This not only had more high rpm power, but also lowered the exh. temperature a lot!

[cheeky_chops]

On higher boosts the exhaust timing becomes very important on a LET engine!

yep, the theory is only swap the x20xev inlet cam, not the outlet

[Duncan VXR]

Spoke to Garry Curley today at Piper regarding the cam / pulley set for the LEH engine and my requirments. All sounds very good so will whip my cams off and get them to him and also my pulleys so they can make sure they have the correct ones as he was not 100% sure the eco tec engine tooth spacing was the same. Very nice guy and certainly knows his stuff

[Crabash]

Been looking at this myself but I decided it's something I would do as part of an "stronger" engine rebuild at a later date.

But a site I used to find out about the how's and why's is....

http://www.max-boost...cams_C20LET.htm

Might be a usefull read for those looking into it.

[karlbac]

Ok I exhume this topic because I need a pair of cam pulleys and it's not so easy it seems.

We've got an half ring behind the exhaust pulley that's used by the camshaft position sensor and the only manufacturer that offer this option is RnD, but this guy don't want to sell me these pulleys

So is it possible to use the pipercams pulley for example, do the ECU would work without the camshaft position sensor and do a remapping could sort an eventual problem ?