Camshaft For 1.9 122bhp Cat Version

[B1ack_Mi16 67]

A guy I know have asked me some advice on tuning his 1.9 122bhp cat version engine.

He only want's a little extra grunt, and is not going to spend much money on bottom end ++.

 

I've adviced him to get the head refurbed along with a little porting and 3 angle seats just to be sure it's in good condition. I also said that a 4-2-1 exhaustmanifold and a camshaft would be a good place to start (and maybe also stop, as this is just to get a little extra grunt).

 

Coincidently a mate of mine have a Dr Schrick cam lying around, he brought it over to my place this evening and I've found this information about the camshaft:

 

12mm lift

Dur in; 268

Dur ex; 268

Lobecentres: 112

 

22-66-66-22

Lift (In/Ex) @ TDC: 1.7mm

 

Clearances:

In: 0.20mm

Ex: 0.35mm

 

Will this cam be too wild to run on a standard plenum and with standard management?

I'm not very into this 8v engines so really don't have a clue about how it will work.

 

Think I read somewhere that the standard 1.9 cam has 9.7mm lift, so this one surely must be quite a bit wilder.

 

Possibly need other valve-springs too?

 

Thanks for any input.

 

Edit: Also forgot to ask.. what compression should be run with this camshaft?

Edited July 27, 2006 by B1ack_Mi16

[petert 587]

12mm is border line for the OE springs. You'd need to check. The XU9JAZ cam still has 0.445" lift on the inlet, the same as the XU9J2. The 75kW DFZ smog cam is 0.405". The best thing he could do is prep the seats as suggested and skim the head 1mm to get 10+:1 CR. You'd need to compare the two cams more thoroughly, as there may not be much difference.

[B1ack_Mi16 67]

I see, so that's why catcams only go to 11.9mm lift on their lairiest OEM cam.

 

Probably better of getting a catcam then, a little more plug and play when the valvetrain can remain untouched.

 

Is anyone using this catcam then? Experiences, powergains?

 

duration [0.1mm+cl] 267° 267° 
duration [1.0mm+cl] 235° 235° 
valve lift [cl=0] 11.65mm 11.65mm 

peak angle  110° 110°
timing [1.0mm+cl] 8/47° 48/ 7° 
lift at TDC [cl=0] 2.10mm 2.00mm

 

And btw.. specs of the standard cam for the cat version, anyone got it?

[petert 587]

And btw.. specs of the standard cam for the cat version, anyone got it?

 

It's around 225 deg. @ 0.050". The Catcams figures above are similar to a grind I use and gives a nice power devilery to 6500. Idle is not smooth, but fine for the AFM.

[PumaRacing 2]

12mm is border line for the OE springs.

 

Not according to my measurements. At the normal fitted height of 42.5mm the standard spring is 2mm from being coilbound at 12mm lift and could theoretically cope with 13mm lift

 

The std cam has 233 degrees at 1mm lift and 11.3mm lift. No point at all in fitting something with less than 5 more degrees duration or you won't notice any difference. That's why the Kent PT36, Piper 270 and the lowest duration Catcam are no better than the std one.

Edited July 28, 2006 by PumaRacing

[petert 587]

Not according to my measurements.

 

We're both probably correct, because I was thinking of the DFZ head. The JAZ cam is a bit tamer than the 130hp version.

[B1ack_Mi16 67]

So basicly there may not be too much in that catcam either?

 

Maybe I shall just try the dr-schrick one and see how it works, at least it's probably a tad hotter than the car-version cam and doesn't cost anything.

[Dino 3]

As your friends car will be running Motronic management (albeit 1.3 still running an AFM) it shoud be able to handle an uprated cam. (mine idled fine with an uprated cam although it was only a piper 270 which are only slighty lairier than std)

[PumaRacing 2]

So basicly there may not be too much in that catcam either?

 

Maybe I shall just try the dr-schrick one and see how it works, at least it's probably a tad hotter than the car-version cam and doesn't cost anything.

 

You need to measure the duration at 1mm lift. Going by quoted seat durations is pointless.

[Anthony 1,003]

The std cam has 233 degrees at 1mm lift and 11.3mm lift. No point at all in fitting something with less than 5 more degrees duration or you won't notice any difference. That's why the Kent PT36, Piper 270 and the lowest duration Catcam are no better than the std one.

Are you sure that's not the 1.6 cam that you're talking about, as I was under the impression that the 1.9 cam had somewhat less lift that than? The figures for the two cams listed on the main site are...

 

1.6 XU5JA 115 bhp

Lift 11.5 mm

Duration 230 deg (inlet) 223 deg (exhaust)

 

1.9 XU9JA 130 bhp

Lift 9.7mm

Duration 234.5 deg (inlet) 228 deg (exhaust)

 

I've never measured them myself so I've no idea how accurate those figures are, although the 1.6 cam does look more pointy and like it has more lift from comparing the two side-by-side (and judging by a friend that put a 1.9 cam in his 1.6, somewhat different characteristics as the 1.9 cam seemed much less revvy at top end like you get with a worn 1.6 cam)

[PumaRacing 2]

Are you sure that's not the 1.6 cam that you're talking about, as I was under the impression that the 1.9 cam had somewhat less lift that than?

 

Quite sure thanks. I've measured enough of them. As PeterT has already noted, the 1.9 gti cam has 0.445" (11.3mm) lift and the duration at 1mm + CL is as I say.

 

No XU cam I know of has as little as 9.7mm lift so I don't know where that info came from. Anyway it's wrong.