16V PERFORMANCE CAMSHAFTS
XU10J4R/XU10J4RS
XU10J4R
The XU10J4R engine, as fitted to later 306 and 406 models, has a detuned version of the GTi6 (XU10J4RS) engine. The inlet cam is very mild, having a duration of just 200 deg. @ 0.050" lift and 0.360" total lift. This makes it an ideal candidate for more aggressive profiles that have been so popular in the XU9J4/XU10J4 engines. Please keep in mind that these are a big step up from the standard camshaft.
Valve springs are the biggest issue with this engine. They only have a single spring compared to the double fitted to the RS version below. Whilst it is possible to fit a standard RS camshaft to one of these engines, you risk valve spring bind at full lift. Consider 0.380" (9.65mm) as a safe maximum lift when using standard valve springs on an XU10J4R engine.
Stage I
This grind will work with the standard ECU and injectors, just. Use with either the standard exhaust cam, or the same grind on the exhaust.
| Advertised Duration | 260 |
| Duration @ 0.050” | 219 |
| Maximum Lift | 0.362" |
| Lift @ TDC | 0.050" |
| Lobe Centre Angle | 110 |
| Part Number | RH432B |
Stage II
Aftermarket ECU and bigger injectors are mandatory with this cam. For the exhaust cam, use the Stage I grind above (16R432B).
| Advertised Duration | 260 |
| Duration @ 0.050” | 226 |
| Maximum Lift | 0.350" |
| Lift @ TDC | 0.065" |
| Lobe Centre Angle | 109 |
| Part Number | 16R426B |
XU10J4RS
The XU10J4RS was fitted to the Peugeot 306 GTi6 and Citroen Xsara VTS. The cams in this engine have more duration and lift than the XU10J4R. Standard specifications are 205 deg. @ 0.050" lift and 0.395". This is still quite mild by performance camshaft standards however. More power can be unleashed cheaply with a camshaft upgrade. Because the standard cam has a healthy amount of lift, more interesting profiles are available for regrinding than is possible with XU9J4 and XU10J4R camshafts.
A major issue with these engines is the lack of valve to piston clearance at TDC. Many tuners have bent valves through not timing camshafts correctly. These engines have adjustable pulleys as standard so there is no excuse for not setting up the cams correctly. For this reason, I have revised the regrinds available for these engines.
I currently can not supply new cams for XU10J4R or RS engines.
Stage I Inlet (regrind only)
| Advertised Duration | 250 |
| Duration @ 0.050” | 215 |
| Maximum Lift | 0.380" |
| Lift @ TDC | 0.042 |
| Lobe Centre Angle | 111 |
| Part Number | RSH435A |
Stage II Inlet (regrind only)
| Advertised Duration | 255 |
| Duration @ 0.050” | 221 |
| Maximum Lift | 0.399" |
| Lift @ TDC | 0.050" |
| Lobe Centre Angle | 111 |
| Part Number | RSH436A |
Exhaust Cam Options
Stage I - Use the standard XU10J4RS exhaust cam or RSH435A
Stage II - Use the RS435A grind on the exhaust