The figures are based on OE spec where possible and where not they are based on my personal average obsevations when checking many of the same type of cam. Of course the info is correct (to the best of my knowledge) at the time of writing and I may change the info when I have confirmed new or updated info.
Here is a (very bad) image of the mule 998 motor I use for cam checking;
This image shows the oil pump slot drive which is common to all A+ cams. All the standard cams listed below are the A+ slot drive type, with 1/2" wide lobes.
This is the OE 848 A+/early 8.3:1 Low CR 998 A+ cam. It has 2 x 1/8" raised rings between lobes 3 & 4.
Checking height: 0.015" @ lobe
Timing: (Intake): 5/45 (Exhaust): 40/10
Nominal lobe lift: (Intake): 0.235" (Exhaust): 0.235"
Duration (Intake): 230 (Exhaust): 230
Lobe centre angle (Intake): 110 (Exhaust): 105
Lobe separation angle: 107.5
Lift on overlap: 0.025"
Accuracy: Very Good
This is the OE A+998 Cam (9.6:1/10.3:1 CR), It is also used in economy versions of the metro 1275, such as HLE and LE models, identified by the 1/8" raised ring between lobes 5 & 6.
Checking height: 0.017" @ lobe
Timing: (Intake): 9/41 (Exhaust): 49/11
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.249"
Duration (Intake): 230 (Exhaust): 240
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.031"
Accuracy: Very Good
Shown Below is the OE 1275 A+ sprite/injection(50hp) cam.
It has 2 x 1/8" raised rings between lobes 7 & 8.
Checking height: 0.017" @ lobe
Timing: (Intake): 9/41 (Exhaust): 44/6
Nominal lobe lift: (Intake): 0.235" (Exhaust): 0.235"
Duration (Intake): 230 (Exhaust): 230
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.025"
Accuracy: Very Good
The standard A+ 1275 cam as fitted to normal non-economy non performance engines is unmarked.
Checking height: 0.017" @ lobe
Timing: (Intake): 9/41 (Exhaust): 55/17
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.263"
Duration (Intake): 230 (Exhaust): 252
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.040"
Accuracy: Very Good
Below is the SPI Copper cam as fitted to all injection coopers (63hp) Interestingly it has the same profile as the standard 1275 A+ above. It has 3 x 1/8" raised rings between lobes 7 & 8.
Checking height: 0.017" @ lobe
Timing: (Intake): 9/41 (Exhaust): 55/17
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.263"
Duration (Intake): 230 (Exhaust): 252
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.040"
Accuracy: Very Good
This is the MPI cam as found in all factory MPI's. It has no ID marks as the other cams, but is identified by the lack of distributer drive gear (is actually machined off), and it has a lobe (where the fuel pump accentric was on all other A-series engines) to enable the ECU to sense its position.
Checking height: 0.017" @ lobe
Timing: (Intake): 14/46 (Exhaust): 55/17
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.263"
Duration (Intake): 240 (Exhaust): 252
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.040"
Accuracy: Very Good
A new addition, this is a rare item. It an A+ version of the old 2A948 profile. I have only ever seen these on some early MG metros, and as a result I do not know if this was ever a truly standard fit in an A+ engine. It is identified by having 3 x 1/8" rings between lobes 3 & 4.
Checking height: 0.017" @ lobe
Timing: (Intake): 20/52 (Exhaust): 56/18
Nominal lobe lift: (Intake): 0.265" (Exhaust): 0.265"
Duration (Intake): 252 (Exhaust): 252
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.048"
Accuracy: Very Good
This is the MG Metro cam, as fitted to MK2 metro VDP's, RSP Mini coopers, Metro Gta'a and 1275 Metro Sports.
It Has a 1/4" groove machined into the cam after the number one lobe. (piccy shows a reprofiled MG cam, with the same marking)
Checking height: 0.017" @ lobe
Timing: (Intake): 16/56 (Exhaust): 59/29
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.263"
Duration (Intake): 252 (Exhaust): 268
Lobe centre angle (Intake): 110 (Exhaust): 105
Lobe separation angle: 107.5
Lift on overlap: 0.054"
Accuracy: Very Good
Below is an image showing the fairly typical wear pattern that I find on strip down of a road engine equipped with 1.5:1 ratio rockers. Typically mileages from 10,000 to 50,000 depending on use and oil changes etc.
This cam used to be OE SPI cooper.
Here is another pic of a worn cam, this cam from a 18,000 mile MPI with a typical 90hp kit fitted. It shows an intake lobe;
This shot shows what it should look like;
This is another lobe from the same cam, this time an exhaust lobe;
Ok lets move on to the Aftermarket cams,
First off is the excellent Swiftune SW5 road cam, these figures are based on my observations based on 2 new examples I measured about 2 years ago. The figures are to be read as average of the 2,
Checking height: 0.016" @ lobe
Timing: (Intake): 16/48 (Exhaust): 52/12
Nominal lobe lift: (Intake): 0.281" (Exhaust): 0.281"
Duration (Intake): 244 (Exhaust): 244
Lobe centre angle (Intake): 106 (Exhaust): 110
Lobe separation angle: 108
Lift on overlap: 0.036"
Accuracy: Good
Ok at last the SW5-07
Checking height: 0.016" @ lobe
Timing: (Intake): 15/47 (Exhaust): 52/10
Nominal lobe lift: (Intake): 0.286" (Exhaust): 0.286"
Duration (Intake): 242 (Exhaust): 242
Lobe centre angle (Intake): 106 (Exhaust): 111
Lobe separation angle: 108.5
Lift on overlap: 0.0385"
Accuracy: Exceptionally Good
The next in the Swiftune family is the SW10, which is basically a real hot road cam like a 286 but with better emissions and suited to road use where wear characteristics are more important than outright performance.
b]Checking height:[/b] 0.016" @ lobe
Timing: (Intake): 34/66 (Exhaust): 70/30
Nominal lobe lift: (Intake): 0.291" (Exhaust): 0.291"
Duration (Intake): 280 (Exhaust): 280
Lobe centre angle (Intake): 106 (Exhaust): 110
Lobe separation angle: 108
Lift on overlap: 0.070"
Accuracy: Good
Next is the much under used Kent 246 a nice all round road cam that has a little more bite than the SW5, these figures are based on kents own specs, plus with my own additions looking at 1 cam.
Checking height: 0.0125" @ lobe
Timing: (Intake): 18/54 (Exhaust): 54/18
Nominal lobe lift: (Intake): 0.285" (Exhaust): 0.285"
Duration (Intake): 252 (Exhaust): 252
Lobe centre angle (Intake): 108 (Exhaust): 108
Lobe separation angle: 108
Lift on overlap: 0.048"
Accuracy: Good
Next is the Kent 266 a nice all round road cam, these figures are based on kents own specs, plus with my own additions.
Checking height: 0.01225" @ lobe
Timing: (Intake): 24/56 (Exhaust): 61/29
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.268"
Duration (Intake): 260 (Exhaust): 270
Lobe centre angle (Intake): 106 (Exhaust): 106
Lobe separation angle: 106
Lift on overlap: 0.054"
Accuracy: Average
Here is the Kent 276;
Checking height: 0.0125" @ lobe
Timing: (Intake): 29/61 (Exhaust): 66/34
Nominal lobe lift: (Intake): 0.293" (Exhaust): 0.315"
Duration (Intake): 270 (Exhaust): 280
Lobe centre angle (Intake): 106 (Exhaust): 106
Lobe separation angle: 106
Lift on overlap: 0.078"
Accuracy: Below Average
Here is the 286;
Checking height: 0.0125" @ lobe
Timing: (Intake): 34/66 (Exhaust): 71/39
Nominal lobe lift: (Intake): 0.315" (Exhaust): 0.324"
Duration (Intake): 280 (Exhaust): 290
Lobe centre angle (Intake): 106 (Exhaust): 106
Lobe separation angle: 106
Lift on overlap: 0.088"
Accuracy: Below Average
Here is the new Billet 286;
Checking height: 0.0125" @ lobe
Timing: (Intake): 34/66 (Exhaust): 71/39
Nominal lobe lift: (Intake): 0.315" (Exhaust): 0.324"
Duration (Intake): 280 (Exhaust): 290
Lobe centre angle (Intake): 106 (Exhaust): 106
Lobe separation angle: 106
Lift on overlap: 0.090"
Accuracy: Good (much better than the older regrind)
The Kent 296;
Checking height: 0.0125" @ lobe
Timing: (Intake): 39/71 (Exhaust): 76/44
Nominal lobe lift: (Intake): 0.324" (Exhaust): 0.340"
Duration (Intake): 290 (Exhaust): 300
Lobe centre angle (Intake): 106 (Exhaust): 106
Lobe separation angle: 106
Lift on overlap: 0.112"
Accuracy: Average
Kents Version of the good old 649;
Checking height: 0.0125" @ lobe
Timing: (Intake): 43/64 (Exhaust): 61/40
Nominal lobe lift: (Intake): 0.323" (Exhaust): 0.323"
Duration (Intake): 287 (Exhaust): 281
Lobe centre angle (Intake): 100.5 (Exhaust): 100.5
Lobe separation angle: 100.5
Lift on overlap: 0.110"
Accuracy: Average
Piper's BP255. These figures are based soley on 1 pair of lobes checked in my jig.
Checking height: 0.016" @ lobe
Timing: (Intake): 12/48 (Exhaust): 44/16
Nominal lobe lift: (Intake): 0.287" (Exhaust): 0.285"
Duration (Intake): 240 (Exhaust): 240
Lobe centre angle (Intake): 108 (Exhaust): 104
Lobe separation angle: 106
Lift on overlap: 0.045"
Accuracy: Average
Piper's HR285. These figures are based soley on 1 pair of lobes checked in my jig.
Checking height: 0.016" @ lobe
Timing: (Intake): 28/64 (Exhaust): 60/32
Nominal lobe lift: (Intake): 0.320" (Exhaust): 0.320"
Duration (Intake): 272 (Exhaust): 272
Lobe centre angle (Intake): 108 (Exhaust): 104
Lobe separation angle: 106
Lift on overlap: 0.080"
Accuracy: Not known
Piper's BP300. These figures are based soley on the avergae of 3 cylinders checked in my jig.
Checking height: 0.016" @ lobe
Timing: (Intake): 47/75 (Exhaust): 75/47
Nominal lobe lift: (Intake): 0.315" (Exhaust): 0.315"
Duration (Intake): 302 (Exhaust): 302
Lobe centre angle (Intake): 104 (Exhaust): 104
Lobe separation angle: 104
Lift on overlap: 0.125"
Accuracy: Good
The Morspeed phase 2 (Fast road) Based on 1 example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 20/54 (Exhaust): 54/20
Nominal lobe lift: (Intake): 0.305" (Exhaust): 0.298"
Duration (Intake): 254 (Exhaust): 254
Lobe centre angle (Intake): 107 (Exhaust): 107
Lobe separation angle: 107
Lift on overlap: 0.048"
Accuracy: Good
The Morspeed phase 3 (trackday cam) Based on 1 example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 28/62 (Exhaust): 62/28
Nominal lobe lift: (Intake): 0.315" (Exhaust): 0.311"
Duration (Intake): 270 (Exhaust): 270
Lobe centre angle (Intake): 107 (Exhaust): 107
Lobe separation angle: 107
Lift on overlap: 0.065"
Accuracy: Good
The Morspeed SL12 (Ultimate trackday cam) Based on 1 example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 36/66 (Exhaust): 81/43
Nominal lobe lift: (Intake): 0.317" (Exhaust): 0.328"
Duration (Intake): 282 (Exhaust): 304
Lobe centre angle (Intake): 106 (Exhaust): 108
Lobe separation angle: 107
Lift on overlap: 0.105"
Accuracy: Good
The Minispares Evolution 1 Based on 1 new example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 20/54 (Exhaust): 65/29
Nominal lobe lift: (Intake): 0.263" (Exhaust): 0.285"
Duration (Intake): 254 (Exhaust): 274
Lobe centre angle (Intake): 106 (Exhaust): 109
Lobe separation angle: 107.5
Lift on overlap: 0.054"
Accuracy: Good
Keith Calvers (not his own I know) , RE13 Based on 1 example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 34.5/61.5 (Exhaust): 63.5/32.5
Nominal lobe lift: (Intake): 0.290" (Exhaust): 0.290"
Duration (Intake): 276 (Exhaust): 276
Lobe centre angle (Intake): 103.5 (Exhaust): 105.5
Lobe separation angle: 104.5
Lift on overlap: 0.085"
Accuracy: Good
Avonbar PH2 turbo cam, Based on 1 example only figures quoted at split overlap;
Checking height: 0.016" @ lobe
Timing: (Intake): 15/47 (Exhaust): 62/14
Nominal lobe lift: (Intake): 0.289" (Exhaust): 0.320"
Duration (Intake): 242 (Exhaust): 256
Lobe centre angle (Intake): 111 (Exhaust): 109
Lobe separation angle: 110
Lift on overlap: 0.048"
Accuracy: Very Good
Ok, a little differnt this time, but a very good cam company none the less, this is a B646 from NEWMAN cams Based on 1 example only;
Checking height: 0.016" @ lobe
Timing: (Intake): 14/58 (Exhaust): 51/21
Nominal lobe lift: (Intake): 0.302" (Exhaust): 0.298"
Duration (Intake): 252 (Exhaust): 252
Lobe centre angle (Intake): 112 (Exhaust): 105
Lobe separation angle: 108.5
Lift on overlap: 0.047"
Accuracy: Good
Edited by ACDodd, 13 October 2013 - 02:57 PM.
