My MV cam has DG exhaust. Cam experts advise/input please?

[mattcfish]

When I bought a rebuilt bottom end for my 2.2L boxer project a few years back it was supposed to have a 2.1 stock camshaft.
After painstaking measurements over and over again using solid lifters, a dial indicator, and a degree wheel, with the engine on a stand, this is what I came up with.

My cam
Valve timing at 1mm lift
Inlet opens.13° BTDC
Inlet closes. 48° ABDC
Exhaust opens. 38° BBDC
Exhaust closes. 4° ATDC


Max lift intake=.36" to .37" with 1.1 ratio rockers
Max lift ehaust=.35" to .36" with 1.1 ratio rockers

DG
Valve timing at 1mm lift.
Inlet opens. 5° BTDC (1° from 01/86)
Inlet closes. 34° ABDC( 30° from 01/86)
Exhaust opens. 38° BBDC (36° from 01/86)
Exhaust closes. 4°ATDC (8° from 01/86)

MV
Valve timing at 1mm lift.
Inlet opens. 10° BTDC
Inlet closes. 48° ABDC
Exhaust opens. 50° BBDC
Exhaust closes. 0° ATDC

More info on this thread http://www.shoptalkforums.com/viewtopic.php?t=115260

That makes it a cross between a DG and an MV. MV intake, DG exhaust.
The intake is advanced around 3-4 degrees over stock with 3-4 degrees more duration.
The exhaust is 12-14degrees retarded with 9 degrees less duration.
Looks like something got messed up in the regrind.

The intake is close enough to an MV, with a little advance that should actually help low end.
The DG exhaust bothers me though. The engine has had lumpy idling characteristics from the beginning, despite having the entire fuel injection system , wiring harness and ignition replaced. Could this cam grind be the cause of my idle issues? Can't see how the retarded exhaust valve opening and shorter duration on a 2.2 engine could help anything. Am I wrong?

Short of replacing the cam, could putting 1.25 ratio rockers on just the exhaust help smooth the idle out by allowing the exhaust to breath better in relation to the intake?
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[buildabiggerboxer]

I doubt the cam is asymmetric, i think you are getting anomaly's because of the way you are doing it with an assembled motor, its hit and miss doing it via the rockers etc, suppose there is rocker pivot wear? there is also a chance you may not have the DTI axis directly aligned square with the valve axis as you have to swop it over between the two valves, obviously you will get the pointer 'skidding' slightly with the retainer moving and therefore a false indication. far more accurate to use direct measuring at the follower, a modified extended follower or a DTI extension would be required, given a choice, i like to check the cam direct before the cases go together.

[mattcfish]

I wasn't satisfied until I had measured many ways. I measured several ways using different brackets. I measured at the valve and then I measured directly at the pushrod with the rockers removed and the engine tilted so the pushrods were vertical. Only varied by 1°. I know that The cam was a regrind put in by the builder. Why this grind though?

[buildabiggerboxer]

Try it at the recommended lift check at .050", other than that, yes, could be a naff cam, happens with re grinds, a well known English supplier i 'spose?? i have the last one left, BNOS German DJ/MV cam here in the UK if you require one, un run apart from the factory cold cranking pressure testing they did, they came from new core built race motors done over the years, but they are not cheap as they are now hens teeth.

[mattcfish]

According to the charts above, the lift should be at 1mm which equals .0394". .050" would give me close to 1.25mm lift, right? I gleaned the specs from this forum. I guess I'm making an assumption that that information is correct.
DG
Valve timing at 1mm lift.
Inlet opens. 5° BTDC (1° from 01/86)
Inlet closes. 34° ABDC( 30° from 01/86)
Exhaust opens. 38° BBDC (36° from 01/86)
Exhaust closes. 4°ATDC (8° from 01/86)

MV
Valve timing at 1mm lift.
Inlet opens. 10° BTDC
Inlet closes. 48° ABDC
Exhaust opens. 50° BBDC
Exhaust closes. 0° ATDC

[mattcfish]

I did some measuring at .050.
Here are my results
My Cam measured at lifter .050 lift

IO=9 BTDC
IC=43 ABDC
EO=35 BBDC
EC=3 ATDC
Overlap: 12.00 degrees
Intake Duration: 232.00 degrees
Exhaust Duration: 218.00 degrees
Intake Installed Centerline of 107.00 degrees ATDC.
Exhaust Installed Centerline of 106.00 degrees BTDC.
LSA=106.5

The only figures I can compare that to are
Those measurements supplied by "Tencent"
Can anyone certify that those .050 measurements
Are accurate?

Tencent MV at lifter .050 lift

IO=5 BTDC
IC=40 ABDC
EO=39 BBDC
EC=2 BTDC (note BTDC vs ATDC)
Overlap: 3.00 degrees
Intake Duration: 225.00 degrees
Exhaust Duration: 217.00 degrees
Intake Installed Centerline of 107.50 degrees ATDC.
Exhaust Installed Centerline of 110.50 degrees BTDC.
LSA=109