dave_nz
10+ Year Contributor
- 55
- 14
- Feb 3, 2012
-
Oamaru,
New_Zealand
Hi there, I'm installing a new head onto my block in car. The head has Crower 280's in it.
I have 2x solid lifters in there set to zero lash and check springs.
Here is the cam card:
The cam card says correct only at 0.050" at the tappet. Which is 0.085" at the valve. I'm measuring at the valve.
First thing - the duration @ 0.050" listed doesn't match the valve event timings listed.
Intake is listed as 196° but if you do the math from the picture it's 180 + 8 + 24 = 212° (this matches my measurements)
Exhaust is listed as 198° but if you do the math from the picture it's 180 + 33 + 15 = 224° (this doesn't match my measurements)
When measuring at 0.085" at the valve I can get the intake cam within spec. (I've retarded 4 degrees for valve clearance)
Measured Intake Opening: -4° BTDC
Measured Intake Closing: 28° ABDC
However the exhaust cam closing event has me baffled. It's out by 31° I must be doing something wrong here but I can't see how. I measured it 3 times. This would be a duration of 180 + 28 - 16 = 192°
Measured exhaust Opening: 28° BBDC
Measured exhaust Closing: 16° BTDC
I'm almost at the conclusion that the exhaust cam is not a Crower 64414 or the cam card is junk - I'm pretty sure it's Crower as that is what I was told when I bought it and it has 64414 on the end.
Please help. What should I do?
I have 2x solid lifters in there set to zero lash and check springs.
Here is the cam card:
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The cam card says correct only at 0.050" at the tappet. Which is 0.085" at the valve. I'm measuring at the valve.
First thing - the duration @ 0.050" listed doesn't match the valve event timings listed.
Intake is listed as 196° but if you do the math from the picture it's 180 + 8 + 24 = 212° (this matches my measurements)
Exhaust is listed as 198° but if you do the math from the picture it's 180 + 33 + 15 = 224° (this doesn't match my measurements)
When measuring at 0.085" at the valve I can get the intake cam within spec. (I've retarded 4 degrees for valve clearance)
Measured Intake Opening: -4° BTDC
Measured Intake Closing: 28° ABDC
However the exhaust cam closing event has me baffled. It's out by 31° I must be doing something wrong here but I can't see how. I measured it 3 times. This would be a duration of 180 + 28 - 16 = 192°
Measured exhaust Opening: 28° BBDC
Measured exhaust Closing: 16° BTDC
I'm almost at the conclusion that the exhaust cam is not a Crower 64414 or the cam card is junk - I'm pretty sure it's Crower as that is what I was told when I bought it and it has 64414 on the end.
Please help. What should I do?