Degree wheel, confused!

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swedefish

swedefish

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When using a degree wheel with 90 degree only. My first reading BTDC reads 44 degree and the second reading ATDC reads 79 degree. Here´s where I gets confused.
Do I ad 90 to the 79 readings to calculate the numbers where the cam is installed?
Any help is appreciated.
Just checking the cam install I did 8 years ago, he he. Not sure that I did this correct back then.
Thanks
Lenny
 
Thanks fisher, but they use a 360 degree
wheel.
It's a purple cam, .484/284.
Anybody who ever used a 90-90 degree wheel?
 
How did you determine TDC? Are you on an intake or exhaust lobe? At what lobe lift are you checking this?
 
I made an pistonstop by using a sparkplug. Put the piston at TDC, zero the wheel put the pistonstop in place, turned the crankshaft to the stop clockwise noted the reading, turned the crank counterclockwise to the stop noted the reading. Added the two readings divided by two, set the wheel on the result. The zero on the wheel match the mark on the damper.
Zeroed the indicator at max lift then I took the reading .050 before and after max lift, all this on #1 intake.
The result was 44 and 79 degrees on the
degreewheel, but this a 90-90 degree marked wheel, and its here I don't get it. If I add 90 degrees to the 79 degree and add 44 degree reading divided by two I come up with 106.5 degree and that's the number I installed the shaft at when I assembled the engine.
However I'm not sure of that this is way to calculate the centerline.
 
44 degrees before TDC + 180 degrees to BDC + 79 degrees after BDC = 303

303/2=151.5

151.5 - 44 BTDC = 107.5 ICL after TDC
 
Intake Duration, Nominal
284°
Exhaust Duration, Nominal
284°
Intake Duration @ .050”
241°
Exhaust Duration @ .050”
241°
Intake Lobe Centerline

108° ATDC
Exhaust Lobe Centerline

108° BTDC
Lobe Separation Angle

108°
Overlap
68°
Intake Opens
34° BTDC

Exhaust Opens
70° BBDC

Intake Closes
70° ABDC

Exhaust Closes
34° ATDC

Intake Lift
.484"
Exhaust Lift
.484"
Note: as installed on 108° centerline per Chrysler

Thanks IQ
Above are the numbers on the shaft.
Sorry if the figures comes up sort of random
Would you say that shaft is correct degreed?
Thanks fot your help :thumbsup:
 
Now advance it 6 degrees... :)

Unless you have a bunch of static compression.
 
Wait a minute! I misunderstood. Are your measurements from before and after top dead center of the piston or top dead center of the intake lobe?

If you are using TDC intake lobe, your timing would be...........
44 + 79 = 123
123/2 = 61.5
61.5 + 44 = 105.5 ICL
 
Last edited:
IQ, the measurement is from (TDC intake lobe) max lift #1 intake lobe.
 
swedefish said:
IQ, the measurement is from (TDC intake lobe) max lift #1 intake lobe.
Click to expand...

Then, as calculated in post #10, your ICL right now is 105.5 or 2.5 degrees advanced on a 108 LSA. Sorry about the earlier confusion.
 
Thanks IQ, no worries about the other post. Thanks for the help with sorting things out.:thankyou:
 
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