Weird #'s on cam?

[LameHoof65]

Well, the guy has a good reason, but my head won't be ready for awhile, so I have been taking my time with the cam. I waited until this weekend to finish degreeing and I have gotten some #'s that can't be right.

To begin with I went ahead and set TDC at 4 degrees advance on the crank sprocket. Once I found pos. tdc I started on the lobe center. Now I have the dual pattern 264/274 110* clay smith cam.

Anyway my readings are as follows:

Intake at .050 tdc reads 79* down one side and 169* down the other
Exhaust at .050 tdc reads 53* down one side and 141 down the other

this gives me 124* on intake and 97* on exhaust after dividing by 2.

then for finding lobe center I added 124* + 97* and it comes to 221/2 gives me a lobe center of 110.5* which looks right or close enough. But then that means I am at 14* retard---which I thought should be at 14* advance? I thought advance gave you the low end torque and retard was for torque at higher rpms...Please, someone straighten me out here.

 

[StrangeRanger]

264/274 are "advertized durations;" they really don't mean much. What duratons did Smith quote you at .050" lift, those are the numbers you need.

 

[LameHoof65]

The cam card says intake at .050 duration is 214*
" "exhaust at.050 duration is 224*

 

[LameHoof65]

Okay, went out and ran through the process again, took off the degree wheel, realigned my sprockets...tightened everything up and started over. This time looks better I think:

Intake at 62* down one side and 148* down the otherside.
Exhaust at 62* down one side and 160* down the other.

Intake was 210*
Exhaust was 222*

after dividing and adding 105* + 111*

216*/2 = 108*

Looks like I am at 2* advance----right?

I am not sure what I did wrong the first time other than I installed the chain with several rotations counterclockwise this time

 

[wsa111]

Darwin, you just use the intake lobe center. 62 + 148+ 210 divided by 2 = 105 which is 4 degrees advance. Your are right on the money.

My camshaft the 264 degreed right on the exact #'s. William

 

[LameHoof65]

Thanks William...I'm very insecure about my numbers---that's why my wife don't allow me to balance the checkbook..

 

[xctasy]

Having a wife affords you the priviledge of never balancing the check book! That's why we have wives.

Cars are the same.

Hmm. At least with a car, you can time it with a socket wrench and not get put in prison for assult!

The 50 thou figures remove the affect of the lifter and cam ramp. Since the cam is measuring pure lift verses degrees of rotation, not ramps, not lifter clearance.

Darwin, its good to measure twice and adjust once. Funny thing is, after you go to the trouble, you end up installing most cams to the recomendations but then find out the cam sproket to crank sprocket dots are way off, and then you have to fit an aftermarket offset crank key-way.


At least with the FSPP parts stuff, you can set it to the degree.


You engine is gonna L-O-V-E that cam!