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 Post Posted: Mon May 14, 2012 10:17 am 
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driftbuster wrote:
The cam was supposedly for the low compression to try and build cylinder pressure.


The cam will fill the cylinder at high enough RPM but it will work against you at RPM below its effective point. The problem comes when you have to set a mixture for the inefficient zone then change it to a different mixture to get power in the efficient zone. Neither of them turn out right.


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 Post Posted: Mon May 14, 2012 8:08 pm 
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Did I miss the intake C\L on this cam or was it not stated?

Have you pumped the engine?


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 Post Posted: Mon May 14, 2012 8:35 pm 
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Scott Smith wrote:
Did I miss the intake C\L on this cam or was it not stated?

Have you pumped the engine?

Intake centerline 104.2 atdc
Exhaust. 112.2 btdc



No the engine wasn't pumped, the machine shop figured the compression when they did the heads.


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 Post Posted: Mon May 14, 2012 8:43 pm 
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Quote:
No the engine wasn't pumped, the machine shop figured the compression when they did the heads.


That's static compression.
Running a cranking compression test is a good base line for how close the cam is.


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 Post Posted: Mon May 14, 2012 8:44 pm 
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Quote:
Intake centerline 104.2 atdc
Exhaust. 112.2 btdc


So it's a 108 advanced 4 degrees. Interesting that the LSA is that tight on BBC.

Those numbers are more common for a Small Block


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 Post Posted: Mon May 14, 2012 8:46 pm 
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I will get my hands on a guage to see where it's at.


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 Post Posted: Tue May 15, 2012 6:17 pm 
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I found my old guage and checked it with another one and both read 130 lbs. Still haven


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 Post Posted: Tue May 15, 2012 7:02 pm 
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Yikes.
Did you have all the plugs out?

I'm not a guru on low compression engines but if it was less that 165 I would be concerned.
We shoot for 235 on our race engines.


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 Post Posted: Tue May 15, 2012 7:14 pm 
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I thought it was real low, my harley is 190. No i didn't have all the plugs out, only the one for the guage.


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 Post Posted: Tue May 15, 2012 8:37 pm 
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driftbuster wrote:
I thought it was real low, my harley is 190. No i didn't have all the plugs out, only the one for the guage.



Pull'em all then crack the throttle open before you test it. It usually takes about three pumps to get max pressure for any given cylinder. If they're all low, then shoot some WD-40 or motor oil in one of them and re-pump it so you can see how the rings are.

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 Post Posted: Wed May 16, 2012 4:29 am 
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Man i feel like a bonehead, should've known that ken. I took care of the suspension and driving on the dirt cars while the guy that owned the engines took care care of them. I will check it the right way today after work.


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 Post Posted: Wed May 16, 2012 5:02 pm 
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Today it read 150, the starter doesn't spin real fast if that has anything to do with it. It does idle great now and only drops 75-100 rpm when going in gear from 950. I also went for a short ride and everything felt pretty good and the plugs cleaned up pretty good so i will be throwing the new ones in before further tuning.


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 Post Posted: Wed May 16, 2012 7:04 pm 
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Location: Greensburg, Pa
Is the innovate digital mtx wideband a decent guage?


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