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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473638
08/17/13 04:18 PM
08/17/13 04:18 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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I would lean toward a little extra advance if it still pings I would look to head gaskets. power valve 1.5 to 2.5 below the in gear idle vacuum so it gets some fuel right away on light acceleration . looser torque converters help. slightly rich is better than slightly lean and a colder range spark plug can all help! I think Edelbrock sells these bigger bore head gaskets for a reason as many of us have seen the the fel pro 1009 hanging in the combustion chamber and burnt off in some cases http://www.summitracing.com/parts/edl-7325/overview/make/plymouth
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Dodgem]
#1473639
08/17/13 04:31 PM
08/17/13 04:31 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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I would definately go with a higher power valve and maybe up 2 jet sizes all the way around.  looking at demon 850's 3 had 85/93 with 6.5 power valve and one was 85/94 with 6.5 power valve since your fuel is most likely ethanol blend I would start at 87/96 with 6.5 power valve. 
Last edited by Dodgem; 08/17/13 04:39 PM.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473641
08/18/13 07:32 PM
08/18/13 07:32 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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well the holley performance tuning books say 1.5 to 2.5 below in gear idle. So it's a stock vac mod cam thing! Holley now say half so a 17 in vac cam would want a 8.5 power valve (I ran a dual 10.5/8.5 on a stock cam 318 once) Trust me the vac drrops much more faster on a 17inc vacuum cam than a 9 inch vacuum cam to get the power valve open to get the fuel running to accelerate ! 
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473643
08/19/13 01:50 PM
08/19/13 01:50 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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A lot is trial and error and some help from asking questions. My thoughts on the 3.5 power valves that pop up now is it takes the power valve out of the equation in tuning for dummies but then it does not work the way it should on the road lowest I ever used was a 5.0 with some pretty big ass cams. Not a bad ideal if you don't understand things to use one with way to low a number with hotter cams until you get your in gear idle right (ideal in gear idle advance set) usually with faster advance curve or shortened advance slots. me I like long slots and real light springs for ease of starting but final destination is a tomato tomato thing.  
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Re: Degree a cam for the 1st time. What a PITA. * UPDATE*
[Re: Kern Dog]
#1473646
08/23/13 08:44 PM
08/23/13 08:44 PM
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Joined: Aug 2003
Posts: 43,218
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,218
Bend,OR USA
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Quote:
Isn't it a funny moment when things that were once a pisser just suddenly start to fall into place?
It is a common theme with me. Being the adventurous type, I often jump into projects with no experience and fumble my way through. When I encounter poor results, I wonder if it is due to my inexperience or the cheap tools that I am using.
THIS time I bought some decent stuff. Not top of the line, but not from Harbor Freight either. I went about the degree process and came up with some odd results. The flimsy piston stop and loose fitting crank hub made it difficult to establish TDC. Having the spark plugs in and rocker arms on made the engine hard to turn. With the advice of some helpful members, I forged ahead and am happy to report the following:
I decided to skip the crank turning hub and instead I mounted the degree wheel directly to the crank using the stock dampner bolt. ZERO slop, so now TDC was accurately established. Next I followed the instructions and checked the #1 intake valve timing. My first number was 73 degrees and the second number was 139 degrees. This totalled 212. I almost crapped a brick ! The cam card calls for a 106 centerline and I am exactly at 106 with the timing set at the ZERO/dot-to-dot setting. The slop in the crank turning hub was a full 4 degrees. Now with the degree process finished, I can proceed with the rest of the job.
Lots of gremlins out there blocking the light   I'm glad it is starting to make sense Now is the time to check the exhaust lobe center before changing the intake to verify the actual cam LSA 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Degree a cam for the 1st time. What a PITA. * UPDATE*
[Re: Dodgem]
#1473648
08/24/13 03:11 AM
08/24/13 03:11 AM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
Striving for excellence
Joined: Feb 2010
Posts: 18,493
Granite Bay CA
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Quote:
How did that new piston stop work??
let us know how it runs.
That thing is great. There was virtually NO chance of bending it, so it was easy to determine TDC.
I started in on the rest of the job: Changing valvesprings, installing the rocker arms and setting lash...I totally forgot CAB'S suggestion about checking exhaust lobe centerline. I hope that I didn't screw up by forgetting that!
The Lunati cam card showed a valve lash setting of .020 INT and .022 EXH. I set the lash on the engine, but then remembered that their specs are for "hot lash". Obviously I can't do that yet, so what would be an acceptable spec for a cold engine with aluminum heads? I may check the Lunati website to see if they have a tech section. Of course I need info and the weekend is here...JUST in time for these companies to take 2 days off!
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Re: Degree a cam for the 1st time. What a PITA. * UPDATE*
[Re: Kern Dog]
#1473650
08/24/13 09:34 AM
08/24/13 09:34 AM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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Yea I had better luck with my home made piston stops then when a friend got a comp cams one it's just to wimpy.  I have not had a chance to try the new crane one yet but it sure seems nice? I should just but my bigger cam in so I can use it! :-) yup almost everybody does lash cold 6 tighter on Eddy heads seems to work great. Hot the job really sucks and almost impossible to get very far before the aluminum heads start to cool and contract. So do them cold 6 tighter and don't worry be happy. Just make sure lock nuts are tight. on 906 iron heads I used to go 2 looser intake 4 looser exhaust hot that seemed bang on.
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