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1939A Guest
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Posted: Sun Dec 09, 2012 3:48 pm Post subject: Camshaft information |
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I am working on degreeing in my camshaft on my A . It calls for 108 degrees and that is were i have it. My question it should the intake valve close at bottom dead center in the dwell time or after it goes through the lost motion of the crank. I hope this makes sense im just wanting to double check all my baises before i put it back together tha ks for any help. The cam card says 108 degree and 112 overlap |
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Buzzman72 Tractor Guru
Joined: 10 Aug 2003 Posts: 8096
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Posted: Sun Dec 09, 2012 5:06 pm Post subject: Re: Camshaft information |
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Try this link:
Degreeing A Camshaft
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Gary Baker Regular
Joined: 18 Mar 2012 Posts: 113
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Posted: Sun Dec 09, 2012 7:22 pm Post subject: Re: Camshaft information |
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112 lobe seperation is not good. Who ground your cam? |
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1939A Guest
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Posted: Sun Dec 09, 2012 9:51 pm Post subject: Re: Camshaft information |
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I would rather not say who built the cam , they done all my work and have been happy just thought the intake valve should b closed be for the piston starts up on compression. I could advance it and give up some on the exaust side but i think that would be better. |
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buickanddeere Tractor Guru
Joined: 31 May 2003 Posts: 23627 Location: in front of computer
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Posted: Mon Dec 10, 2012 6:27 am Post subject: Re: Camshaft information |
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That is why they call it a long duration cam with overlap.
There is supposed to be enough airflow and velocity that the cylinder is still filling during the very early stages of the compression stroke.
How many rpm are you hoping for ? |
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1939A Guest
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Posted: Mon Dec 10, 2012 3:22 pm Post subject: Re: Camshaft information |
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We are running 10% overstock. Could i retard the if i retard the cam a couple degrees i think the exaust wont be fully closed when it starts the intake side . It runs pretty good just trying to get a little more out of it. Thanks for all the help |
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north puller Long Time User
Joined: 05 Jan 2010 Posts: 789
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Posted: Mon Dec 10, 2012 6:28 pm Post subject: Re: Camshaft information |
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Would 112 LSA be stock for an A? I know when I was calling around about 2 cylinder cam grinds, many of the grinders would only add lift and duration, but not change valve timming. |
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north puller Long Time User
Joined: 05 Jan 2010 Posts: 789
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Posted: Mon Dec 10, 2012 6:41 pm Post subject: Re: Camshaft information |
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My 70 cam is timmed at 108. I run 10% over stock also. I would see if you could advance the cam a bit more - say 105 or 106.
My grind has 105 LSA. Engine works good, but could use a little more lug. I don't think that 112 LSA is going to give you what you want.
May want to consider something different. Josh Blackburn or Gary Baker can give you a better cam grind. Rumor is that they worked together developing a cam grind for A/60's. |
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rumor has it New User
Joined: 10 Dec 2012 Posts: 1
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Posted: Mon Dec 10, 2012 6:48 pm Post subject: Re: Camshaft information |
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Speaking of rumors, didn't this motor come from josh? |
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1939A Guest
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Posted: Mon Dec 10, 2012 7:37 pm Post subject: Re: Camshaft information |
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No this motor did not come from josh i wasnt aware of him when i built this motor from the things i have seen and learned he appears to knowwhat he is talking about. When i get my A together im going to work on my little boys G and i will talk with him. Thanks to all that have giving me advice im still learning |
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buickanddeere Tractor Guru
Joined: 31 May 2003 Posts: 23627 Location: in front of computer
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Posted: Tue Dec 11, 2012 9:22 am Post subject: Re: Camshaft information |
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Retarding the cam reduces low rpm lug and increases peak rpm power.
You want to run the cam moderatly advanced to increase low end torque. |
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