440 initial timing mystery

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josekh7

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Hi guys so i just completed my build and broke in the camshaft. My engine is very weird it loves to have alot of advance timing or i might be wrong retard timing when looking at the damper which is a HTC-440 i see it likes 19-22degrees of initial timing no vacuum. I know my damper slipped since i checked tdc with a camera and TDC is at 10 so in essence timing right now is at 28-30degrees(-10 for slippage) its really hard to start and vacum is super low once started im pulling about 5 of mercury at 800-900 rpm (idle). i understand my cam is a bit loopy
Isky 280 mega cam Hydraulic.
(RPM-Range: 2500-6800
Value Lift Int/Ext: .485/.485
Value Lash Hot Int/Ext: .000/.000
ADV Duration Int/Ext: 280/280
.050 Duration Int/Ext: 232/232
Lobe Center: 108)

I do have a 850CFM carb with edelbrock rpm performer that are ported. Please help out is it normal for such advance? When i try to bring it down to something more normal it start to want to shut off. I have to increase idle to 1000 to keep it on
 
It aint just yours. Everybody gets better run/drivability with about 18 initial, including the bone stock. The root cause is todays fuel.
 
My 5.9 Magnum likes 20, and I have a limited distributor so it doesn't go over about 35 total without vacuum.
With vac advance it runs up to about 52.

Listen and watch the plugs for signs for awhile just to be safe.
 
ok now a final piece of the puzzle, i marked TDC using a camera scope at piston 1 i cranked till the piston reached the top then notice the piston stayed at the top for about 6 degrees of being turned i divided it by two and well marked it which came to be 10 on the damper. Would it be possible then that true TDC is when the piston reaches the top the first time or when its divided by two? remember this is a visual examination suing a scope
 
Divided by 2 the way you describe.

Piston stop/camera either way would work fine, and think about it this way.
When using a piston stop method you divide stop to stop by 2 also, right?
 
You either need a balancer that is completely marked, a timing tape for that balancer, or a digital timing lite. Set total timing with a vac distributor with the vac line off. you should have total timing in by 3000 rpm. A digital lite and marked balancer is nice, this way you can see the timing curve come in and how fast or slow its coming in.
 
My guess is doing an excellent job with a camera, at best you might get to 8 degrees of actual timing. You will get a better number using a dial indicator on each side of TDC, to get the same reading at least 20 degrees apart. The travel is flat near top, that is why best to use sides and split.
Here is a good article on piston travel. Piston Motion: The Obvious and not-so-Obvious, by EPI, Inc.
 
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