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Discussion Starter #1
I have a 81 Bronco 4.9 for Speed I just rebuilt the motor and we getting ahead of a crank no start about the third day at fired up but not long enough to break in a cam. Now I'm back to where I started crank no start. Did it compression check only did it dry. I got 60 across the board what I missed what am I doing wrong.?
 

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For compression: Is the rocker preload correct? Cam timing?
 

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That's low. I had low like that on 2 adjacent cylinders. Across the board? Timing of valves opening is my first thought.
 

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Discussion Starter #4
I've been turning wrenches for about 29 years and line up the timing marks on you saying seems to be pretty easy and really hard to get misaligned about the valves opening time to I'm not really sure how would I go about checking. Yeah this is an 81 motor and I know that the valves death have to be lashed but I thought I had a valve problem before so I went and got it ahead and it's a newer model head where they're torqued to spec. I have 60 across the board with the other head to do I have the wrong cam?
 

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On the V8s the pedestal mount rockers should be set to zero lash and hit the torque spec in 1/4 to 1 turn.

If the block and/or head have been decked the rockers may need shims.
 

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1982 FSB 302, c6, NP208 manual, manual hubs, manual windows, 3.00 gears LSD rear, 235/75/15 HK ATM
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Maybe you are 180 out? It surely has to be a timing issue if you are steady across the board on a fresh motor.
 

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85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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I was gonna suggest 180 out as well.
 
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Discussion Starter #9
Ok so I get it. Everybody is saying timing. And that it mite be 180 out. I have two questions. 1 will it still start and run and 2 how would I go about checking that?
 

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85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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14,063 Posts
If it starts and runs, 180 out is very unlikely. Whats more likely is being just one cylinder off. Gonna have to bring the engine to TDC and re-stab the distributor.
 
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Discussion Starter #11
I checked the distributor 4 times it's right on the money. I think I will rip the front cover off see where my marks are. The only thing I can think of is the rings. I set the opening a part from each other. One at 11 O clock the other at 4 and again at 7. Plus it's the same in every hole. I just don't get it.
 

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85 Bronco, 309ci I6 w/4bbl, np435, 4" lift, 37" Irok NDs, 4.56 w/ Detroit Locker and tru trac
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The ring orientation is perfect.

So lets take a step back.

Low compression, across all cylinders. So its not a broken piston or cracked head. All valve seals would have to be really bad to cause it. So i doubt its that. All exhaust valves bad? Again, I doubt that. The rings are in their proper orientation.

It almost has to be timing. So, since the distributor is installed correctly, I would indeed suspect the cam gears may not be lined up properly. Do you have the fiber gear or all steel gears?
 
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