Valve adjustment check
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Valve adjustment check
The truck had a fair amount of neglect when I got it so I'm also wanting to just give it a once over to make sure everything is running properly.
The motor has a fair lack in power right now.
I've changed the manifold gaskets, replaced fuel filter, started changing vacuum lines, took the carb off and dumped all the rust out of it and cleaned it.
I did the best to search, but wasn't able to find all that I wanted.
I have a 1979 f-150 with the 300ci and am wanting to check the valve adjustment. I have a miss somewhere and am wanting to check the valves for the correct torque. I've never done this so don't think you're insulting by going into too much detail.
Thanks
The motor has a fair lack in power right now.
I've changed the manifold gaskets, replaced fuel filter, started changing vacuum lines, took the carb off and dumped all the rust out of it and cleaned it.
I did the best to search, but wasn't able to find all that I wanted.
I have a 1979 f-150 with the 300ci and am wanting to check the valve adjustment. I have a miss somewhere and am wanting to check the valves for the correct torque. I've never done this so don't think you're insulting by going into too much detail.
Thanks
Mountain Pass
Joined: Oct 2007
Posts: 158
Likes: 0
From: Oaklnad TN
Seems you would want a complete tune up first unless you have some valve noise. The miss may simply be a bad plug or wire. If its been neglected its most likely in dire need of the basics. You may want to overhaul the carb too if it was full of rust.
Postmaster
Joined: Dec 2006
Posts: 3,603
Likes: 10
From: Spokane, WA
What BVA said X2. A vacuum gauge is the cheapest but handiest diagnostic tool in the box.
Tips on Reading Gauges: Vacuum Gauges
Tips on Reading Gauges: Vacuum Gauges
Fleet Mechanic
Joined: Nov 2002
Posts: 1,643
Likes: 69
MY POST ON THIS SUBJECT FROM THE FORDSIX.COM WEBSITE:
Q: Can somone tell me the proper procedure for adjusting the valves on a 300 with it not running?
A: Adjusting the valves on a 300 is EASY. For beginners I recommend writing down the firing order, 153624, thusly:
1 5 3
6 2 4
With a breaker bar or long handled ratchet and a 15/16 socket rotate the engine damper until the timing mark comes up to top dead center. Watch #6 cyls and #1 cyls rocker arms as you do this. On one of these two cylinders the exhaust will just be closing and the intake will start to open as you approach top dead center. If that happens on #6 then adjust #1. If it happens on #1 then adjust #6, because these two pairs are matched, as in the diagram above (5 & 2 and 3 & 4 are the other two matched pairs). So lets say you just adjusted #6. The next cylinder to adjust in the firing order is #2. Rotate the crank about a third of a rev, watching #2's buddy, #5. The exhaust rocker for #5 will be closing and the intake starting to open as you get to TDC. Adjust #2 when the two #5 rockers are in alignment, one closing and one opening.
Continue this process until you go through all six, then go through it again, to double check. With this method you can adjust all six cylinders with only two revolutions of the crank.
To speed things up you could mark your damper in three places spaced 120 deg apart. But any more I dont even look at the damper.
With practice you can run through your valves in five minutes. It will take you longer to remove the valve cover than to run the valves. Whats more you wont even have to look at the damper, just find the cylinder in the overlap cycle and start from there, adjusting the buddy cyl. Good luck. THE FRENCHTOWN FLYER
Q: Can somone tell me the proper procedure for adjusting the valves on a 300 with it not running?
A: Adjusting the valves on a 300 is EASY. For beginners I recommend writing down the firing order, 153624, thusly:
1 5 3
6 2 4
With a breaker bar or long handled ratchet and a 15/16 socket rotate the engine damper until the timing mark comes up to top dead center. Watch #6 cyls and #1 cyls rocker arms as you do this. On one of these two cylinders the exhaust will just be closing and the intake will start to open as you approach top dead center. If that happens on #6 then adjust #1. If it happens on #1 then adjust #6, because these two pairs are matched, as in the diagram above (5 & 2 and 3 & 4 are the other two matched pairs). So lets say you just adjusted #6. The next cylinder to adjust in the firing order is #2. Rotate the crank about a third of a rev, watching #2's buddy, #5. The exhaust rocker for #5 will be closing and the intake starting to open as you get to TDC. Adjust #2 when the two #5 rockers are in alignment, one closing and one opening.
Continue this process until you go through all six, then go through it again, to double check. With this method you can adjust all six cylinders with only two revolutions of the crank.
To speed things up you could mark your damper in three places spaced 120 deg apart. But any more I dont even look at the damper.
With practice you can run through your valves in five minutes. It will take you longer to remove the valve cover than to run the valves. Whats more you wont even have to look at the damper, just find the cylinder in the overlap cycle and start from there, adjusting the buddy cyl. Good luck. THE FRENCHTOWN FLYER
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Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
I'd also recommend replacing all of the rocker arm nuts, as these get fatigued and cracked over time. They're not too expensive.
Also, be sure to turn the engine clockwise while checking the valves.
Also, be sure to turn the engine clockwise while checking the valves.
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Post Fiend
Joined: Dec 2007
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From: Lost
Counter Clockwise? Isn't that backwards?
Moderator
Joined: Dec 2007
Posts: 7,987
Likes: 104
From: Boise, Idaho
Shoot, you're right. I was thinking that if the distributor turned clockwise that the engine would turn counter-clockwise. But that's the CAM that turns counter-clockwise, which makes the engine, then, turn clockwise. 
I'll fix it.
I'll fix it.
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