Ford Truck Enthusiasts Forums - Timing Marks, TDC, Valve Adjustment

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Timing Marks, TDC, Valve Adjustment

Hey all -

Working on a 76 Supercab 2wd, with a carbed I6.

It has a newer engine that has about 5k on it, and I'm sure the previous owner had done none of the re-adjustment after the initial break in period. I'd noticed some misfiring, especially at idle and have done all the regular tune-up components, including a new carb but the misfiring remained.

So, I decided to open up the valve cover and check the valve clearances.

I have two questions:

1. What's the most accurate way to calculate TDC for each cylinder?

The Haynes manual says to mark 120 degrees on either side of the timing pointer to mark TDC for cylinders after the first...I don't see how anyone could accurately measure that on a greasy vibration damper on the bottom of the engine. Does it have to be super-precise in order to correctly adjust the valves? The only other motor I've adjusted valves on was a Toyota 22R, and as I remember, all I did was rotate the crank 180 degrees for each adjustment.

2. Most of the pushrods were loose - does this mean that they were out of adjustment?

With #1 cylinder TDC, I could easily twirl in my fingers all but two of the pushrods. This means they're loose, right? Initially, they all should be tightened until the pushrod engages the rocker, then 1 turn more according to the Haynes manual.

Thanks!

Justin

TDC....remove plugs, insert screwdriver, rotate engine manually til tool peaks.

I'd inserted a socket extension and been calculating TDC that way for the other cylinders, I just wondered if that method (the same as you desribed) is too imprecise - there's a window of several degrees where the piston sits at the top - as long as it's within that range it should be fine? How precise to I have to be with it in order to get the valves adjusted properly?

i just replaced cam gear and crank gear had a friend help me with lining up timing marks didnt check to see if piston was up only put key locks tdc am i gonna have a problem

Disregard all the tdc crap. Read what I wrote in the Tips and Tricks section at the top of the forum threads. It is the easiest way to adjust the valves. Once I did it I will never go back to the tdc crap.

Get a remote starter switch, and take your plugs out, and use the system I mention. It works. Taught to me by a pro engine builder with 40 years experience. Just use 1/2 turn after zero lash.

Quote:

Originally Posted by F-250 restorer (Post 10147961)

Where is the "tips and tricks" section you referred to in this post? I have looked at all the tabs at the beginning of the thread and forum page and can't find it. I also did a search of the site and the only thing that came up was your post...
Thank you for your time and assistance.
v/r
'bonz

Quote:

Originally Posted by cbbonz (Post 11437318)

https://www.ford-trucks.com/forums/1...nd-tricks.html

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Read First: Tips and Tricks ( 1 2)

First thread on this Forum page.