replaced heads/intake wont start

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1984c10

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Point being, the lifters spring will have to be fully depressed and compressing against the solid components of the lifter before there would be a significant enough change, in rotating force, to be detectable with the fingers, at least with My fat O`l finners. :p
That is why the up to down movement is the best method. I think the Motors manual may even tell it like this. I will have to go looksee now just to be sure. LOL

I didnt find this to be true. I first adjusted them with the intake off and they were maybe half way compressed. Wont be able to get back to it until Wednesday. I'll charge my battery and see what happens
 

towjoe

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I'm going guess he still don't have distrubuter timed right. If he is using top dead center with #1 valves overlapping it will be 180 out. #6 valves should be overlapping while #1 is firing. Use the terminal pointing towards #1 on distributer cap for #1 plug wire and go clockwise around 1-8-4-3-6-5-7-2 once you have rotor pointing to #1 while at tdc on firing
 

crazy4offroad

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180 out would be easy to fix but if it were 180 out it would still at least backfire.
 

chengny

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I hate to sound like a broken record, but finding the zero lash point and setting pre-load on a hydraulic valve lifter is not rocket science (and does not require the "skilled hands of a surgeon" - as I once read). It's all about compressing the plunger return spring down to a point that is approximately at the midpoint of it's total stroke.

The low point is when the plunger is bottomed out in the cylinder body (and the spring is completely compressed).

The top of the stroke is when the cup is hard up against the underside of the circlip.

A diagram of the internals:

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And the parts laid out on the bench:

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From someone smarter than me:

Every hydraulic unit of any type in an internal combustion engine has the same optimum operating range; the center third of its total travel. So if you have a flat hydraulic lifter that typically will have .210" travel your optimum operating range is .070"-.140" (.210/3=.070). However if you have a HLC with a travel range of .045" your optimum operating range is .015"-.030".

The plunger in a standard General Motors hydraulic valve lifter has a total travel limit of about 5/32" (.160").

Images of me measuring the total stroke of a stock lifter with one hand - try not to laugh.

Depth with plunger bottomed out = 8/32"

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Depth with plunger pressed up against the circlip by the return spring = 3/32":


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So, shooting for halfway between the top and bottom of a .0160" inch stroke, the plunger would have to be depressed about .0080".

Someone, at some point, researched the threads per inch dimension of the rocker studs. After getting that number they did a series of complicated mathematical calculations.


The end result: they determined that, if the rocker adjusting nut was tightened about 3/4 of a turn, the rocker arm would force the push rod down about .0080".

Also, it follows that, provided there is no gap/lash in the valve train, the push rod would depress the valve lifter plunger an equal amount.

The whole concept of zero lash is just to be sure that there is no clearance in the valve train and that the plunger is at the top of it's stroke (i.e. not depressed at all - it has to be up against the circlip).

Then to set preload, tighten the rocker adjusting nut about 3/4 of a turn (or 1/2 turn, or a full turn, etc. - whatever you have been taught) The thread pitch of the adjusting stud is fine enough that an exact number of rotations of the nut is not critical. About 1 full turn will depress the plunger to about the middle of it's total available stroke distance.
 
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350runner

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1/4 turn just try it:) or back off a1/4 turn either way you'll see
 

1984c10

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How can I tell if im 180 out? Im cranking it by hand and watch the #1 exhaust valve open and close and then the intake valve open and close and keep turning until im on 0. Then drop the distributor so the rotor is on the #1. Both #1 valves are closed at this time
Is this not correct?
 

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Yes, that would be the correct procedure to roughly (close enough to start) set the ignition timing.

But the timing of the spark is just one of the two required conditions that need to be met for proper ignition. The other is the quality of the spark itself. What was the disposition of the "light orange" spark issue?

Has it been resolved - do you currently get a bright blue spark across the electrodes of a grounded plug?

The engine will not fire if the intensity of the spark is inadequate. It needs to be a sharp blue arc - end of story.

Trust me (and the others who have stressed this point), this is key: If the spark is light orange, you are not going to get combustion and the engine will not start.
 
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foamypirate

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Yes, that would be the correct procedure to roughly (close enough to start) set the ignition timing.

But the timing of the spark is just one of the two required conditions that need to be met for proper ignition. The other is the quality of the spark itself. What was the disposition of the "light orange" spark issue?

Has it been resolved - do you currently get a bright blue spark across the electrodes of a grounded plug?

The engine will not fire if the intensity of the spark is inadequate. It needs to be a sharp blue arc - end of story.

Trust me (and the others who have stressed this point), this is key: If the spark is light orange, you are not going to get combustion and the engine will not start.

Yep, what happens when you have a weak spark, is you essentially "blow" the spark out with the compression. A more obvious example is a boosted engine, you often have to tighten up the plug gap at higher boost levels to prevent spark blow out (for lack of a better term).
 

1984c10

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Yes, that would be the correct procedure to roughly (close enough to start) set the ignition timing.

But the timing of the spark is just one of the two required conditions that need to be met for proper ignition. The other is the quality of the spark itself. What was the disposition of the "light orange" spark issue?

Has it been resolved - do you currently get a bright blue spark across the electrodes of a grounded plug?

The engine will not fire if the intensity of the spark is inadequate. It needs to be a sharp blue arc - end of story.

Trust me (and the others who have stressed this point), this is key: If the spark is light orange, you are not going to get combustion and the engine will not start.

Thank you. Im charging the battery on wednesday and will recheck the spark and then go from there
 

1984c10

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So I charged the battery and i'm getting the same weak orange spark. I'm just going to get a new distributor since this one looks old anyway. I'm starting to think that I might have the wrong balancer on this truck or maybe the rubber spun. After watching several other videos of people setting to TDC I noticed that after the intake valve closes on thiers the balancer mark in at about the 9 oclock position and they dont have to turn the crank too far to get to tdc. On mine it is at 2:30/3 oclock position and have to turn it about 3/4 of the way around to get to 0. I know engines are different so I also placed a plastic coat hanger in the #1 spark plug hole and turned the crank and it feels like the piston is at the top of its travel while my balancer is at about the 9 oclock position. When I turn it to 0 I cant feel the piston at all with the coat hanger. What do you guys think?
 

1984c10

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Im looking to get a new distributor now and all of the ones I find have one single plug coming out that connects to the cap. The one I have now has the same and an additional plug that plugs into the firewall. Do I need to get an exact replacement? Would the distributors with only the single plug work?
 

1984c10

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This is the slowest forum of any kind i've been apart of. squarebody.com is so much better. i'm out of here. thx to the people that actually helped
 

350runner

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This is the slowest forum of any kind i've been apart of. squarebody.com is so much better. i'm out of here. thx to the people that actually helped
I asked Earlier about your valve adjustment. What's up?
 

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