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Atikin9000

78 620, L20B foreign matter in combustion chamber.

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The point is that it was running like this, so nothing has been changed and it will start and run as before.

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A car could be running before but things may not have been aligned and was just enough to run. Since the head is off, good to check if everything is buttoned up.

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There's no correct way just the way most set theirs up. 180 out isn't 'correct' but works perfectly. There are 40 possible positions with 4 working perfectly at 90 degree increments and possible a tooth on either side that still allows timing adjustment. This can be done to turn the module away from exhaust heat or spin the vacuum advance around or to move the distributor to get adjustment on one of 6 ? different timing plates.  I have a modified Z24 timing plate on my '79 matchbox.  

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Are we not talking about setup here now, how to set it up so it starts without valves hitting pistons and such.

If the block is at TDC(there is no 180 out on the crank when setting it up), and the cam gear notch is where it is on the plate then this part is good.

His rotor is close in the photo he took of it, if it points directly at a spark plug wire post, that is number 1 spark plug wire as long as he has timing adjustment room like I have in the photo below.

DSCN7426.jpg

If the bolt is not in the middle and the rotor is not pointing directly at a post on the distributor then some adjustments will need to be made to the dist/oil pump drive shaft.

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Are we not talking about setup here now, how to set it up so it starts without valves hitting pistons and such.

If the block is at TDC(there is no 180 out on the crank when setting it up), and the cam gear notch is where it is on the plate then this part is good.

His rotor is close in the photo he took of it, if it points directly at a spark plug wire post, that is number 1 spark plug wire as long as he has timing adjustment room like I have in the photo below.

DSCN7426.jpg

If the bolt is not in the middle and the rotor is not pointing directly at a post on the distributor then some adjustments will need to be made to the dist/oil pump drive shaft.

 

Distributor is not centered but the rotor is pointing to the post on the cap.

 

REZGB0D.jpg

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U mean its not at 11.25 position

No just not centered on the ears, I didn’t pop it off only had a quick minute to look.

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Should be enough space to adjust timing if need be.

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Distributor is not centered but the rotor is pointing to the post on the cap.

 

 

You may have the timing advanced from when it was running, my photo is of an engine that has never been run yet, I just centered it when I mounted it.

The fact is if you are way off on the dist drive gear/shaft, that slotted hole the small bolt is in maybe so far off that you cannot get the small bolt in when the rotor is point at a spark plug wire post, that slot would be somewhere else, the point is that with the rotor pointed directly at a dist cap spark plug wire post, you should be able to put that small bolt in that slot that sets and holds the ignition timing.

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Well finally caught some good weather today and I thought I’d work on the old man.

 

Everything is set and everything is torqued.

 

Haven’t removed the wedge yet cause the chain is slightly slacky so I just wanted to make sure I’m good to take it out this way.

 

 

 

HxUassZ.jpg

 

MNATw7M.jpg

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I was also reading that the tensioner is ran on oil pressure so I think the little give will be ok, that and I think the wedge is holding a little tension back.

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The tensioner has a very stiff spring to provide tension. There is an oil feed hole in the back, but I worked out the area of the piston and the 60 PSI oil and it's around 7 pounds of extra push on the shoe. The oil is more for lubing the tensioner and it probably gets on the chain as well.

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Hope you didn't put that cam cover on over the dry cam in the previous picture.

 

If you turn he engine backwards, there is enough force to depress the tensioner, and the other side of the chain will go slack.

As soon as the engine is turned forward (clockwise when looking at it from the front) everything should go back, and all slack should be gone.

If not, something is amiss.

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Hope you didn't put that cam cover on over the dry cam in the previous picture.

 

If you turn he engine backwards, there is enough force to depress the tensioner, and the other side of the chain will go slack.

As soon as the engine is turned forward (clockwise when looking at it from the front) everything should go back, and all slack should be gone.

If not, something is amiss.

Doused in oil, valve cover is on hand tight just so stuff stays out. I’ll pull the wedge today and see how the chain feels then.

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Pulled the timing chain wedge, turned it over once back to tdc and took this video. Does the chain look ok?

 

 

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Looks good. The right side may have some slack the left side (driver's) should be much stiffer.

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Noticed a couple of spots on the thermostat for vacuum lines, I deleted a bunch of that egr crap, and prior to taking the head off there was only one hose going to it.

 

Is it ok to block off or does it need to be routed somewhere.

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That would be for the TVV thermal vacuum valve. It's an air leak connected to the ported vacuum signal from the carb to the BPT valve. The ported vacuum only works above idle and drops to zero at full throttle. The air leak destroys the vacuum signal but when the engine warms this TVV closes and passes the vacuum signal to the BPT valve. So no EGR at idle, no EGR at full throttle, and no EGR when the engine is cold. Under certain other conditions the BPT valve allows the EGR to operate... and that's it.

 

So you see, it doesn't do much really but reduce emissions. Has no effect on full throttle performance. Just leave the hose off the TVV and the EGR is deactivated. If you want you can remove the TVV and put a pipe plug in the hole. You can unbolt the mini EGR manifold from the side of the intake and seal all the holes or make a cover plate. Just make sure you drill and tap a hole for the PCV valve. Definitely keep that.

 

 

Take this off...

JmOnTu1.jpg

 

You can make a cover plate and gasket to cover everything using those three threaded bolt holes. You must drill and tap a hole for the PCV valve

CFOY8X4.jpg

 

 

Or grind away and fill holes with JB weld and sculpt it to look like an earlier L16 without the emissions stuff. NOTE... I kept the PCV valve.

55gOPt8.jpg

.

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Just to make sure we’re talking about the same thing I have a pic. Circles is the two fittings and the hose off the egr system.

 

 

WJXJeyA.jpg

 

aen2oSz.png

 

And as far as the intake I have a plate I made, I blocked the 3 holes off as well. Im also running the pcv valve T’d off into the hose off the valve cover that runs into the carb.

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WJXJeyA.jpg

Yes the TVV valve.

The PCV should be screwed into the intake on that plate you made so all cylinders get the fumes equally. The fumes come from the crank case vent pipe that comes up out of the block below the manifolds.

 

wEYnx4M.jpg

This pipe, although the L20B is different. The PCV draws fumes out of the crankcase using intake vacuum. The hose on the valve cover draws in filtered air from the air filter to replace fumes drawn out by the PCV. Under some heavy throttle conditions the blow by gasses exceed what the PCV can handle and the fumes back up and travel to the air filter where the carb sucks them in to be burned. It's simple and benign in operation, but it has to be connected up properly.

.
 

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