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Burnt Valve ? '78 620


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the ticking tends to go away on acceleration, otherwise it comes and goes randonly. i'll see if i can get a video of it today after i do an oil change if it's still there

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noticed a nick on the edge of the cam's lift lobe, did you file that down before running it after resetting the rocker ?  Noticeable in the 2nd pic. 




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yes that's the damage i was referring to and no, there was nothing protruding out... that i could feel. obviously im not using a microscope and just ran it as is and very aware that could be making the noise

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Welp, 15-40 in there, 4.5qts with a new filter... still ticking 

Gonna moth ball it til the cam comes in. Will update after it comes in and i get it in


Thanks for the help so far all

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6 hours ago, Sh00bs said:

the ticking tends to go away on acceleration, otherwise it comes and goes randonly. i'll see if i can get a video of it today after i do an oil change if it's still there


A mechanical damage is likely to be constant and wouldn't go away if just accelerating. Similar to a loose valve clearance.. it's not going away just because you speed up. One thing that does change when accelerating is the oil pressure. The timing chain tensioner does have an oil supply behind it and this does push out on it when the pressure goes up. Not a lot, I worked this out once and came up with 7-8 PSI added but this would reduce the chain flopping about on the slack side to some extent. Perhaps the plastic is wearing off the chain guides and the ticking is just the chain rattling on it. This should be able to be tested without driving. Let it idle when hot with the hood up and then slowly rev the engine in neutral.

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where you getting this cam?Who makes it? regrind or New? to install correctly provides more than just a cam  , yoiu need lash pads. austraila makes ones that dont need new taller retainers.Mainer or Crashed on here recenty got some of those cool lash pads.


I think youll still have the tick.

i would get a KA oil pump also

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Agree on the KA pump. It builds pressure at lower speeds than the stock pump. I have them on all my Datsuns.

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Ask other on here I just bought a KA pump but mine was near 70$  ays made in Japan on the Hitachi box

but I see them for 20-40 $ those got to be chinese clones  unless some body can conferm this


this one would work




KA part number is 0023 I think

Edited by banzai510(hainz)
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I ordered an isky 


The tick wasn't really there until I started reutilizing that lobe on the cam. I have an undamaged rocker with a very slightly damaged cam lobe 

Before it had a very very small tick, but I believe that was the miss... since cyl 2 had 0 compression due to the rocker being off the valve 

What changed ? Intake Rocker and valve are now being used with cyl 2 (has compression btw, don't recall if I mentioned that earlier) with a slightly damaged cam lobe. If it wasn't really there before, I wouldn't think it to be the chain ?

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10 hours ago, banzai510(hainz) said:

be honest bulid another L20 on the side and just run this one


found it OUP0023  this is the one you want  


$66 that aint bad! 

i was going to grab the lash pads off z car depo as well, unsure if i need 4.6 or 6.6 though and what i'll have to set the valves to with the new cam. havent dug that deep yet.... on today's to-do list


edit: Noob question here. why do i need lash pads, what happens if i run the stock ones ? 

Edited by Sh00bs
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lash pads are abest guess dependin on New or a regroind and if one has the valve cut and the seats cut affects the size of the lash pads.


Mainer 311 on here got the Aussie lash pads bu you could get ahold of him toguide you thru this.

I have the whole assortment of pads and and I do each one to get the right size. one can be off a .010 .020 and maybe even .030 to get center wear of the rocker arm

Edited by banzai510(hainz)
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Yup. I see why I need lash pads now... ordered the 4.6mm ones 


Will update when installed 

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