My '79 620 Ground up Custom King Cab Build - Ebay & classifide here soon!

[Wheezie]

I hear theres a way to upload here, but don't know how.so this is being hosted on my personal website.
it took me 4 hrs to make this page and would take me wayyy too long to upload each link to about 47 pics and provide details.

If you would like to check it out from the Ground up...

Here's the link: http://thelittleredbedtimebook.com/Datsun_620

 

[datzenmike]

If this is for selling purposes start a for sale ad in our classifieds section and link this page for pictures. This forum is for displaying and discussion of our projects. If this ends as an ad it will be removed.

[Wheezie]

Ok thanks and "Understood"
right now it is just what I am doing & progress being made (My Build).
 

When it is done in a few weeks i will post in classifide only.

Question: When I am done am I allowed to post here that it is in the classifide section? 

[Wheezie]

Well today I messed with the valve lash (ALL were tight), and advanced the cam a tooth (There's no V mark on the back of the gear) and the Cam dowl was alligned with the dash on the cam retainer, so I put the cam dowl @ 12:00, did a cold-n-dry  comp test and WALA!
(#1) 157 (#2) 155 (#3) 160 (#4) 155

with my comp tester that bleeds down a bit (Slowly) and only 5lb increments, so #'s may actualy be closer.

5 lb diff isn't bad anyways...

Happy boy here! :thumbup:

[datzenmike]

Ok thanks and "Understood"

right now it is just what I am doing & progress being made (My Build).

 

When it is done in a few weeks i will post in classifide only.

 

Question: When I am done am I allowed to post here that it is in the classifide section?

 

Sure, no problem.

 

Well today I messed with the valve lash (ALL were tight), and advanced the cam a tooth (There's no V mark on the back of the gear) and the Cam dowl was alligned with the dash on the cam retainer, so I put the cam dowl @ 12:00, did a cold-n-dry comp test and WALA!

(#1) 157 (#2) 155 (#3) 160 (#4) 155

Even-ness is the key to a good running smooth engine. Bonus for having above 150.

 

The stock sprocket is set on the #2 hole for best overall running. If it doesn't have the V in it then it's been replaced and should be relatively unworn and the chain. The stock sprocket is set on the #2 hole for best overall running. If in the #1 hole it will advance the cam taking some away from the lower RPM but adding to very high RPMs. If on #3 hole it favors lower RPM only. If you have the time try them all for a few weeks and see if it runs better.

[Wheezie]

It's set in #1 hole,
dowel @ 12:00 on 0-TDC

Might change it to #2 later to have Holes to play with.
We will see how she runs first... :sick:

 

Funny thing is it ran GREAT all messed up (Timming 180 out-no advance opt. - seriously tight valves- and cam tooth off) when I got it.... Comp test waas 130-90-65-105...
#3 valve in. - which I couldn't loosen enough for .010 now is 160 ?? wth?

 

Curious, what is the stock comp. #'s for L20B?

[datzenmike]

8.4 but compression check in pounds I don't know.

 

In theory just over 108? But in reality you can't get anywhere near that because the intake valve does not close at bottom dead center.  On a stock L20B cam the intake closes about 52 degrees later or almost 1/3 of the way up the cylinder towards TDC. So you don't compress a full cylinder. Also there will be some losses past the rings, more if worn out or bad valves. Maybe 170 - 180?? on a fresh rebuild.

[Wheezie]

Feelin' a lil' sick right about now... :poop:

I put all this time & $$ into this thing because it seemed to run good an didn't smoke.
I shoulda run #s first and made adjustments.

now with the valves adjusted & compression up and cam where it sould be....
IT BURNS OIL! :hyper: 
 

Obviously valve guides? Or maybe advancing the cam a tooth more than it was is making it  suck oil from somewhere because valves are opening to soon?

 

Or have I been proffessionaly duped into buying an oil burner, by someone tightening the valves till it runs but not suck oil?? :frantics:

 

(Thanks for your input by the way... I am appreciating your help a LOT!  ) I don't have anyone to bounce this stuff off of...

  
 

[ggzilla]

Impossible to tune it to not smoke

 

 

If the oil level is too high it will smoke

 

What smoke symptoms do you have?

[Wheezie]

Well, It didn't smoke (Maybe an unoticable amount?) Until I adjusted the valves (They were tight) & put the cam dowl pin @ 12:00 as suggested by many.
This raised the compession to near normal & even #'s .

Now it has throttle response from an Idle But smokes pretty good until warm.. then just smokes casualy an seems to be intermitant.. ?

I know it didn't hit any valves.
And I only advanced cam 1 tooth to put the pin up instead of on the - mark

[datzenmike]

Check oil level.

 

Drive it for a while, use up the old gas..

[Wheezie]

Gas is new. I dropped an cleanned the tank when down to the frame.

Maybe driving will clean up or expand a seal/valve guide???

Edit:
Ok well i just went out an check the oil level (Good thought) and it is a lil low between the H & L marks.


I'm over it for today...
I'll play with it tomorrow....
Thank you for your replies.
night all.

[Wheezie]

Star date: Sunday, May 12, 2014

Update post: #13
I let it run this morning for an hour & smoke seemed to be clearing.
I shut it down and let it cool.

 

I noticed the water in the rez had dropped about a pint.
This raised my eyebows a bit and I refilled it to the line, checked oil (looking for milk  or increase in level ) and took the cap off then started it again looking for bubbles.There were none & no milk or raise of oil level.

 

 When I first started it it did not smoke at all, until warm and then a bit of the well know semi sweet smell water coming out of exaughst.

Prognoses:
Head gasket is getting ready to blow, but is only weeping at this point when warm.

Perhaps this is the reson it got parked for so many years???

Question is... do I atemp just retorquing the head bolts?
Or do I go the distance and replace it?

Input is welcome as I sit an twittle my thumbs pondering what might be the inevitable.

(Expereinced input with just trying a retorque before prefered)
 
  

[datzenmike]

I did my '78 620 for $23. Or the cost of a cheap NAPA HG. Lift the head off with the manifolds attached and tip up only enough to wire wheel the head surface to avoid stirring up sediment in the carb. (or take carb off) Block the cam sprocket and loosen the nut, then set to TDC and block the chain so the tensioner can't fall out. Clean the block till it shines, chase the threaded holes and clean the reusable bolts. Both head and block must be spotless. Torque in this pattern to 20# then again to 40# and a last torque to 60#...

 

R A D

7...8

3...4

1...2

5...6

9.10

[cj8281]

You should also check the head for wear.  The head gasket usually wears into the aluminum head and normally should be resurfaced for a proper seal. 

 

Also something to check since you mentioned you had a valve that had no adjustment to it.  Look down the line of the valve springs, is that one valve spring that has no adjustment left sticking up a bit higher than all of the others?  If it is, then that valve is sinking into the head, you might need to have that valve seat replaced.   It could also be that that valve is tulliping, meaning that the head of the valve is folding up.  Make sure you turn the engine to make sure the cam is not about to open that valve when you check it.

[bonvo]

You should also check the head for wear.  The head gasket usually wears into the aluminum head and normally should be resurfaced for a proper seal. 

 

.... accept that machining a head for an ohc engine can cause issues such as in the case of a datsun engine throwing the cam timing off this can be compensated for but why go threw the hassle when you can just clean the surface? usually machining a head is to make sure its true not to make sure the mating surface is clean 

[Wheezie]

Thanks guys!

Wanna hear somthin funny ?

I just relised I did the comp check with throttle closed... :blush: 

I know this has nothing to do with the unajustable tight valve (Which also happens to be the high comp cyl. #3 160) or the water consumption or the smoke/oil burnning...
 

Just sharing a "Duh" momment... That releives me from the thought of Bad rings... unless it at some point got hot enough to colaps the the oil rings .. ??? 

Dunno --- I guess I im going in for a HG replacement and the rest will reveal itself overtime o_O


I will check V-stem highth while i am in there. (TY fer the info)

 Napa here I come....

Note: When I do HG on a Datsun i use "Copper coat" always "Just in case" there is any warpage.
It is also recomended for Diesels.
The thing of it is... when it is used .. the gasket adheres so well, the gasket tears in half when removed again & takes a lil' effort to clean.
"BUT" I had a D-sun that kept blowning gaskets (3-times) obviously a warped head. I used The stuff in the can (Not spray) and the lil' brush.. & WALA! End of story! I like the spray for other apps.
I like to let it become "Tacky" not dry> set the head down & let sit (with bolts @ about finger tight) over night.
Comence Torquing seq. in the AM. :thumbup:

[Wheezie]

I did my '78 620 for $23. Or the cost of a cheap NAPA HG. Lift the head off with the manifolds attached and tip up only enough to wire wheel the head surface to avoid stirring up sediment in the carb. (or take carb off) Block the cam sprocket and loosen the nut, then set to TDC and block the chain so the tensioner can't fall out. Clean the block till it shines, chase the threaded holes and clean the reusable bolts. Both head and block must be spotless. Torque in this pattern to 20# then again to 40# and a last torque to 60#...

 

R A D

7...8

3...4

1...2

5...6

9.10

 

 

  :baby:  :no:

I can't beleive you suggested the "Wire wheel" on an ALUMINUM head.

A Wire wheel will DESTROY aluminum very quickly and should "ONLY" be used on cast iron or steal/ metal surfaces.

Even a soft one can round edges or gouge.

 

[dr.feltersnatch]

depends on the wire wheel. you can safely use a wire wheel on aluminum. just have to do it right. 

[Wheezie]

mmmmk.... "Not this boy" too scrary for me! :rofl: 

Well back to the topic...

This thing is gonna give me nightmares!

I took the V-cover off to check/retorque the heads.
For giggles I ran the feeler gauge over the lash pads and they were all tight AGAIN!
Not as bad as first time but not 8 & 10 where I left 'em  :crying: 
So... I did the retorque first @ 60 where they should have been.. some moved a lil'  some didn't . so i did it again at 70# (this is the max I ever use) and again some moved some not, so i left it and re adjusted the valves, then did a new comp. test, this time opening the throttle.
Numbers came back MUCH happier!

#1) 167

#2) 167

#3) 170 (this is the tight intake (less than .006) & no more adj adjust  ) O_O
#4) 168

It seems as if the rings are good so I am now leaning any oil/water--Burning/consumption torwards the head an valve seats.

I'm gonna let my bro drive it a few days as KR suggested (No licence in my wallet).
Hopefuly with the retorque something will change for the better... If not I'll have to do what I am seriously avoiding... :sick:
 

[Wheezie]

Welp..
I replaced the valve guide seals and it quit burnin' oil :D 

Still have one tight intake on #3 that won't adjust out. It runs @ about .006 (what everrrr)
It has the highest of comp so no harm-no foul....
 

I am going to do one more comp test now that i have messed with everything just so i know what the #'s are.

 

Then I gotta buy ANOTHER $70 windsheild seal as some how/for some reason the one I just put in tore in the cornner when the sun hit it and it got warm??? :baby:  :frantics: