1980 720 L20b California junkyard rescue

[california720]

Can't thank you guys enough for all the info, this is great.  Yeah I have seen and heard bad experiences from California Datsun, however I haven't been able to find anyone else.  Is there anyone else available?  The idea of getting a good working head for $600 that will get me driving again is nice.  Maybe not rational though.

 

I went to the local machine shop and talked with a trusted welder.  He looked at it and thinks the corrosion would need some extensive welding.  Welding alone could be $3-400.  Overall finishing the head would cost a lot more.  To spend that on a head, when the rest of the truck will most likely have more surprises is definitely not exciting to me.  That would go down a rabbit hole that is totally doable, but expensive and taking me out of the comfort zone for how much I've spend on the truck. I will absolutely hang on to the head, but if possible really need to get the truck running without dumping a ton of money in it.  If I could get a cheap risky head to slap on there, I could at least drive it and worst case sell it to someone cheap who is willing to keep her alive.  Current situation just doesn't have a budget for a proper rebuild.  I'm reaching out to junkyards for a head with no luck.  If I'm stuck I guess I'll have to bite the bullet, but these are uncertain times to be dumping money.  To add to all of this, I'm planning to move across the country in the next few months and need to start trimming down my possessions.

 

I'm going to talk friends and other machinists to see if I can get a better opinion.  If things keep looking grim, I'm going to start searching for someone willing to take on the project.  As of now, the truck has cost me less than $3,000 and for 3 years been a great truck, so I'm happy walking away.  My main concern is to make sure it gets to live on.  It's important to me to keep these things alive.

 

 

[Charlie69]

There is a 1980 720 in the wrecking yard here in Phoenix.  I will go see if the head is there tomorrow.

 

Contact Gene Knight he might have a L20B head

[Chopper Jim]

I'm waiting to hear from my local wrecking yard. They had 5 or 6 L20's in the yard.

Will know tomorrow.

 

Chopper Jim

[california720]

I'm reaching out to friends about other options and have a good lead.  either way I'll probably spend this weekend taking the head apart so I can get a more accurate quote on the weld. 

 

Thank you so much for checking!  That's amazing. 

[Chopper Jim]

He said $100.00 for the head plus the ride from Kingman Arizona.

 

Chopper Jim

[Charlie69]

 The  here in the Phoenix yard is missing the motor.  It looks like from the way the front inner fenders and firewall are cut that it is a victim of a hack engine swap.

[gene knight]

california720:  hit me up i have some heads for sale 

 

Charlie69: thanks for the shout out 

[california720]

Ok, I have a replacement from Gene (thanks!) and am looking to make one good head out if these two.  Should I just strip the new head down to the aluminum block and replace everything from the one that worked in the truck?  Or will I have to clean and restore this new head piece by piece?

 

I’ll try and get some pics up later 

 

[california720]

OK, had a friend come by yesterday and we made a lot of progress.  Had the head machined, rebuilt and assembled everything.  got the block cleaned up real good and right when everything is bolting together, realized that we may have dropped the chain at some point....  I can't think of anything else it could be.  The timing gear just won't fit on the cam.  There is not enough slack in the chain and even though it has been wedged and I've been very careful, it must be that?  needs a solid centimeter more of clearance.  Here's some pics.  Anyone have other ideas?  Do I have to remove the front of the block now?  How fucked am I?  😅

 

Almosssst

 

 

but not quite enough slack...  I'm running out of time and might have to pass this off to a lucky person with a fresh wallet and time.

 

 

 

Any opinions are appreciated.  I'm moving to Texas in a couple days and wanted it running before I left.  If I can't get anywhere, this is going to be sold real cheap to someone willing.  It's soooo close I can't believe it's not going to make it in time.

[Duncan]

Can't say for sure, but by the looks of where your chain block is placed, I suspect you missed holding the tensioner and it's over-extended itself.  That will keep the cam gear from going back on.

 

Here's a photo, and the tensioner is on the left side, and very low.

 

Somewhere here on Ratsun, there is a thread where someone did just that, and was able to use some rods and actually get the tensioner back into place whithout taking the front cover off.  I imagine it would be quite tricky to do, but he explains it in his "how-to" thread.

 

Again, I'm just guessing, but I'm currently doing a replacement on mine at the moment and have run into similar problems..

 

Just found the thread.  timing chain thread

 

Edited July 31, 2020 by Duncan

[Stoffregen Motorsports]

I've been able to get the tensioner back in with a looooong screwdriver. It is possible.

[Charlie69]

This is a problem that most peopele the work on an L motor have experience at one time.  Pull the timing cover and reset the plunger. also while the timing cover is off good tme to inspec every thing and replace anything wore out or damaged.  This might be a good thing in the long run.

[Duncan]

8 minutes ago, Charlie69 said:

 while the timing cover is off good tme to inspec every thing and replace anything wore out or damaged.  This might be a good thing in the long run.

 

That's what I'm doing currently.  I'm struggling a bit with it, but I'm getting there...

 

 

 

[Charlie69]

It is easiest to loosen all the oil pan screws.  I personaly remove the front ten bolts so I can pry the oil pan down away from the timing cover.