Datsun5280 Posted September 5, 2014 Report Share Posted September 5, 2014 Sorry if you already have seen my thread, I'm moving it here instead of the Project Datto section. Hello all I'm Omar, I'm a new 79 Datsun 620 owner as of this morning. Had been creeping through the forum for a while but since I didn't own one yet I hadn't joined in. Picked her up from another member in Wyoming, it currently runs and drives but has a blown head gasket. That's first on my list, to get her back to her glory days. It is rattle caned black and white but was told it was white originally. Truck was originally a California truck and eventually made its way to Wyoming. There is some rust but nothing that can't be taken care of. PO has already lowered with torsion and 3" blocks. These are the only pictures for now. Pulled the manifolds today at lunch, will be pulling the head off tomorrow. I ordered the timing chain wedge and that should be here tomorrow. Looks pretty clean inside, are they usually this clean when original? or can I assume someone has at least rebuilt the cylinder head at one point? Pistons don't have much for deposits. Pretty sure someone did a rebuild at some point. Quote Link to comment
Datsun5280 Posted September 5, 2014 Author Report Share Posted September 5, 2014 Also dropped off the head at the machine shop to get milled today. I'm thinking it was not done when the engine was rebuilt previously which could've led to a premature headgasket issue. That or, I'm pretty sure the truck has been driven with out a properly functioning cooling system for a bit. In particular the coolant like that comes from the lower coolant port to the thermostat housing had been cut and not plugged off at all. There Is no way this would have gone un noticed as it would've created a huge coolant leak. Quote Link to comment
laotsu Posted September 5, 2014 Report Share Posted September 5, 2014 oh people are gonna talk aboot that oil filter. 1 Quote Link to comment
Z-train Posted September 5, 2014 Report Share Posted September 5, 2014 What's the casting number on the head? Quote Link to comment
Datsun5280 Posted September 5, 2014 Author Report Share Posted September 5, 2014 It's a w5ocho Quote Link to comment
Z-train Posted September 5, 2014 Report Share Posted September 5, 2014 Never heard of that.The number is on the bottom of the head between #1 & 2 spark plug holes.It should be something like "W-53 or U67". Quote Link to comment
Datsun5280 Posted September 5, 2014 Author Report Share Posted September 5, 2014 Sorry, W58 Ocho = 8 Quote Link to comment
Z-train Posted September 5, 2014 Report Share Posted September 5, 2014 You can measure the height of the head on the block if need be with calipers.I THINK factory spec for that head is 4.260 new and 4.245 minimum.A machine shop should have the specs. Quote Link to comment
Datsun5280 Posted September 5, 2014 Author Report Share Posted September 5, 2014 I didn't measure height, but I put a straight edge on it in various places but was well past the spec in the area between cyl 2 and 3. Block was straight tho. Quote Link to comment
Datsun5280 Posted September 13, 2014 Author Report Share Posted September 13, 2014 So I made a deal today and should be picking up a 77 KC this coming up week. Really good body, don't find any rust or dents. Interior is pretty good, dash is in WAY better shape than my current one. Runs and drives. L20b with an automatic tho. Quote Link to comment
Z-train Posted September 13, 2014 Report Share Posted September 13, 2014 Height is going to determine if you can even use the head.If it's a rainbow and there isn't enough meat left-it's scrap. 1 Quote Link to comment
Datsun5280 Posted September 13, 2014 Author Report Share Posted September 13, 2014 Yea I got the head back from the machine shop, there was enough left to mill but the cam was a little tight. They told me if used the shims it should be good to go. If it doesn't work out, I will now have another head but I'm gonna give it a good ol' american try. Quote Link to comment
banzai510(hainz) Posted September 13, 2014 Report Share Posted September 13, 2014 you can mill both sides to get it straight on top if cam is tight. But If you can can it by hand with the cam sprocket just call it good. turn with fingers if the rockers are not on would be perfect. I had a head done 15thous top and 15 thou bottom and got head shims from Silver Seal 2 Quote Link to comment
Datsun5280 Posted September 13, 2014 Author Report Share Posted September 13, 2014 I was able to turn by hand with the sprocket but i did have to give it a bit of an umff, I definitely couldn't do it with fingers but I'm hoping I will be able to once I throw the shims in. They should be here Monday or Tuesday. Quote Link to comment
banzai510(hainz) Posted September 13, 2014 Report Share Posted September 13, 2014 be careful on the shims. I had 2 stuck together and didn't know it and that cam would not turn. then I figured out it was double stacked. Quote Link to comment
Datsun5280 Posted September 24, 2014 Author Report Share Posted September 24, 2014 Been waiting for the head for a few days now, i took it back because I decided to do it right and not leave it like it was with the drag on the cam. It wasn't too bad but it was just getting to eager to get it back on the road, decided to take a step back and not rush things. I also picked up the second truck, super straight body and no rust, I realized I was too caught up in the moment with my first 620 that I didn't bother to check everything. This other truck is in very good condition, minus a little carburetor issue, I'll be rebuilding the carb In the next couple days. Quote Link to comment
Datsun5280 Posted September 24, 2014 Author Report Share Posted September 24, 2014 Quote Link to comment
Datsun5280 Posted September 25, 2014 Author Report Share Posted September 25, 2014 Accelerator pump check ball was not there, looks like someone screwed up and put it in the wrong place as the pump discharge had two check balls and no spring. Quote Link to comment
Datsun5280 Posted October 1, 2014 Author Report Share Posted October 1, 2014 Here is a picture of the 77 I finally picked up. Gave up on the Craptachi and threw on the webber off the 79, actually I wanted to make sure it was a carb issue, but she runs great now. I'll be focusing on this one as it's I'm much better shape, I don't know what I'm gonna do with the 79 later on. The only bad thing about the 77 is that it's an auto. Quote Link to comment
Datsun5280 Posted October 14, 2014 Author Report Share Posted October 14, 2014 Got a few parts in. Quote Link to comment
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