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KDW_80-720

'80 720 L20B

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I have never owned one of these with the L20B, I did have an 86' with a Z24 in it at one time, just bought this yesterday.

 

My questions are this:

 

This is burning a ton of oil and blowing blue smoke.  I'm assuming it's just the rings that need to be replaced..

 

The gears are SUPER loose.  When I look at the transmission where it bolts to the block (brain fart on what is' called) it looks like there's about a 1/8" gap there where I'm assuming it should be flush?

 

It looks like it's had head work done, but I haven't torn into it yet. 

 

The guy I bought it from said that if you put fuel in the weber 32/36 it will run.  I notice no issues on start up outside of the blue smoke when it runs.  Someone had eliminated all of the EGR stuff and I have no idea what all he eliminated..

 

Any advice helps! It's a project so I have time..

 

https://imgur.com/gallery/Wu2wpAP

 

 

 

 

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As far as the transmission gap it looks like your missing the metal plate the goes on the block... I believe I goes behind the fly wheel.....

 

This thing 

Screenshot-20200625-113409-e-Bay.jpg

 

Just searched ebay for a pic and a couple came up.... 

 

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crap cant open the photo

 

why would they not put the plate on?

 

Once a oil burner its a oil burner, One could replace the valve seals but to me   maybe put on a spare head and have this one redone and do the motor at sometime.

 

I would love a 720 with a L20 but haven't seen to many of them.  Just find a l20 on side and build it up and install one shot

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Yknow I think I have one of those in the spare parts bin he gave me.  I wonder why they didn't put it on, but then again the ebrake was ziptied to the frame..

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Just now, banzai510(hainz) said:

crap cant open the photo

 

why would they not put the plate on?

 

Once a oil burner its a oil burner, One could replace the valve seals but to me   maybe put on a spare head and have this one redone and do the motor at sometime.

 

I would love a 720 with a L20 but haven't seen to many of them.  Just find a l20 on side and build it up and install one shot

 

 

I will get a better photo of the head tonight, but it looks redone or someone really cleaned it up..  I want to do an LZ anyway, so I might just keep this and rebuild/bore etc

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Welcome. Sounds like the truck needs some love. 

 

Here is the pic of no plate. 

 

fbdgJUN.jpeg

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Just now, ]2eDeYe said:

Welcome. Sounds like the truck needs some love. 

It sure does.   The floor is rusted out, the exhaust is rusted off, but I paid $750 for it, so I can't complain too much about the stuff it needs done.

Just now, ]2eDeYe said:

 

 

 

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28 minutes ago, Crashtd420 said:

As far as the transmission gap it looks like your missing the metal plate the goes on the block... I believe I goes behind the fly wheel.....

 

This thing 

Screenshot-20200625-113409-e-Bay.jpg

 

Just searched ebay for a pic and a couple came up.... 

 

Yes the steel plate goes behind the flywheel/flex plate.

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2 hours ago, KDW_80-720 said:

I have never owned one of these with the L20B, I did have an 86' with a Z24 in it at one time, just bought this yesterday.

 

My questions are this:

 

This is burning a ton of oil and blowing blue smoke.  I'm assuming it's just the rings that need to be replaced..

 

The gears are SUPER loose.  When I look at the transmission where it bolts to the block (brain fart on what is' called) it looks like there's about a 1/8" gap there where I'm assuming it should be flush?

 

It looks like it's had head work done, but I haven't torn into it yet. 

 

The guy I bought it from said that if you put fuel in the weber 32/36 it will run.  I notice no issues on start up outside of the blue smoke when it runs.  Someone had eliminated all of the EGR stuff and I have no idea what all he eliminated..

 

Any advice helps! It's a project so I have time..

 

https://imgur.com/gallery/Wu2wpAP

 

 

 

 

 

The smoke/oil use issue depends on what is wrong with the engine, if a good head(usually rebuilt) is put on an old wore out block then it sucks oil thru the rings, or it could be the valve seals are bad/toast, I had an L20b with this issue(work truck), it used a lot of oil(gallon a week), most every morning I would add oil, sometimes it took 2 or 3 quarts depending on how much I drove it the day before or if I had not added any the day before, when I started it it was fine for a few seconds, then it would start smoking and make a giant cloud of white smoke, this cloud was the result of oil getting into the cylinders when I added the oil because the valve seals were useless/toast/bad, sometimes it took minutes for it to burn the oil out and clear up, but in the end it was too expensive buying that much oil every week so I built an LZ23 for the work truck and never thought about it again except for how nice it was not to have to add oil everyday.

 

You have a photo of the truck?

Edited by wayno

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if the slave and T/O bearing  if fully released it might be OK  But I think some the x member bolt might be sightly off

 

 

maybe you could take one bolt out at a time and slide a washer in there if you think that gap is needed. I don't know myself. abut Datsun owners still amaze my what they do sometimes

Edited by banzai510(hainz)

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2 hours ago, KDW_80-720 said:

 

Oops, I just put the engine.  Here is one linked.

 

https://imgur.com/gallery/BDojMBR

 

You can 'copy image' and paste it in the reply window. 

 

lV4SQXw.jpeg

 

Nice looking truck. 🙂

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Just now, ]2eDeYe said:

Nice looking truck. 🙂

 

Thank you.  

 

I have a lot to learn on this but I did find a FSM for pretty cheap on Ebay, so hopefully I get that next week so I can tear into it.  i gotta put a new clutch etc etc in.

 

Is there a Disk brake conversion for these?

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isn't this have disk up front?

I wouldn't worry about the back

 

How you know clutch is bad. ? maybe just bleed the slave cylinder

Edited by banzai510(hainz)
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Just now, banzai510(hainz) said:

isn't this have disk up front?

I wouldn't worry about the back

 

How you know clutch is bad. ? maybe just bleed the slave cylinder

 

I should probably put my foot in my mouth for a bit until I actually get to drive it for longer than 5 minutes.  It's burning so much oil and putting so much smoke out that I can't really handle driving it for longer than that lol, I swear I can taste oil after getting out of it..

 

I'll start with all that fun stuff and see what happens.  I know for sure I need to bleed the brake system, so I'll do slave while I'm there... The master has like black fluid it in, it's awful.

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It has ball joints and disc brakes, not the greatest disc brakes. They can be upgraded fairly easily though with newer hardbody parts. 

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Also, gears super loose is likely the shifter bushings. You can get bronze replacements for the 280z. 

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Didn't you take for a drive before buying it??? Take it back and get your $50.

 

Without engine plate the clutch arm and release bearing is 1/8" closer to the engine. It may not be able to move back far enough to fully engage the clutch and it slips. Take it back.

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I do have that plate, it was in the basket of parts.  I drove it a little bit, I didn't notice anything funny but I am NOT an expert by any means in transmissions.  The truck sat for 6-8 months before I bought it.  The kid had never driven it, couldn't drive a standard. 

 

 

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Kid fucked it up tells you he couldn't drive it. Missing engine plate so flywheel was off. Engine and/or transmission were out at some point by someone who didn't know what they were doing. 

 

 

Excessive (oil) smoke....

 

Check oil level is maybe too high. Drain out.

Wrong dip stick, oil too high. Too high and spinning crankshaft will splash it on cylinder walls. Empty and put in 4 liters (4 3/8 QT) read stick to confirm.

Gas in oil thinning it or over filling it.

Water in oil, over filling it. Will look milky instead of black. Blown head gasket or damaged timing cover/water pump

Worn or missing/broken valve guide seals. (not much smoke except on start up)

Damaged piston (hole) and/or rings broken (LOTS and LOTS of smoke) Compression test will show almost no reading.

Worn out rings. Leak down test. Hissing sound at valve cover hole is getting past rings.

 

 

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4 hours ago, datzenmike said:

 

Gas in oil thinning it or over filling it.

 


Oil was very thin and gassy, kind of smelled like exhaust. 
 

Coolant looks good. I’ll have everything pulled tomorrow to get the whole transmission thing squared away. Whoever put it in didn’t even have bolts in the transmission mount because they are off center. since I have to put that plate on, I’ll do the clutch and stuff while I’m there.. I know this isn’t the Best Buy/build I could do but I want to do it. 
 

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How was the level?

 

Oil can get gassy smell if the choke is on a lot or carb is rich. I was thinking a ruptured fuel pump diaphragm and the gas leaks down into the timing cover and into the oil pan.

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The level seemed a little low last night after I ran it. Added 1/2 quart and seemed okay. I ran it tonight before I started taking the rad out and all that and it was a bit high. 

The only place I can see oil on the block itself is from under the exhaust manifold and onto the exhaust pipe. That’s the only place I can see anything. Front of the engine looks good.

 

https://imgur.com/gallery/mkoPvgp
 

 

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