Need help with 521 out of long term storage.

[nortryder]

I picked up a 521 that has been sitting since around 1985. It's kind of a mystery vehicle as the PO. isn't available for questioning. I'm trying to get it started and have not been able to get it to fire. It cranks okay but no fire. I have jump the coil to no avail. today I did a compression test and found that the rear cylinder is at 0. question is is this from sitting open? Or am I looking at a valve job. I'm not a big fan of unnecessary work so am hesitant to rip and tear before I know why I'm doing it. Also I'm not a big fan of dual points is there an electronic conversion I don't know about? I also have single point distributer off a 1600 Fairlady will that work? Or for that matter would the whole motor work? Thanks for any insight on this.

[Draker]

1978-79 620 and other dizzy is electronic. Easy to get.. and works good.

 

Buy a leak down tester and that will tell you where the problem is.

[flatcat19]

Engine cranks, no fire. But you have 30 year old gas in it.

 

 

 

Hm.

 

Suck. Squish. Bang. Blow.

 

Air is going in. Check.

No compression on 1 cylinder. It should still run, just not great.

Spark to all 4 cylinders? Spray some brake clean down the carb if you have spark.

Totally assuming exhaust isn't smashed.

 

 

As for your lack of compression. Do a wet test. Rule out the rings. Then remove valve cover to I spent valves.

[banzai510(hainz)]

olddatsuns.com read tech section.

 

you get sparkat end of coil wire?????????  otherwise points are fucked or condenser. work on that first.

 

You get 12 volt at the blk white wire at the ballast resisitor. ?

 

then if spark ck the valave lash. there is YOUtube vid on this from Mike Klotz on how to do this.

 

If spark and valves ok I would pore some gas in the carb and see if it at leadt fires.

 

Hoever as mention I would be scared to see whatsin the tank. I would maybe drain it and run 2 filters if you think its somewhat ok to run it.

[racerx]

I would consider cleaning ur tank and changing ur fuel filter. Then set timing to base and make sure ur points r ok

[datzenmike]

Need spark and gas to run assuming there will always be some compression. It should fire up even without rings in it. Only way to have Zero compression is a hole in a piston or one of the valves stuck open. Take valve cover off and crank engine over and watch which one does not close. It was parked so probably had a problem but not worth the bother to solve and fix. If it was running then it likely would be running now. A blown head gasket left with wet cylinder and valves for 30 years got rusty and does not close.

 

 

Pull coil wire off and hold near ground, crank engine... got spark??? NO?  Either points are not closing and opening or no power to the coil. Get test lamp for $3 and find out which one.

 

YES there's spark.... probably fuel related... too much or too little.

 

1/ Is the choke on? Has to be on for cold start.

2/ Look at front glass. Is it filled with fuel to the full line mark?

3/  Pump throttle and look down into carb. You should see squirts of fuel. Three or four squirts should give you enough gas to fire it at least.

[nortryder]

Fuel isn't an issue as the tank is dry and I've been dumping gas down the carb. The tank and carby are nice and clean unlike the ones on my roadster when I got it. It seems to be electrical which always baffles me. The 0 compression on the rear cylinder didn't cheer me much. I'm hoping that a valve is stuck open from sitting. Fat chance.

[datzenmike]

Take the valve cover off and look. Find the one hanging up, hell the rocker may simply have jumped off and is jammed under the cam. 

[nortryder]

That's what I was hoping. I had the cover off today and everything looked okay but I didn't check all that carefully. Maybe a valve isn't closing all the way. I'll look more closely. I like the electronic ignition idea. How hard is it to find 620 parts? Up here in Vt everything turned to rust years ago. It was a fluke that I found this one in such good shape.

[banzai510(hainz)]

before you get wraped up with a electri ignition its EZ to get the points to work. before we try 10 pages worth of how to put a new distributor in.

[datzenmike]

Yup. Points are a visible mechanical working part. Easy to see if not working, easy to set, easy to figure out. Get running then jazz it up.

[nortryder]

I have a 1970 521 that has been sitting since 1985. The motor has no compression on 3 cylinders. I have a good R16 engine out of a Fairlady. does anyone know if these are interchangeable or what kind of a job it would be to switch them? Would I be better off rebuilding the L16?

[datzenmike]

NOT interchangeable.

 

You could eventually get to work if you have a transmission too. Engine and transmission mounts, rad connections, exhaust, throttle linkage or cable, maybe shorten or lengthen the drive shaft to match.

[wayno]

The roaster engine has a lot of negatives, I am not sure that the exhaust manifold(basically header) will work in a 521, also parts for the Roadster engine are expensive, anything Roadster is expensive.

If you don't have a Roadster transmission then forget it, they are expensive unless you can find a 4 speed, but if it needs rebuilt, it is expensive if you can even find the parts, back in 1994 I had to buy another 4 speed so I could make one good 4 speed.

If you could find a Datsun/Nissan SD22 diesel transmission, that would likely work as the have the same front case pattern as the Roadster, but I don't believe it is a bolt in.

I would try to find a L20b in your area, see if you can find a good one, or maybe if shipping isn't too bad have a good one shipped to you, it is a bolt in, but if you go that route, you also need the throw out bearing collar that matches the clutch cover you get with the engine, as you have a 5 bolt 200mm flywheel/clutch cover, some L20B engines have a 225mm flywheel/clutch cover and they all are 6 bolt, you need the flywheel with the engine, you also need the throw out bearing collar for that 225mm clutch cover, as yours is for a 200mm clutch cover.

If you get an L20b engine you will need to use the L16 oil pan/oil pick up tube you have on the engine you have in your 521.

[Stoffregen Motorsports]

That's taking a step in the wrong direction. The L16 is a vastly superior engine in every way compared to the R motors.

 

Depending on why the compression is low, you could probably rebuild the L16 for $500 in parts and outside labor, if you did the assembly yourself. Get new rings and bearings, a gasket set, a timing set, ball hone the cylinders, clean the oil pump, have the head rebuilt and call it done.

 

Don't worry about an over bore or cutting the head, grinding the crank or resizing the rods. If it's just tired and worn out, none of these machining operations will benefit you one bit except maybe the head cut, that would give you a bump in compression.

 

If the L16 is rusted, seized, spun bearings, cracked head, you could run into the thousands to get it done right. At that point, I'd look into a L20B.

[MikeRL411]

I have a 1970 521 that has been sitting since 1985. The motor has no compression on 3 cylinders. I have a good R16 engine out of a Fairlady. does anyone know if these are interchangeable or what kind of a job it would be to switch them? Would I be better off rebuilding the L16?

 

Whatever you do, save the R1600 engine!  They will eventually be worth far more than your 521.  As is, they are vital to restoring the PL311 series roadsters, and with suitable modifications the restoration of RL411 SSS cars.

[flatcat19]

Find a running L20B.

[nortryder]

Latest news on this is that we pulled it inside and played around with it yesterday. I had dumped a bunch of PB Blaster into the cylinders a while ago. There hasn't been any fuel in the tank or any where else for years. Pulled the drain plug and the tank is dry. Any way we did a compression test and 3 cylinders were down to around 20/40 lbs and one was at 100 lbs. pulled the valve cover and all the valve seemed to be going up and down the way they were supposed to. A little history on this this truck (very little). A friend owns a salvage yard and picked up a dozen or so cars that were at a property being sold by the bank. Among them was this 1970 521 and 3 Fairladies. I've been a foreign car type of guy foe years. I'm 65 and I drive VWs and Hiluxes back in the 60/70s we also had a fleet of 520/521s where I worked when I was in college. So I've been around this kind of stuff for a while. Back to the truck, the SP311s were pretty rotted this being Vt and the land of ice and salt. The 521 looked bad at a glance (faded, sanded down paint) But on closer inspection it was real solid. I weaseled it away from my friend and set about to get it running. The truck had been a squirrel condo and I shoveled out about a foot of chewed up pine cones from inside the cab and the bed of the truck. The bed had a cap on it and was full of parts that had been removed from the truck. It seems to have been a science project. I found what turned out to be the original engine amongst the debris. Seems that the P.O. had lunched it and replaced it with a different engine. He did a good job and everything is hooked up right. The original motor was partially disassembled with the head removed. one of the pistons is sticking up above the block by a couple of inches. The oil pan is still attached so I can't tell if it's a broken or unbolted rod. It's all all rusted  soild because of exposure to the elements. The motor in the vehicle spins like no compression when cranked over. My guess is stuck rings. Ive dealt with this on a lot of motorcycles that Ive rebuilt over the years. I haven't had much luck freeing them up with out disassembling the motor. Sometimes soaking the bores with different helps, but not much. So it seems my choices are to pull the head off the engine thats in the truck and beat on it with various tools and hope the rings free up. Or look for another, running engine and swap them. Or  pull the existing engine and have it rebuilt. Or try and stick one of those R16 motors out of one of the fairladies in which would look cool with the twin carbs but, I guess would be very practical. The rebuilding option is looking like the best move. Any ideas? Sorry for being so long winded.

[nortryder]

Thanks for the replies and info. Kind of what I figured. Too bad though. That R16 would would look pretty cool in there with the 2 carbies and all. I'm looking for a running motor L16,L18, or L20b with out much luck. I'll most likely pull the motor thats in the truck and have it rebuilt. Thanks again.

[Stoffregen Motorsports]

http://www.car-part.com/

 

I use them for engines all the time. It's a nationwide database and you can search by region.

 

I just searched it for '79 Nissan truck engine, and there are a ton available on the east coast. A couple in PA. Very close to you.

[Stoffregen Motorsports]

Try sticking to one thread. Having them all over the site gets confusing.

[nortryder]

Nice! I'll check it out. What should I look for exactly? A L20b? Is that the later version of the L16?

Thanks

[banzai510(hainz)]

go to you tube and look up my vid Hainz L series Datsun.

 

or olddatsuns.com tech section

 

 

I would do a valve lash adjust first to make sure the valve are closing.

 

I would get spark for the coil. Most coils don't go bad. its the distributor is the spark issue mostly lightl points gronded out or condenser or points need adjustment. 

If you have 12volt at the black white wire and power from the other side of the ballast  most like is good.

 

then dump some gas in there to see if fires off.

 

cycle the carb to see if gas is squirting in carb other wise maybe fuel pump make be back or carb needle valave sticky not letting gas in carb

 

al this is about a 15min cheak

 

 

I had a 520 I was working on and the dist would not spark with dist cap on. But with it off from the coil it would spark.  was condenser wire I believe.  We got it running but truck sat for months later to who knows what happen to it now.

[racerx]

Yea, L20 is later version.

[datzenmike]

Nice! I'll check it out. What should I look for exactly? A L20b? Is that the later version of the L16?

Thanks

 

In worldwide use, there were L13, L14, L16 and L18 four cylinder engines The L20B is only a B because there was already an L20 six cylinder. This L20 was later referred to as the L20A when the L20B was introduced.

 

The L20B is 3/4" (2cm) taller, is 25% larger displacement, and has a 6 bolt crankshaft, otherwise outwardly looks identical to the L16/18.