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My new 521


Datsunthug

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Big question of the day??????

I have two different crank pulleys. One from each motor. The one that came off my truck is a single groove pulley with balancing holes drilled into it on the back. The other pulley off the spare motor is a double groove design with no balancing holes or weights. So my question is ? ARE SOME L16s internally balanced while some rely on the crank shaft pulley weights holes.

Want to make sure that I use the right parts

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L-16 engines are internally balanced.  By that, I mean L-16 engine do not need an out of balance flywheel, or crank pulley to balance the engine.  However, Nissan may have made a minor adjustment in the assembled engine balance by putting some drilled holes in the crankshaft pulley, or the holes could have been drilled to balance the individual crankshaft pulley before it was put on an engine.  I believe the pullet is cast steel, and casting variances do occur and after the v-belt grooves are machined, the pulley is then "spin" balanced.

 

Most USA L-16 engines, from 1970 on had an air pump to reduce exhaust emissions.  That is what the double groove pulley is used for.

 

Datsun used a few different methods to put ignition timing marks on an engine.  Some pulleys have several notches, and use a single pointer on the cam chain cover.  Other pulleys use one notch, and a saw tooth pointer on the cam chain cover.  The ignition pointer can be on the right or left side of the engine. 

Use the pulley that works with the ignition timing pointer style, and position that matches the cam chain cover you use.

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Thanks Daniel. I got the block back today from getting tanked. all the pulleys, brackets etc were painted also. Checked the clearance on the top rings of each cylinder.

.046 cylinder 1

.050 cylinder 2

.045 cylinder 3

.046 cylinder 4

The manual specs out between .25-.40 (0.0098-0.0157 top ring end gap.

Don't know how much compression will be lost with it being a little beyond tolerances

Trying to find someone or a place to rent a dingleberry hone

EDIT: top ring specs. Sorry

.25-.40

(.0098-.0157)

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I cleaned my pistons, slapped new rings on there, deglazed the cylinders and fired her up. Runs like a champ for over two months now. All stock rings replaced. shouldn't have to worry about it too much. Just my opinion though!

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  • 3 weeks later...

Engine is together!!!!!! Just need to check the valve lash and then take it off the stand to install the rear seal and new clutch!!

Had some trouble with the front cover. A bolt had broken off to mount the water pump and I didn't see it until I had mounted it. Fail on my part. Luckily I had another from the extra motor. And extra gaskets and a front seal.

Thanks for the tips guys. Pics soon

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  • 2 weeks later...

Engine was put in yesterday! Going through the wiring to find out why the starter isn't getting juice. When I first got the truck there was an issue with the wiring it wouldn't start, and then I jostled around some wires and magically it started. There must be a short somewhere and I hate electrical so this will be fun

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521 electrical diagram.

521wires.jpg

 

Battery negative grounds to head, by fuel pump.

Big battery positive, to big terminal on starter solenoid.

A thick wire also goes to the fusebox from battery positive.  This wire is connected on the engine side of the fuse box to a thick white wire, that goes into the wiring harness.  This white wire goes into the cab, and to the ignition switch.  The ignition switch connects power to a black wire, with a yellow stripe, when in crank position.  the ignition switch makes other connections too, but black wire, yellow stripe is the "crank" wire.  The black wire, with a yellow stripe goes to the 1/4 inch spade connector on the starter solenoid.

 

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Yeah the u shaped pieces that lock in the adjuster from the back side of the drum

 

Oh by the way........ Got her running!!!

Might have to pull the distributor and oil pump to get the timing right. Had to adjust it totally retarded ( dizzy adjusted all the way left) to get it to run.

The muffler seam was rusty and broke so now I have no exhaust which makes it sound like a mini stock at the racetrack. But the no muffler is more quiet than my birthday party last night. Haha

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$207 Rock auto (all the internal engine shit)

$120 battery

$7 car wash

Free oil and filter

About $30 worth of silicone, anti seize, lithium grease etc.

and probably 250 beers

Yep that's what it costs to rebuild a Datsun.

And all the pointers from you fellow ratsun members

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