The 521... OK, after eliminating all the other culprits... valves???

[hessianben]

hessianben

you have to dial the mark up to the most left notch on the crank that is Zero. Otherwise I think your motor cam timming is fine.

I swear in my vid I show myself dialing it up to zero going 20 15 10 5 then zero.

 

Datsun Mike or anybody elese could bens proplem been with the 2nd set of points or does that only work in 3rd gear only or 3rd gear and above.

 

That head looks OK. I wonder if just a wore out distributor????????

 

head gasket dident look that bad either in my opinion!!!!!!!

 

Is there a way to tell if the distributor is worn?

It looks like someone replace the cap not too long ago with a Bosch unit.

If it is a dual point dist. , would I see 8 contacts in the cap? (I don't know much about distributors)

The four contacts in the cap look clean- no burnt marks or anything.

[banzai510(hainz)]

open the cap using the 2 clips

youll see 2 sets of points/contacks

Those need to be adjusted sometimes.

Now if you NEVER cked this this possibility could have been part of the proplem. I figured you cked this already.??????????????????

 

LETS US KNOW!!!!!!!!!!!!!!!!!!!!

 

the blk and yellow striped wire is the second set of points which only works on 3rd gear(4th Im not sure)

The other wire is the main wire(lt blu and yellow) I always thought it was blk/red myself at least on the 510s.

This is the main wire. The gap should be about .020.

 

The ck for dizzy wear I would wiggle the shaft once you pilled the cap off and see if there is side to side slop. enough to make the points open. Open is when the coil fires.

 

the condensors is on the side of the distributor. 1 for each points.

olddatsuns.com has the color codes

 

 

I kinda wished you didnt pull everything apart yet.

 

Just going by the photos everything looked ok,just maybe a little bit of oil burn.

 

till tommorrow

Edited January 12, 2009 by banzai510(hainz)

[hessianben]

There are only 4 points inside the cap.

I'll take some photos when I can find the camera...

[datsunaholic]

You're misinterpreting what points are.

 

It has nothing to do with the cap; in fact the single point L16 dist and the dual point L16 dist use the SAME cap. I can tell you have dual points by looking at the distributor... it has 2 sets of terminal lugs. Single point dists only have one.

 

The dual points refers to the contact breaker points in the distributor, under the rotor. They open and close as the engine turns; when each set of points open, it makes the coil fire one spark. Dual Points have 2 sets of breaker points, so that the spark plug gets fired twice instead of once like most normal vehicles. However the second set of points only operate under a very narrow set of circumstances. It's for emissions.

 

The points themselves are a wear item. The cam rider on each set wears down, making the points harder to open, and there's an adjuster for that. The points also can get burnt and eventually wear out all by themselves under normal use.

[datzenmike]

Doug. I'll have to disagree on that.

 

In lower gears, less than full throttle, engine warm the retard set of points are selected to lower emissions:

 

The first set of points close and power is sent to coil, then the second (retard) set close about 7 degrees later. At the proper time the first set opens, but because the retard set are still closed... nothing happens. Finally about 7 degrees later the retard set opens and the coil fires.

 

 

Forth gear selected, more than half throttle and or engine cold, the retard points disconnected

 

First set of points close and open normally and spark is now 7 degrees sooner.

Edited January 13, 2009 by datzenmike

[datsunaholic]

I see your point. It'd have to work that way; when "switched" in both sets would need to be open in order to fire.

 

 

Honestly never really looked to see how they worked because I've pitched the dual point dist on every car I've owned.

[datzenmike]

Retarding the ignition specially at idle always lowers the emissions but ruins the idle characteristics. More advance is required at idle not less.

[ggzilla]

Dual-point distributors for 620 are for emission control to retard timing? How sad. Earlier Datsun dual points were for longer dwell, therefore higher performance spark. At least that's what I always understood.

[datzenmike]

Could be. My '70 Dart had dual point to extend the dwell.

 

You could use the dual point this way. All you do is wire them both on all the time and time it on the retard set. This would give you about 7 degrees of extra dwell.

 

Thing is... an EI dizzy beats it in every way.

[banzai510(hainz)]

hessianben

You really need to see if the points are opening up when it come up on a point lobe.

Turn motor and youll see if the points open and close. Pick the highest point and make sure a feeler gauge is at least .018 .022 gap(i think it is).The main point set(which has the bigger cap. The second set I disconnect the wire,but its too late now since the motor is apart.

 

 

I dont know how old you are if your younger youll probably know nothing about points But its best to get rid of them soon as you get this running again. with point distributors you can have

1) bad condensor

2) burnt points

3) loose wire

4)just out of adjustment

5)shaft bushing wear

Not counting avcum adv weight falling off ect

[hessianben]

hessianben

You really need to see if the points are opening up when it come up on a point lobe.

Turn motor and youll see if the points open and close. Pick the highest point and make sure a feeler gauge is at least .018 .022 gap(i think it is).The main point set(which has the bigger cap. The second set I disconnect the wire,but its too late now since the motor is apart.

 

 

I dont know how old you are if your younger youll probably know nothing about points But its best to get rid of them soon as you get this running again. with point distributors you can have

1) bad condensor

2) burnt points

3) loose wire

4)just out of adjustment

5)shaft bushing wear

Not counting avcum adv weight falling off ect

 

Haha- you're right, I know nothing about distributors... this truck was born 8 years before I was!

I'll check gap in a few-

so you're saying that the gap when open (on the bigger of the two lobes) should be .022, right?

...and I think what was being explained above by the other guys was that the second set of points is to retard the timing at cruising speeds? so, I can just disconnect the second unit?

 

Also, I was trying to find information about converting to electrical ignition?

I found a guy here in town who races buggies, (he set up my Weber) and said he can get a Petronics unit to replace the points.

Is that what most of you guys do anyway?

 

Thanks

[datsunaholic]

You can get a pertronix but you'd have to replace the distributor. The Pertronix kit doesn't fit the dual-point distributor.

[banzai510(hainz)]

the VW guy can tell if the points are w/in spec or not.

 

I dont use the 2nd set of points myself when I had dual point set up..

as Doug said the dual point dizzy CANNOT BE CONVERTED!!!!!!!!!!

 

when you get the motor back together let us know.

Edited January 13, 2009 by banzai510(hainz)

[hessianben]

MID ASSEMBLY QUESTION:

 

When I removed the head, I lost the tension in the timing chain-

Now, I've got the head back on and torqued-

 

any tips on the best way to compress the tensioner so I can get the timing sprocket back on?

 

THanks!

 

(When i took it apart, i did not remove the water pump/timing cover, just the head)

[banzai510(hainz)]

broom stick ,try to push it in.

I heard of rubber hose also folded in half and shoved down in there.

 

Good luck as I never was good at doing that

 

 

I only mention the water pump removel if your going to remove the engine from the truck.

[datzenmike]

Remove oil pump/drive spindle, water pump and crankshaft pulley. Loosen front oil pan bolts, remove the 2 10mm bolts between the head and top of timing chain cover, unbolt timing chain cover and slide forward to get at tensioner. If tensioner has become dislodged try to collect parts before they fall into oil pan. If the spring does find it's way there, leave it. It'll work it's way to the lowest part of the pan and won't cause any trouble. Get a new timing chain set and replace everything, unless you have, or can find a replacement tensioner and or spring.

Edited January 14, 2009 by datzenmike

[hang_510]

any tips on the best way to compress the tensioner so I can get the timing sprocket back on?

dont let the chain slacken or :cursing: too late... http://forum.ratsun.net/showthread.php?t=1678

[hessianben]

Last question before I tear it all apart again....

 

Is it possible to remove the timing cover, water pump, oil pump ect...

WITH the head still on?

 

Thanks

[Farmer Joe]

yeah you can, but its kind of tricky.

 

leave the head torqued but take the 2 12mm bolts off the front. undo the timing cover bolts. then take the bolt off the oil pan on the bottom of the timing cover and loosen the oil pan so that the front can slightly drop down. try not to mess up any gaskets, but if you do, i think the hainz video says that you can get the front of the oil pan gasket at NAPA. so now that the front of the oil pan is down a little the timing cover should come off. i dont remember if the front cover has dowels that hold it in place or not, but be careful not to mess up the loop part of the headgasket. if that gets fubar'd up, youll prolly need another headgasket all together.

 

oh yeah, and take the oil pump off the front cover before you take the cover off. its alot easier to get it apart and back together with the oil pump drive gear not in the way. then just set it back up per the hainz video.

[lynchfourtwenty]

lol, see.. i told ya a few pages ago to just replacing the timing set... always better safe then sorry bro not to mention if your timing was off to begin with due to chain strech this is a good way to fix that... i guess what i mean is, if your gonna go as far as takin the head off... you might as well replace all the other "wear" items that may need replaced.... so you dont end up wasting another head gasket.. OH an by the way... i dont reccomend takin the front cover off with the head still on.. i damn near had to buy a new gasket cause of that..

[hessianben]

Yeah, I had a feeling...

I'm ordering a timing set right now-

Might as well do it all right the first time.

[datzenmike]

The front of the head gasket doesn't have to seal in compression, only fumes and oil spray so don't worry about the gasket sealing. Put a small amount of silicone on it and you're good.

 

Farmer, you're right 2 bolts on front of head, 4 on the Z series.

Edited January 14, 2009 by datzenmike

[lynchfourtwenty]

thats what i had to do mike, its worked pretty good so far, i was never able to get the 2 front bolts that connect the timing cover an head tho.. :( no problems tho... infact mine was so messed up i cut it off an straightend it the best i could then just covered both sides lightly in silicone an attached it to the top of the timing cover an slid it on

[Farmer Joe]

The front of the head gasket doesn't have to seal in compression, only fumes and oil spray so don't worry about the gasket sealing. Put a small amount of silicone on it and you're good.

 

Farmer, you're right 2 bolts on front of head, 4 on the Z series.

 

yeah its been a while since ive had a L series open. like junior year of high school. but these datsun motors are very similar to the isuzu G series. they have 2 bolts that connect the head to the front cover and you set the timing up the exact same way as an L. hell i dont know how many times i had to dig into the numerous engines i had in my luv. lol

[hessianben]

YAAAAY ANOTHER NEWB QUESTION!!!!!

 

 

Question:

 

If I put the head back on once and torqued the head bolts to spec,

but then realized that I might as well change the timing set too,

(and because I let the chain go slack- rookie mistake)

 

Is it a terrible idea to use the head gasket again?

The motor wasn't even turned over- the gasket was on there for 3 hours total,

and looks exactly like it just cam out of the box.

 

My gut says suck it up and pay the $15, don't take the chance...

...but if i'm making a big deal over nothing....

I like $15 in my pocket better.

 

Thanks