new here, first 521, first Datsun, finding parts?

[rodjr]

I hear ya but there does not seem to be a ported vacuum nipple on this carb,......new challenge.

[wayno]

I suspect the port is on the valve cover side down really low where it is hard to see, but I don't own any L16 carbs to tell you where it is for sure.

[datzenmike]

Air filter is also missing the snorkel so the heated air from the manifold has no where to go.

 

Vacuum advance is ported from a fitting on the base of the carb on the valve cover side. It will work a lot better but will probably need the timing reset.

[rodjr]

Yep air cleaner housing is a hacked up joke, already have some leads on parts though, lot's of good folks here.

No ported vacuum on the carb, there is a dimple in the base, but was either not originally machined or has been plugged, hard to tell.

I did get another carb with the truck but it is in 3 different ziplocks, i do see a ported vacuum nipple in the throttle plate for that one.

 

Question:

are the original Hitachi carbs worth going down the rabbit hole, or would i do better to go weber and put my energy into making an adapter to use the stock air cleaner?

[mainer311]

Depends on how worn the butterfly shaft is. I just rebuilt mine, but only because the throttle shaft doesn’t appear to be leaking yet. If you can move the shaft side to side on the linkage end, it most likely leaks. At that point, probably not worth the hassle.

 

Supposedly the Webers flow slightly more CFM.

[datzenmike]

 

Port should be a small brass tube end sticking out just below or in front of that mixture adjusting screw. This carb has an extra for the EGR but your carb will only have the one.

.

[rodjr]

 

Port should be a small brass tube end sticking out just below or in front of that mixture adjusting screw. This carb has an extra for the EGR but your carb will only have the one.

.

 

No nipple there whatsoever, just a dimple in the casting maybe .030" deep.

[DanielC]

Air cleaner Lid

Air Filter, I think this may still be available from your friendly neighborhood Nissan dealer.  This is not a Nissan air filter.

 

Carb heat duct

 

The metal nut with a small pipe line going in to is ported vacuum to the distributor.

 

To avoid confusion, the phillips head screwdriver is resting on the distributor vacuum port nut.

 

Distrubutor vacuum line, small line below the two other hoses.

 

Distributor vacuum line on distributor.

[rodjr]

that's the spot, but just a dimple in my carb base, plugged solid, no nipple no threads. looks like it was cast that way, or somebody did a nice job of plugging it to make it look as cast. I will pull the carb soon and if the throttle base is in fact drilled at the throttle plates and someone just plugged the outside, i can throw it on the mill and drill it out. I will also check the shafts, if they are loose, maybe i can turn some bushings providing the base plate has room to bore and sleeve.

 

I have that air filter lid and support bracket but no base.

 

Thanks for the pics.

[banzai510(hainz)]

Truck looks great

I would buff it out  Leave the pantina color, sort out what is wrong and maybe lower it down abit. Paint the rims white and run the stocksamll white wal tires .(this is me off coarse and dont need to spens 30K$ on this to have a cool truck. All the kids give me the thumbs up and didnt have to spend alot on Pimp wheels ect...... 

 

 

change the oil and ck the oil in diff and trans and grease the kingpins and drivelline

[rodjr]

With a huge thank you to Wayno on here, it looks like i will be picking up a seat (and possibly a few other goodies) on Tuesday. Found an air cleaner in Oregon on craigslist. Hoping to get time later in the week to pull the carb and see if i can drill the ported vacuum open. 

 

At the moment, we have a fire in the wood stove, it is snowing, there is lot's of really really yummy stuff to snack on and i am not going to do diddly.

[rodjr]

Finally got a minute to work on things a bit. Here is what i have learned so far:

 

1) Kingpins are beyond gone! i can gab both front wheels and pull the bottom of either out well over an inch.

2) vac port on carb has been plugged with some kind of epoxy, working on this tomorrow.

3) runs good but falls on its face when taking off in first, maybe related to vac advance being wrong?

4) adjusted clutch, much better but still engages at the top of the pedal travel.

5) all the joints up front have no dust seals remaining and zerks are seized so no new grease going in till they are replaced.

6) brakes adjusted well but pedal is soft on the first hit, second time they are right at the top. Thinking air or a bad wheel cylinder.

7) pcv valve is connected to...nothing, what appears to be a vent tube coming from the block is attached directly to the intake manifold. Anybody now where i can find a diagram of how this is supposed to be? All the air pump stuff is gone.

 

Picked up my new seat and a window regulator from Wayno yesterday, 9 hours of driving but it was worth it.

Also ordered all new window seals from Thailand, that was all i could find.

[wayno]

The PCV valve is connected to the intake manifold, the block vent should be connected to that PCV valve.

See the rusty PCV valve in this photo right below where the carb mounts, that is where that engine case vent connects on this intake manifold, the valve cover vent goes to the air filter housing.

[rodjr]

Well that is just lovely.

My pcv is sticking vertical where the threaded vac fitting is in your pic. the crankcase vent is connected to the manifold directly with no valve!

NOT GOOD.  

[wayno]

Well that is just lovely.

My pcv is sticking vertical where the threaded vac fitting is in your pic. the crankcase vent is connected to the manifold directly with no valve!

NOT GOOD.  

 

That is not the best place for it, but plug the hole that the case is vented to now and connect the vent to the PCV valve, it will work there, but not the best place for it.

I would imagine you are having issues with your idle the way it is piped now.

[rodjr]

That is not the best place for it, but plug the hole that the case is vented to now and connect the vent to the PCV valve, it will work there, but not the best place for it.

I would imagine you are having issues with your idle the way it is piped now.

Oh yeah, idle is unpredictable.

[wayno]

Oh yeah, idle is unpredictable.

The reason it is unpredictable is you have a vacuum leak, a major vacuum leak, I am surprised it will idle at all, my PCV valve broke once, my idle was uncontrollable, is jumped from 800rpms to over 2000rpms, and mine was not near the leak you likely have unless it has a PCV valve where you case hose is piped and you just cannot see it.

[banzai510(hainz)]

I just noticed the vaccum advance on the manifold now. Yes as mentioned that is wrong. I would disconnect it if you don't have a port fro the carb and retimed to motor to run best as it can. But should be a port on side of carb as this one has a metal line you should be able to find where it USED to go.

 

 

faster you go to a Weber DGV 5A(manual choke) the better. these carbs are pushing 50yrs old. they not going to be perfect anymore.

[rodjr]

I disconnected the vac advance and put a timing light on it.

I have a pulley with 6 notches. Looking from front of engine left to right, small notch, large notch, then 4 small notches. I assume 5 after, tdc, 5,10,15,20 btdc?

If that it the case my distributor runs out of adjustment at 5 btdc.

Either i have the wrong pulley or the wrong dizzy / mount or the pulley makes no sense to me.

 

There is a pcv valve on the breather hose, just could not see it. The hose is completely split so it does nothing anyway, just acting as a plug. Going to have to fab a reducer pipe to get that back together.

[wayno]

You need to either plug that other PCV you have or remove it and put a plug in that hole in the intake.

That hole is the one I use for power brakes.

[DanielC]

"I have a pulley with 6 notches. Looking from front of engine left to right, small notch, large notch, then 4 small notches. I assume 5 after, tdc, 5,10,15,20 btdc?"

We all know what happens when you assume, but in this case, you are right.

There is a bolt with a 8 mm head that goes up through the timing plate between the distributor, into the distributor, under the distributor.  It also can be used to set timing, it also has a slotted hole in the timing plate.

[rodjr]

Got the timing dialed in and ordered some hoses and a plug to fix the currently dysfunctional pcv system.

 

Curious.... My dizzy is dual point but one side is not connected to any thing, so it is effectively single point. Can anyone tell me how this is SUPPOSED to be connected/wired?

[wayno]

If it works the way it is leave it alone, otherwise by a real Matchbox distributor/coil(used), don't buy a new copy from anyone else.

[wayno]

By the way, you need to fix everything vacuum related, once all of it is fixed and working properly, then time it again.

I mean everything, get the vacuum advance sorted out so it works properly, replace that PCV valve pointed up with a plug, everything needs to be properly piped.

[rodjr]

Thanks Wayne, Don't suppose you would know where i can find a matchbox and coil in good condition? This one does work but i would like to find a matchbox and keep this for an emergency spare.