The 521 runs again (thanks Adam!!! "Motavated")

[hessianben]

Well, after trying to get the EL dizzy from my scrap 620 to work in the 521,

the 521 is back running the stock setup.

 

Adam (motavated) came over with a spare coil, some spare resistors and some knowledge, and we went through and ruled out possible culprits.

 

He pulled the Matchbox from his well-running L18, (That motor sounds so strong!!! no valve noise or anything!! just exhaust note and air sucking through the weber!!)

 

 

this is Adam's L18 in his 620

 

 

We tried the EL setup from his truck in my 521, with the same result i had with the EL i was working with-

even after timed to best running position, it still bogs and falls flat on its face at about 3000. ???

This is the dizzy shaft position that gave enough room to adjust the timing with room on either side of '0'.

 

I had to go to work this day, so we decided to re-install the stock points dizzy and coil just to get it running.

 

Re-clocked to 11:28.

 

 

The PO had for some reason disconnected the resistor (I can't believe it didn't burn up!!) so we re-connected it, and it fired right up!!

 

timed to about 12deg adv.

 

SloDat is sending me a known working matchbox, and i'm picking up a MSD blaster from Omar in Garden Grove (thanks BTW!!),

 

So, I'll give it another shot with that setup.

 

 

Upon inspection of the Matchbox that I was using and comparing it to Adam's,

it looked like the gap between the rotor lobes and the ring was closer on some sides than others?? fishy.

 

 

anyway, we got some stuff done, so was good.

Adam got his reverse lights wired up and re-timed his motor to about 14 deg.

(now he's just got to get a 2" y-pipe to match his 2" exhaust!!! it's choking!!:D

 

 

back to points for the time being...

 

[banzai510(hainz)]

put your electric dizzy in his truck!!!!!! then see if it works.

 

if it worked up to 3 k its just off a tooth in my opinion or another issue ,electric or carb related.

 

if the points work all the RPM range then its not carb related but dizzy off a tooth or wrong pedastal. Try just timming th dizzy with your hand. then hold it not tighten that 10mm head bolt holding ght edizzy down and rev it up!!!!!

[hessianben]

The reason I don't think it's carb related is because the carb is tuned really well for the points setup. Runs strong with stock dizzy/coil.

 

Would there be a reason that the carb would need to be re-tuned for an EL setup???

 

When I first installed the EL dizzy/coil, I set it to 11:28 and timed it by turning the dizzy by hand until it ran the strongest.

The reason that I THEN moved the oil pump shaft a tooth was because I couldn't rotate it any farther clockwise,

even with the 8mm and 10mm bolts loosened.

Once I moved a tooth:

 

 

I was able to turn the distributor by hand and get enough range from retard-advance. Even when it was turned to where it ran best, it still stuttered when throttle was applied, and was slow to accelerate.

 

I'm not sure what the issue is here-

Even when we used adam's matchbox, it didn't run any better.

 

I suppose the coil could be bad... (i'll know when I get the MSD from Omar)

 

It runs as stock for now... so I'm happy:D

 

hanks

[hessianben]

Just wanted to say thanks to Omar ("OC" '71 521) from Garden Grove- he let me borrow his 2 extra MSD coils to get my EL setup working. He's working on a show-quality KA swap for his 521, and he's got a sick old chevy truck in the driveway with some candy blue paint, really slick wheels and custom fiberglass inside.

Lot's of projects going... (he's in the same boat as we are: gotta move out by the 31st! bogus.)

 

Thanks again Omar! I'll post up when I get things running.

[mklotz70]

If it's falling on it's face at 3K...my guess would be that the mechanical advance weights are sticking....or stuck. If they were working and you were getting too much advance, you'd get detonation....but your not...so I don't think there swinging well. The vac advance is for just off idle..it's out of the picture by the time the rpm gets up there. Just a thought.

[0.C.]

Just wanted to say thanks to Omar ("OC" '71 521) from Garden Grove- he let me borrow his 2 extra MSD coils to get my EL setup working. He's working on a show-quality KA swap for his 521, and he's got a sick old chevy truck in the driveway with some candy blue paint, really slick wheels and custom fiberglass inside.

Lot's of projects going... (he's in the same boat as we are: gotta move out by the 31st! bogus.)

 

Thanks again Omar! I'll post up when I get things running.

 

Glad to help out a fellow ratsuner. Both of the coils should work. One of them was running on my truck and the other one I pulled it out of a running 454 chevy motor.

You can always drop by and borrow my single prong electronic dizzy.

I don't know if this could be the problem, but when I went from points to EI dizzy I had to regap my spark plugs.

Also make sure you are running constant 12v at the coil.

[motavated]

But Mike when I installed my dizzy in his truck, it still acted all retarded with his newer coil. When we ran the stock setup with stock coil, resistor, and distributor. It ran better. I'm really guessing its the retarded newer model coil that's dead. You know Ben go to an Auto zone. If they are smart enough, they can test that coil for you. I use to do it alllll the time when I worked there....

 

My dizzy works great on my truck. Really!

 

Thanks alot Ben for letting me use your timing light and letting me have some left over 620 parts. I just went to the junk yard this morning and got me a Mark VIII Lincoln electric fan that I plan to use on my 620 and other stuff I got planned with this new paycheck. I might head back over there for some measurements of your 620 clutch sleeve. Or you can just tell me in a note the measurements. That would be nice!!!

[hessianben]

lemme know what you need.

cool.

[fisch]

This thread is Ratsun at its best guys. Brother dattos helping brother dattos. Thanks for sharing the love.

[mklotz70]

You may have more than one thing going on here. If you are using the same method to install both dizzy's.....you may be doing them both wrong.

 

From the way I'm reading your info....and possibly misunderstanding.....it sounds like you are turning the dizzy while it's running to get it to run the strongest...I'm assuming by that you mean the fastest. That could be your prob right there. If you are setting a dizzy by ear, you want it to run as slow as possible and still be smooth. As you keep turning it for more advance, the rpm's go up. They can go up high enough that the mechanicals are kicked in too.

 

I'm not as much a motor guy as some here, but I'm pretty sure you can only run about 35 deg of total advance. If you already have it advanced 25-30 at idle, when the vac adv kicks in, it over advances and will run worse. As it revs up and the mech adv kicks in, same thing...too much adv and runs worse. You only want about 10deg at idle, then the mechinicals will add another 20 or so as it revs up. the vac adv will add 15ish?, but once the throttle is open too far, it doesn't get a vac signal any more....so it's expecting the mech adv to take over. The guys running high initial timing advance at idle don't run vac adv. I'm guessing that when you put the original back in, you set it visually for where it was originally...or, since you're probably taking it out at the pedestal, it never gets moved.

 

If your rig runs great with the point dizzy, then the carb, coil, are fine. The matchbox dizzy handles a lot more current than the point dizzy. You really need to have a dedicated ground wire from the vac adv screw to the batt/body/or chassis. Also....if you put the resistor back in with the EI dizzy.....make sure the dizzy gets hooked to the full 12v side. It won't run worth beans if it gets it's juice after the resistor. If the PO had an EI coil in there with a point dizzy.....then he was probably running the dizzy after the resistor. Make sure that with the key in the run position, you have full batt voltage at the matchbox. If you have an EI coil....then you don't need the resistor in the circuit at all......so make sure you have full batt volts at the coil as well.

 

Hope some of that helps.

[mklotz70]

it is also possible that the coil is the prob......The higher voltage and current the matchbox wants may be causing a prob for the coil. If you take the working dizzy out of one truck, take the coil with it. If it doesn't work in the second truck.....it's the setup/wiring, not the components.

[Buzzbomb]

You may have more than one thing going on here. If you are using the same method to install both dizzy's.....you may be doing them both wrong.

 

From the way I'm reading your info....and possibly misunderstanding.....it sounds like you are turning the dizzy while it's running to get it to run the strongest...I'm assuming by that you mean the fastest. That could be your prob right there. If you are setting a dizzy by ear, you want it to run as slow as possible and still be smooth. As you keep turning it for more advance, the rpm's go up. They can go up high enough that the mechanicals are kicked in too.

 

I'm not as much a motor guy as some here, but I'm pretty sure you can only run about 35 deg of total advance. If you already have it advanced 25-30 at idle, when the vac adv kicks in, it over advances and will run worse. As it revs up and the mech adv kicks in, same thing...too much adv and runs worse. You only want about 10deg at idle, then the mechinicals will add another 20 or so as it revs up. the vac adv will add 15ish?, but once the throttle is open too far, it doesn't get a vac signal any more....so it's expecting the mech adv to take over. The guys running high initial timing advance at idle don't run vac adv. I'm guessing that when you put the original back in, you set it visually for where it was originally...or, since you're probably taking it out at the pedestal, it never gets moved.

 

If your rig runs great with the point dizzy, then the carb, coil, are fine. The matchbox dizzy handles a lot more current than the point dizzy. You really need to have a dedicated ground wire from the vac adv screw to the batt/body/or chassis. Also....if you put the resistor back in with the EI dizzy.....make sure the dizzy gets hooked to the full 12v side. It won't run worth beans if it gets it's juice after the resistor. If the PO had an EI coil in there with a point dizzy.....then he was probably running the dizzy after the resistor. Make sure that with the key in the run position, you have full batt voltage at the matchbox. If you have an EI coil....then you don't need the resistor in the circuit at all......so make sure you have full batt volts at the coil as well.

 

Hope some of that helps.

 

^ I'd bet he's right about the advance being the problem. This happens a lot in V8's when people put in a huge cam and the car won't idle right.They advance the heck out of it AT IDLE, but don't realize they need to somehow limit the mechanical advance for correct TOTAL TIMING.

 

http://www.centuryperformance.com/ignition-and-timing-settings-spg-219.html

 

You really need to check timing by the light and not by ear. Ear works for some people, but they also have done it so much that it's second nature. Sometimes they are even wrong, hence a timing light. I'm not an expert on these engines, and am not sure if the air gap ever need to be adjusted, but what about checking the air gap clearance?

Edited March 17, 2009 by Buzzbomb

[motavated]

He has a timing light. I timed my car around 15 and his about the same. Is that too much?

[hessianben]

it is also possible that the coil is the prob......The higher voltage and current the matchbox wants may be causing a prob for the coil. If you take the working dizzy out of one truck, take the coil with it. If it doesn't work in the second truck.....it's the setup/wiring, not the components.

 

You make a good point there.... We used the timing light to set it at about 10-14 deg advance, but also tuned it a little by ear to get the best (also faster) setup, so maybe I need to keep it around 10 and at a slow idle.

Omar (OC) let me use 2 of his MSD coils, and SLODat is shipping me a newer Matchbox, so I will go that route in a few days.

 

Thanks again everyone!

[mklotz70]

Make sure you have the ground wire connected. One dizzy can be more sensitive to ground than the other.

 

Did the new dizzy work okay in the other truck?.....or is it that 2 dizzy's don't work in the same truck? If the bad dizzy is bad in the other rig and the timing is set right....it's the dizzy. If that's the case, check the mech adv is working.

 

You can watch the adv with the timing light as you are revving it up. As you crack the throttle, you'll see a jump in the adv if the vac adv is working okay. As you rev up, you should see the timing adv smoothly from the mech adv.

 

It could still be in the coil setup....check the voltages like I said. Run the ground wire too!!! Can't hurt, but it could help immensely!!!

[Buzzbomb]

On other engines I'm familiar with, this is how you find total advance without having to buy a dial back timing light or using timing tape. Since the crankshaft pulley is set to give the timing reading on a Datsun, I don't see why it wouldn't work the same. First you need to make sure to verify TDC or scribe your own mark. After you do that, measure your crankshaft pulley and substitute it's size for the 8 in these equations..

 

If you want 36 degrees of total timing,

 

8 * 3.14 (pi) = 25.12

25.12/360 (degrees in circle)= .0697777 INCH

.0697777 INCH = 1 degree

.0697777 INCH x 36 desired degrees = 2.5119972 INCHES

 

Take a piece of paper, cut it to 2.51 inches, and mark your balancer 2.51 inches to the right of the TDC mark. Keep going up in RPM's until the timing mark quits moving, and you've hit the end of the advance and have some idea where it's at. If you have a dial back timing light, it's basically a moot point.

 

Keep in mind that other engines limit their advance by way of spring kits that let you tailor it to what you want. I honestly don't know if this is available for Datsun, but my guess would be no, unless Z cars have it. If that's the case, I'd time it stock. An L20B with a matchbox distributor is timed stock at 12 BTDC.