How many degrees BTDC should I run???

[hessianben]

Hi, I'm carrying this over from my other thread because the question has changed...

 

After installing an L20 matchbox distributor and matching coil, I was having trouble getting enough rotation on the pedestal to get a good timing setup.

 

 

I ended up dropping the oil pump and reclocking the dizzy drive shaft to approx.

10:30, which now gave me plenty of room to adjust before and after TDC.

 

 

 

 

 

It would idle fairly smooth from the TDC mark to about 15 degrees before (counterclockwise on the crank pulley) the TDC mark,

 

(it would also idle a little higher in between- around 7 deg. BTDC)

 

Before the 15 deg. mark and after the TDC mark, it would lope and try to die.

 

However, when I set it to a good-idling position, and drive it, it feels like it is really bogging, and even when I climb to about 3500, it never really picks up power.

 

I have taken a lap 'round the block for each interval of about 2 deg. from TDC to about 14 BTDC, and some run a little better than others, but all lack power, expecially as the rpm's climb.

 

I have tried driving it with the vacuum advance connected, and plugged.

I tried setting the timing with the vac advance connected and plugged.

 

I haven't been able to find a driveable setting! It has about half the power it did with the stock dual points diz and stock coil!

What gives????:mad:

 

If I'm overlooking something, please let me know!

I am running the same plug wires and plugs, which I think should be replaced anyhow... but worked perfect with the stock setup.

(I haven't replaced wires yet, 'cause I tend to run out and buy things before I track down actual culprits!)

 

 

Helppppp!!! anyone???

 

 

Thanks guys! (and gals;))

Edited March 9, 2009 by hessianben

[Cuts metal like mad]

10-12...

[Cuts metal like mad]

also sounds like the vacuum advance may be bad, also check your advance weights, spring fell off??

[littlekeeley]

i think we share the same problem. i too have the swapped matchbox dizzy, but it worked fine before i pulled it off to replace some timing cover gaskets, now it feels like half the power - even AFTER i hit it with the timing light. my vac hose is hooked up... its the strangest thing but at least its isolated to the dizzy and not some compression leak

[hessianben]

also sounds like the vacuum advance may be bad, also check your advance weights, spring fell off??

 

Weights would mean it's centrifugal? In addition to vacuum?

It's from a '79 620 if that makes any difference...?

 

I haven't taken it apart other than cap and rotor... there is slight rotational play in the shaft (less than 5 degrees) but no vertical or side to side play.

would that be a big problem?

[hessianben]

i think we share the same problem. i too have the swapped matchbox dizzy, but it worked fine before i pulled it off to replace some timing cover gaskets, now it feels like half the power - even AFTER i hit it with the timing light. my vac hose is hooked up... its the strangest thing but at least its isolated to the dizzy and not some compression leak

 

Yeah, feels like driving in syrup!

 

I bought the timing light so I could be precise! Didn't help me much!

[Cuts metal like mad]

yes all datsun dizzys, whether electronic or points, are boh vacuum and mechanical advance. I have done several elctronic dizzy conversions and had 100% success with pertronix... but only about 25% success with matchbox.

[littlekeeley]

Yeah, feels like driving in syrup!

 

I bought the timing light so I could be precise! Didn't help me much!

 

after i realized the timing light (40 bucks) didnt help much, it reminded me of the time my brother slap shotted a hockey puck to my balls :eek: when i was forced to play goalie (i was six years old or something)

 

we needa figure out this shhhhhtufff cuz it really IS like driving in syrup. if you figure it out on your own, PLEASE PM me!!! i will do the same

 

OH HEY i just thought of something... i know that the matchbox has the red n black wires that hook in, but there is also a black ADDITIONAL wire that does some random task... if i recall, mine is detached and has been since its run terribly... maybe thats it! im not in front of my car right now so i cant take a pic, but do you know if yours is attached by chance?

Edited March 9, 2009 by littlekeeley

[hessianben]

Keeley- mine only has two wires running to the matchbox unit.

they are labeled 'B' and 'C'.

 

Maybe I'm missing a wire??

 

 

 

 

Zuum- What diz. did you convert to Pertronix?

 

Could I use the M'Box coil without the resistor?

 

Thanks Guys!!!

[littlekeeley]

its definitely possible that wire is important. its next to the black box, but not actually on it. if you see a random terminal that could be the culprit. i will check mine out tomorrow to see if thats whats up. :D

 

or in all likelyhood, im entirely wrong lol

Edited March 9, 2009 by littlekeeley

[hessianben]

its definitely possible that wire is important. its next to the black box, but not actually on it. if you see a random terminal that could be the culprit. i will check mine out tomorrow to see if thats whats up. :D

 

I'll look at mine in the morning... maybe it's a ground??

 

There wasn't another wire when it was on the donor truck....

 

let me know ,

thanks

[Cuts metal like mad]

some say you DO need a ground on the body of the matchbox dizzy. I have a single point dizzy converted. You can also convert the single point L20b dizzy with a minor mod to the shaft... I think you have the Hainz vid so you prolly know this.

 

If you have the correct EI matchbox coil, then you DON'T need the resistor.

[hessianben]

some say you DO need a ground on the body of the matchbox dizzy. I have a single point dizzy converted. You can also convert the single point L20b dizzy with a minor mod to the shaft... I think you have the Hainz vid so you prolly know this.

 

If you have the correct EI matchbox coil, then you DON'T need the resistor.

 

 

Were I to run a ground to the matchbox... what would I need to attach it to?

the metal distributor body? or the 'matchbox' unit?

 

thanks

[Cuts metal like mad]

the box grounds against the dizzy body, so either should be fine. Do it the easiest way.

[bonvo]

im looking at one thing and thats that you had to reclock the oil pump are you sure your using the correct mount? is it the one that the dizzy was attatched to at the j/y or the one that was on you dual point dizzy

[ggzilla]

Set it to 7 degrees BTDC -- make sure the vacuum advance is Disconnected when you check. And idle is around 700 rpm. If you check timing at higher RPM it throws it off.

 

Matchbox grounds to the distributor body, and distributor grounds to engine. And engine grounds to battery cable.

[hessianben]

im looking at one thing and thats that you had to reclock the oil pump are you sure your using the correct mount? is it the one that the dizzy was attatched to at the j/y or the one that was on you dual point dizzy

 

Yep, I made sure to pull the whole pedestal.

[banzai510(hainz)]

a matchbox dizzy

You dont need a ballast resisitor only if you use a matchbox coil.

never use a point coil wit no ballast.

 

ck Valve lash again.

 

If you can adjust the timming with a light and have adjustability I think it would be fine,Even if you drop the oil pump and put it off a tooth.

 

But if you had to di this either this dizzy cam from a Z series motor or some fucked with it from the orginal donor vehicle. As every L series is at TDC 11.28 position and the dizzy should drop right in and be pointing to a plug wire pretty much righ on and have enough travel in the dizzy timming plate for ADV and retard.

Edited March 9, 2009 by banzai510(hainz)

[hessianben]

a matchbox dizzy

You dont need a ballast resisitor only if you use a matchbox coil.

never use a point coil wit no ballast.

 

Hainz- are you saying that I need to use a ballast resistor with a matchbox coil?

I'm using the matchbox dizzy with the coil that was paired with it, and no resistor.

[motavated]

Man I have the same setup... Its the carb man. I think its too much gas. Mess with the carb man... I think that is your problem. Check your plugs!!!!

[littlekeeley]

Man I have the same setup... Its the carb man. I think its too much gas. Mess with the carb man... I think that is your problem. Check your plugs!!!!

 

see i tried that, thinking the same thing. pulled the plugs, and they were telling me it was way lean of a mixture. despite this being a problem needing fixing - i know that the car performed just fine with said tuning (or the lack thereof)

 

point being, the only thing that changed since it worked well, to running like my fat manager from work is the dizzy. im sure thats gotta be the issue ...but again, wont know for sure til i have a chance to do work on it :(

[banzai510(hainz)]

I'm using the matchbox dizzy with the coil that was paired with it, and no resistor.

 

 

Correct!!!!!!!!!!!!!

 

 

when in dought put the old(another one) back in .

 

 

 

My rule of thumb is If mach timmed then electrical timmed then look at the carbs.

But make sure eleltrical timmed is for all the RPM ranges. Then it could but vaccum advance or the weights. then look at the componets used.

Edited March 10, 2009 by banzai510(hainz)

[SHADY280]

to dynamically check your dizzy, rev the engine at 2500 rpm, then check the timing, i never use vac advance, you really dont need it except at cruise for mileage. the timing will be around 30-34 total timing. this also lets you know what the weights inside are doing. the flash should be nice and smooth. if your gun has a dial on the back, you would set it to 30 and the timing marks will line up at zero. i also always put white out or paint on the mark to make it easier to see. if all the timing stuff lines up i too say carb. by changing one system on an engine, all systems must be tuned to work together. otherwise they fight. at 36 total timing my initial on my z car is at nearly 18 degrees. runs great there, but its a race motor and the dizzy has had its curve checked/modified as well. total timing is the best way to check timing in the end, but most ppl never do it. they never know what their dizzies curve is or should be.

[lynchfourtwenty]

i cant help but notice you have the dizzy drive shaft at the 10:30 position????? that for one isnt right.. set it to the 11:28 position an start all over.. weber carbs are great, mine works fine.. i run a little advanced on the timing an 2 and a half turns out on the mixture screw, check valves, check plugs an wires.. most imporantly get that dizzy shaft to 11:28

[hessianben]

i cant help but notice you have the dizzy drive shaft at the 10:30 position????? that for one isnt right.. set it to the 11:28 position an start all over.. weber carbs are great, mine works fine.. i run a little advanced on the timing an 2 and a half turns out on the mixture screw, check valves, check plugs an wires.. most imporantly get that dizzy shaft to 11:28

 

I initially began with it set to 11:28.

However, at that position, I didn't get enough adjustability (couldn't move enough to the clockwise side enough to get enough advance)

That's why I had to re-clock the pump.