Timing question

[Swiftdoog]

I have a g16 engine, 16v, carbureted. The original vacuum advance canister is damaged, and decided to buy whatever was close to it to fix it. I got a G13 vacuum advance, I did noticed the spring being softer than the g16, but I still installed it to get the car running.

Yes, it didn't work as expected, lots of ping at 2krpm under mild acceleration.

Since I haven't been able to find the canister, I wanted to know, it there any other way to fix the initial timing so that the engine runs better without vacuum advance? At how many degrees?

Also I am missing the timing cover and so far I have used a protractor to set the static timing at +/- 6 degrees, is that an ok method to do it?

[Swiftdoog]

Just finished completing my profile. I´m from Venezuela, Swift came only with carburetor, G13 and G16 (but you say SF416, so the other model would be SF413). So, no plates on the car either, just plain metal plate on the dashboard near the windshield with the serial number. And it doesn´t even look like the one on the plates US car have.

The distributor has a shallow cap, but the vacuum advance looks like the one on the C41, plus the internals are also different but only the electrical part, the rest seems the same mechanically speaking. Not surprised since both models can be found here with both shallow and tall caps, with different internals. Yep, quite a mess.

Small edit: it is the C41, the diagram is exactly like the one I have installed, but the C10 I have seen it on other SF416 like you said.



                (uploaded attachments but they don´t seem to load properly)

Now, back to the importan question, being unable to find the vacuum advance that is for that distributor, can I just disconnect the advance and advance the timing up to certain point? No emissions testing here so I don´t worry about that, just want to get the car with the best performance possible.

I forgot to add that it has mechanical advance (checked it by using timing light), so at really light throttle I see advance, plus I can see the vacuum advance lever moving, pushing a little more the gas and there is more advance, so that means both mech and vacuum advance are advancing... (that sounded so weird... )

As service manual states, I am at +/- 5 or 6 degrees, that means I should advance, the question is, how much?

P.S.: some youtube videos

[Swiftdoog]

Did I tell you that I came across fixkick like 2 years ago? and many of your info I have used to fix my SF416 engine, I mean, the block and part of the head is actually G16, funny thing that the Tracker came with the 8V head that comes on the SF413, plus all the info I have seen confirms that the SF416 and the SF413 can exchange heads depending on the application you want to do, plus some intakes from the geo metro 1.3 fit straight on both heads (of course, covering the spaces for the injectors).

[fixkick]

the SF416, 16v , is different
but the G13 head will never run right ever.
pushing 400cc of air/fuel in to the G13 combustion chamber is hopeless
correct market there is E95 Venezuela
suzuki

all this be gone....i bet. for that SU CARB.


no EGR
NO CAT
NO ecu
no 02 sensors
just weber and a failing bad distrib that has no mechanical advance all just vacuum advance.

no G13 matches this.... just 2 ,,

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hose 17 and 18 are ported vacuum and was (when stock) the only from of advance.
the porting is critical is such a system...

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im guessing the thermal valve prevents vacuum retard hot or cold. not sure..which, if still used
the G13 had 5 different engines.

https://en.wikipedia.org/wiki/Suzuki_G_engine#G13

the left top side of head, has stamps , telling the class if G13 it is.


first is compression ratio.... it must not be allowed to go way high. mixing part.
then spark advance. what is max advance, and at what RPM< using timing light. (called the all IN point)

[Swiftdoog]

But, that's the thing inside of it there are weights, the max advance, well is hard to tel right now since I will have to go to the garage with the timing light and the tachometer.

Oh well I'will just do it anyways. But I assure you mine do have mevh advance, the last time I cleaned it I greased the weights and they move freely now.

And yes, originally I saw in the service manual that they came with a cat... and that's all.

Edit: well it didn´t take long, from my observation, this is what I found.

Fast advance, that is vacuum, starts at 1000rpm and stops at 1600rpm, then there´s slow advance up to 3200rp, that is then mech advance.
                   

[Swiftdoog]

                   

More pictures of my install. I had to say bye bye to the original su carb because of the lacks of parts and gaskets, and even orings for it, it would be too rich all the time and no one was able to get it right, and that was the first 3 years of ownership of the car. And yes, we use 91 and 95 octane, no ethanol yet (stone age gasoline here, you can google and find reports of being the most pollutant fuel ever made over the world, yay... oh wait, that´s bad ) But with everthing that is happening, something tells me that 91 is not 91 and neither 95, but I don´t have any scientific proof, but what I do notice is that gas looks more red than usual (91) and 95 looks more dark yellow than before.

Now, thinking about my finding, I kinda think that the advance from 1000 to 1600 is quite sharp, and then after that it climbs more slowly. I know is because the current canister I have, that belongs to a G13 head or for a SF413 engine (didn´t knew there were different, just wanted to fix the car and naively thought it will work).

I just want to plug it and be done with it until someday (when the economic crisis induced by these bad politicians we have here ends) I will get the correct part. Until then, what do you think I could do?

Yes, I have tried moving to another country, still on it man, I am still working on it

[fixkick]

so, true orig. carbs are near impossible to fix. unless just gasket bad.
great set of photos, and is dual advance, vac/mech,super !
it might be able to limit the vacuum effect.inside by using stops,? added?
or back off on base timing, try 0degrees the work up to 5. util it pings then back off
so glad to see the mech advance working,for you,, the parts drawings pretend they dont exist, HAH !

G13 engines are great. and ok, just don't mix heads, unless you do the CC chamber tests. for CR calculations..

ok that distrib, dizzy has its own, cmp pickup coil and its own ignitor, and work just like our 1989/90 G16s, same deal , only you have 2 vacuum nipples on the vacuum advance servo..

your doing good.
and crossing fingers or exit visa for you !!!

[Swiftdoog]

mmm it is a G16 but with the vacuum advance of a G13.

Actually, believe or not, it pinged at 0 degrees too (bummer) so far I just feather the throttle until it passes the 2500rpm mark then I can floor it more.

[fixkick]

PING (aka. detonation ) has many causes. hopefully not all at once,
1: too lean, (on a turbo, you blow the engine)
2: too far advanced spark. (in fact the distrib is tuned for the AFR used for above) (air fuel ratio) a dyno tune works best.
3: CR wrong, (too high) due to milling, wrong,, etc. ( needs more fuel and more retarded spark than stock to run)
4: EGR defeated the , stock 1991 car we have will ping under load, with the EGR disabled, due to the spark and fuel tables in side ECU are tuned for a working EGR. (not true on the JDM ECU, its has no EGR) did you defeat your EGR?
5: less that 87 octane fuel. (not possible here) it can ping.
6: other minor issues, (hot spots, pre-Igniton, wrong pistons (or hacks there) wrecking the top quench sections there.)
That quench stops detonations. not only this but Changing CR by milling can wreck the quench, effects.

(keep in mind, ive only the most basic idea of what you have, there, what parts, what modes, etc) G16 block and head, and non stock carb,
non stock vacuum advance.) (keep in mind the CARB and vacuum advance work as TEAM and are both wrong now,hummmmmm)
yes, (G16 but, what was total advance, ? in degrees, you measured)?
It be near impossible to check advance driving, and is why Custom EFI is done on a DYNO... just to that, and AFR.

on all distrib's like this, (most times we had the problem, years ago, for 3 reasons, boring out block for more displacement and higher compression ratios)
(bigger pistons, milled deck , milled heads all raise CR, in to the danger zone. over 750psi peak pressures, it will Detonate on REG GAS.
or someone hacked your distrib, and is all wrong inside..? (for sure vacuum advance is wrong, )

there are only 5 solutions.
1: move static timing point. (failed now at 0)
2: (mech advance)file the weights down or stronger springs.
3: add Vacuum limit stops (screws, or pins) to stop total advance, limits its travel, mechanically.
4: Do not use vacuum advance at all , defeat it, and use only RPM (might take changing #2 above )
5: upgrade to EFI or custom EFI and make your own tables. no more, advance allowed inside the distributor. (pure software, like all our 1991 here)
#5 would take creating a CMP signal. from inside old distributor to the outside, and then to ECU , like all 91+ cars here have.

the hard part is finding the OLD Suzuki tables on your engine , the distrib..
on better cars, we have that, we have both tables, or a unified table showing, the actual advance curves of both devices, (rpm and load)

this is the machine we used then to make the distributor behave.
https://www.youtube.com/watch?v=Hur8afp0oYo

back in the day,, distribs, can be stuck , hacked, or have wrong parts inside.
this machine we discovered these facts and corrected, it .
the other issue is the , carb vacuum ports, must work correctly too, or the vacuum advance or retard fails.

i can not see your vacuum setup in your photos.
the stock car had 2 vacuum ports. does the G13 vac have 2 or 1?
my guess ? just one? and where does it Go, show the exact location of your , vacuum line on the engine side (plenum>? or carb , if carb where?)

, so , when you start the engine, you have a vacuum line there, what is the vacuum at idle.
then gently raise idle speed, vacuum now?> then gun the throttle what is vacuum on that hose now? this checks to see if the port you are using is correct.
It seems to me the engine pings, with high vacuum (feathering means that) so that would say the Vacuum advance is setup all wrong.
at idle if you pull the vacuum line what does advance do? (pull it and pinch/plug the hose fast) see timing now? do nothing,advance or retard?




lots of issues
what is engine compression warm or hot, ? spec, is 170 but all mine did 185psi at sea-level, if you see why higher, maybe someone violated
the HEAD milling (shaved) rule and sent CR to moon, way too to high....

there are 3 kinds of advancing systems
1: tuned for max power.
2: tuned for max economy
3: tuned for smog, (that 2 nipple, vacuum servo tell me your car came like this) some use push/pull one nipple advances, other retards.

OCTANE ISSUES:
fuel our fuel here is a mixture of RON and MON, averaged.
Regular will PING easy, it's 87 octane here, called 92 RON, elsewhere, and is same fuel.
the 87 ping happens (CR causd, not wrong for bad spark timing) and the PING tells you , you exceeded the 750psi rule. for 87 octane.
you can not measure that pulse. its a lab test. but shows clearly what happens.
the purpose of spark is to keep that pulse at the right point, (time) at all RPMs and ALL loads., High loads need less advance.
at high engine loads the pressures is much higher, and needs less advance. (the load causes the natural peak to happen sooner is why)

Actual cylinder pressure below:
this shows the peak pressure happens about 15degrees, After TDC. the best point, is due to the rod acting like lever making more power.
if if the fuel detonates, (pings) the pressures are gigantic and can put hole in the piston(damage). this is for 87 octane.



what helps, is to see how EFI does this.
see the 3D map , no Dizzy can do this, and is why EFI can save 20% in fuel waste.
on a race engine, we'd use 12.5:1 AFR and more advance, for more power all the time.... and waste some fuel.

Please note the pressures are ABSOLUTE Vacuum not like any hand tool. on the left is WOT, on the right is fast driving then cut throttle and huge vacuum 100kPA = 29"HG vacuum wot is NO no vacuum or near zero on this engine, its 8 inches. or 30 kPa)

here is a 3d map, kPA 100 wide open throttle (1 atmosphere) absolute pressure, vacuum) the white numbers are ADVANCE.
65 kPa is about idle vacuum.


note how the advance, goes toward zero , under huge engines loads. see that 13?, in bottom right corner, this is max load.
The modern computer (ECU/PCM) uses this classic table, and then changes it if the knock sensor (a microphone) hears knock, (the stronger the knock the more retard)
your car will never do that..... it can't.( a zero brain engine)
what does that mean, that means carb cars are purposely DETUNED to not knock, when real hot, and under full load.

Some get confused on ABSOLUTE pressures,( using different systems world wide does not help)
consider, (sorry, if old hat to you)
next time you hear the radio weather news, listen to "barometer readings to day..." here its now my barometer on the wall reads 99 KpA (or 29.2 inches HG column) 100kPA = 1 bar
this is also called one atmosphere. at sealevel, (the highest road in world is 1/2 that)
or in the engine, near wide open throttle, a carb engine you can not have too big of carb because, at WOT pressure near 0 absolute, the carb does DEAD! (nozzle stalls)
EFI cures that. (no venturi to make happy!) this is why EFI makes more power. (that and perfect tables)

Does this help?

and a parting shot:
i'd not drive it pinging,,, not me, i'd at least defeat the vacuum advance.
then set static advance 8 degrees before TDC.
and ive no clue as to the original designers, advance strategies, (max power, min smog or what? and lacking the carb in hand , impossible to reverse engineer it now.)
the only clue to that , if lucky is buying an FSM matching your car.

same holds true with any G13 vacuum advance unit, im clueless there. but id try to get data off it. (testing)
one why is at idle to (strobe flashing on scale)
attach a hand vacuum pump (Mitivac™ and see what advance does?, a 0Hg and max vacuum.... no hose to carb, just tool to VAC pot.
then....
Test 2:
the stock distrib mech advance may put you into the ping zone at high rpm , up hills, all by its self.
this can be proved, with vacuum defeated and driving up a hill and lug engine. (5speed?)
on some cars, this happens and the VACUUM POT retards the spark on hill.s... (low vac = less advance)
but that is all theory, i have no FSM for market E95.

pitfall common in test 2
is the TUNER, finds to get full power , with mech, advance only, that now engine wont start.
he keeps setting static timing more farther advanced, until engine now has full power. and bam wont start.
cause, vacuum and mech advance work as a team.
In some shop.s the guy here recurved the whole mech advance so it would reach his desired, max advance, starting at 5degBTC, (so engine does not try to start backwards)
then uses bigger weights and weaker springs to attain his goal.

sorry for long post, but there are many paths to getting a custom engine, tune., and stop ping and get full power on demand.

[Swiftdoog]

Now, you see, You helped me, at last no one else on the net helped me like you did. And for that, Thank You Fixkick.

Since my wallet is bound to the economic crisis, I will advance the timing. But with a twist, I'll try limiting the vac advance to avoid losing the part throttle response but I'll advance the static timing to compensate.

That sound about right, right?