Finding CAM TDC

[Zackman]

Dear Fixkick:
I am purposely starting this new thread, because the last thread had become so extensive, and for the benefit of others, I like to keep this issue (i.e., finding CAM TDC), separate from all what was covered about vacuum, etc.

I do not know how to thank you for the time you take to answer me (and everyone!); all I can say is that it is MUCH MUCH MUCH appreciated.

I totally agree with you that I have issue with cam timing. I am going to check that next week-end, since I have to fly out of town tomorrow.

Please confirm my understanding about establishing CAM TDC.

From reading everything you wrote in my last thread, I believe the simplest way to establish CAM TDC is by looking at the cam sprocket (wheel) mark as shown in your picture above, being at 12 O'clock, while the 4th cylinder piston is at its upper most position; is that correct?

With respect to this topic, in one of your instruction pages you mention the following sentence, for which I need a little clarification.
You state: If unsure that the dizzy is timed correctly? , you must pull the valve cover and find #4 at TDC and all valves with loose lash and cam lobes on the heals. (this is the only true path to success) turn the crank until ,this is attained.

By "all valves with loose lash and cam lobes on the heals."; do you mean all valves, except valve 4, or including valve 4. Please clarify.
Thanks agin,
Zackman.

[fixkick]

your very welcome, mr, Zackman!
that is best.
cam timing, that is why I have a step in my procedure (step 42), to check compression, if that fails stop and correct errors.
there are many ways to get errors. (when done)
lash set wrong,?
cam timed wrong,?
bad valves.?
if you time it correctly and say just one cylinder is at 100psi, no need to put engine back together and drive. see? head needs to be pulled. (or lash corrected)
if all 4 cylinders read 100 , then the cam was timed wrong(sea-level , you are at 25 meters altitude, yes, sealevel)

yes, that needs to be edited, but i cant now,, i don't have admin on those pages, now.

let me explain
there are many ways to find TDC firing. i have a page just for that. http://www.fixkick.com/t-belt/TDC/TDC.html
but in this case, there is no reason to do that, or some odd ways, Like blowing air in cylinder spark plug holes, with lips.
the valve cover is off, and the cam and valves are fully exposed.
there is also no need to do that, at all.

The HEEL, is the back side of the lobes.. and is the firing side of cam lobes, thusly
#4 is firing, when the 2 cam lobes on #4 (only) are at the rocker lifter contact points. (on a running engine (fully serviced), 2 valves lash is loose (per cylinder) means, its FIRING.)


but but but none of that matters, (its only commentary, and observation, to the belt installer, )
lets say the belt was installed wrong and the #4 rocker pair (you just looked there now) and were, on the lobes, lifting valves.
you'd know in 1 second you timed the cam , dead wrong, see?
and what might be wrong, that is easy, to say, you used the wrong KEY , the (I)key.
"I" is WRONG. (or use "I" marks, , all "I" marks are wrong)

if you used the "E"key and the 60a spoke, "E" outer edge mark (machine cut mark) (do you have this, cam cog type? with I/E keys? you never said,
if you use that correctly , there is no need to even look at the #4 valves or lobes. ever.
you can for confidence building sure. and validation.
sure wish I knew what cam cog wheel you have the 60a or the one with only 1 titty mark like the 1990 had. (the exact day suzuki changed in 1990 , ive no idea)

Facts:; the cam is in fact timed at #4 firing at TDC, and with rockers on #4 on heels of the cam, this is a fact.
"all valves, #4 with loose...." it should read, But on 8v you had them all set loose, (this comment is for 16v)
I used to have the 2 engines, on one page and then slit them in to 8v and 16v pages, so this comment is wrong, well needs to say look at lobes"


the timing is simple , there is no variances.
if the cam mark 60a, is at 12m aligned with top back pan mark this is #4 firing, the CAM design is fixed that way, no way to change that.
then
the crank is at 12pm, TDC firing, 0degrees, 12pm, at the top edge of the crank cog, is TDC 0, and the pump has TDC 0 ARROW both at 12pm.
the #4 and #1 pistons share this same TDC mark. ONLY the cam dictates which cylinder fires.
all that matters (timing wise ) is these 2 photos.


this shows, crank at TDC and cam at #4.


this shows the false marks, clearly , as you can see the CAM key IS down at 6pm, clearly. it also shows where 60a spoke goes. (up)

---

see my 4 white painted marks.
the 4th mark unseen is the pump 12pm ARROW.

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best is just time it , ignoring the #4 cylinder, comments, the FSM from Geo makes no mention of #4 at all.
ignore, #4 totally.
set it correctly using the correct marks!
then set lash. to spec. (rolling the crank per FSM pages)
then check compression, 150 PSI min. at your altitude. (is your gauge in BAR or kPa"?) 10.34 bar. minimum! at wide open throttle
it's good, now time the distributor, with the freeze jumper planted.

keep in mind if the distributor was removed, for any reason,
timing it will take patience. and futile if cam is timed wrong.
and know that it can be timed, with a none running engine. using a strobe light. (timing light) just cranking with fuel pump relay pulled.(green socket)
sure can, and you can turn the distributor, and get #1 to hit near 0 TDC, , then put back the fuel pump relay and engine now starts.
then plant the timing freeze jumper (hot) and set timing to 8deg. BTDC per the hash marks on the TDC scale. on front cover. 2,4,6,8 marks.
per my page (i added comments)
http://www.fixkick.com/IGN_timing/8v-pro...l#drawing2

2 degrees per tick. it is.

---

facts more??
if you set the static timing wrong
then scan tool report this

lies + added advance = reported timing

the vacuum line on the EGR is dead at idle on all G16;s made.
to the vsv or out of it, zero vacuum at idle.
this is double true.
1: ecu has valve closed.
2: TB , ported vacuum blocked.

[fixkick]

The distrib (the Dizzy) can be timed , using my find TDC page.
this page shows all known ways of finding #1 firing, (i hoped)
12 ways from Sunday.
http://www.fixkick.com/t-belt/TDC/TDC.html

[Zackman]

Thank you very much, as per usual. I appreciate you take time to provide such thorough answers.

Unfortunately, I have to leave home for the rest of this week. I will get to the car hopefully next week-end, and report back.

Again, I cannot possibly express my sincere appreciation, the way you deserve it.
Regards,
Zackman

[fixkick]

no hurry ever, have a good trip.
you are very welcome and we can find all bugs, in car ,1 by 1,
glad to help you.

[Zackman]

Just a quick question: Firing cycle is equivalent to compression cycle, correct? In other word, the distribute is set at 11 O'clock when cylinder No. 1 at its TDC at compression cycle; is that correct?
Regards,
Zackman

[Zackman]

Dear Fixkick
I was wondering whether you could clarify the following question for me?


Is Firing cycle equivalent to compression cycle? In other word, the distribute is set at 11 O'clock when cylinder No. 1 at its TDC at compression cycle; is that correct?
Regards,
Zackman

[fixkick]

the compression stock, (goes up) compresses the 400cc of air/fuel in to a 55cc combustion chamber (all valves are closed,) and at about 8 degrees (before) TDC the spark fires.
on #1 the rotor most point to #1 spark wire, and bam, #1 cyl. fire and starts the power stroke (going down)

firing happens at end of compression cycle, 8 degrees before the end of it. in fact.
the distrib can be timed on any of the 4 top cap terminals.
but the harness will not reach on all 4. so.. it's timed at the 11 o-clock term. this is the factory setup. and referred to over and over in the FSM, to do other things related,
so that is why we use 11-oClock
the CMP has no idea at all were #1 is, it only knows how to fire 4 times per turn.

the Otto Cycle engine:
intake stroke (sucks, while piston going down) sucks in 400cc of air.
compression stroke , piston rises from BDC to TDC)
firing instant, is now, 8degreses BTDC. (combustion or power cycle starts NOW)
air fuel burns fast. and piston is at power stroke TDC to BDC.
now at BTC , piston goes up and exhaust cycle happens.

the distributor is installed so that the rotor points to 11 oclock cap terminal. #1 firing
with crank at TDC 0degr. mark (there is only 1 mark) or attempt 8degrees before TDC., id not try.
and both #1 cylinder intake valve are closed. (called lash loose #1)
then the clamp bolt is set,(tight) on distrib, base
the #1 wire inserted to 11oclock to #1 plug
then CW 3 to 3 plug.
then CW 4, etc.
last CW 2.
per drawing on timing page 8v

start engine, use timing light to hit 8 degr, BTDC, with light. timing freeze jumper in place.

[Zackman]

Dear Fixkick:
As per usual, thank you for the great explanation your provided above).

Today, I took the timing belt cover off to check whether the Crank TDC was set right, and that also the Cylinder 1’s TDC (at the firing cycle) was also set properly, so my distributor’s installation would be correct. Well, they were are set correctly.

However, again, I have another fundamental question. There is a video on the Youtube that very beautifully, with a great detail, explains and demonstrate valve adjustment of 1.3L 8V Suzuki Samurai (1985-1995) engine, which seems to be almost identical to 1.6 8V engine that I have. In that video, when the technician wants to adjust the valves, he states that adjustment should be done when the lobe of each cam is at 6 O’clock , so that rocker arm is at the heal the cam of the valve being adjusted (that is the heal would be at 12 O’clock). This makes complete sense to me.

(Please see the video at: https://www.youtube.com/watch?v=ZPVn2xwO81Q - check at time 1:14)
However, I have now two engines; one being the new (used) one that I have recently installed in the car, and my old engine (which used to work perfectly before one of the connecting rods snapped!). When I put the engine at the TDC of Cylinder 4 (that is when the notch on the cam wheel is at 12 O’clock, as shown in the picture you posted in my thread), then the lobe of the intake cam of the cylinder is not exactly at 6 PM. If I put the lobe of the cam that corresponds to the intake valve of cylinder 4 at exactly 6 PM (which I suppose should put the lobe of the intake of cylinder 1 at 12 O’clock), then the factory notch on the cam wheel moves to 2 O’clock position, instead of the 12 O’clock. Exactly the same thing also happens when I check the old engine.

Can you please explain to me what is going on? The two engines cannot be coincidentally set incorrectly at exactly the same positions! I would appreciate your comment in regard to the above issue.

Now, if the setup is correct, I am going to conclude that the only reason I cannot get rid of the backfiring and low power is the car’s computer, since the distributer is also set properly, and that the timing is set at exactly 8 deg. BTC, with a strobe light (and the static timing jumper).
Looking forward to hearing your comments.
Regards,
Zackman

[fixkick]

Dear Fixkick:
As per usual, thank you for the great explanation your provided above). your welcome. and all good questions!!!

Today, I took the timing belt cover off to check whether the Crank TDC was set right, and that also the Cylinder 1’s TDC (at the firing cycle) was also set properly, so my distributor’s installation would be correct. Well, they were are set correctly.

However, again, I have another fundamental question. There is a video on the Youtube that very beautifully, with a great detail, explains and demonstrate valve adjustment of 1.3L 8V Suzuki Samurai (1985-1995) engine, which seems to be almost identical to 1.6 8V engine that I have.
In that video, when the technician wants to adjust the valves, he states that adjustment should be done when the lobe of each cam is at 6 O’clock , so that rocker arm is at the heal the cam of the valve being adjusted (that is the heel would be at 12 O’clock).NO in the beginning of the video his finger touched the center of the heels and he spoke 6pm (his rules on PM)

This makes complete sense to me.
(it should "heels", that this the generic way to set lash on engines at the heels. the heel is a 1/2 circle, and the valve is open then.)
My lash page if you read it, covers the SUZUKI book why (even has the FSM pages too) and covers the ASE way, heels,(6pm?) he said proper way, not that is ASE way, my page cover
ASE (proper) and Suzuki way, (less turns with Suzuki way)
you posted and not even show a photo of you cam cog, so cant guess which one you have, nor how to time it... very hard for me lacking 1 photo of your cam.


(Please see the video at: https://www.youtube.com/watch?v=ZPVn2xwO81Q - check at time 1:14)
However, I have now two engines;
When I put the engine at the TDC of Cylinder 4 (that is when the notch on the cam wheel is at 12 O’clock, as shown in the picture you posted in my thread), then the lobe of the intake cam of the cylinder is not exactly at 6 PM. (now we must have cam timing , rules, ok I have one drawing,suzuki does not publish this. but ISKY did)
the back of the cam is a huge heal, the heel is flat, no lobe. so the valve is closed during that huge period, of the heel.
http://www.fixkick.com/t-belt/heel.jpg
the cam is not timed like and air compressor, no its timed for like best air flow at say 4000rpm. (max torque) so at idle or hand turned, then timing looks a tad funny.
The ASE way sets last at 4 TDC firing points, 0degrees. (works on all engines)
The Suzuki way cheats using the LONG flat heels using only 2 steps, (it works perfect) "after all lash can not change if on the heels."
we have the FSM on his engine too. the G13 for the SAMMI , need it? it too cheats the ASE way.
see my page, see I present the 4 way s to set lash, way one is the Suzuki cheater way.
http://www.fixkick.com/t-belt/LASH/Lash8v.html
way 2, is ASE way , 4 stops , 1,3,4,2 (as taught in all ASE schools and means you dont need the FSM book to set lash, just the lash gap spec. on hood sticker)
way 3 is 4,2,1,3 : same as 2 but new order)
way 4 is random heels way, (what ever comes up now, at heals, we set lash) same as 2 but random, (what ever floats a persons boat)


If I put the lobe of the cam that corresponds to the intake valve of cylinder 4 at exactly 6 PM (which I suppose NO should put the lobe of the intake of cylinder 1 at 12 O’clock), NO !
then the factory notch on the cam wheel moves to 2 O’clock position, instead of the 12 O’clock. Exactly the same thing also happens when I check the old engine.
you dont understand cam timing. (it is tricky and will be shown here, last below here with a real cam profile card,)


Can you please explain to me what is going on?
The two engines cannot be coincidentally set incorrectly at exactly the same positions! true, (they have same cam)
I would appreciate your comment in regard to the above issue. no problem

Now, if the setup is correct, I am going to conclude that the only reason I cannot get rid of the backfiring and low power is the car’s computer, since the distributor is also set properly, and that the timing is set at exactly 8 deg. BTC, with a strobe light (and the static timing jumper).
the engine is first. (not spark)
the 3 rules are (called basic) GOOD engine, (compression at spec) , good spark, timed right, and last good fueling,
in that order, going backwards, is impossible. in that order you have proper cylinder pressures, (timing) and you cant burn fuel with bad or weak spark, and the ECU can not undersand
bad engines or bad spark, leaving fueling dead last.



1: ENGINE GOOD, MEANS , lash good, cam timed to 12pm, notch at #4
2: lash good.
3: compression at spec, I never fail to check this ever, (150psi or more , all equal) why not check your work, ?
4: set the distributor last and use Bosch mag wires, (or NGK if you can afford them)
5: egr closed and defeated.
6: new cap, rotor , and Mag spark wires work best.... in all cases... no carbon wires or silicon bs wires... real mag wires WIN. suzuki spark, is weak so use the best wires.
spark gap to 0.028" not .045 out of the box, never.
7: now we attach the ECU and it sensors.
but first bad inputs to ECU, never ECU first ever.,... after all its just a computer and like such, makes gross errors with bad inputs.
so that is:
a; fuel pressure at spec, key, on and running.
B; thermostat in engine works.
c: ECT reads 300 ohms hot (unplugged hot)
d: IAT reads like 100f? or 1000 ohms or a scan tool makes both sensors easy to check.
e: MAP reads right keyon, idling and gunned.
f: 02 not stuck. (it must swing about 6 times a second at hot idle) if not closed loop is dead, if dead, we work this NOw..
g: no exhaust leaks near o2.
h: injector dont leak, (can be watched, ask how)
i: injectors not clogged. (has 10micron screen and when removed super easy DIY clean up, unlike the MPI engine.
j: ECU flashes 12s on demand and even driving (really this is step 1. sorry)
k: no funny spark plugs, use real suzuki spec, J plugs.

there can be other problems. sure. bad wiring to distrib. or to any sensor. sure. bad coil, bad ignitor. see tachometer jump? oddly?

on the hard nut cases?, knowing what it is not, points to what might be failing.



Looking forward to hearing your comments.
Regards,
Zackman

this is G13 cam, L-110
the intake closes late. 54deg after BTC ! (valve over lap this is called, and is for max power at say 4000 rpm, and weak compression cranking, (say)
and opens 32deg before TDC, ( this means it opens early before the exuast stroke is finished, (same reason.0

http://www.fixkick.com/isky%20cam%20card.jpg

all that matters, here, is lash done (ANYWHERE) a the HEELS
both crank and cam code keys are not damaged.
the cam not keyed at "I" slot (no photos yet so?) and not timed using the "I" markers on outer rim.
and engine makes 150PSI.
as you can see the cam is time unlike any compressor..... a compressor will make max compression, no engine does.


now sammi PDF, G13
http://www.fixkick.com/sammi-stuff/books/sammi-v1.pdf

page 3-54. step 4. (lash)
see them check using only 2 steps, just like the G16
1257
3468
and forgets to say Clockwise turn it, oops.
this is the SUZUKI way and works ever time. makes the job 2 times more easy.

none of the cam lobes are centered on TDC, not one. (like compressor)
how ever if engine was VVT engine,its closer to TDC.

but lash is loose and valves are closed, At TDC and makes 150psi min, compression cold , under starter power. W.O.T
that matters.
that 150 on mine does, 170psi warm, easy. even with 190k miles on it.

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back firing can be bad timing (top reason) cam or spark.
or burned valves.
not doing compression tests is a travesty.
on a new engine we do it on the pallet.
why put a dead engine in a car.? huge labor, all just a huge waste of time.
the compression tests, tell you, that the valves are not burned up, and the rings, not collapsed and more..
its a bench mark, the engine will do like near 300 PSI with a compressor cam in it (theory and fact)
with engine cam in it , it does 150 to 170 , cold to hot. (the cylinders get more round hot)
the CR dictates the compression, never displacement
and the cam profile and altitude.
the car has a stock cam so you will get 150psi, min, at sea level to 1000 feet.
this test is a very good test. as is the leak down test. for finding where the leak is.

I cant hear or see it backfire,
so cant speculate too well!
are the HV wires timed right, if it runs ok at one rpm , the wires are right.
does it have china rotor in it, that times 3 ways, (bs), then buy a bosch rotor , they dont.
misfiring is complex and best to know when it happens and not. under all conditions. and what it sounds like.
is it backfiring, to air cleaner, or to exhaust muffler.
is it worse cold or hot engine?
can you get full wot power from engine?