TRICK I LEARNED IS TO PUT A LITTLE PLASTIC PIPE PLUG(PUSH IN KIND) INTO #1 SPARK PLUG HOLE. TURN CRANK UNTIL PLUG SHOOTS 8 FOOT IN THE AIR AND VOILA YOU ARE ON THE COMPRESION STROKE. SET CRANK AT 0.

And what is your trick for getting the plug out when you suck it into the cylinder?

Good trick, especially when you ain't in a position to watch the #1 or #6 rockers to confirm that. & if I am confirming the dampener TDC with the screw in tool, I get the dampener to 15 BTDC then screw it in till it makes contact then I go back around CCW till it touches again (hopefully at 15 ATDC) & I repeat it once for good measure.

Best question ever.

or pay the neighbor boy a buck to hold his finger over the hole while you move the breaker. On the plastic plug if it is shaped right to where it could not get sucked inside that'd resolve that (potential) or stick a pin in it sideways. decades ago I had a plastic piece of something fall in there & people said to fire it up & I did & no issue but it was a fairly small piece iirc.

never had it happen. I put the plug in fairly loose and turn the crank with a ratchet slowly. it may suck in a little but it makes it easier to blow out. it is also important to have the right size plug. err on the side of a little too big.

I do also use the plug with the outer lip that is bigger than the insertion diameter.

i just use a remote starter and my thumb

Same here, it's worked for over 4 decades for me...

Try that with a Hemi

A clean Hemi pushrod always works when working on a Hemi.

I do t remember ever working on any car that I couldn’t bar the engine over while holding my finger over the plug hole.

Need a pic

I have used for years a simple paper ball and never have had a problem being sucked in! Valve is opening so why would suck it?

I would think the intake valve would be opened to prevent that from happening

Stop making sense will ya The only way it could get sucked in is if there were no rockers on the engine

Gus

so if it happens to be on the power stroke as he's cranking it around it won't generate a vacuum?

That TDC marks hits TDC twice and only one of the is the one you want.

Come on, guys...The OP was trying to be helpful.
Sure, he first posted in
ALL CAPS WHICH ANNOYS MANY PEOPLE.
He was trying to be a good guy though.

For $12 bucks these are pretty cheap and work great. Whistle Stop TDC

take a old sparkplug,beat the tip out on the bottom,weld a short piece of rod in the hole,screw in the head,turn engine by hand till it contacts the rod,mark the dampener,turn engine the other way till it hits,mark dampener,halfway between the two marks is TDC

Is amazing how ppl gets in doubts still with testimonials of some other ppl who already has made it!! Myself even with a ball made of paper, somehow threated into the hole threads. WON'T BE SUCKED IN!! AS FAR VALVES ARE WORKING!

yeap, but that's doesn't mean on compression stroke

MoparMad, I am looking forward to your next "tip" (please hurry!). EDIT & I am being facetious, it's all good brother.

what is the issue? Trying to figure out compression stroke?
I remove the #1 plug, insert a long piece of copper wire and watch it as I turn the crank bolt. I'm not building rockets in my garage.

That takes to TDC but its a 50% is the compression stroke chance

Take off oil cap and watch for the intake valve open (Slant Six).

I turn the crank while looking thru the window at the pushrods. When the intake valve closes on #1 I know that I'm coming up on the compression stroke.

Sorry about all caps. I know some people are sensitive. But some of us can’t see well so we use all caps. My tip was just to help someone out. Also you don’t have to remove anything but the spark plug. I was also using this tip on a complete engine in a vehicle, not half apart on an engine stand. I didn’t put down anybody else’s tip. I guess I’ll try my best to be less helpful. Not in my nature but I’ll try.

Really?!?! I never met a Mopar owner that was judgmental and ignorant till I joined here. They are usually some of the nicest most down to earth people I’ve ever met.

That’s the plugs there

Welcome to Moparts, where sometimes it looks like you are going through an initiation process in a street gang.

After enough punches in the face you either make it or you give up.

I’ve been jumped by 5 guys, beat over the head with metal chairs and stabbed in the back. That was easy compared to this. Lol

Don’t take these mostly old farts personal. It’s winter and the vast major of them are grumpy old Gus’s. I’ve been here for quite awhile and have had good interactions with most but some here just like to antagonistic. Some jobs have a phenomenon that’s called “eating their young”, nursing, the fire service etc. this place is not different. And you don’t have to be physically young just new “young”

The collective (25K+) knowledge of the Mopar heads here is off the charts (I learn here every day). In fact where I am at knowledgewise is a direct result of being (on) here for 16 yrs.

i HAVE to rely on those here because i keep "loosing" what i used to know !

Hey, the title says top dead center, it doesn't say about compression stroke. But the hint was to find the top of the compression stroke.
Thanks, pardner! I never thought of that.

There are two things one might want to check:
1. Where is TDC? (is my harmonic damper and pointer correct?).
2. What stroke am I on? (top of exhaust stroke or top of compression stroke?).

The OP's trick was good for #2. The piston stop method was good for #1.
I don't worry about what if the plastic plug sucked in because it'll burn up sooner or later. Same with the little paper ball. We don't always turn the engine over with the cam, lifters, pushrods and rockers installed. I've had my finger sucked partway into the spark plug hole. The whistle is nice but I have never seen one in a store.

OP, the occasional snarky reply is what you pay for being in on this outstanding accumulation of wisdom.

R.

come on , just screw in the compression tester and be done .

I look at the dampner.

once again... that's a TDC mark but not on compression stroke necesarilly

Half the moparts members need to go to the top dead center school. So they know what it means...

There will be suction. Depending on what your using for the plug, and how it's being turned over will determine how much suction and if it'll get sucked in.

ok... the piece of paper I have used never has being suctioned. I use the starter motor. Admision valve prevents the suction.

If there is suction will be also "exhaustion"... right ? well, the plug/paper is not being spitted out either on exhaust stroke. Just blows out when the comnpression stroke comes in. God... I have made it many times!!!

Its like the ohms law! the flow will go throught the less resistant path! having any kind of plug, air will leave and get in just throught the valves. The minimal amount of suction or exhaustin over the plug won't affect it having the valves in working order.

Anyone else had problems with piston stop tools on wedge engines? The stop is at such an extreme angle, almost horizontal to the top of the piston, that the force of the piston can easily deflect the stop if the stop isn't REAL stiff and rigid and too much force is applied. Insert joke here.

It's the power stroke that will cause suction during down stroke with both valves closed.

If you don't believe it, go out in the garage, pull a plug, put your finger on the hole and crank it over.

The paper or the plug used was already blown out due the previous compresion stroke by then which is the goal on this

Once again, come on! I have made it many times! And the paper ball has being bever sucked in! It is of course a bit bigger than the hole and even being able to, somehow, get threated into the hole

This is allmost becoming like the eternal ammeter/alt upgrade discussion... LOL, for lot of guys I'm crazy and I'm using my imagination inventing everything LOL

Not sure if that was directed to me.

I have made no comment on whether your little paper wad or a plug would get sucked in. I have no idea the physical details of either. Frankly finding TDC is so easy I would have never thought of it as a trick.

But you are the one that implied that it was impossible to have suction because the intake valve was open. I think you said it twice. I simply pointed out that you were incorrect.

Seeing those spark plug thread whistles brings up the cheapskate idea of copying the expensive NASCAR cylinder compression ratio tester ($4700) cheaply.

Mount a “slide whistle” to spark plug threads,
pipe a steady air supply to it from a battery powered mattress inflator,
then use a smartphone microphone along with an APP
to measure the frequency of the low frequency sound at bottom dead center,
and the higher frequency sound at top dead center.

Yes but no LOL. Actually being general.



yes, correct, but on this case after the plug was already spitted out . I meant because the plug won't be sucked on that moment because there is not a plug on that moment .

and still, I have made it many times installing a plug there without consider that and never have had anykind of plug made being sucked in

Unless you happen to start the process at TDC on the compression/power stroke. Then....suck city.

Ok, never it happened to me... I plugged on any time it was without pay attention to the stroke it was and it never happened to me. Maybe some time met the power stroke and it has NEVER happened to me