TDC with oil pan off

[7DCUDA383A]

Is there a way to do TDC with the oil pan off , I'm replacing the pan and I wanted to make sure I'm at TDC , there is a white mark on the balancer but not sure if it's right .

 

[Deathproofcuda]

Why are you trying to find TDC? In other words, how accurate do you need to be?

 

[7DCUDA383A]

Why are you trying to find TDC? In other words, how accurate do you need to be?

When I got the car it never ran right , so since I have the oil pan off I want to see if its good on that.

 

[moparleo]

The crank shaft won't show you if the cam is installed correctly.
You can only check if the piston is up.
Rotate crank until number one piston is all the way up but you can do this by just pulling number one spark plug and checking from the top.
If the engine is still in the upright position and you want to find out if the piston is exactly at TDC, here is what you do.
you can buy a TDC tool or make one from an old spark plug. It is just a piston stop.
Always disconnect battery, negative side first.
1. Remove the spark plugs.
2. Insert your tool into number one spark plug hole. This will be on this engine the drivers side front plug.
3. Rotate the engine by hand until it stops. put a mark on the balancer.
4. Rotate the engine now in the opposite direction until it stops. Again mark the balancer.
5. Measure the distance between the 2 marks and divide by 2.
6. This is exactly TDC.

 

[7DCUDA383A]

The crank shaft won't show you if the cam is installed correctly.
You can only check if the piston is up.
Rotate crank until number one piston is all the way up but you can do this by just pulling number one spark plug and checking from the top.
If the engine is still in the upright position and you want to find out if the piston is exactly at TDC, here is what you do.
you can buy a TDC tool or make one from an old spark plug. It is just a piston stop.
Always disconnect battery, negative side first.
1. Remove the spark plugs.
2. Insert your tool into number one spark plug hole. This will be on this engine the drivers side front plug.
3. Rotate the engine by hand until it stops. put a mark on the balancer.
4. Rotate the engine now in the opposite direction until it stops. Again mark the balancer.
5. Measure the distance between the 2 marks and divide by 2.
6. This is exactly TDC.

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View attachment 137345

Well here's what I know so far, I have whatever marks these are lined up and I put a screwdriver through the 1st spark plug hole and it barely went in , now the rotor on the distributor looks 180 off I think , I'm really trying to understand this stuff but it's taking awhile and who mixes spark plugs like this , no wonder this thing runs crappy , well one reason .

 

[Deathproofcuda]

#1 piston hits TDC twice per cycle, one during compression and once during exhaust, so rotor being 180 degrees off makes sense. Just means that the piston is at TDC during the exhaust stroke (exhaust valve is open) instead of during compression when both are closed.

The accurate way is what Moparleo posted above. To verify that #1 piston is in compression cycle, you can seal the spark plug hole with your finger and see if compression builds while advancing crank toward the TDC mark on your balancer.

 

[7DCUDA383A]

#1 piston hits TDC twice per cycle, one during compression and once during exhaust, so rotor being 180 degrees off makes sense. Just means that the piston is at TDC during the exhaust stroke (exhaust valve is open) instead of during compression when both are closed.

The accurate way is what Moparleo posted above. To verify that #1 piston is in compression cycle, you can seal the spark plug hole with your finger and see if compression builds while advancing crank toward the TDC mark on your balancer.

Would that mean the mark on the balancer is wrong .

 

[Deathproofcuda]

Would that mean the mark on the balancer is wrong .

No.

Your crank turns two times for every revolution of the cam and distributor. So every time the distributor makes one complete rotation, the mark on the balancer will pass the TDC mark on the timing cover twice.

Typically we want to know when TDC is on the firing stroke (compression), which is why I suggested the finger over the spark plug hole trick. With both valves closed, advancing the piston up toward TDC will push your finger out of the hole.

Based on your photos, your engine looks to be at TDC on the exhaust stroke.

 

[moparleo]

What you need is education/information.
Download this link and you will get everything you need. Service manuals, parts book, Factory repair videos and more
-> Resource Library – MyMopar

 

[7DCUDA383A]

No.

Your crank turns two times for every revolution of the cam and distributor. So every time the distributor makes one complete rotation, the mark on the balancer will pass the TDC mark on the timing cover twice.

Typically we want to know when TDC is on the firing stroke (compression), which is why I suggested the finger over the spark plug hole trick. With both valves closed, advancing the piston up toward TDC will push your finger out of the hole.

Based on your photos, your engine looks to be at TDC on the exhaust stroke.

ok , so keep turning the crank until the finger gets pushed off then the mark should be close or on the 0 mark and the rotor turned the right way .

 

[7DCUDA383A]

What you need is education/information.
Download this link and you will get everything you need. Service manuals, parts book, Factory repair videos and more
-> Resource Library – MyMopar

I have read and watched videos , but it's just not registering this in my head , when I think I know what I'm doing my mind goes blank , I really appreciate the info and time y'all take to explain to people like me just getting started .

 

[Deathproofcuda]

ok , so keep turning the crank until the finger gets pushed off then the mark should be close or on the 0 mark and the rotor turned the right way .

Starting where you are now, with the balancer mark pointing at TDC:

Start turning the crank clockwise and continue until the balancer mark gets about 3/4 of the way around.

Now place your thumb over and try to seal the open spark plug hole on the # 1 cylinder (you may need a helper to do this).

Continue advancing the crank clockwise with the balance mark moving towards the TDC mark. If the valves are closed (compression stroke) you should feel the piston pushing air against your thumb.


Would imagine that as the piston passes TDC you could also feel the transition as the piston begins to suck air in through the spark plug hole since both valves are closed during the piston's downward power stroke.

 

[moparleo]

When you feel pressure, you are on the compression stroke. That is all it tells you.
The Chrysler distributor shaft is like a standard screw driver and fits into a slot/ So it can only go 2 ways correctly or 180° off

 

[moparleo]

This information is in the service manual. Download the link. Look in the engine section

 

[Deathproofcuda]

When you feel pressure, you are on the compression stroke. That is all it tells you.

Correct, no argument there. As I previously stated, the method you previously posted is the accurate way to determine TDC. But still helpful to know if #1 is in compression or exhaust stroke when trying to set up dizzy for a first start.

 

[moparleo]

You are correct. He needs to download the service manual. It will answer most of his questions.

 

[7DCUDA383A]

Starting where you are now, with the balancer mark pointing at TDC:

Start turning the crank clockwise and continue until the balancer mark gets about 3/4 of the way around.

Now place your thumb over and try to seal the open spark plug hole on the # 1 cylinder (you may need a helper to do this).

Continue advancing the crank counterclockwise with the balance mark moving towards the TDC mark. If the valves are closed (compression stroke) you should feel the piston pushing air against your thumb.


Would imagine that as the piston passes TDC you could also feel the transition as the piston begins to suck air in through the spark plug hole since both valves are closed during the piston's downward power stroke.

Clockwise or counter clockwise

 

[7DCUDA383A]

You are correct. He needs to download the service manual. It will answer most of his questions.

I do but hearing real time info helps understand it better.

 

[Deathproofcuda]

Clockwise or counter clockwise

Sorry, clockwise.

Good catch! Dumbass me contradicting myself in the same post. I went back and fixed it.

 

[7DCUDA383A]

Sorry, clockwise.

Good catch! Dumbass me contradicting myself in the same post. I went back and fixed it.

You made me drink a beer on that , lol , thanks dude , hopefully in a couple days I can get back to it , crawling on the ground at 50 yrs old is tuff especially since I broke my neck in 2018 , I hope ya'll are going to be ready when I start to tune the carb , there is more videos on that though , thanks again Mr Death .