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Question about TDC (Updated) I messed up

Started by 400/6/PAC, September 09, 2009, 12:04:41 PM

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400/6/PAC

OK So I'm not to good with motors.
How do I know if I'm TDC on the firing stroke?
I need to adjust My hydraulic lifters and I have to start on TDC #1 on the firing stroke.
Thanks

frederick

Both valves should be closed, rotor arm pointing to no1 cylinder.

400/6/PAC


firefighter3931

The piston will be at the top of the bore @ TDC. If you're unsure just pull #1 plug and stick a small section of wire in the hole and feel for the piston. Another way is to bump the engine over while keeping your finger over the #1 plug hole (sparkplug removed) and when the piston comes to TDC it will push air against your fingertip.



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

maxwellwedge

And remember, using anything other than your finger will hurt!  :cheers:

green69rt

Isn't there a mark on the pulley or harmonic balancer that marks TDC??  That's how you set the timing, that seems the easiest way.  Bump the starter till the mark and the pointer line up, you have TDC on cylinder #1!

frederick

Quote from: green69rt on September 09, 2009, 10:04:19 PM
Isn't there a mark on the pulley or harmonic balancer that marks TDC??  That's how you set the timing, that seems the easiest way.  Bump the starter till the mark and the pointer line up, you have TDC on cylinder #1!
But you are not necessarily on the firing stroke, 50% chance.

Todd Wilson

Quote from: firefighter3931 on September 09, 2009, 08:38:36 PM
The piston will be at the top of the bore @ TDC. If you're unsure just pull #1 plug and stick a small section of wire in the hole and feel for the piston. Another way is to bump the engine over while keeping your finger over the #1 plug hole (sparkplug removed) and when the piston comes to TDC it will push air against your fingertip.



Ron


I've always liked to use a straw to put thru the spark plug hole.


Todd

greenpigs

So you have valve covers off if your adjusting rocker arms? The second valve spring is the intake. So when it moves and the timing mark lines up with zero, your where you want to be.
1969 Charger RT


Living Chevy free

400/6/PAC

I can't get My finger out of the sparkplug hole. :lol:
Just kidding.
Thanks Guy's
That was the confusing part for Me, Which was the firing stroke.
Was it TDC before the intake and combustion stroke or at the end of combustion.
I"m not to lucky when it comes to those 50/50 chances.
I think I got though. going to test the motor tonight.

Nacho-RT74

I use a plug made with some paper, on even a bottle cork ( slightly tapped ), that will blow out on TDC when cranking starter motor. you will HEARD THE BLOW...

I made it and works, making small touchs when jumping starter relay
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

TylerCharger69

Harmonic balancer mark on TDC  (0)   and at the same time rotor pointing to cylinder 1 on the distributor cap......

Troy

Just a word of caution... not all distributors are indexed/clocked the same way and balancers can "slip" (mine reads 24 degrees when the piston is at TDC). Physically checking the piston location is the best solution.

Troy
Sarcasm detector, that's a real good invention.

TylerCharger69

Troy....is that a stock balancer?   Just curious....

Troy

Sarcasm detector, that's a real good invention.

TylerCharger69

Good tid-bit of info there Troy......I never had that occur before.....something to look for in the future!!! :2thumbs:

Ghoste

It's one of those things that seems to be cropping up more and more here lately as these old cars hit the same basic magic age.

Nacho-RT74

Quote from: TylerCharger69 on September 10, 2009, 01:13:17 PM
Harmonic balancer mark on TDC  (0)   and at the same time rotor pointing to cylinder 1 on the distributor cap......

dunno why, but my balancer have 4 marks
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

TylerCharger69

Yeah....my 440 has 4 marks as well....... :shruggy: :scratchchin: :shruggy:

Nacho-RT74

honestly my ORIGINAL balancer had just one mark, but since the crank on my engine was seriouslly damaged and I used a Donor engine, I interchanged all the rotation parts from one to the other, including this balancer. Donor was 2 bbls 400... also used the camshaft. I didn't know the difference between 2 and 4 bbls engine cams on those days :brickwall:
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

400/6/PAC

Well
I've really done it this time.
Long read but let Me explain.
It all started when My car wouldn't"t keep timing.
I checked all the exterior parts, even pulled the MSD distributor and had it checked.
No problem with MSD.
I finally decided to check the timing chain, Got down to the chain and didn't really see a problem.
Found no stamps at all on the cam, only some hand scribed #s.
Now having a cam that I knew nothing about, I decided that since I was this far into the motor I would replace the cam.
I got a Mopar performance cam and new lifters.
Installed the cam and checked the centerline, I was off 5 degrees so I installed a button and rechecked.
I sat the piston at TDC, found maximum lift on the lifter, zeroed My degree wheel and dial indicator. Turned the motor until the dial indicator read 0.50 before maximum and recorded the number on the degree wheel, then went back to 0.50 after maximum lift and recorded that number. The two #s added up to 216 divided by two is 108 which is exactly what the cam centerline is.

I reassembled the motor checking all the torque specs, Adjusted the hydraulic lifters and went to turn the motor over.
I  had zero compression and the motor sounds like it's free spinning . :brickwall: :brickwall:
Yes I put the spark plugs in. It also sounds like the starter is about to blow up even though I never touched the starter.
I guess I get to take it all back apart and try to figure out where I went wrong.
I'm going to give Myself one of these :slap: and go back to work.
Mabey I should take like A CLASS on how to build motors. :flame:


green69rt

Sounds like you degreed the cam in right but you also said you put in new lifters.  Oh-Oh!   Thats the first place I would look...and also sounds like that engine top end is coming apart again.  Did you compare the old to the new lifters.  Finally did you really lube up your cam lobes before you spun the engine.  You can wipe a cam lobe in minutes if it isn't lubed right.

Oh, and what do you mean that you adjusted the hydralic lifters?  They're self adjusting.  If you have adjustable rockers and tried to adjust the lifters with no oil in them (fully collapsed) then you may have set your valves up so they never close.  Therefore no compression, and the engine turns like the spark plugs are out.  Also the starter will have greatly reduced load on it and will spin the engine like crazy.

Just some thoughts.

400/6/PAC

Yes
I used cam lube.
I did compare the old and new lifters, The'y looked Identical.
It was My understanding that the lifters were to be set at zero lash and then adjusted in 1/2 turn and tighten the locking nut.


400/6/PAC

Thanks Green69
Yeah, I do remember that thread and revisited it.
So many more questions have come up and so many different people giving the wrong advise ( Meaning all My backyard mechanic friends )
That's why I come here, The advise I get here is almost always correct and if it's not someone else will point out why it"s not correct.
I really thought I did everything the right way.
I don't even know where to start trying to figure out where I went wrong.
It is very frustrating but makes Me want to learn motors inside and out.


green69rt

Yeah, I know.  Sometimes the only solution is to rip everything apart and try again.  I'm at a the end of my advice.  It still sounds like your valves are staying open.  OK, one last thing.  Did MP send you solid lifters verses hydraulic??  worse things have happened.  If you did the right things then all I can think of is someone else added to your woes.
Keep us updated on you progress.


green69rt

Ok, reread your thread again.  You didn't see anything wrong with the timing chain.  Did you take it off to inspect it?  I'm really reaching here but there has to be something wrong somewhere!!!!

frederick

I agree with the others, you've probably overadjusted the preload, completely compressing the hydaulic lifter.

To make setting the preload easy, I bought another hydraulic lifter.(same brand)
I opened it, removed the spring and shimmed it so it now acts as a solid.
To set the preload I insert the "solid lifter" adjust so there is no preload, then add another 0.030".
Take the "solid" out and insert the normal lifter.

Frederick

firefighter3931

Sure sounds like the valves are hanging open. Time to start over and re-adjust the valvetrain.  :yesnod:


Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

400/6/PAC

Oh Man
What if The'y are solid lifters and not hydraulic.
How bad would that mess things up????