Tdc With Slack On Chain

[madkaw]

Isn't all this advice based on the hope that the pulley and pointer are in proper condition? More than likely it is. Finding TDC in the above suggestions should all be done in the same direction of rotation.

 

 

The only true way to find TDC is with a degree wheel and a piston stop-but that's for true cam timing adjustments! This way you can go back and forth and take the difference and eliminate the chain slack aspect.  

[Zed Head]

That's the assumption.  I built a piston stop from an old spark plug.  It was so easy, and easy to use that if I ever get another engine, checking the marks at TDC will be the first thing I do.  Too much time spent wondering what's right otherwise.  I checked my one spare engine and it was correct.  Comforting to know the lump of metal taking space in the garage is correct.

 

Here is the easy piston stop build method.  I messed around once before, but the key is the hack saw.  I think an 8mm tap was the right size for the bolt.  A grinder helps to round the bolt corners.  The plug I used wasn't even glued, the ceramic just fell out. The hardest part after that is carefully rotating the engine so that you don't doink a piston in to it. 

 

 

p.s. that's not me, I stopped wearing flannel many years ago.  No offense.

[240260280z]

Probably a dial gauge in a drilled spark plug could be fashioned as well.

 

I have seen water in tubes  move to the max compression point as well.

[siteunseen]

I have some Swiss made dial calipers from this construction company I used to work for with the depth feeler that comes out the end.  Similar to these below.  I must have rolled that thing a mile inside my garage!  The lowest number I got was 1.060".  That's from the plug thread beginning to the top of the piston.  I am going to get to TDC and reclock the distributor and oil pump spindle again.  When I put in that ZX distributor when I first bought the car I got in a hurry to get it running, a mistake I will try and correct.  

 

Thank you all for your help. 

Cliff

 

[siteunseen]

That's the assumption.  I built a piston stop from an old spark plug.  It was so easy, and easy to use that if I ever get another engine, checking the marks at TDC will be the first thing I do.  Too much time spent wondering what's right otherwise.  I checked my one spare engine and it was correct.  Comforting to know the lump of metal taking space in the garage is correct.

 

Here is the easy piston stop build method.  I messed around once before, but the key is the hack saw.  I think an 8mm tap was the right size for the bolt.  A grinder helps to round the bolt corners.  The plug I used wasn't even glued, the ceramic just fell out. The hardest part after that is carefully rotating the engine so that you don't doink a piston in to it. 

 

 

p.s. that's not me, I stopped wearing flannel many years ago.  No offense.

My dumb arse did what the video says not to do, hit it with a hammer then put it to a bench grinder.  I even tried to use a hacksaw to cut through the ceramic before the metal base.    I was going to put the the dial caliper through the hollowed out spark plug base.  What do you do? wait until the piston top kisses that bolt head?

 

After watching I may try that again!  Thanks ZedHead.

[rossiz]

to use a piston stop you need a degree wheel, or some way of measuring/marking crank position. the process is as follows:

 

1. put in the stop, slowly rotate the crank until the piston gently stops against it, mark the degree wheel (or in your case, make a mark on your crank pulley indicating the 0 pointer)
2. rotate the crank in the opposite direction until the piston gently stops against it, mark the degree wheel (or in your case, make a mark on your crank pulley indicating the 0 pointer)
3. tdc is now exactly halfway between the two marks (or degree wheel readings)

a degree wheel is just a big circular plate with degrees marked around the edge (like a 360 degree clock face). you can find one online, print it out, glue it to something flat (plastic, cardboard, metal, whatever) and mount it to your crank pulley, then you'll need to make a pointer of some kind that will read against the degree marks (an L-shaped piece of wire will do) and bolt/clip it to the engine so you can see/note the crank degree position. you can also wrap a tape measure around the crank pulley (a tailor's tape is perfect because it is flexible) and use those number markings.

 

again, for finding tdc it doesn't matter if you use degrees, inches, milimeters, whatever, it just matters that you can record the crank pulley position on either side of the piston stop, then split the difference accurately. using a degree wheel is specifically needed if you're trying to do very accurate measurements of specific degrees for cam timing (not an issue here).

 

hope that helps... probably a youtube video which explains it better than my words...

[240260280z]

These guys all talk too much but here are a few other ways:

 

Vacuum gauge 

 

Manometer

[Zed Head]

 I even tried to use a hacksaw to cut through the ceramic before the metal base. 

During manufacture, the spark plug ceramic portion is inserted in to the metal base then the lip of the metal is crimped over to hold the ceramic in and seal it.   The hacksaw is used to cut off the crimped portion.  Basically cutting off the top of the metal base, around the ceramic.  Just place the blade in the corner at the base of the crimp and cut a thin ring of metal off.  You have to work your way around bit by bit.  You could probably also put the plug in a lathe or drill press and spin at low speed to cut a consistent cut.  Don't let the saw get driven in to your gut though.

[siteunseen]

First off thank you all for your input, it what keeps me going.   

 

I'm confident I've found TDC.  Spent the afternoon trying different ways and making marks with a Sharpie.  I kept landing at the same spot so then I started measuring the distance from the adjusting end of my rockers to the top of the cylinder head on #1 intake and exhaust.  Hit the same numbers 3 times, that's good enough for me.  1.700" on the intake valve's rocker and 1.640" for the exhaust.

 

It's about a 1/2" below the 0 degree notch from the factory.  I'm going to set the timing again and go fill up with petrol and drive, 60 degrees and sunny today, yippee!  Then start planning the motor rebuild project to get to know this motor personally.  I keep finding things I don't like.

[240260280z]

Good stuff.  Clever way to measure rocker too.

 

I think the oiling rod on #6 exhaust is on the way out with the bend.

[Captain Obvious]

On edit, I just took out a whole bunch of stuff that you knew already... Teach me to read page two without thoroughly reading page one first. Sorry. Carry on.

 

And what Blue said about that spray bar... That rear block isn't long for this world. Looks to me like the tip of that rear tube has already contacted the lobe. Looks like there is a clean spot wear mark on the corner of the tube closest to lobe #12?

 

PS - I don't like your stamped fuel pump. I know you don't either. Just cosmetic, but I prefer the vintage look. 

[rcb280z]

Yeah that oil bar is getting rubbed on the end. Probably can hear it too.

 

I need to do engine work also. Are you going to post the process site?