Find the TDC

I have the complete motor but without the head mounted now.
How do I find the TdDC only with cylinder and Pistons mounted?
I have the graduated wheel mounted on the crankshaft.
Please explain with easy words because I get lost in translation.
Thanks.
Piero

You need dead stop, for the piston one that holds it down one inch or so from the top of the stroke.
Than using the stop both ways clockwise and anticlockwise center your dial up repeat to check many times.

Pull the centre electrode out of an old sparkplug, fit it to the engine, and make a soap bubble over the hole. When the bubble is max size, that is TDC.

"You need dead stop, for the piston one that holds it down one inch or so from the top of the stroke. "

What he said!

This will be helpful: http://www.doov.com/apps/nortoncompanio ... &Itemid=10

Using a dead stop involves making a fitting with a spark plug thread, why would you make things more difficult than they have to be ?

Best to take any 2 equal points with piston before TDC and after TDC, half that on degree wheel to make TDC. Repeat several times for accuracy.

Dave
69S

Hi Sirs,
note that i do not monted the head, i have only cylindr and pistons monted!
Thanks.
Piero

Just put a dial indicator touching the piston. Note where it stops and reverses at the top.
Jaydee

jaydee75 said:

Just put a dial indicator touching the piston. Note where it stops and reverses at the top.
Jaydee

Click to expand...

Not the best approach as there is substantial crank angle with little to no crank piston movement at TDC.

Best approach is dead stops and spilt the difference. It's an easy task with the head off and pistons exposed.

Dances with Shrapnel said:

jaydee75 said:

Just put a dial indicator touching the piston. Note where it stops and reverses at the top.
Jaydee

Click to expand...

Not the best approach as there is substantial crank angle with little to no crank piston movement at TDC.

Best approach is dead stops and spilt the difference. It's an easy task with the head off and pistons exposed.

Click to expand...

By using DogT's method and Jaydee's method combined finding TDC, without the head mounted as was stated, should be real easy as noting where the dial indicator stops moving before TDC and where it starts after TDC.
Count the # of degrees and divide by 2.
Put the piston in that position and mark where TDC shows on the degree wheel and mark the engine.
Buona fortuna il mio amico

Way too complicated. Oh well.

You whack it round till the pistons are at the TOP ( T.D.C. being a abbreviation of ' Top Dead Centre ' .

Now if youre nailing on a Degree Wheel , and a Pointer . We can get Excited . It all gets a bit vauge , at the Top .

So 'we ' get it up there , & about centered . Now comes the demanding bit . We get ' something ' that holds the piston down a bit .

Say 1/8 in. or 1/4 in. Like a strap with the end bent down . a bit of steel ( ford alternator strap ? & a nut , under it . Or w.h.y.
( abreviation for something thatll do the trick )

NOW . . . swing it ea. way . C A R E F U L L Y ,

as it stops , check the degree wheel mark . IF for example it said ( or was ) 8 degees off the ' O ' ( zero ) one way , and 14 Deg. of the Zero the other we would go , 8 + 14 = something , such as 22 .
therefore 22 / 2 = 11 .

8 from 11 is 3 , or 14 from 11 is - 3 . therefore its about three out , so , we shift the degree wheel , or whack the pointer , so the sucker reads the same , with the crank swunng the same distance down , Ea. way . Reading the same , before & after .

this gets us spot on the mark , for ' zero ' degrees , AT T.D.C. = pistons & more importantly CRANKPINS at the top .

While we're at it , particularly if weve got a dial guage , we get 3/8 B.T.D.C. also , checking the Zero's still right . and
weve got the Ignition Point . or thereabouts . So it pulls wheelies of the line correctly .

actually , you can put a few marks there re;lateing to Ign.
Fully advanced , fully retarded ,
& say one at 1/3 or 1/2 advance .
Then with a strobe on the ignition , you can evaluate your advance curve .
Or set it Static .