finding top dead center #1 for timing ignition & cam



finding top dead center #1 for timing ignition & cam

Postby grumpyvette » December 27th, 2008, 11:27 am

INSTRUCTIONS, on the procedure
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Find Top Dead Center
before you can set the ignition timing or install a cam correctly youll need to know how to locate TOP DEAD CENTER on cylinder #1

THE PROFORM SOCKETS ARE ALUMINUM
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http://www.summitracing.com/parts/PRO-67492/

http://www.summitracing.com/parts/PRO-67491/

when purchasing a crank socket try to find one designed to easily accept and lock down a degree wheel

THE COMP SOCKETS ARE FAR MORE DURABLE STEEL
http://www.jegs.com/i/COMP+Cams/249/4914/10002/-1 LS ENGINES
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http://www.jegs.com/i/COMP-Cams/249/479 ... ProductId= BBC ENGINES
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http://www.jegs.com/i/COMP-Cams/249/479 ... ProductId= SBC ENGINES
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http://www.rbracing-rsr.com/compstaticcalc.html
READ RELATED LINK
viewtopic.php?f=53&t=3554&p=9433#p9433
YOU CAN AVOID POTENTIAL CONFUSION & PROBLEMS IF YOU TAKE THE TIME TOO, DEGREE THE CAMSHAFT IN, instead of relying on "dot-to-dot".
btw when checking for TDC its usually best to pull all the plugs it makes spinning the engine by hand FAR easier
Fasten the degree wheel to the crank, with a washer and a crank damper bolt.
http://www.circletrack.com/enginetech/c ... to_12.html
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Proform Parts 66830 - Proform Cam Checking Fixture Kits
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Take a stiff 1/8-inch TIG welding rod or similar material and sharpen one end to form a pointer, and wrap the other end around your needle nose pliers so that a 360 degree loops formed so a bolt and washer can secure the pointer wire to the block in a convenient bolt hole location.
Attach this pointer so that it rests very close to the damper and the point is at the degree wheel edge to eliminate parallax viewing error.
IF THE HEADS ARE OFF THE BLOCK
Obtain a stout strip of steel about seven inches long, drill three holes, two for head bolts and one centered on piston.
Put a bolt in the center hole to stop piston movement.
OR IF youve got the tool required, ...A deck bridge you can bolt it in place and insert a bolt that prevents the piston from reaching and passing thru top dead center in its rotation,
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This strip or the correct tool,is then placed across the center of No. 1 cylinder bore and bolted on each end to secure it to the block.
Caution: Be sure that the strip of steel is rigid enough so that it will not be deflected when the piston contacts the center bolt stop.
Incidentally, the positive stop should be adjusted so as to stop the rotation the crankshaft in normal running direction (clockwise) until the piston crown lightly strikes this stop.

Now, radially turn and lock the degree wheel to the crankshaft at 40 degrees before T.D.C. at the pointer.
Rotate the crankshaft backwards to the positive stop.
If the degree wheel reads 40 degrees from T.D.C. you have hit Top Dead Center exactly, and the zero mark between the two 40 degree readings is absolute T.D.C..
However, if your readings were unbalanced, you will have to split the difference (your errors in degrees) by moving the degree wheel radially on the crankshaft.
Then, try again until you get exactly the same degree readings against the positive stop on either side of T.D.C.
NOTE: The lower the positive stop is located below T.D.C., the greater the degree readings will be.
The results will always be accurate.
T.D.C. always lies equidistant between the two positive stop readings.

IF THE HEADS ARE ON THE BLOCK


youll screw a piston stop into a spark plug thread hole and accomplish the same thing

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yes all the instructions and details are located in the links so youll want to read thru them

http://www.frontiernet.net/~ennis/tdc.html

http://www.iskycams.com/techinfo_index.html

http://www.lunatipower.com/Tech/Pistons ... eight.aspx

http://www.2quicknovas.com/2qntdc.html

http://www.romac.com.au/Std_&_Offset_Crank_Info.pdf

viewtopic.php?f=44&t=464

viewtopic.php?f=52&t=90

http://www.classiccarauto.com/impala/ho ... _tdc.shtml
YOULL WANT THESE TOOLS TO DO IT EASILY

http://store.summitracing.com/partdetai ... toview=sku
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http://store.summitracing.com/partdetai ... toview=sku
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http://store.summitracing.com/partdetai ... toview=sku

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ttp://www.fourwheeler.com/howto/67578/index.html

http://www.youtube.com/watch?v=Aw7IdW4Qxcc

http://www.2quicknovas.com/happyTDC.html

http://www.summitracing.com/parts/MRG-4599/?image=large

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http://forum.grumpysperformance.com/viewtopic.php?f=50&t=723

http://www.summitracing.com/parts/MRG-4598/

http://www.rodandcustommagazine.com/tec ... index.html

http://www.hotrod.com/techarticles/sett ... index.html


they make these for BOTH SBC AND BBC , and IN SEVERAL DIFFERENT DAMPER SIZES ,SO BE SURE YOU ORDER THE CORRECT ONE FOR YOUR APPLICATION
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: finding top dead center #1 for timing ignition & cam

Postby brad.arcova » December 19th, 2009, 12:37 pm

I want an accurate measure on TDC; the process looks pretty simple except for the feel when the piston hits the stop when using this tool. How hard is it to feel the top while turning the crank (plugs out) without damaging anything?

Brad

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Re: finding top dead center #1 for timing ignition & cam

Postby grumpyvette » December 19th, 2009, 12:51 pm

while your verifying tdc, if your turning the engines crank with a breaker bar on the front crank/damper bolt its done, with the engine out of gear, slowly and carefully turning the assembly and its rather obvious when its stopped solidly, against the piston stop, you then mark the line on the damper, reverse, rotation and use the second mark when it stops as a second marker,the true TDC is 1/2 way between the marks, obviously having a degree wheel installed, and a stiff wire as a pointer on the rim of the degree wheel, makes this far easier
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: finding top dead center #1 for timing ignition & cam

Postby grumpyvette » June 17th, 2011, 7:52 am

"HEY GRUMPYVETTE??
I tried to use a spark plug hole piston stop on my 496 and had to use a 4" bolt to bottom it out (the included stop didn't bottom out). Trouble is no matter what I did to turn over the engine it never stopped. (My guess is that the piston stop bottomed out in the head not the cyl. and piston top). I turned over the engine 720 degrees but not stop at all.
So here is the question:
Can someone explain this better than I have? Is there a special BBC head on piston stop? "
http://www.summitracing.com/parts/SUM-G1057/?rtype=10

the problem you experienced is not rare with flat top, or dish pistons in a BBC simply because the spark plug entrance angle is very shallow in the heads of most bbc engines. before you start,be sure to take the rocker arms loose and remove the push rods on that cylinder on that big block Chevy because if you do not TAKE THE PUSH RODS FOR THE CYLINDER BEING POSITIVE STOPPED, OUT OF THE ENGINE WHEN YOU DO THIS OPERATION, its possible to cause internal damage, bend valves etc.
thats one reason most guys do that with the heads off. a piston stop with a bent bolt in the plug adapter, thats inserted then, you turn the bolt so the bent part is facing down and the lock it with a outside nut, can be custom made but bend the bolt so you can have the screw slot aligned with the bend as it helps you get it indexed.
[/color]Id also label BOTH ends of each ignition wire, any decent label maker can produce sticky number tags far cheaper that the kits but even the kits are cheap
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viewtopic.php?f=50&t=6098&p=18837&hilit=label#p18837
3M sells these really handy number tape tags

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http://www.clarcorpindustrialsales.com/ ... -p/wmd.htm
[color=#FF0000]at about $30- $45 for a fully loaded dispenser it seems expensive but its really a bargain


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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Site Admin
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Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida

Re: finding top dead center #1 for timing ignition & cam

Postby grumpyvette » December 23rd, 2011, 2:26 pm

Hey grumpyvette?
I had to buy an adjustable timing tab for my new 8" balancer. So I used a degree wheel and found TDC (0* degrees) and pointed the red arrow in the picture at it. However, the white 0* mark on the balancer doesn't match the true 0*on the timing tab ?. Should I etch a new line on the balancer at the true 0* mark and paint black over the existing timing marks, as you can see the damper is about 4 degrees out from the timing tab arrow?

Any help would be appreciated.


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the REASON you have an adj pointer,is that it allows you to move the red arrow pointer to point to the TRUE ( 0 or TDC) on the damper, so obviously in this case the timing tab red arrow gets moved about 4 degrees to make the lines on the damper, arrow and reality match, it makes no real difference if the dampers a few degrees off provided the timing tab used is matched so it shows exactly the correct timing, theres no need to mess with the damper; just set the pointer to point at the 0° mark on the damper when the piston is at TDC.

the marks on the cheap stamped metal tabs are rarely correct
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the arrow adjusts to show reality using the marks on the damper
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KEEP IN MIND that theres TWO totally different damper and timing tab locations that are correct on the SBC engines and you must use matched components for almost all years the ting tabs and dampers show TDC to be at about 2 o,clock, but theres a few applications that used a 12 o,clock timing tab and damper combo and you can,t mix&match the two types

if you find having the timing tab marked distracting you should use an adjustable pointer like this one below
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while you have the engine on an engine stand with the heads off ,and having the correct crank snout adapter and a decent degree wheel and a stiff coat hanger wire makes it easier to locate TDC

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IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Site Admin
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Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida


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