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Top Dead Center

2K views 4 replies 3 participants last post by  68NovaSS 
#1 ·
How can u tell when engine is at Top Dead Center #1 Piston Compression Stroke?? The Engine is a 1978 Ford Pinto 2300 ovrhead Cam.

I am having trouble getting the engine to start-- I have tried numerous suggestions but it will still not start and seems to be getting hard for it to even turn over........

Any hel would really be appreciated

tks

Mike
 
#2 ·
Mike, pull the plugs, put your thumb over the #1 plug hole while someone turns the engine over slowly BY HAND. When you feel pressure escaping from the cylinder, start watching the pointer and TDC mark on your balancer or wherever the reference mark is on your Pinto. You're coming up on the compression stroke and when the pointer and mark are aligned you're very close to TDC, unless you've done something to the cam/crank timing gears or chain. When you're there, trace the #1 plug wire to the distributor cap, mark the side of the housing where the #1 tower is, pull the cap and see if your rotor tip is pointed at or near it. If it's not, chances are the distributor needs to be lifted, rotated and set back in to align things. Put it all back together and hit the key, leaving the distributor snug but movable to make a quick timing adjustment as soon as it starts to keep it running until you can do an accurate timing set. You may have to rotate the distributor a small amount back and forth to get it fired, but not much.

Uuummmm, don't lean over the carb, if the timing is far off you could singe things.....

Good Luck, Larry
 
#4 ·
Cylinders 1 and 4 are companion cylinders.
Remove timing belt, pull the valve cover, rotate the cam with a wrench until number 4 is on overlap then number 1 will be on compression, rotate crank till 1 and 4 are at TDC, pull distributor cap and get rotor pointing to number 1.
Reinstall the belt, put everything else back together, and start it up.


If you must rotate the crank of assembled engine always turn crank in direction of normal rotation. Going backwards is a good way to strip teeth off belt. Also much easier to turn over when plugs are out.
 
#5 ·
Well, with the timing cover off you should be able to see the cam and crank alignment marks. I don't know about the Pinto but most have a dimple or other mark on each that needs to line up. Also, some line up one at 6 o'clock the other at 12, some are both at 6 but whatever you have, they must be in line with each other. Do the thumb thing and when you start to feel the pressure escaping look at your marks. You know you're coming up on TDC on the compression stroke so keep turning the engine until they align and you're there.

If you want to be really back yard you can turn it until you feel the pressure then insert a thin shank screwdriver or something similar, let the piston push it up and when it stops moving up note the location of the timing gear, keep turning until it starts to move down slightly, then turn the other direction until you think you're about in the middle of the slack movement. Make sure whatever you put in the spark plug hole doesn't bind or jam in the cylinder! That should get you close enough to try a start moving the distributor a little until it fires.

This should get lots of laughs from some of the guys, but I doubt you have a positive stop tool you could put in the hole or a degree wheel that you'd also need to compute TDC correctly, and it's tough with the head on anyway.

As far as advancing the cam, you just remove the belt from the cam pulley and rotate it in the advance direction one tooth and reinstall the belt. Jmark can tell you the specifics for your car, most after market timing sets, the ones with gears and chains, have optional key-ways to advance or retard the cam, which moves the power band up or down the rpm range.

Have at it - Larry
 
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