jjlabinski

Hi folks, Can anyone tell me if an engine will run if the cam is 180 out? If so what would I be experiencing to indicate such condition? Also, how do I find top dead center with heads on engine? I bought a spark plug hole piston stop but the piston doesnt hit it. I have sportsman II angle plug heads thanks in advance for your help Jeff

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Ain't nothin' but a thing!

danandamy

Well, you really can't get the cam 180 out. If you put it together with the timing marks 180 out (tdc exhaust stroke instead of compression stroke), as soon as you rotate then engine one full turn everything is where it needs to be. Now if you put the distributer in with it on exhaust stroke instead of compression, then the distributer will be 180 out and no, it won't run. If you are trying to find exact tdc it's just about as easy to pull the timing cover off and line the marks up. If you are just wanting to check and be sure you're not 180 out on the distributer, you can actually pull the valve cover off and bump the engine around and watch the valves open and close. After the intake valve opens and closes and you hear it hiss out of the spark plug hole (spark plug removed of course) you'll be in the ball park. It's not exact by a long shot but you can look at your rotor position with your distributer cap off and it will be real obvious if you're 180 out. Hope I explained that all well, it's been a long day. Good Luck.

Dan

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86 Camaro tired 305 low output only heaven knows how many miles on it. Lunati cam, Edelbrock torquer intake, Holley 670 Street Avenger Carb, Hei distributor, Headman headers, 373 gears, lock rite locker, shift kit, 2500 rmp stall converter. Best 1/8 mile time so far: 8.89

midwest

Yes, in fact most people setup the cam 180 because its easier to align the marks that way then the correct way.
The correct way would be to have both the dots on the cam and crank sprocket to be at 12:00. Most people have the cam at 6:00 and the crank at 12:00. It realy doesnt matter once you put the chain on. Just turn the crank a full turn and both marks with be at 12o turn the crank another full turn and it will be 6:00 and 12:00.
Do not confuse this with installing the dissy 180 off.

How to find tdc.
Pull the valve cover for the bank that has #1 cylinder. Turn the crank so the balancer groove lines up with the timing pointer and so that both vavles are closed. You should be able to spin both push rods easiely.

jjlabinski

Thanks for the reply's!

One more for ya how would it run if I was 1 tooth off either direction on my chain?

thank you

Jeff

Damon

If the DISTRIBUTOR is off by 180* it will NOT run. It will merely "sneeze" out the intake occasionally when you're trying to start it.

AlkyIROC

The cam can never be 180* out. It's easier to line up the timing marks when the marks on the crank gear are on the top and the cam gear marks are on the bottom. This just means the #6 cylinder is at TDC of compression. Rotating the crank 360* puts the #1 piston at TDC of the compression stroke.

The cam can't be 180* out but the distributor can be if you drop it in pointing to #1 cylinder when the cam is at #6 cylinder.

As for finding if #1 is at TDC or not, you can simply look at the timing mark on the balancer. When lined up it will be #1 or #6. With the rocker covers off you can see which valves are opened or closed. #1 or #6 will be loose and the other set will be tight. You can also take out the spark plug and put your finder or the end of a screwdriver over the hole. Bump the engine over. When a puff of air tries to escape, look to see where the timing mark on the balancer is. If it's past the zero mark, you've gone past TDC. If it's coming up to the zero, bar the engine over until it lines up.

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jtrescot

I have seen one off by 1 tooth, but I can't remember which direction it was off. The engine ran, and was able to move the vehicle, but it had VERY little power.