Timing problems

[calebw]

So i forgot about this website after fixing my house when a tree fell on it. Then around 6 months later now i got a new project and ran into trouble. I cant get my 1976 124 spider to fire its turns over and is getting gas. I checked the spark and its strong. My best guess is the valve timing is off and dont want to try to turn it over again untill im sure its right. Did i mention i heard metal on metal Any help would be a great help

[So Cal Mark]

yikes, the 76 is an interference engine so incorrect valve timing can bend valves. Turn the engine by hand, very slowly and stop if you feel any resistance. Line up the crank on tdc, then see if the cam wheels are lined up. If it's been sitting for awhile, are you sure it's pumping fuel?

[calebw]

I am getting fuel to the carb. I moved the piston to tdc and it is hitting a valve. I just cant get the valves timing right the marks for some reason arent correct with the haynes manual. Im not sure what to do.

[ventura ace]

Where are you? Maybe there is another Fiat owner in the vicinity that can assist.

If the valve timing isn't correct, you need to loosen the timing belt, remove it, set the engine to TDC and set the cam pulleys to their timing marks, then reinstall the belt. Your manual should cover this, be sure to read it carefully.

Alvon

[Fi8spider]

Ouch, you moved the piston to TDC and its hitting a valve. If you ran the motor in this timing position the bet is you have bent valve(s), it dont take much. The motor will probably run once you reset the timing but it will always run like a dog and fine tuning will be impossible. Good luck.

[So Cal Mark]

first, turn the engine away from tdc so that all of the pistons are down in the bores. Otherwise you will bend a valve in trying to time it. Then with the belt off, turn the cams so the marks align.

[calebw]

the timing is set to the haynes manual but i think the timing marks of wrong. what should the two front lobes look like when its set correctly?

[So Cal Mark]

if you are facing the motor, the #4 exhaust lobe will be about 1pm, the #4 intake lobe will be about 11pm. Maybe your cam sprockets are reversed? Do your cam gears have guards on them? The intake guard should be on the rear, the exhaust guard on the front

[calebw]

im pretty sure the cam shafts were put back in reverse (exhaust being in intake and intake in exhaust) by the previous owner inlight of the new information. does this mean i have to change them back and when you say #4 do you mean over the fourth piston or first?

[ventura ace]

#4 is closest to the firewall (rear of engine). If the previous owner swapped the camshafts, there would be no gear teeth to drive the distributor (unless both of your camshafts have gear teeth between #3 and #4 lobes). The intake and exhaust camshafts are pretty much identical, except for the gear drive for the distributor, which is normally only on the exhaust camshaft. The camshaft pulleys, however, are different, and need to be in the correct position as Mark explained. If swapped, your engine would not start up, and would probably blow and spit gas out of the carburetor.

If your timing was off at some point, and the valves struck the pistons and bent, you will need to take things apart to fix. Don't expect it to run if the valves have been bent.

Are you sure that the distributor is set up correctly? The rotor should be pointed to #4 position of the dizzy cap when the engine is positioned at the timing marks (look inside the dizzy cap for the terminals, not where the external wires are located). This is a common error, since most other engines I'm familiar with have timing marks set up for #1 piston.

The position of the aux shaft pulley is important, too, or else you can have a metallic sound from interference of the aux shaft lobe with the connecting rod. It should be at about 1:00 position when the rest of the engine is dialed to the timing marks.

Do you have a compression gauge to take compression readings?

Alvon

[calebw]

Thanks for the help i got it properly timed and checked the compression it was bad and since the rings have been replaced its not the piston. Now i need help with valves how do i replace them ive never done it before. Do i need any special tools and what should i buy exactly springs, factory spec valves, shims?

[So Cal Mark]

the cylinder head will have to be removed and disassembled in order to replace valves. The springs don't have to be replaced, but they should be checked for proper rate. Usually they have to be shimmed. Since you don't have experience with this job, I'd suggest you take the head to a machine shop after it's removed. They'll grind the seats and make sure the new valves are seated properly