Dead Cylinders

[Taylorman]

Today i discovered that i have two cylinders that are dead at idle.Number 1 and 3 are no worky. Basically i noticed that the left exhaust sounded different from the right. Its obvious that the left side of the engine is not firing on all 4 holes. When i would rev it up it would clear up. My buddy said he thinks its either the carb or the valve not adjusted right. I switched plugs and plug wires around and same thing. The engine has been not been run most of the summer and the carbs have been sitting. I have dual carbs on a tunnel ram. Im thinking it may be the left side of the front carb not getting fuel to 1 and 3 cylinders. My second thought is rocker arms not adjusted right. Could this cause my problem. I just put on a new set of roller rockers. This is my first time dealing with adjustable rocker arms. I think i installed them and adjusted them correct. Adjusted them till no slack and then another 1/2 turn. Im going to readjust the valves and see it that does anything. If not, i will pull the carbs and go through them. Any other possible solutions would be appreciated.

[Squirtin Thunder]

Today i discovered that i have two cylinders that are dead at idle.Number 1 and 3 are no worky. Basically i noticed that the left exhaust sounded different from the right. Its obvious that the left side of the engine is not firing on all 4 holes. When i would rev it up it would clear up. My buddy said he thinks its either the carb or the valve not adjusted right. I switched plugs and plug wires around and same thing. The engine has been not been run most of the summer and the carbs have been sitting. I have dual carbs on a tunnel ram. Im thinking it may be the left side of the front carb not getting fuel to 1 and 3 cylinders. My second thought is rocker arms not adjusted right. Could this cause my problem. I just put on a new set of roller rockers. This is my first time dealing with adjustable rocker arms. I think i installed them and adjusted them correct. Adjusted them till no slack and then another 1/2 turn. Im going to readjust the valves and see it that does anything. If not, i will pull the carbs and go through them. Any other possible solutions would be appreciated.
Yes !!!

[Moneypitt]

The tunnel ram is open under the carbs so I doubt that is the problem. Since it worked ok prior to the rocker arm change that is the area I would go back to 1st....And since the exhaust sounds different on that side, maybe the exhaust lifters pumped up. (You do have hydrolic lifters, right?) If you are pulling plug wires to find the dead holes, beware, that doesn't always work. I've found a wet rag held over the header tubes and squeezed on each tube will quickly tell which tubes are hot, and which tubes are warm.....sizzle/no sizzle....How did you go about adjusting the valves?............MP

[Tahiti350]

Could also have lost the head gasket between 1 & 3. Compression check is in order if the rockers aren't the problem.

[OMEGA_BUBBLE_JET]

just a thought here........you did adjust the rocker arms with the individual cylinders at TDC with both valves closed right :hammerhea If not that is probably your problem. Just in case you didn't you need to start on the #1 cylinder and bring it to TDC with BOTH valves CLOSED. set that cylinder and then rotate the crank 90 degrees, you are now at TDC on #8 repeat process rotating crank 90 degrees for next cylinder in firing order, etc.
Omega

[Foggerjet]

check the compression. It tells alot and is very easy. If I don't see an obvious problem i.e. plug wire burned in half. That's the first thing I'd do.
fog

[Tahiti350]

When I was running circle track cars, I found that adjusting valves with the cylinder at TDC actually put the lifter on the lobe ramp with the cams I was running (BMF's), and found TDC was not working for me. This is a good way to remember how to lash them:
Exhaust opens adjust Intake/ Intake closes adjust Exhaust
This puts the lifter on the back side of the cam, and you just bump the motor over to set the valvetrain in the right spot, bump to the next valve, then spin it until the next cylinder is set up. No following firing order, trying to remember where you were at before you got interupted, Etc. Work down one side then the other.
If you are running a big solid cam set it at TDC then check it as above and you'll see the difference, but this also helps when you are setting hydraulics, pull each rocker down until the push rod snugs SLIGHTLY (contact), then another 1/2 to 1 turn depending on your prefered lash setting. Have never had a problem since I started doing it this way.
Hope it helps.
Tahiti350

[Taylorman]

Im going to readjust the valves tonight and see. When i set them they did not have any oil in them so they were soft. I did the best i could to put 1/2 turn of pre load. They way i set them was with the intake full open, set the exhaust and vis versa. I will go back and set them with the EO/IC. I had the intake off when i set them before so it was easy to see where the cam lobes were. Now with the intake on, i wont be able to see where the cam is so the EO/IC seems like the easiest way to do it.

[obnoxious001]

If you set the exhaust with the intake open, that should end up being your problem. Going back and properly adjusting the exhaust valves should clear it up. Good luck.

[OMEGA_BUBBLE_JET]

Im going to readjust the valves tonight and see. When i set them they did not have any oil in them so they were soft. I did the best i could to put 1/2 turn of pre load. They way i set them was with the intake full open, set the exhaust and vis versa. I will go back and set them with the EO/IC. I had the intake off when i set them before so it was easy to see where the cam lobes were. Now with the intake on, i wont be able to see where the cam is so the EO/IC seems like the easiest way to do it.
for future use I always take a small bowl and fill it with oil and submerge the hydraulic lifters in the oil and take a pushrod and 'pump them up' just prior to install.
Omega