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

[Moneypitt]

When adjusted for the 1st time with the intake off priming the lifter is not necessary. Just watch closely for the pushrod cup to depress ever so slightly. The spring will hold the cup to the top until you start to exert some pressure on it. .050 or so and you're done......MP

[GofastRacer]

the EO/IC seems like the easiest way to do it.
That is the only way to do it properly!..

[Taylorman]

Just got done re setting all the valves. I'll try to run it tomorrow to see if it makes a difference. I set them by EO/IC. Pretty easy. Thanks for all the advice. I hope that was my problem.

[Tahiti350]

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
FYI,
None of the lifter manufacurer's recommend "pumping them up" anymore. Better to pre lube the engine (run the oil pump with a drill) until you have oil pressure and oil at the rockers, roll the motor 90 degrees spin it again, repeat until you are back to the original position. Now everything has oil for startup.
Pumped up lifters give a false reading when lashing hyd lifters,adn can cause engine damage. Not to say you "will", but that is has happened.

[Tahiti350]

Just got done re setting all the valves. I'll try to run it tomorrow to see if it makes a difference. I set them by EO/IC. Pretty easy. Thanks for all the advice. I hope that was my problem.
Have you checked compression yet?? A blown head gasket between 1 & 3 would bleed compression at idle, but would build and start firing as the RPM's come up. Hopefully the valve lash was the problem, but......
GaryB> Tahiti350

[Taylorman]

I checked compression in all 8 cylinders and pressures were 150 to 160. I really dont think its a blown head gasket as i just had the heads rebuilt. Ive only run it at idle. Has not been in the water yet. Not to say its not possible, but highly unlikely.

[Tahiti350]

That's good news. Probably just the valve lash. Is this a Ford, or a Chevy? Ford numbers cylinders different (1-4 on one bank and 5-8 on the other) and if you wire the plugs like a Chevy it will miss on 2 cylinders right next to each other (you did put the plug wires on in the right order?- I've cross-wired and driven myself crazy). Just another thought.
GaryB> Tahiti350

[Taylorman]

Well i think it was a little fuel problem. I took my carbs apart this weekend and cleaned them good and blew them out with compressed air. Put them back together and it runs like a champ.

[Foggerjet]

That's good, Must have had a blocked Idle circuit that fed that corner. Makes sense with tunnel ram and 2 fours. Glad that's all it was.
fog

[Taylorman]

The other small problem i have is oil coming out of the dipstick hole in the block. Its not a whole lot, just a little dribble and enough to make a mess. Any possible thoughts on what is causing this. This is the first time ive had this problem. I just put the motor back together and it only has about 1 hr of run time.

[Foggerjet]

Is the motor vented properly, or is the oil level high? sometime crank windage can sling oil right up the tube.
fog

[Taylorman]

Ok, i have finally seen the light. I totally trust most opinion about how to adjust valves using the EO/IC method. Until now, i could not fully understand how that would work. I thought the overlap area was after the intake and before the exhaust. Thinking along those lines, when the exh starts to open, the intake would not be fully closed yet. After studying this picture, i see that the overlap occurs after the exh and before the int. Now that i see that i can totally see why the EO/IC is the easiest way to adj. valves.
http://carcraft.com/techarticles/116_0403_basic_10_z.jpg