engine question

[hobsiscool]

Help me diagnose...truck starts fine, runs fine, doesn't seem to be leaking anything...i had the carb rebuilt, but now that I got it back, it makes a clacking noise while running....runs and idles strong and smooth, but loud noise....if you give it gas it smokes a TON, doesn't seem to really smoke a lot while idling...HELP

[stump]

what color is the smoke? white,black or blue

[westie 666]

I may be way off here, but the people who did your carb may have dropped some thing down the intake like a washer or nut.

[hobsiscool]

who knows if he dropped anything, if he did i'd be pissed to say the least....the smoke is grayish in color...any ideas?

[Corts60]

Man this is weird! I just did the same thing this morning on my pick-up. I built a new carb and put it on and then after a couple minutes a crap load of white smoke and a bunch of clattering. I must have dropped something.

Best of luck to you, I would take it back!

[DB Smith]

Originally Posted by westie 666

I may be way off here, but the people who did your carb may have dropped some thing down the intake like a washer or nut.

That's a scary thought, but it's possible. That would be loud. It sure will be a ***** to pull the manifold/heads to find out.

Whitish/gray smoke usually means you're running too rich.

You might be able to narrow down the source of the noise with a sethoscope.

+1 on taking it back. If it was fine before and it's clacking now, I'd get it back to them and have them check it out before too much time passes and they blame it on you.

[joe231]

if something was dropped, it should sound something like popcorn popping, kinda sporadic......

[hobsiscool]

this isn't a popcorn sounds, it's a more constant noise...any more ideas?

[1BadC10]

Noise could be a loose rocker if the frequency of tapping increases/decreases with engine RPM. Improper air/fuel in combustion chamber may result in improperly burned fuel exiting exhaust... possible explanation of gray-ish smoke.

I'm no certified tech, so please correct me if I'm wrong.

[grinch4om]

something like a washer in the cylinder can bust a piston. pull the plugs and look at them, chances are if anything is in the combustion chamber, it has slapped the plug tip a time or two

[Cherub]

is it detonating?

[hobsiscool]

I don't think anything was dropped, but the loose rockers sounds like a possibility...is that an easy fix? Pop the valve cover off and tighten or more in depth?

[DB Smith]

More in depth.

You can do it with the engine running. Make sure to get it up to operating temperature first. Then pull one of your valve covers, You can get a set of clips at pretty much any auto parts place. They will keep it from spewing oil all over the place. If you have an old set of covers they can be cut to keep the oil under control. Do one bank at a time.

Do one rocker at a time. Loosen the rocker nut until you begin to hear it clatter, then slowly tighten until the clatter just goes away (that's about 0 lash. Then tighten the nut 3/4 turn. Then move on to the next one, and the next, an so forth.

Check out this video....

YouTube - Sin Wag'n small block Chevy valve...

If you have "Cool Nuts" you will need an allen and a box end to do the adjustments and lock them down..




The valves can be done cold too. I only do it this way on a new build on the engine stand.

0 deg TDC on #1, both number one valves shut. Adjust each push rod on the first list to zero lash (barely able to spin it with you fingers) then tighten 3/4 turn

Adjust the #1 exhaust valve
Adjust the #1 intake valve
Adjust the #3 exhaust valve
Adjust the #5 intake valve
Adjust the #7 intake valve
Adjust the #2 intake valve
Adjust the #4 exhaust valve
Adjust the #8 exhaust valve


Now rotate the engine 360 degrees. The mark on the balancer should be back at the TDC mark. Keep in mind that this is not the TDC where #1 would be firing! It's where #6 would fire. Adjust each push rod on the second list to zero lash (barely able to spin it with you fingers, then tighten 3/4 turn

Adjust the #3 intake valve
Adjust the #5 exhaust valve
Adjust the #7 exhaust valve
Adjust the #2 exhaust valve
Adjust the #4 intake valve
Adjust the #6 exhaust valve
Adjust the #6 intake valve
Adjust the #8 intake valve