Thread: Looking for another opinion. What is causing my backfireing.

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No i value your opinion obviously you know more about the subject then I do it's just frustrating. I have tried all these different ways to set the valves spending hours of time and no improvement I just wanna take my kid for a ride rather then wrench the same thing over and over again. Would be nice if there was a set in stone way to do it not 15 different ways to achieve the same thing.

Surely I don't want to ruin the new engine just blew thousands of dollars don't need to do that again.

I will check the distributor Tomorrow see about that and redo the valves one last time on the weekend with your proposed method of each cylinder threw the firing order. And if I can't get anything more then 11inches of murcury then that's it with valves I know at that point the engine just can not achieve any more.

Originally Posted by HDSBC

Would be nice if there was a set in stone way to do it not 15 different ways to achieve the same thing.

The method I gave you is the most foolproof method out there, it is practiced successfully by thousands. Most of the other methods assume the user knows not to apply too much pressure, which gets most into trouble.

Originally Posted by HDSBC

I will check the distributor Tomorrow see about that and redo the valves one last time on the weekend with your proposed method of each cylinder threw the firing order.

Notice on the method I gave you it instructs you to hold the rocker tip firmly against the valve stem, this assures there nothing pushing down on the lifter. Your trying to just take the slack out, not compress the lifter. You should be moving the push rod up and down quite a bit at the beginning with the rockers loosened, then tighten a little (remove the wrench each time so it doesn't put down), slowly gently with the up and down movement taking out the slack. This takes time, it's not a race, do it right and you'll never have to look back.

Originally Posted by HDSBC

And if I can't get anything more then 11inches of murcury then that's it with valves I know at that point the engine just can not achieve any more.

Low vacuum is just one symptom, by itself it may not be too concerning, however, combined with your other symptoms it certainly points towards the valves being slightly tight, and why I suggested backing off the rockers slightly to see if the vacuum comes up a little.

The best advice I can give you about hot rods, is learn to enjoy working on them, chances are you'll spend more time working on em than driving em.

OK so I had some time tonight with the young lad to do some valvetrain setup. I did exactly like what your pdf said even printed it off taped the indicator to the balancer and followed the instructions to a T.

I didn't start the engine ran out of time tonight before I could get the valve covers back on.

But what I did uncover was interesting spark plug colors
#1 black and dry
#3 Dark Brown Dry tip but wet threads
#5 Dark Brown Dry tip but wet threads
#7 Dark Brown completely wet tip and threads
#2 Dark Tan wet threads
#4 Black Dry tip but wet threads
#6 Dark tan dry
#8 Black completely wet tip and threads

I checked all plugs all seam to be firing fine and blue arcs.

I popped the distributor cap off and spun the rotor it can defiantly spin more then a 1/4inch with light pressure and springs right back to where it was. I would estimate more like 3/8ths of rotation. again with light pressure I was not forcing it.