[smitty454]

This post is a continuation of my last post "Thinking of Going Roller"

The chevelle started misfiring the other night and it sounded like a lobe going flat so.....

After removing the valve covers I noticed one rocker was very loose. I could probably fit a finger between the pushrod and rocker arm. The stud looked good. It did not appear to be coming out of the head at all. The nut did not look more loose than the others. So this led me to believe that a lobe has gone flat.

Well I removed the intake and inspected the lifters and they look fine. The cam lobes look ok too from what I could see. The only thing that did not look good were some pushrods. A few of them were scarred from rubbing on the guides. Is my geometry off?

Flat or not, im removing the heads to have them decked to increase the CR and stabbing in a roller.

Ill have the cam out tomorrow so we will see. And pics posted also.

 

[smitty454]

Well the cam is out and it looks fine! The lobes show the normal amount of wear. I did not notice anything out of place, which is awesome! I really wasnt up for taking the engine to the machine shop!

Im at a fork in the road now. I can either remove the heads and have them decked to up the compression. Or, I can leave them on and just put in another cam. Which brings me to my next question.

How much compression is there to gain by decking the heads? Is it worth it?

The heads are eddie performer rpms. As is, my engine has 9.7:1. I THINK the block was decked .10 but im not positive. Thats what my friend recalls when he had it done before I bought it from him.
Having the block 0 decked is not an option at this time.

 

[Ray Gasser]

Why do you want to increase the CR; is this a street engine?
What caused your suspected flat lobe and the excessive clearance in the valve train?
Food for thought...
Ray

 

[smitty454]

Why do you want to increase the CR; is this a street engine?
What caused your suspected flat lobe and the excessive clearance in the valve train?
Food for thought...
Ray

Raising the CR was suggested so I could run a larger cam to go with my 4.10s. Its is a street/strip engine.

I have no idea where the clearance came from. The cam is fine, the lifters are fine, the studs are fine, the pushrods are fine. The nut did not look like it was any more loose than the others, so I really have no clue.

 

[Tom Mobley]

rocker arm nut backed off?

 

[smitty454]

rocker arm nut backed off?

Thats what im thinking too. When I took off the valvecover it really looked like the nut was even with the others. It has the regular nut, no polylocks and they are new so I really wasnt anticipating them getting that loose.

Back to my orignal question. How much compression is there to gain from decking the heads? Is it worth it?

 

[bracketchev1221]

Milling the heads is not going to get you that much unless you mill the heads a bunch. Find out why the rocker was loose and put it back together.