What are the problems resulting from camshaft lobe wear?

001 of an inch of wear on the lobes can negatively impact your valve timing by as much as 3 degrees? This wear leads to loss of horsepower and fuel economy, among other problems. And that’s not even considering the impact of more extensive damage caused by mechanical interference or other serious issues.

What causes worn cam lobes?

Lobe wear is often caused by improper lubrication during installation. Use only the manufacturer recommended lubricant, which is generally included with the cam. This lubricant must be applied to every cam lobe surface, and to the bottom of every lifter face of all flat tappet cams.

Is the Chevy TBI 454 having Idle problems?

Recently rebuilt the 454 in my 1990 TBI Burb. I am having a terrible time with getting it to idle smooth. The engine has a little over 500 miles on it. I have spent countless hours going over the engine looking for vacuum leaks and believe every thing is OK on that front.

What happens when the cam lobe and lifter fail?

During this break-in time, verify that the pushrods are rotating, as this will show that the lifters are also rotating. If the lifters don’t rotate, the cam lobe and lifter will fail. Sometimes you may need to help spin the pushrod to start the rotation process during this break-in procedure.

How many inches of vacuum stock does a TBI use?

Hook it to all ports on that throttle body. When you get to the map port just move map to a different port on the throttle body. Typical TBI motor will idle with 20-21 inches of vacuum stock. Pretty much any of the cams I recommend or have listed on the website will pull at least 17-18″ of vacuum at idle.

Is the O2 sensor on a Chevy TBI new?

I took it to get smogged (Ca) and it failed (high NO). The tech said it would pass easily with a new cat. The old one was just 2 years old. About the only parts that aren’t new is the O2 sensor (replaced 2 years ago), the iac and the egr vacuum solenoid.

Why does a cam lobe miss at high RPM?

So a miss from a single, slightly flattened cam lobe will often start to go away as engine rpm rises and the lifter pumps up, but will probably reappear at very high rpm as the cylinder begins to once again starve for airflow. Engines with solid lifters may or may not experience low-rpm or idle problems.

How can you tell if you have bad lobe on your camshaft?

First, because there’s no reason not to, and it’s probably easier to access the top of the cam lobes than the valves. Secondly, because engines with VTEC-comparable systems won’t show a flat secondary lobe at the valve when you’re turning the engine over by hand.

What kind of fuel pump does a TBI 454 have?

Stock TBI 454 makes 230hp and 380tq so stock fuel pump is maxed out right off and a typical 454 will run better with a fuel pump upgrade even with stock chip. GAS MILEAGE. Always a big complaint with 454 TBI trucks. 90 and older is particularly bad and that is largely due to NO OVERDRIVE.