Ever since I had the Vortec 5.0L/305ci V8 in the Monte Carlo, that engine has always had this loping, sluggish lethargic demeanor about it. It would start up real fast but when you accelerate it, it would show just how gutless it really was. In some way it seemed like it was out of tune. In other ways it seemed like there might've been something internal that was failing. Well I had the theory that maybe I need to check the camshaft to see if there's any compromise in the lifters or the camshaft itself as it just seemed like one or more cylinders wasn't cycling properly.
Of course to do this required me to tear the front of the engine completely apart. We're talking about all the accessories, intake manifold, valve covers, timing cover, even the oil pan would have to drop some. This is a job I've done before during a time when it wasn't critical to get the car back on the road because it would take at least a couple of days to get things done. Getting started I pulled the radiator from the car and got all the accessories removed. Since I installed a newer serpentine belt system, the accessories were bundled into two large brackets holding everything. After removing the belt and a few bolts and disconnecting some hoses, I had the front of the engine opened up. The timing cover was quick to remove as it only required the removal of a few small bolts. The harmonic balancer had to come of first but was removed quickly with a puller, all of which I'm thankful to have on hand. As I continued to pull things free I was starting to amass a pile of parts. Some of the parts I wasn't too concerned with leaving outside in case it rains as they weren't super critical. Things like the harmonic balancer had to go under cover as I did not want the surfaces of the shaft where they contact the front seal of the timing cover or where the shaft slides over the crank shaft, need not get any surface rust on them otherwise they could make reassembly difficult and could result in premature seal wear. Those items and things like the distributor went in the trunk. I pulled the distributor without checking where the rotor was pointing or setting top dead center since I would end up moving things around quite a bit before everything is said and done. Plus I would want to re-seat and re-time the distributor anyway as part of reestablishing the tune of the engine. As stated before, that went in the trunk. I had to pull the dizzy out in order to pull the intake manifold, which needed to come out to access the pushrods and lifters. Valve covers would have to come out to access the rocker arms in order to pull the pushrods to get the lifters out. With the intake off and also stored in the trunk, since I didn't want the carburetor to take on water if it rained, I was able to loosen up everything to get out the pushrods and lifters as stated before. Upon pulling everything free, the lifters, which in a Vortec V8, are roller lifters, all looked in good condition. Pushrods were all straight as well. Other than the grime that was present in the tops of the cylinder heads around the rocker arms, everything looked the same as before, which was just old and used but not broken. After pulling the timing chain/gear set free I was able to remove the cap holding the camshaft in place. Upon examining it, I found no sign of wear on the lobes that would indicate a worn camshaft causing one or more valves not to open. After comparing it with the non roller cam I had, I found that the curvature of the lobes allowed for a longer duration of opening on the valves while still having about the same amount of maximum opening between the two cams. Obviously from the way it looks the Vortec camshaft should allow for better performance because of these conditions. With that I ended up just reassembling everything without actually replacing anything. In the process I did get to re-time the distributor and check the wires to make sure they were all in order, which they were. I did take time to do a little trick with zip ties for organizing the plug wires to help keep them off the headers or any other compromising surface. A zip tie is looped around every wire in the set on one side, then another zip tie is used to connect the two zip ties between the two wires. Another zip tie connects the other side of the 2nd wire with that of the 3rd wire and another for the other side of the 3rd wire to the 4th wire. After doing this I was able to at least neaten up the wires so they won't get damaged on anything hot. While this really didn't solve the mystery as to why the engine still runs sluggish, it did eliminate a critical component and part of the system, the valve train. The next move might be to put some more measuring equipment back on the carb to measure vacuum and even check the timing and try to set everything where it should be by the book then go from there. I may even put in a hotter coil and replace the plugs too, see if a hotter spark will do the trick. The carb was a recent rebuild and it doesn't leak or anything so I can't see that being a deciding factor, but it isn't completely off the table as far as something that may need addressing again. But until the next time, I can at least say for right now the Monte should be ready to hit the road again when the need arises.
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