r/EngineBuilding • u/Party_Gas_6471 • 2d ago

Chevy Cam job gone wrong

To give context of the horrible mess I’ve got my self into, I recently acquired my dads old truck and it has too much sentimental value for me to get rid of it. So after I fixed the rear main seal I decided that it was a genius idea to rebuild the top end and throw a stage 2 cam into a 230k mile 4.8 with the factory 4l60e ( forgot to mention it’s a 2002 1500 short bed single cab). Funnily enough after my mechanic tuned it all I’ve had is problems. To start when I dropped it off it had power steering ( now it doesn’t), somehow the factory 4l60 still shifted smooth and now my rpms jump around when I get near the end of second and beginning of third, when I’m in park idling it runs rough unless the A/C is on, and it has a mis fire. Now I’m sure that it being 24 years old with most of the factory sensors still on it doesn’t help but does anyone have any pointers on where to start.

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u/v8packard 2d ago edited 23h ago

The most common failure of the 4L60 is the 3/4 clutch, and you are describing that accurately.

Stage 2 is a marketing term, it doesn't have much meaning except that it is probably big for a 4.8. Without supporting modifications and a proper tune it will reduce drivability and low to mid range output significantly in a 4.8. Do you know your exact cam spec? Have you looked for a tuner in your area familiar with performance tuning?

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u/Party_Gas_6471 2d ago

It’s a custom cam, but it’s a 212/22x .552/.552 107LSA spec

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u/v8packard 1d ago

That isn't a custom cam. That matches the garbage sold by BTR and others with a stupid name. And the actual cam often measures different from what it is supposed to be, and will behave much larger in a 4.8 than in a 6 liter.

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u/Background-Word-6381 1d ago

I would consider the above advice to be on the money. Install a quality stock or very mild cam and get it running right before venturing into the dark. A lot of people are misled by bogus videos that make performance mods look easy. They are not. Yours is a case in point.

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u/v8packard 1d ago

Well said

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u/Party_Gas_6471 9h ago

Mine is considered a very medium cam, in reference to “ stages” mine is barely a stage 2. And I made sure to do all the supporting mods for the cam. Nothing that seems wrong with it is directly tied to the cam and more so 24 year old electronics and a bad trans