How high it will rev (with power) will depend on what components are in the engine (or the "combo")- the cam's duration (the amount of time the valves are open) controls the rpm range or "powerband" and the other components (carburetion, porting, valves and exhaust) all have to be sized to produce power in the rpm range the cam will run in. Of course, depending on displacement (size of the engine), components (carbs, heads, exhaust) that allow a smaller engine (eg- 1776) to rev with power to say, 7,000 rpm would only rev to about 6,000 rpm in a substantially larger engine (2110). I'm simplifying this somewhat, of course, but let's keep it easy to understand....
Even a mildly built VW engine with dual carburetors should rev to 5,000- 6,000 rpm with power, depending on the combo. Next time you're out with your car, try revving it (in 3rd gear) and note at what rpm the power seems to "peak" or run out of steam. It will rev higher than this, but in 3rd gear you should feel a definite peak to the powerband. It will rev fairly quickly to this point and then go higher, but you'll feel it slow down after it hits peak rpm. And give yourself some room on an open road; this is not something to attempt in traffic....
After you figure out peak rpm, this is the point you can rev to OCCASIONALLY; for normal traffic still use 3500-4,000 rpm as the shift point most of the time, but when you want to play, now you know how high you can go. Remember, revving it past the powerband's peak doesn't make the car any quicker (it will actually be slightly slower) and since the engine won't be built to go past that point, doing it on a regular basis will be very hard on parts. Also, engines that spend a lot of their time at or near redline don't last very long. Al
Do you have any information (cam, carbs, valve sizes and porting, exhaust) on what's in the engine?
