How long before an engine rebuild?

I was wondering how long (miles) before a speedster engine would require an engine rebuild. I heard that some really tuned VW motors may be 9000miles before it needs rebuilding (I'm not sure if he was B.S.ing me or not) Anyways, What are your experiences with your motors?
thanx
DeanK

A high performance type 1 engine will probably need a valve job somewhere between 30,000 and 50,000 miles depending on the cam specs and how you drive the car.

If you run a really radical cam the engine case may need to be dismantled and the lifter bores sleeved.

There is no simple answer; mild performance engines can go 100,00 miles when properly built, driven, and maintained.

Every VW motor I've owned needed a top end rebuild just before 50,000 miles the first time, and both the top end and case just before a 100,000 miles. I drive them hard and maintain them well. Yes, the heads are big valve and the valve springs are double wound. And yes, they see 5,500 RPM every week.

Thanx George,
Thanx Jack,
My driving habits are more like Jacks, 5,500rpm is pretty much the norm. I do alot of highway driving at about 120-150kph (65-95mph)and little city driving. Hard on the gas at lights, and exiting corners, but some days I love to just putput around the area, Is there any recomendations 1.which type of engine
2.will they be (almost) bullet proof for this type of driving
Thanx again
Dean Kats

Then it might blow in the first 4K.

Signed,
Parts is everything
Now on #2 with 18,000 miles and running great.