Cams

Straight into a bit of controversy - most VW people put far too much cam into their engine.

Quite simple - the extra duration of  a "performance cam" is to allow for the inertia  of the mixture or exhaust to traverse the ports.

Mention the specs of a stock VW cam to a Ford guy and he'll think you are talking about a "sports cam."

Face it, the mathematics and science of fluid dynamics are known.It's a bit pricey these days (I run my old copy on an old OS on an old PC) but Performance Trends "Engine Analyser" can really open your eyes!  - doesn't matter how many cylinders engines have, the maths are the same! Engines are engines, guys.

Look at the originators of VW performance - it is possible to almost double the original HP of a VW engine whilst keeping the stock cam! Of course you will need ratio rockers, a decent exhaust, carbs, some headwork and maybe 88mm cylinders to achieve this - and your engine won't liive long, but it is doable. In such a configuration the engine can pull well to 6k or more, but the rotating assembly and valvetrain aren't really
up to it.

This is the Gene Berg/HTVHRVWs method - 85.5 bore, 69 stroke, stock cam with up to 1.5 rockers, good carb/manifold combo flowing about 250cfm, free flowing extractors and work the heads. Won't look so good "on the dyno" - i.e. the classic peak HP figure marketing guys love,but it will be a lot of fun to drive if you get it right - tons of torque when you need it, and just keeps winding when you want it to!

Eventually it would run out of puff and the easy fix was tofit a cam with longer duration - ever noticed the popular Engle cams are advanced 4 degrees, almost the same as the stock cam?

Trouble is; your valves  are floating, your crank is pounding your centre main and everything is running a bit
hotter than what is healthy.

But shoot - guys put 50,000 MILES or more on those things, and had a lot of fun doing it!  you're wondering what my problem is, right?
 
Trouble is then, even more than now, good heads were expensive, so the easiest and cheapest way to get more power (or at least peak power) was to fit a wilder cam. So we have a world where 300 degrees at 50thou' is considered by some to be "streetable!"  Think about it - a full revolution (two strokes) is 360degrees -where the heck is your induction  or compression going to occur at any normal engine speed?

I  love drag racing as much as the next guy, but it's not the same world as any kind of driving on the road.Top Fuel guys admit the actual parts are all off the shelf, according to the rules - races are won by fuel delivery (they use mechanical injection,)  clutch setup (a multiple plate setup - no gears,) a little bit of suspension/tyre setup and quite a bit or driving.  But let's face it - these engines can't idle as we know it, and have no useable torque in the range we use!