It does help that they only have to TURN LEFT!

A little more info dredged up:

"With unrestricted motors:
Previous to the 9500 RPM rev limit rule, NASCAR Nextel Cup engines were producing close to 900 flywheel horsepower. This is when they were spinning up to 10,100 RPMs. Of course, the best teams were making this horsepower, and the independent/small teams were a bit behind.
Here is an approximation of horsepower numbers produced over the years:
2004: 875 (or more) fwhp
2003: 840 fwhp / 750 rwhp
2002: 825 fwhp / 735 rwhp
1998: 750 rwhp / 680 rwhp

All of this data is based on post-race dyno testing posted on jayski.com. All of the teams tend to underestimate and keep their real horsepower numbers a secret (which is why most sites tend to say no more than 800 horsepower)."

I seem to remember reading some years back that they ran very high Comp ratios (15:1 on the restricted engines?) but didn't see this on web.

I don't really follow NASCAR but the engine development/technology interests me. On any NASCAR sites at present there seems to be lots of discussion around Toyota engines (which were let in last year) - seems they have a material BHP advantage.
Quite interesting to see that most of the forum comments I read seemed to be along the lines of "tough luck GM/Ford/Dodge, try harder/back to the drawing board" - I would have expected more parochialism and whinging.

The cost of competing in NASCAR is a moving and high-priced target. The teams carry an inventory of 15 to 20 chassis. Part of the COT was to minimize this inventory but you can't keep the guys from spending money. The chassis specs are just liberal enough to make the bigger teams go after that last little bit of performance that is afforded by running all of the dimensions to the minimums and maximums, stacking them up one way or the other to give the maximum performance at a given track. There is much less variance with the new car but it is still there.

Engines are impressive for what they are, even though they are purpose built race engines they are still carburetted 2-valves. I guess that the biggest reason that they still use the carb is the expertise that exists in Charlotte NC around them. The other thing that NASCAR is very against is any type of electronic aide to the driver. They currently feel that the Fuel Injection could hide some Traction control in various ways and they view that as bad.

The good thing about Nascar is that it has a controlled field. It takes a skilled driver to win the race, not a faster car. Auto Action recently did a price comparison between Nascar and V8 Supercars and the price difference to build them is austounding. All beit that Nascar is oval track and runs a steering box still but it is a budget sport believe it or not. A car cost approx $250K to build then maintain. V8 SC costs abou $1 Million to build them maintain. IT all comes down to the blueprints of the car build. V8SC are trying to make the cars more cost effective and reduce overheads to make it a more viable sport as it seems to be heading in the same way as the AFL.

I have a friend that raced NASCAR a while back he now roars around in a Mitsubishi Evo. The carb thing is a regulartory thing as is most of that class. I was astounded at the regs, the cars are all the same apart from body shape and badge work. I asked my mate, How are you supposed to win in these events? The answer was quite simple, Make the guy in front do something wrong! I couldn't see the point of that type of racing. It looked to take no skill at all! I was invited to a test weekend that changed my view. In two days of suspension tests he blew up 2 motors @about $20k each and 1 diff about $5k. It was an experience, old skool tech at its best. But no sport for the faint of heart, I had a couple of laps at no where near race pace and it was scary fun very scary fun. As far as skill goes, I didn't have enough. Battling that V8 monster that was hell bent on putting you into a wall was just pure nut-case, adrenalin junkie, death wish FUN!!! Don't ever want to do it again.

and fuel churns..
and 5 stud wheels..

358 cubes is around 5.8L?? thats of the top of my head you can convert it using a conversion table etc
probably use carbs for regulations or just cause you dont have the issue of the sensors/computer playing up
engine longetivity depends on a few things i spose the would strip it down completly after every couple of races or race and give it a rebuild check for stress etc i dont think you would want an engine of that expense to go bang

how many litres is 358 cubic inches?
why do the americans push on with carburetors etc. in nascar instead of more modern technology like fuel injection?
also how long does an engine have to last?
sorry for all the questions but i'm quite interested.

It comes down to the old saying
"They dont build them like they used to"

Yes I find NASCAR interesting too given the technology is comparable to our Datsun A series. Illustrative too of well over 100hp/litre from 2 valves per cylinder and carbureted.