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<x-charset iso-8859-1>Interesting... this goes to the archives. Couple questions though: 1) Berg cannot be totally off the wall as he has built alot of very powerful and durable engines and Im very happy with the HP output, gas mileage and running temp of my mere 1679. 2) Why does the best Muscle engine ever made (the Chrysler Hemi) use a hemi head with no quench area? 3) Why did Toyota use a full hemi head on thier older econoboxes? they got great gas mileage and ran pretty darn well! Keith Keith Park Top Notch Restorations topnotch@nycap.rr.com 71 Squareback 65 Notchback 65 Squareback 75 Opel 87 Golf 88 Rx7 10th Anniversary ----- Original Message ----- From: "Shad Laws" <shad@aircooled.net> To: <type3@vwtype3.org> Sent: Wednesday, June 19, 2002 1:31 PM Subject: Re: [T3] Compression Ratio Recommendations > Hello- > > I forgot a couple things in my previous post... sorry... read that first, > otherwise this won't make too much sense. > > Two other things that can lead to detonation: > - excessive cylinder temperatures. Like excessive pressures, if you are > running way too hot, detonation will happen. > - low octane gasoline. If you lived in 1940s Germany, before the > revolutions in petroleum cracking, then you needed a low CR to keep from > detonating. Same goes for parts of the world without quality gasoline, like > perhaps some parts of Mexico. > > The Type 3's had their CR dropped primarily so that VW had a bigger margin > of error before hell broke out. Between inaccurate fuel mixture, imperfect > manufacturing tolerances, customers pushing the engines too hard (a Type 1 > in stock form is NOT good for a constant 50hp duty) and getting them too > hot, the large variations of formulation in early unleaded fuels, etc., it > was difficult to push the engines to their limit without problems. However, > if you build the engine very carefully, tune the induction system's fuel > mixture well, remember that the stock engine will overheat if pushed all the > way all day long, use decent gasoline, and watch the head temperature, > running a higher CR is just fine. I wouldn't recommend 13:1 any day of the > week, but 8:1 or so is fine. If you are modifying the engine, then > depending on your combination of parts, more *might* also be acceptable. > > Take care, > Shad Laws > LN Engineering - Aircooled Precision Performance > http://www.LNengineering.com > > > ------------------------------------------------ > To unsubscribe, E-mail to: <type3-off@vwtype3.org> > For more help, see http://vwtype3.org/list/ > ------------------------------------------------ To unsubscribe, E-mail to: <type3-off@vwtype3.org> For more help, see http://vwtype3.org/list/ </x-charset>