Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site ncr-tp.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxj!houxm!whuxl!whuxlm!akgua!sdcsvax!sdcc3!sdcc6!ncr-tp!goodwin
From: goodwin@ncr-tp.UUCP (Tom Goodwin)
Newsgroups: net.auto
Subject: Re: Having your cake and....
Message-ID: <138@ncr-tp.UUCP>
Date: Tue, 5-Mar-85 19:47:25 EST
Article-I.D.: ncr-tp.138
Posted: Tue Mar  5 19:47:25 1985
Date-Received: Fri, 8-Mar-85 04:53:15 EST
References: <367@wjvax.UUCP>
Organization: NCR Corporation, Torrey Pines
Lines: 46

> There's something that's starting to bother me about the
> super high output fours, such as the turbo daytona, etc.
> Are these machines reliable?  Gives me pause to think 
 ... 
> I buy cars to keep, not to get rid of in 3- years.  Seems to me
> that a medium tuned normally asperated V8 will have a chance of
> hitting the big 100K, where the *comparable output* super high
> performance turbo'd four banger will die a horrible death in a
> short time.

   I think there are several factors in reference to getting reliability
   from a *performance* engine beyond the question of original design.

I haven't seen many cars with 4-cyl engines that will run the miles an
american V8 will without requiring major work(my own BMW 2002-190K and
never had the head off, is an execption).  I think long term wear can  
be related to how much of the power of the engine you use.  An example
would that in typical driving you use about 25% of your V8's available
power while the typical four is putting out 40-50% of its power.  The
V8 loafs its way through 95% of your driving while having the power the
5% of the time when you need it(depends on how you drive).  Few american
or japanese cars would last a thousand miles if they were driven flat
out.  Car&Driver magazine had an interesting article about trying to 
reach 200mph with a turbo 350 firebird.  Even though thier engines were
built by a shop that hadn't had trouble with turbos before, they went 
through about 4 engines before they got one to last to 200mph.  Very 
few people get full power out of an engine for more than 10 seconds.

If a turbo four is designed to withstand the short term stresses and
is not mistreated, it should probably last at least as well as a non-
turbo four.  The turbocharger itself is of course a reliability problem,
but there have been a lot of improvements in the technology lately. 
The turbo engines actually run lower compression ratios than the non-
turbos, and so have have less stress during cruising conditions.  Some
people have only two speeds, on and off, but for the rest of us who put
a lot of miles in traffic where the speed is limited don't use the power
often.

I don't think the reliability of any of the general run of fours will
be equal the the good V8s though, especially if loaded heavily.  That's
why I'll keep my 289 for one of our cars and rebuild when necessary.
For a commuter car which can also be fun to drive, however, the turbos
look good.

				Tom Goodwin