From: ah335@cleveland.Freenet.Edu (Richard Banks)
Newsgroups: rec.autos.sport
Subject: [A.H.Henry@gdr.bath.ac.uk: Re: Honda RA168E (a.k.a. that '88 Honda engine) and fuel preheating]
Date: 7 Oct 92 18:36:30 GMT
Reply-To: ah335@cleveland.Freenet.Edu (Richard Banks)



    ================= Begin forwarded message =================

    From: A.H.Henry@gdr.bath.ac.uk (Andrew Henry)
    To: ah335@cleveland.freenet.edu (Richard Banks)
    Subject: Re: Honda RA168E (a.k.a. that '88 Honda engine) and fuel preheating
    Date: Tue, 06 Oct

    
    Hi Richard.
    
    I'm sorry about the delay in replying but I wasn't feeling very
    lucid when your mail arrived !
    
    >The article said that those engines had block made from a light Al-Si-Cu
    >alloy 2.0-3.5mm in thickness.  Today's 3.5 litre engines are made of
    >steel but they rev about the same as the turbos.  Why must they use
    >a stronger metal now?  Because more heat is generated?
    
    The turbos were revving to ~13,000 rpm at most whilst this years Renaults,
    Hondas and Ferraris are revving to 14,500-15,000+ max revs.
    
    The high boost Honda turbos were producing 900-1000 bhp with reasonable
    reliability.  Even with the funny fuels, this years Hondas and Renaults
    were only at or around 800 bhp.  They might have been more drivable without
    turbo lag and almost as quick, but they certainly haven't the same top
    end power as the turbos.
    
    I don't know about the choices of material.  Post a summary of the
    article to rec.autos.sport and see if anyone else has any pearls of
    wisdom to offer on the subject. It might be that they wanted the
    strongest possible metal for the size and that the extra weight of the
    cast iron was a reasonable trade-off.  Cast iron brake discs can be
    made with friction coefficients than carbon ones.  The main advantage
    with the carbon brakes is that they are about a half of the weight of
    the iron ones.
    
    The heat produced by an engine is proportional to the power output
    and to the efficiency of energy conversion.  
    
    I don't know whether the turbos were more efficient than today's engines.
    So I don't know which makes the most heat.  You should be able to get a
    reasonable idea from the sizes of the air intakes for a turbocharged and
    normally-aspirated car.
    
    >Also '88s turbo engine made less HP than todays 3.5 litre engines do.
    >Yet many critics say that if we still had turbos today, they would expect
    >to see alot more drivers hurt or killed.  How is this when the 3.5
    >litre engines make more HP?
    
    The temperature around the turbochargers and exhaust manifolds were much 
    higher for the turbos so fires were more common.  On the other hand the
    normally aspirated engines are a bit more drivable.  The problem with
    these sort of statistics is that there could be a massive accident at
    the next Grand Prix killing half a dozen drivers.  Would that suddenly
    make F1 unsafe ?
    
    There have been some improvements in circuit safety in the last few years
    and carbon fibre tubs are better at withstanding some types of impact.
    Its difficult to say how much safer particular rules have made the racing.
    
    
    Andrew