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Re: [turbobike] Re: SOHC Honda headgasket problem

Joe Allan (beak@seaside.net)
Thu, 20 May 1999 15:56:58 -0700

John and fellow listers;
 Good info John, thanks, I didn't mention it in my original posting but I am
running a 50/50 mix of gas/ alcohol in the supercharged SOHC, I would run
100% alcohol but the internal passages in the carb are too small to
accommodate that much flow (suck through system, bigger carb coming), my
thinking is that the alcohol will help the detonation problem. I run the
timing at the stock advance setting...is this ok?...thoughts, help
gratefully accepted.
 Joe Allan

-----Original Message-----
From: John C Williamson <john.williamson5@virgin.net>
To: Bob Shammas <b.shammas@worldnet.att.net>; Rick <gsxr1100@ptw.com>; Turbo
list <turbobike@natvideo.com>
Date: Thursday, May 20, 1999 3:45 PM
Subject: Re: [turbobike] Re: SOHC Honda headgasket problem


>After thinking about this for a bit I think that the main reason that coper
>gaskets 'go' as such (apart from the oil seep / cappiliary problem) is that
>the head may 'lift'. The PEAK cylinder pressure goes up enormously with
>ignition advance but power output may only increase marginally. So if you
>have clamping / barrel stud strength problems causing you to blow gaskets
it
>makes much sense to reduce full advance to a lower figure, and up boost
>instead, producing less peak pressure but more where it counts ie, later!
>when the crank is in a better or more advantagous position to take
advantage
>of the increased cylinder pressure to produce more torque from less
>pressure. I suspect most detonation / pre-ignition / head gasket probs are
>caused by too much advance.
>This is one of the reasons that Nitrous does not seem to cause detonation
>and head gasket probs as often, because it is inert (and can put out
fires!,
>like C02 does!) and only breaks down into Oxygen & Nitrogen (most of the
>atmosphere - and does not support combustion) LATER in the chamber as it
>takes time for this to occur. Just the same as less advance really.
>
>So basically if you want to go fast safely, go rich - less advance - and
>loadsa boost and Nitrous and you will not break the engine.. look for black
>smoke (a little!) and anything that sounds harsh or 'pings' (you cannot
hear
>it on a bike...) nedds less advance... This will still blow gearboxes /
>clutches etc,  even more so in fact but the motor should be OK without
>expensive parts.
>
>I welcome your coments (Rick?) , anybody!
>
>JOHN WILLIAMSON