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Re: [turbobike] Re: SOHC Honda headgasket problems ' et al'

Jeff Churchill (jcperformance@juno.com)
Fri, 21 May 1999 12:45:17 edt

  EXTREMELY  well put John,........

Jeff Churchill

J.C. Performance    617-06  Bicycle Path   Port Jefferson Station   NY  
11776    USA
tech:  516-928-6679  or  516-928-9863
website:     http://www.jcperformance.com/


On Thu, 20 May 1999 23:29:26 +0100 "John C Williamson"
<john.williamson5@virgin.net> writes:
>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
>----- Original Message -----
>From: Bob Shammas <b.shammas@worldnet.att.net>
>To: Rick <gsxr1100@ptw.com>; Turbo list <turbobike@natvideo.com>
>Sent: 20 May 1999 22:16
>Subject: Re: [turbobike] Re: SOHC Honda headgasket problem
>
>
>> I like the multi-layer steel head gaskets.  They probably don't make 
>one
>for
>> that application but I've found they seal compression very well 
>without
>> o-ringing (I either use Yamabond-4 or Gasgacinch as a sealer) and 
>tend to
>> leak much less oil than solid copper.  I still use solid copper for 
>my
>KZ/Z1
>> dragbikes (and put up with the oil seepage), but go for MLS anytime 
>it is
>> availbable for one of my newer projects.
>>
>> Bob
>> -----Original Message-----
>> From: Rick <gsxr1100@ptw.com>
>> To: Turbo list <turbobike@natvideo.com>
>> Date: Thursday, May 20, 1999 10:33 AM
>> Subject: Fw: [turbobike] Re: SOHC Honda headgasket problem
>>
>>
>> >
>> >----- Original Message -----
>> >From: Rick <gsxr1100@ptw.com>
>> >To: John C Williamson <john.williamson5@virgin.net>
>> >Sent: Thursday, May 20, 1999 6:25 AM
>> >Subject: Re: [turbobike] Re: SOHC Honda headgasket problem
>> >
>> >
>> >> I would try like john said but I use Yamabond on the head 
>gasket.
>> >> Silicone gasket sealer made things worse than nothing at all for 
>me.
>> >> If that doesn't work then try oringing the cylinder.
>> >>
>> >> Turbo Rick
>> >> 350HP Turbo GSXR1100 Street bike
>> >> Web Site  http://www.ptw.com/~gsxr1100/
>> >> Southern California Timing Association 1998 Fastest Bike of the 
>year
>> >> EL Mirage Land speed Record holder 204.626 MPH
>> >> E-mail gsxr1100@ptw.com
>> >>
>> >>
>> >> > Slightly more seriously, make sure that the gasget is well 
>annealed,
>> and
>> >> > that the surface of the head / block is FLAT and not polished. 
>A
>> >flycutter
>> >> > usually used to machine the surfaces leaves a 'machining' 
>pattern on
>> the
>> >> > surfaces. This 'bites' into the gasket and holds it into 
>position.
>Make
>> >> sure
>> >> > that the surfaces are fully degreased, and then use a SMALL (I 
>mean
>> very
>> >> > small smear!) smear of silicone gasket sealer (very thinly!) 
>around
>all
>> >> the
>> >> > bore edges, and oilways. This stops the capilliary effect that
>actually
>> >> > makes the oil penetrate under the gasket, which allows the 
>gasket to
>> >blow
>> >> > out of position. Try to get stronger studs as they probably 
>lift /
>> >stretch
>> >> > under boost.
>> >> >
>> >> > John Williamson
>> >> >
>> >> > ----- Original Message -----
>> >> > From: Joe Allan <beak@seaside.net>
>> >> > To: <turbobike@natvideo.com>
>> >> > Sent: 20 May 1999 06:13
>> >> > Subject: [turbobike] Re: SOHC Honda headgasket problem
>> >> >
>> >> >
>> >> > > Hello All;
>> >> > >   Just came back from trying out my supercharged 750 
>Hondamatic
>dirt
>> >> > > dragger, goes good but after the 10th run down the track the 
>copper
>> >head
>> >> > > gasket blew :-(  Pulling it apart tomorrow....any hints??
>> >> > >   Stock studs only allow 16 pounds torque.
>> >> > >  Joe Allan
>> >> > >  Vancouver Island
>> >> > >  Canada
>> >> > >
>> >> > >
>> >> >
>> >>
>> >
>> >
>>
>
>