X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Jan 2006 01:44:01 -0500 Message-ID: X-Original-Return-Path: Received: from web34902.mail.mud.yahoo.com ([209.191.68.181] verified) by logan.com (CommuniGate Pro SMTP 5.0.6) with SMTP id 928917 for lml@lancaironline.net; Mon, 16 Jan 2006 17:19:55 -0500 Received-SPF: none receiver=logan.com; client-ip=209.191.68.181; envelope-from=n103md@yahoo.com Received: (qmail 5243 invoked by uid 60001); 16 Jan 2006 22:18:41 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=BpeuEn3y54kP5233yYPk6bHR/PNygaIXPewdMeKxPJX1aI2Zj+93sYmTIfXVp82bvF8hD8xvvvIa7DhbD70X+jw6k02Gzo5vrmCxeifwdcdupucROXp3euAcGQPo4TnJ8VmFXuwTk6ugfQwel+OJb/Sd0Vs9mDLQ9zTsXlfNbBQ= ; X-Original-Message-ID: <20060116221841.5241.qmail@web34902.mail.mud.yahoo.com> Received: from [12.146.139.19] by web34902.mail.mud.yahoo.com via HTTP; Mon, 16 Jan 2006 14:18:41 PST X-Original-Date: Mon, 16 Jan 2006 14:18:41 -0800 (PST) From: bob mackey Subject: Re: [LML] Re: Porting and Polishing X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-550547425-1137449921=:2744" Content-Transfer-Encoding: 8bit --0-550547425-1137449921=:2744 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit > Tom said, > V2 = V1 * cube root ( 1 + delta HP/ HP) > Is that cube root (1+ (delta HP/HP)) > or ((1+delta HP)/HP) Depends on whether DeltaHP = HP2 - HP1 or the other way about. Easier to avoid confusion this way: V2/V1 = (HP2/HP1)^1/3 or (V2/V1)^3 = HP2/HP1 The majority of the advertised HP increase for the IO-360 (from 180 to 200 HP) would be due to the compression increase. If the compression ratio before was 8.0:1, then increasing to 10.5:1 would raise the HP output (for the same air/fuel input) to 194 HP. see for example: http://www.bgsoflex.com/crchange.html The HP gain from porting is harder to predict. Basically it depends on how bad the ports were before modification. There might negligible gain in power, but some improvement in smoothness by making all four cylinders the same. There might be 5-6 HP gain for "free" by simply measuring the engine on a dyno. The LyCosaurus specs for power output refer to the *minimum* power output for an engine off the production line. The average engine has a few HP more than the worst engine. --------------------------------- Yahoo! Photos Got holiday prints? See all the ways to get quality prints in your hands ASAP. --0-550547425-1137449921=:2744 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: 8bit
> Tom said,
> V2 = V1 * cube root ( 1 + delta HP/ HP)

> Is that cube root (1+ (delta HP/HP))
> or ((1+delta HP)/HP)

Depends on whether DeltaHP =  HP2 - HP1 or the other way  about.

Easier to  avoid confusion this way:

V2/V1 = (HP2/HP1)^1/3

or

(V2/V1)^3 = HP2/HP1

The majority of the advertised HP increase for
the IO-360 (from 180 to 200 HP) would be due to
the compression increase. If the compression ratio
before was 8.0:1, then increasing to 10.5:1 would
raise the HP output (for the same air/fuel input)
to 194 HP.

see for example:
http://www.bgsoflex.com/crchange.html

The HP gain from porting is harder to predict.
Basically it depends on how bad the ports were
before modification. There might negligible gain
in power, but some improvement in smoothness by
making all four cylinders the same.

There might be 5-6 HP gain for "free" by simply
measuring the engine on a dyno. The LyCosaurus
specs for power output refer to the *minimum*
power output for an engine off the production line.
The average engine has a few HP more than the
worst engine.




Yahoo! Photos
Got holiday prints? See all the ways to get quality prints in your hands ASAP. --0-550547425-1137449921=:2744--