Re: [omc-boats] Re: omc-boats-digest V1 #581

----- Original Message -----
From: <lib1@...>
To: <omc-boats@...>
Sent: Tuesday, September 12, 2006 8:21 PM
Subject: Re: [omc-boats] Re: omc-boats-digest V1 #581

Simple...Chevy rules

. "Wierd thing is why did the Ford 302 only make 175
> and 190 hp when the Chevy 307 is 210-215-225. There just shouldn't be that
> much difference in my mind."
>
>

>
> ----- Original Message -----
> From: "Thomas Klauber" <tklauber@...>
> To: <omc-boats-digest@...>
> Sent: Tuesday, September 12, 2006 7:18 PM
> Subject: [omc-boats] Re: omc-boats-digest V1 #581
>
>
>> In 1971 the auto guys changed horsepower ratings to accomodate emissions
>> etc on the new cars and that changed the HP ratings however the numbers
>> went down, I think as they were reporting netHP with all things attached
>> rather than raw HP as had been the previous. I remember some of this as I
>> used to hang around Corvettes in the 70s and 80s. TK
>> ----- Original Message -----
>> From: "omc-boats-digest" <owner-omc-boats-digest@...>
>> To: <omc-boats-digest@...>
>> Sent: Tuesday, September 12, 2006 12:00 PM
>> Subject: omc-boats-digest V1 #581
>>
>>
>>>
>>> omc-boats-digest Tuesday, September 12 2006 Volume 01 : Number
>>> 581
>>>
>>>
>>>
>>> [omc-boats] Through Transom Exhaust
>>> [omc-boats] venting the cowling
>>> RE: [omc-boats] venting the cowling
>>> Re: [omc-boats] venting the cowling
>>> Re: [omc-boats] Through Transom Exhaust
>>> RE: [omc-boats] venting the cowling
>>> Re: [omc-boats] venting the cowling
>>>
>>> ----------------------------------------------------------------------
>>>
>>> Date: Mon, 11 Sep 2006 23:08:58 -0700
>>> From: "Scott E. Veazie" <scottveazie@...>
>>> Subject: [omc-boats] Through Transom Exhaust
>>>
>>> Would there be a horsepower increase by changing the exhaust from the
>>> stern
>>> drive to a through transom setup? I've always wondered this, besides
>>> the
>>> "muscle sound" gained going this route.
>>>
>>> ~Scott
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Mon, 11 Sep 2006 23:39:46 -0700
>>> From: "jdood" <jdood@...>
>>> Subject: [omc-boats] venting the cowling
>>>
>>> I have a 65 omc deluxe i/o that I know little about. I have been
>>> finding that it seems to be running better without the cowling on the
>>> engine. Perhaps my imagination, but I don't think so. So did those
>>> cowlings ever have vents in that nice flat section of the front that
>>> seems perfect for a vent grill? Would I be screwing anything up to put
>>> one in there? Those little grills in the back seem kind of useless.
>>>
>>> Thanks for any comments!
>>>
>>> jeff
>>>
>>> - --
>>> No virus found in this outgoing message.
>>> Checked by AVG Free Edition.
>>> Version: 7.1.405 / Virus Database: 268.12.3/444 - Release Date:
>>> 9/11/2006
>>>
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Tue, 12 Sep 2006 06:26:42 -0600
>>> From: "knight" <knight@...>
>>> Subject: RE: [omc-boats] venting the cowling
>>>
>>> I have a 69 rogue that is currently running at 6000 to 7000 feet above
>>> sea
>>> level. I completely built a taller cowling with plenty of vent screen.
>>> It defiantly runs better with all the air I can get to it. Try turning
>>> on
>>> your bilge blower and see if that helps too. Joe.
>>>
>>> - -----Original Message-----
>>> From: owner-omc-boats@... [mailto:owner-omc-boats@...]
>>> On
>>> Behalf Of jdood
>>> Sent: Tuesday, September 12, 2006 12:40 AM
>>> To: omc-boats@...
>>> Subject: [omc-boats] venting the cowling
>>>
>>>
>>>
>>> I have a 65 omc deluxe i/o that I know little about. I have been
>>> finding that it seems to be running better without the cowling on the
>>> engine. Perhaps my imagination, but I don't think so. So did those
>>> cowlings ever have vents in that nice flat section of the front that
>>> seems perfect for a vent grill? Would I be screwing anything up to put
>>> one in there? Those little grills in the back seem kind of useless.
>>>
>>> Thanks for any comments!
>>>
>>> jeff
>>>
>>> - --
>>> No virus found in this outgoing message.
>>> Checked by AVG Free Edition.
>>> Version: 7.1.405 / Virus Database: 268.12.3/444 - Release Date:
>>> 9/11/2006
>>>
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Tue, 12 Sep 2006 08:20:56 -0500
>>> From: David <odin@...>
>>> Subject: Re: [omc-boats] venting the cowling
>>>
>>> It wouldn't hurt anything to put a vent in - but I think I would put it
>>> on the port side of the cowling - where the carb is located since you
>>> wouldn't see it there - Dave
>>>
>>> jdood wrote:
>>>
>>>> I have a 65 omc deluxe i/o that I know little about. I have been
>>>>finding that it seems to be running better without the cowling on the
>>>>engine. Perhaps my imagination, but I don't think so. So did those
>>>>cowlings ever have vents in that nice flat section of the front that
>>>>seems perfect for a vent grill? Would I be screwing anything up to put
>>>>one in there? Those little grills in the back seem kind of useless.
>>>>
>>>>Thanks for any comments!
>>>>
>>>>jeff
>>>>
>>>>
>>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Tue, 12 Sep 2006 08:34:42 -0600
>>> From: <lib1@...>
>>> Subject: Re: [omc-boats] Through Transom Exhaust
>>>
>>> Another good question that actually has some historical background.
>>>
>>> Just after OMC quit building our boats and sold the molds and rights to
>>> Chris Craft in 1970-71 they increased the rated power of their small
>>> block
>>> 307 Chevy V8.
>>>
>>> In the 19-footer E/J's that OMC built the 307 was rated at 210 hp. This
>>> was
>>> in models years 1969-1970.
>>>
>>> In 1971 they bumped the 210 to 215 and as far as I can tell from
>>> researching
>>> parts manuals no parts were changed in the process. Perhaps someone in
>>> engineering got a better dynomometer, who knows?
>>>
>>> But in 1971, they also introduced a 235 hp 307 Chevy. (Not to be
>>> confused
>>> with the later Ford-based 235 hp electric stringer). These 235 hp
>>> Chevies
>>> were painted red (as opposed to gray) and had Corvette/Camaro Z-28 cast
>>> aluminum valve covers. Theses engines also had the more agressive
>>> Corvette
>>> camshafts and THRU-THE-TRANSOM exhausts. They didn't idle down as well
>>> as
>>> the 210-215's but they sure do sound cool (or annoying depending on your
>>> point of view)! Not a lot were sold but you see them in the early
>>> Pachanga's
>>> (a Donzi-like v-hull boat).
>>>
>>> The in 1972 -74 OMC upped ante again and moved the 215 to 225. The
>>> "Corvette-Based" 235 jumped to 245. The engines were built to OMC's
>>> spec's
>>> by Chevy as they never offered a 307 in their car or truck lines with
>>> the
>>> QuadraJet and the hot Corvette camshaft. The OMC shifted focus to 302
>>> and
>>> 351 Fords and the short-shaft stringer and Chevy 307 was phased out.
>>> There
>>> are more 225/245's out there than 215/235's becuase they were made for a
>>> couple years longer. As far as I can tell 210-215-225's are all the
>>> carb,
>>> cams, and heads. An the same applies to the 235/245's which are
>>> indentical
>>> twins as well.
>>>
>>> My advice (and this is based on talking to experienced OMC mechanics) is
>>> to
>>> leave well enough alone. About all you will accomplish in changing the
>>> exhaust is a lot more sound, er noise. You may think you're going faster
>>> but
>>> the power gains will practically un-detectable. That's because they
>>> engineered the back-pressure and matched it verywell to the
>>> 210-215-225's
>>> exhaust manifolds and camshaft. A hotter cammed 290-hp 350 might need
>>> less
>>> back pressure, but not our engines. Even the thru-hub exhaust of the
>>> 400-800
>>> stringer probably didn't add more than fractional horsepower gains.
>>>
>>> Probably more than you really cared to know......
>>>
>>> Lee Shuster
>>> Salt Lake City
>>>
>>> - ----- Original Message -----
>>> From: "Scott E. Veazie" <scottveazie@...>
>>> To: <omc-boats@...>
>>> Sent: Tuesday, September 12, 2006 12:08 AM
>>> Subject: [omc-boats] Through Transom Exhaust
>>>
>>>
>>>> Would there be a horsepower increase by changing the exhaust from the
>>>> stern drive to a through transom setup? I've always wondered this,
>>>> besides the "muscle sound" gained going this route.
>>>>
>>>> ~Scott
>>>> -----
>>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>>
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Tue, 12 Sep 2006 08:32:23 -0700
>>> From: "jdood" <jdood@...>
>>> Subject: RE: [omc-boats] venting the cowling
>>>
>>> So if the engine runs better with vents, now I am wondering why they
>>> didn't put them in originally? Noise? Or is there some special
>>> marine/safety issue with venting it?
>>>
>>> - -----Original Message-----
>>> From: owner-omc-boats@... [mailto:owner-omc-boats@...]
>>> On Behalf Of David
>>> Sent: Tuesday, September 12, 2006 6:21 AM
>>> To: omc-boats@...
>>> Subject: Re: [omc-boats] venting the cowling
>>>
>>> It wouldn't hurt anything to put a vent in - but I think I would put it
>>> on the port side of the cowling - where the carb is located since you
>>> wouldn't see it there - Dave
>>>
>>> jdood wrote:
>>>
>>>> I have a 65 omc deluxe i/o that I know little about. I have been
>>>>finding that it seems to be running better without the cowling on the
>>>>engine. Perhaps my imagination, but I don't think so. So did those
>>>>cowlings ever have vents in that nice flat section of the front that
>>>>seems perfect for a vent grill? Would I be screwing anything up to put
>>>>one in there? Those little grills in the back seem kind of useless.
>>>>
>>>>Thanks for any comments!
>>>>
>>>>jeff
>>>>
>>>>
>>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> - --
>>> No virus found in this incoming message.
>>> Checked by AVG Free Edition.
>>> Version: 7.1.405 / Virus Database: 268.12.3/444 - Release Date:
>>> 9/11/2006
>>>
>>>
>>> - --
>>> No virus found in this outgoing message.
>>> Checked by AVG Free Edition.
>>> Version: 7.1.405 / Virus Database: 268.12.3/444 - Release Date:
>>> 9/11/2006
>>>
>>>
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> Date: Tue, 12 Sep 2006 10:57:02 -0500
>>> From: David <odin@...>
>>> Subject: Re: [omc-boats] venting the cowling
>>>
>>> This is a multi-part message in MIME format.
>>> - --------------070905040703020903050202
>>> Content-Type: text/plain; charset=us-ascii; format=flowed
>>> Content-Transfer-Encoding: 7bit
>>>
>>> Probably never noticed it - during my stint in engineering at OMC I ran
>>> a lot of hours testing on Lake Michigan - there were several other OMC's
>>> out on endurance that ran everyday - I do not recall ever seeing anyone
>>> run with the engine cover off - so it is likely no one ever had the
>>> chance to notice the difference - Dave
>>>
>>> jdood wrote:
>>>
>>>>So if the engine runs better with vents, now I am wondering why they
>>>>didn't put them in originally? Noise? Or is there some special
>>>>marine/safety issue with venting it?
>>>>
>>>>-----Original Message-----
>>>>From: owner-omc-boats@... [mailto:owner-omc-boats@...]
>>>>On Behalf Of David
>>>>Sent: Tuesday, September 12, 2006 6:21 AM
>>>>To: omc-boats@...
>>>>Subject: Re: [omc-boats] venting the cowling
>>>>
>>>>It wouldn't hurt anything to put a vent in - but I think I would put it
>>>>on the port side of the cowling - where the carb is located since you
>>>>wouldn't see it there - Dave
>>>>
>>>>jdood wrote:
>>>>
>>>>
>>>>
>>>>>I have a 65 omc deluxe i/o that I know little about. I have been
>>>>>finding that it seems to be running better without the cowling on the
>>>>>engine. Perhaps my imagination, but I don't think so. So did those
>>>>>cowlings ever have vents in that nice flat section of the front that
>>>>>seems perfect for a vent grill? Would I be screwing anything up to put
>>>>>one in there? Those little grills in the back seem kind of useless.
>>>>>
>>>>>Thanks for any comments!
>>>>>
>>>>>jeff
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>-----
>>>>To get off this list send mail to omc-boats-unsubscribe@...
>>>>
>>>>
>>>>
>>>
>>> - --------------070905040703020903050202
>>> Content-Type: text/html; charset=us-ascii
>>> Content-Transfer-Encoding: 7bit
>>>
>>> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
>>> <html>
>>> <head>
>>> <meta content="text/html;charset=windows-1250"
>>> http-equiv="Content-Type">
>>> <title></title>
>>> </head>
>>> <body bgcolor="#ffffff" text="#000000">
>>> Probably never noticed it - during my stint in engineering at OMC I ran
>>> a lot of hours testing on Lake Michigan - there were several other
>>> OMC's out on endurance that ran everyday - I do not recall ever seeing
>>> anyone run with the engine cover off - so it is likely no one ever had
>>> the chance to notice the difference - Dave<br>
>>> <br>
>>> jdood wrote:<br>
>>> <blockquote cite="mid017401c6d680$a56f2380$0a00a8c0@..." type="cite">
>>> <pre wrap="">So if the engine runs better with vents, now I am
>>> wondering why they
>>> didn't put them in originally? Noise? Or is there some special
>>> marine/safety issue with venting it?
>>>
>>> - -----Original Message-----
>>> From: <a class="moz-txt-link-abbreviated"
>>> href="mailto:owner-omc-boats@...">owner-omc-boats@...</a>
>>> [<a class="moz-txt-link-freetext"
>>> href="mailto:owner-omc-boats@...">mailto:owner-omc-boats@...</a>]
>>> On Behalf Of David
>>> Sent: Tuesday, September 12, 2006 6:21 AM
>>> To: <a class="moz-txt-link-abbreviated"
>>> href="mailto:omc-boats@...">omc-boats@...</a>
>>> Subject: Re: [omc-boats] venting the cowling
>>>
>>> It wouldn't hurt anything to put a vent in - but I think I would put it
>>> on the port side of the cowling - where the carb is located since you
>>> wouldn't see it there - Dave
>>>
>>> jdood wrote:
>>>
>>> </pre>
>>> <blockquote type="cite">
>>> <pre wrap="">I have a 65 omc deluxe i/o that I know little about. I
>>> have been
>>> finding that it seems to be running better without the cowling on the
>>> engine. Perhaps my imagination, but I don't think so. So did those
>>> cowlings ever have vents in that nice flat section of the front that
>>> seems perfect for a vent grill? Would I be screwing anything up to put
>>> one in there? Those little grills in the back seem kind of useless.
>>>
>>> Thanks for any comments!
>>>
>>> jeff
>>>
>>>
>>>
>>> </pre>
>>> </blockquote>
>>> <pre wrap=""><!---->-----
>>> To get off this list send mail to <a class="moz-txt-link-abbreviated"
>>> href="mailto:omc-boats-unsubscribe@...">omc-boats-unsubscribe@...</a>
>>>
>>> </pre>
>>> </blockquote>
>>> </body>
>>> </html>
>>>
>>> - --------------070905040703020903050202--
>>> - -----
>>> To get off this list send mail to omc-boats-unsubscribe@...
>>>
>>> ------------------------------
>>>
>>> End of omc-boats-digest V1 #581
>>> *******************************
>>>
>>> -----
>>> To get off this list send mail to
>>> omc-boats-digest-unsubscribe@...
>>
>> -----
>> To get off this list send mail to omc-boats-unsubscribe@...
>>
>
> -----
> To get off this list send mail to omc-boats-unsubscribe@...
>

-----
To get off this list send mail to omc-boats-unsubscribe@...
Received on Wednesday, 13 September 2006