> >>>>>>>>>> Paul wrote:
>>>>>>>>>>
>>>>>>>>>> Hi, Paul. I noticed on the Racing Beat website that
>>>> they claim the
>>>>>>>>>> peripheral ported 13b with a Weber 51IDA is good for 300
>>>> hp. Any idea
>>>>>>>>>> what rpm they need to turn to get that kind of hp?
>>>>>>>>>> Also, I have noted that some of the Weber carbs are mounted
>>>>>>>>>> vertically, and some horizontally. Does "side draft"
>>>> Weber indicate
>>>>>>>>>> that
>>>>>>>>>> it can be installed horizontally?
>>>>>>>>>> I see that they also have a "down draft" Weber, and
>>>> that is the
>>>>>>>>>> one
>>>>>>>>>> that is pictured mounted vertically. I assume that the internal
>>>>>>>>>> workings
>>>>>>>>>> must be different, as the float inside a carburetor
>>>>>>>>>> is typically orientated horizontally.
>>>>>>>>>> Last question....have you ever seen a successful
>>>> modification to
>>>>>>>>>> add
>>>>>>>>>> a mixture lever to a Weber? Sorry for the barrage of
>>>> questions, but I
>>>>>>>>>> was hoping you might be able answer some of these
>>>>>>>>>> questions. Thanks in advance for your reply. Paul Conner
>>>>>>>>>
>>>>>>>>> My guess the HP peak on that engine is right around 9500 RPM.
>>>>>>>>> You will need slightly longer pipes for 7500 RPM max.
>>>>>>>>> providing you have a 2.85:1 gear box. My guess would be
>>>> 250 to 260 HP
>>>>>>>>> at 7500 RPM.
>>>>>>>>>
>>>>>>>>> Wow a 51 mm dual Weber! That is just about exactly 2 inches in
>>>>>>>>> diameter.
>>>>>>>>> Does that
>>>>>>>>> sound familiar or what? :) Side draft and down draft
>>>> never the twain
>>>>>>>>> shall
>>>>>>>>> meet.
>>>>>>>>>
>>>>>>>>> Back in the 60's Weber made a dual 58 mm side draft carb.
>>>>>>>>> When I was working for Chaparral we wanted to run four
>>>> Weber carbs on
>>>>>>>>> our
>>>>>>>>> big block V8. We wanted to run something like them in
>>>> down draft mode.
>>>>>>>>> So
>>>>>>>>> the
>>>>>>>>> Rochester Carburetor Division of GM copied the 58 mm side
>>>> draft Weber
>>>>>>>>> but
>>>>>>>>> converted it to a down draft version for our use only.
>>>> You should have
>>>>>>>>> heard our Group 7 competitors complain.
>>>>>>>>>
>>>>>>>>> It is a float bowl orientation problem Paul.
>>>>>>>>>
>>>>>>>>> Paul Lamar
>>>>>>>
>>>>>>>> Thanks for that information, Paul. Only one question
>>>> missed....ever hear
>>>>>>>> of
>>>>>>>> a successful mixture lever mod to a Weber? Thanks again.
>>>> Paul Conner
>>>>>
>>>>>
>>>>>>> I know it has been done with a Holley but I never heard it done
>>>>>>> with a Weber. I guess it is possible. I think the guys
running Ford V6
>>>>>>> are using some sort of mixture control on their carbs as I recall.
>>>>>>>
>>>>>>> BTW I can understand why you are interested in carbs. What are your
>>>>>>> thoughts on this subject? Just for the record.
>>>>>>>
>>>>>>> Paul Lamar
>>>>>
>>>>>
>>>>>> Hi, Paul....the primary reason is simplicity. I realize
that the EFI has
>>>>>> distinct advantages, such as being able to control the exact
>>>> amount of fuel
>>>>>> injected at various rpm's, and carburetor icing is not a
>>>> concern (with the
>>>>>> exception of the long intake runners that Mistral experienced
>>>> icing in). My
>>>>>> problem is with it's complexity....It requires two high
>>>> pressure fuel pumps,
>>>>>> expensive injectors that can clog, programming maps, and a
>>>> fuel return line
>>>>>> for unused fuel. The system also places considerably more
>>>> current demand on
>>>>>> the electrical system. (Important if you should have an
>>>> electrical failure,
>>>>>> as it shortens the distance you can continue flying to an
airport). The
>>>>>> complexities of setting up proper maps for an ECU can also be
>>>> time consuming
>>>>>> and at times frustrating. I have found it difficult to find
>>>> anyone who could
> >>>>>> assist in programming maps into my ECU. (Every A&P mechanic at
>>>> our airport
>>>>>> could help out with a carb).From what I am reading, there
>>>> seems to be a lot
>>>>>> of people using Webers on rotary powered cars, with many
sites revealing
>>>>>> proper tuning techniques/jetting, etc.
>>>>>
>>>>>> There are advantages and disadvantages to both systems,
>>>> obviously. I am
>>>>>> personally drawn toward the simple nature of the beast, and I
>>>> have had a lot
>>>>>> more experience with carburetors on aircraft (all 7 of my
>>>> previous aircraft
>>>>>> had carbs). I was pleased with their performance and
reliability. Just
>>>>>> needed a throttle and a mixture control. If I could get the
>>>> same kind of
>>>>>> performance and reliability with a carb on a rotary, I
would be just as
>>>>>> pleased as I was with my previous Lycoming powered
>>>> aircraft...No, make that
>>>>>> MORE pleased, as I would have a carb equipped rotary
instead of a carb
>>>>>> equipped hand grenade. Just my opinion, and I could be
wrong. (Again).
>>>>>> Take care. Paul Conner
>>>>
>>>> I have run a Weber on my coot now for 1300 hrs, I used a 51 mm DCOE
>>>> side draft for about 1000 hrs but switched to a 48 DCOE, they also
>>>> make a 55 mm DCOE and the best place to get Weber's is at Performance
>>>> part warehouse in New York.
>>>> I switched to the 48 as it runs very smooth at the bottom end
>>>> compared to the 51 but I did lose some power on the top end but I do
>>>> a lot of slow speed water taxiing so its a tradeoff I will except.
>>>> Also for leaning I use a controllable air ram that creates a
>>>> pressure difference between the float bowl and the Venturi thus
>>>> leaning the fuel mixture.
>>>> I am with you on the simple thing, just hook up a fuel line and a
>>>> throttle cable and go fly, if you need jetting info I can give you
>>>> the jet numbers to put it dead nuts on.
>>>> I have thought about playing with injection but I will use a Weber
>>>> as a throttle body so the if something goes wrong with the injection
>>>> I can just flip a switch to the Weber fuel pump and keep flying on
>>>> the Weber and worry about fixing the injection I get home or whenever
>>>> I get around to it.
>>>>
>>>> Ken Welter
>
>
>>> Heck you can use this system as a back up. Second picture.
>>>
>>> --
>>> Paul Lamar
>
>
>> I don't want something to just safely get me to the ground I want
>> something so that I can keep flying and fix the injection when I get
>> home and I fly way out in BFE and I don't want to be fixing something
>> out there.
>> Like I said flip a switch and keep flying and if home is a week away
>> its no big deal.
>> Ken
> Ken
I have tried to contact you several times again by email and your sever
keeps rejecting my address. Hmmmmm?
Doug in Japan
I have two addresses
rotary.coot@verizon.net and rotarycoot@mac.com
Try the mac address as its more reliable.
Ken
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