---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Sat 01/29/05: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:06 AM - Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 (OHIOFLYBOY@AOL.COM) 2. 08:35 AM - Re: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 (flyv35b) 3. 08:37 PM - Re: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 (TeamGrumman@AOL.COM) 4. 08:40 PM - Re: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 (John P. Farra (Office)) ________________________________ Message 1 _____________________________________ Time: 08:06:24 AM PST US From: OHIOFLYBOY@AOL.COM Subject: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 --> TeamGrumman-List message posted by: OHIOFLYBOY@aol.com Gary, In an earlier e-mail you indicated that the pressure drop was about 10 inches of water versus the stock 6 inches, and that you saw an increase in speed. You then mention that the cooling drag is still to high. I am trying to understand how if the total cooling drag is higher, how you are getting the higher airspeed. The only thing I can theorize is that the increase in delta p is allowing for an increase in mass of airflow flowing through, and reduces the drag due to blockage, which is more than the increase of drag due to the surface drag of the increased airflow over and around the engine, thereby actually reducing the total cooling drag. But I am shaking my head, because I am not sure this is what is happening physically and if it makes sense. Comments? Richard Mutzman AA5A N9682U Phillipsburg, OH 3I7 ________________________________ Message 2 _____________________________________ Time: 08:35:00 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 --> TeamGrumman-List message posted by: "flyv35b" I think what Gary is saying is that there is more airflow through the engine compartment (as evidenced by the 10" delta P), which could be reduced to gain even more airspeed. Cliff ----- Original Message ----- From: Subject: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 > --> TeamGrumman-List message posted by: OHIOFLYBOY@aol.com > > Gary, > > In an earlier e-mail you indicated that the pressure drop was about 10 > inches > of water versus the stock 6 inches, and that you saw an increase in speed. > You then mention that the cooling drag is still to high. I am trying to > understand how if the total cooling drag is higher, how you are getting > the higher > airspeed. > > The only thing I can theorize is that the increase in delta p is allowing > for > an increase in mass of airflow flowing through, and reduces the drag due > to > blockage, which is more than the increase of drag due to the surface drag > of > the increased airflow over and around the engine, thereby actually > reducing the > total cooling drag. But I am shaking my head, because I am not sure this > is > what is happening physically and if it makes sense. > > Comments? > > Richard Mutzman > AA5A N9682U > Phillipsburg, OH 3I7 > > > ________________________________ Message 3 _____________________________________ Time: 08:37:27 PM PST US From: TeamGrumman@AOL.COM Subject: Re: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 --> TeamGrumman-List message posted by: TeamGrumman@aol.com I was able to reduce the parasite drag and reduce the inlet size by about 50% and make the inlets more efficient and therefore still increase the pressure drop across the cylinders. I could probably reduce the inlet openings by another 25% and still have plenty of airflow. I might try to control the flow with cowl flaps. There are still a few areas where I can reduce some parasite drag. Not a lot, but every little bit helps. Plus, there is still spillage drag on the left inlet that I need to eliminate. I'd like to squeeze another 2 or 3 knots out of the cowling. ________________________________ Message 4 _____________________________________ Time: 08:40:22 PM PST US From: "John P. Farra (Office)" Subject: Re: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 --> TeamGrumman-List message posted by: "John P. Farra (Office)" Go Gary, Go! ----- Original Message ----- From: Subject: Re: TeamGrumman-List: Re: TeamGrumman-List Digest: 1 Msgs - 01/28/05 > --> TeamGrumman-List message posted by: TeamGrumman@aol.com > > I was able to reduce the parasite drag and reduce the inlet size by about > 50% and make the inlets more efficient and therefore still increase the > pressure drop across the cylinders. I could probably reduce the inlet > openings by another 25% and still have plenty of airflow. I might try to > control the flow with cowl flaps. > > There are still a few areas where I can reduce some parasite drag. Not a > lot, but every little bit helps. Plus, there is still spillage drag on > the left inlet that I need to eliminate. > > I'd like to squeeze another 2 or 3 knots out of the cowling. > > >