reasonable M20J speeds

[y2kiah]

10 hours ago, Shadrach said:

#3 is typically the hot cylinder for IO360s. The fins on the back of the cylinder stop at the barrel and will not allow airflow around the cylinder. Mooney solved this by dishing out the baffle behind number #3. If the baffle is poorly oriented, there is little to no airflow around the back of cylinder #3. Go out to your hanger at night sometime and put a light in the lower cowl under cylinders 1 and 3. Looking down from the top of the engine youu will note that you can see light and therefore a path for airflow, everywhere but behind cylinder 3. Make sure the dish out on the baffle is oriented in such a way as to allow air to flow behind the cylinder.

I’m going to try this tonight.

[Shadrach]

1 hour ago, y2kiah said:

I’m going to try this tonight.

This is an old thread but may be of interest to you.
 

 

 

[ArtVandelay]

I run LOP, so FF is 9 or less and I do around 150 knots. Wind hurts more than it helps, so ground speed will be less.
The reason is, take the example where the wind is directly from the side at 90°, you might think the wind isn’t hurting but you need to steer into the wind to maintain your course.

[Gagarin]

On 7/4/2021 at 10:08 AM, Shadrach said:

GS is not really helpful to a TAS discussion.  203kts isn’t bad for bragging rights but it’s not extraordinary either.

This was against headwinds

[Shadrach]

On 7/29/2021 at 12:51 PM, Gagarin said:

This was against headwinds

You sir have the fastest J model ever produced.

[bradp]

On 7/18/2021 at 10:06 AM, Shadrach said:

#3 is typically the hot cylinder for IO360s. The fins on the back of the cylinder stop at the barrel and will not allow airflow around the cylinder. Mooney solved this by dishing out the baffle behind number #3. If the baffle is poorly oriented, there is little to no airflow around the back of cylinder #3. Go out to your hanger at night sometime and put a light in the lower cowl under cylinders 1 and 3. Looking down from the top of the engine youu will note that you can see light and therefore a path for airflow, everywhere but behind cylinder 3. Make sure the dish out on the baffle is oriented in such a way as to allow air to flow behind the cylinder.

A little square of baffle seal pushed in there will create a path for airflow. 

[bradp]

I run LOP 7-8k 8.7 gph at 2500 rpm gets me 148ktss and that is what I plan for.  ROP 150 i true out at about 154-155 ktas. 

[Shadrach]

3 hours ago, bradp said:

A little square of baffle seal pushed in there will create a path for airflow. 

This made me smile Brad, thank you!

 It’s gratifying to have someone that one respects unknowingly pass on advice based on one’s own decade old observations and troubleshooting.
 

 

[carusoam]

I think that qualifies for a form of time travel…

A decade old and still relevant!

 

Best regards,

-a-

[A64Pilot]

On 8/3/2021 at 8:50 PM, bradp said:

I run LOP 7-8k 8.7 gph at 2500 rpm gets me 148ktss and that is what I plan for.  ROP 150 i true out at about 154-155 ktas. 

Down low, everything forward as in takeoff power, I can get 168 kts true (18 GPH) at altitude ROP I can get 155 kts true, but it cost me 10.5 GPH.

I most often cruise at 22 squared and LOP at 7 GPH, this gives me 135 kts

Yes that gives away 20 kts, but it’s the same as a 182 and gives huge range and economy, and unless trip lengths are long, it’s not as much wasted time as you may think.

[bradp]

On 8/4/2021 at 1:07 AM, Shadrach said:

This made me smile Brad, thank you!

 It’s gratifying to have someone that one respects unknowingly pass on advice based on one’s own decade old observations and troubleshooting.
 

 

Ha R!  I probably got that from you 10 years ago. I just keep my ears open for wise folk.  Couldn’t remember if I still had my little wedge of silicone in there and sure enough been doing it’s job.  My #1 and #4 alternate who’s hotter depending on summer or winter flying. 

[bradp]

16 hours ago, bradp said:

Ha R!  I probably got that from you 10 years ago. I just keep my ears open for wise folk.  Couldn’t remember if I still had my little wedge of silicone in there and sure enough been doing it’s job.  My #1 and #4 alternate who’s hotter depending on summer or winter flying. 

On the other side #4 for whose with Js and /or vintage with relocated oil coolers - what’s up with this baffle sitting over almost half the cyl?  The oil cooler is efficient.  The cyl is the hottest (for me in summer anyway)- seems like overkill. 
 

 

[PT20J]

Good question. After putting in the new engine with Gee Bee baffle seals on my 1994 J, cylinder #2 and #4 are both hotter than the other side. I think it might be due to the oil cooler and air filter being on that side. I was also curious about the effect of the baffle “ramp” at the entrance to the oil cooler that covers a lot of cyl #4. Anyone modified it and care to report results?

Skip

 

[A64Pilot]

It should be easy to remove it by cutting, leaving a .25” lip and install a couple of nut plates, then duplicate the cut part and the nut plates makes it removable.

‘Why instrument panels aren’t done that way I’ll never understand.