Climbing CHT’s and settings for M20K 305

[louisut]

38 minutes ago, aviatoreb said:

I don't have that setting in my AFM.  That seems to be a lot of pressure in a rather lower rpm.  After 31'', starting by 32'' all recommended rpm's in my afm are for 2400 or greater.  See attached.  My recommended climb is either 35-2500 or full 38-2650 but for reasons we have been discussing the later can be cooler.  I do use 35-2500 as way up here in the north cooling is often an absolute non-issue.  Or even more so - in the winter sometimes I am struggling to get warmth and climbing with cowl flaps closed.

Definitely go 100% - 38''-2650 if cooling is an issue.

I am aware of at least two different rocket AFM's floating around, and I have copies of both on my hard drive - I believe but do not know there was an early one that was soon updated and a bit different to be the one I have that came with my airplane.

In cruise I rarely use anything beyond 75% on a regular use basis since it seems to be that is the point of diminishing returns where the gained speed really starts dropping off but the increased wear and tear my be increasing quite a bit more.  And 75% even not so often - I use 65% or 72% about 95% of the time between them for cruise

305Rocket.pdf 50.2 kB · 1 download

I'm going off the insert that's in the POH. Mine is dated Oct 18, 1995. I've seen the power chart you posted, but didn't know there were two different AFMs. Do you know when it was revised?

Edited May 6, 2020 by louisut

[aviatoreb]

51 minutes ago, louisut said:

I'm going off the insert that's in the POH. Mine is dated Oct 18, 1995. I've seen the power chart you posted, but didn't know there were two different AFMs. Do you know when it was revised?

Look at that!  Now I was going to say that your POH page is different from mine - but ... I looked it up ... and it is not.  Mine is identical to yours!  Marked date on it and all. Oct 18, 1995.  So I simply forgot that 34-2300 is marked on page 6 of the AFM=POH supplement.  And that contradicts the engine setting that is somewhere else in that same book, AND copied exactly as I posed it on to the physical airframe as part of the overhead pilot side visor.

Why would they mark that differently?  It almost seems like an error.  Especially since all the other settings are as I said - 32'' and above are 2400 and above.  And separate from that, I would be reticent to beat the engine up like that personally.

have you ever tried that best angle climb btw - 38''-2650 and 71KIAS?  That is VERY steep and quite interesting and fun, but not for every day use I am sure - just as it says when best angle is needed.  If you do try it keep your eye on the IAS and angle of attack if you have it since you don't want to get slow from there or it will make for a departure stall.

Now I said I have another AFM-POH on my hard drive - one that is different from my own - but I can't seem to find it so I made my self a liar.  Still - memory is that I have it somewhere and that it does exist.

Edited May 6, 2020 by aviatoreb

[Richard Knapp]

1 hour ago, louisut said:

I'm going off the insert that's in the POH. Mine is dated Oct 18, 1995. I've seen the power chart you posted, but didn't know there were two different AFMs. Do you know when it was revised?

Thank you @louisut!!  I'm grateful.

[louisut]

37 minutes ago, aviatoreb said:

Look at that!  Now I was going to say that your POH page is different from mine - but ... I looked it up ... and it is not.  Mine is identical to yours!  Marked date on it and all. Oct 18, 1995.  So I simply forgot that 34-2300 is marked on page 6 of the AFM=POH supplement.  And that contradicts the engine setting that is somewhere else in that same book, AND copied exactly as I posed it on to the physical airframe as part of the overhead pilot side visor.

Why would they mark that differently?  It almost seems like an error.  Especially since all the other settings are as I said - 32'' and above are 2400 and above.  And separate from that, I would be reticent to beat the engine up like that personally.

have you ever tried that best angle climb btw - 38''-2650 and 71KIAS?  That is VERY steep and quite interesting and fun, but not for every day use I am sure - just as it says when best angle is needed.  If you do try it keep your eye on the IAS and angle of attack if you have it since you don't want to get slow from there or it will make for a departure stall.

Now I said I have another AFM-POH on my hard drive - one that is different from my own - but I can't seem to find it so I made my self a liar.  Still - memory is that I have it somewhere and that it does exist.

The page I posted was out of the "FAA Approved Flight Manual Supplement" in the back of the POH. I see the pages you're talking about though; for me, it's in the separate "Rocket Manual", which contains the performance setting grid, "Flight Tips", service manual, and parts drawings.

I'm inclined to go with the "FAA Approved" numbers, but it'd be interesting to find out why the discrepancy exists. Note that the grid also lists econ and econ cruise at 2200 RPMs, something CSB09-11A "strongly recommends" against.

I've never tried 71 KIAS best angle climb. During my checkout, we used the numbers from the grid. Maybe I'll try that next time.

Edited May 6, 2020 by louisut

[aviatoreb]

1 hour ago, louisut said:

The page I posted was out of the "FAA Approved Flight Manual Supplement" in the back of the POH. I see the pages you're talking about though; for me, it's in the separate "Rocket Manual", which contains the performance setting grid, "Flight Tips", service manual, and parts drawings.

I'm inclined to go with the "FAA Approved" numbers, but it'd be interesting to find out why the discrepancy exists. Note that the grid also lists econ and econ cruise at 2200 RPMs, something CSB09-11A "strongly recommends" against.

I've never tried 71 KIAS best angle climb. During my checkout, we used the numbers from the grid. Maybe I'll try that next time.

When I made that last entry you are quoting - I found the page that is identical to the one you posted.  So I didn't post it since it is identical to what you posted.  

From memory - but I can't seem to find it right now - there is yet another AFM-POH that I found somewhere in the internet - not in my airplane - and I presumed it is from an earlier version so not the one that is valid and goes with my airplane.  Nonetheless interesting that it exists.  I found the copy  initially you are quoting from that since your numbers weren't as I guessed.

Yeah - that 71KIAS full power climb is a hoot - it is very very steep.  It feels like you are doing something illegal and the aerobatic police will come pay you a visit.  But there it is in the POH as normal recommended parameters.  Still other than a handful of times - for practice I have never had occasion to actually need it.

Right - that 2200 is there in the POH and that much more recent service bulletin CSB09-11A  http://www.tcmlink.com/pdf2/CSB09-11A.pdf strongly recommends against.  So therefore I no longer do it.  If 30'' I usually will do 2300.  If I really want to run low power like 25 or 26'' then maybe I will do 2250.  So in that spirit, seems like 34'' 2300 should be a lot of pressure.  I think of when I ride my bike - how much pressure in my knees if I am trying to ride at low rpms and a high gear vs higher rpms with an easier gear.

Edited May 6, 2020 by aviatoreb

[PJClark]

Update:  Climbed out at full power today all the way to 14,000...then climbed again to 16,000. All cool, no worries.

AND:  an enormous shout out to @AGL Aviation and Lynn, the crew, and Tamara. FANTASTIC annual.  Magicians with a Rocket TSIO-520NB, two quick turns of the screws and they nailed idle and full power mixture on the first try! Amazing. Fast, efficient, knows everything about Mooneys. I will be back every year.

Meanwhile @Richard Knapp  I hope you're enjoying your Rocket as much as I love mine...I'm within a knot of Rocket book TAS at 16,000 feet:  197 KTAS on 18 gph.

What a machine!

[aviatoreb]

4 hours ago, PJClark said:

Update:  Climbed out at full power today all the way to 14,000...then climbed again to 16,000. All cool, no worries.

AND:  an enormous shout out to @AGL Aviation and Lynn, the crew, and Tamara. FANTASTIC annual.  Magicians with a Rocket TSIO-520NB, two quick turns of the screws and they nailed idle and full power mixture on the first try! Amazing. Fast, efficient, knows everything about Mooneys. I will be back every year.

Meanwhile @Richard Knapp  I hope you're enjoying your Rocket as much as I love mine...I'm within a knot of Rocket book TAS at 16,000 feet:  197 KTAS on 18 gph.

What a machine!

 

 

Cool panel!

[carusoam]

Nice pirep for AGL!  @AGL Aviation

Great pics...

And best of all... great TAS!

Best regards,

-a-

[Richard Knapp]

13 hours ago, PJClark said:

Update:  Climbed out at full power today all the way to 14,000...then climbed again to 16,000. All cool, no worries.

AND:  an enormous shout out to @AGL Aviation and Lynn, the crew, and Tamara. FANTASTIC annual.  Magicians with a Rocket TSIO-520NB, two quick turns of the screws and they nailed idle and full power mixture on the first try! Amazing. Fast, efficient, knows everything about Mooneys. I will be back every year.

Meanwhile @Richard Knapp  I hope you're enjoying your Rocket as much as I love mine...I'm within a knot of Rocket book TAS at 16,000 feet:  197 KTAS on 18 gph.

What a machine!

Thanks for sharing!  So, @PJClark, what speed did you climb at-to 14,000 and then 16,000?  And what MP and RPM was the 197 kts at?

Edited May 7, 2020 by Richard Knapp

[PJClark]

Climb at 130-135 KIAS and I get about 1000 fpm even at that altitude

197 KTAS, 30", 2230 rpm (it's  smoothest and quietest there), 18 gph, 1550 TIT (ROP obviously) 

I misspoke on book speed. Book would be about 201 KTAS (not 198) so I'm about 4 knots slow

[Richard Knapp]

Thank you sir!!

[Richard Knapp]

On Tuesday, I stayed at full power (Mixture, prop and throttle) up to 14,000 and then to 16,000, with no overheating.  Ended up between 130 and 135 knots to keep temps at or below 380.  Still climbed at  1000 fpm or more.  I was quite pleased.  Thanks to all for your help and advice!  :-|)

[louisut]

On 5/6/2020 at 3:46 PM, aviatoreb said:

When I made that last entry you are quoting - I found the page that is identical to the one you posted.  So I didn't post it since it is identical to what you posted.  

From memory - but I can't seem to find it right now - there is yet another AFM-POH that I found somewhere in the internet - not in my airplane - and I presumed it is from an earlier version so not the one that is valid and goes with my airplane.  Nonetheless interesting that it exists.  I found the copy  initially you are quoting from that since your numbers weren't as I guessed.

Yeah - that 71KIAS full power climb is a hoot - it is very very steep.  It feels like you are doing something illegal and the aerobatic police will come pay you a visit.  But there it is in the POH as normal recommended parameters.  Still other than a handful of times - for practice I have never had occasion to actually need it.

Right - that 2200 is there in the POH and that much more recent service bulletin CSB09-11A  http://www.tcmlink.com/pdf2/CSB09-11A.pdf strongly recommends against.  So therefore I no longer do it.  If 30'' I usually will do 2300.  If I really want to run low power like 25 or 26'' then maybe I will do 2250.  So in that spirit, seems like 34'' 2300 should be a lot of pressure.  I think of when I ride my bike - how much pressure in my knees if I am trying to ride at low rpms and a high gear vs higher rpms with an easier gear.

I had a thought yesterday on the Vx discrepancy between the flight manual supplement and the grid. The certified AFM specifies 71 kts for Vx while the grid says 91 kts. I wonder if someone just has handwriting where the 7s look like 9s. 71 kts seems more consistent with other airplanes where Vx is very close to Vs1.

 

On 5/7/2020 at 7:51 AM, PJClark said:

Climb at 130-135 KIAS and I get about 1000 fpm even at that altitude

197 KTAS, 30", 2230 rpm (it's  smoothest and quietest there), 18 gph, 1550 TIT (ROP obviously) 

I misspoke on book speed. Book would be about 201 KTAS (not 198) so I'm about 4 knots slow

Looking at the grid, seems you're right on the money for ~65% "economy" power, no?

[Richard Knapp]

On ‎5‎/‎5‎/‎2020 at 3:18 PM, aviatoreb said:

Hi PJClark - its my new trick.  I got the surefly ignition about 2 months ago - and suddenly I can run LOP wonderfully at almost any setting I want, whereas I was TIT limited before to only do it at about 55%.  Now see in that file i just sent - at about 18 min I do a sweep from ROP back to LOP.  My TIT used to be maybe 1600-1625 if I wanted to run LOP at 55%.  Which I didn't like.  Now, suddenly like night and day since I installed the surefly two months ago, I am running at 72% and TIT is 1375-1390.  I almost wouldn't believe it but look how cool every other sensor is, all 6 EGT and all 6 cylinders are cool too, all cylinders below 300.  And its smooth.  Oh and its 15.8-16 gph instead of 20.  You can see I also have a gami spread of about 0.3gph which I got several years ago just by swapping the stock injectors around rather than buying gami.

So that's my new rocket setup.  But even before 2 months ago, my rocket was not having CHT problems in climb except on a hot day in upper teens where i could easily control it below 400 but I had to pay attention and shallow the climb.

Maybe the difference there is how far north I live?

Hi @aviatoreb, two or three questions from your post.  How fast and at what altitude do you go at 72% LOP and 16 gph?  Where did you get your surefly ignition put in (your mechanic or did you need to travel somewhere else)? And if you don't mind, what did the whole operation cost you.  Sounds like something I need. 

[aviatoreb]

1 minute ago, Richard Knapp said:

Hi @aviatoreb, two or three questions from your post.  How fast and at what altitude do you go at 72% LOP and 16 gph?  Where did you get your surefly ignition put in (your mechanic or did you need to travel somewhere else)? And if you don't mind, what did the whole operation cost you.  Sounds like something I need. 

Hi - Richard. Its still new so I haven't tested it extensively - and with a pandemic I have not had a chance to do some serious traveling so I have not been to the flight levels yet.
I have been to 12000 ft just for testing purposes and it seems to run fine there at that setting.  It seems to be going about 155IAS or so thee which - even though by FF that 16gph is 72% based on the 13.7 conversion factor, when I set the official 72% ROP which is 31'' 2300, 20gph it is much closer to 160IAS.  So its a tad slower but much better mpg.  Also, btw I have noticed my rocket has always been a tad slow compared to a few others and I blame 3 factors - I have a 231 air frame and no smooth belly etc, I have tks which is supposedly a bigger hit, and I have VGs which is not a big effect in my opinion after the flow is already dirtied due to the tks.

Time to install.  Major parts were the surefly itself - $1500 since I pre-ordered last year.  We need a new ignition harness which was $599 and not much else needed for parts.  I was billed 30hrs which was a lot more labor than I would have initially guessed but I was peeking in on them through the process and yes they were spending a lot of time and doing a lot of work.  Primarily leading power back to the tail, etc.  I never know how much time labor takes.  It is a basic job and I had it done on my field.

E

[aviatoreb]

19 minutes ago, Richard Knapp said:

Hi @aviatoreb, two or three questions from your post.  How fast and at what altitude do you go at 72% LOP and 16 gph?  Where did you get your surefly ignition put in (your mechanic or did you need to travel somewhere else)? And if you don't mind, what did the whole operation cost you.  Sounds like something I need. 

Addendum - as I have said I have not been flying with the new setup enough yet to have a strong memory of which settings give which speeds and which altitudes.  I flew once at 12k about 3 weeks ago. I think I may have given too slow a description ...

Yesterday I flew to get some cheap fuel ($2.74!) about 30 min away and I flew at 9500.  I looked at my recorded settings - I see (remember) I was doing 155IAS (recorded) on 30'' 2250 and 15.6gph which I think was about -15LOP and TAS was ~180 with the OAT.

[PJClark]

6 hours ago, louisut said:

On 5/7/2020 at 8:51 AM, PJClark said:

Climb at 130-135 KIAS and I get about 1000 fpm even at that altitude

197 KTAS, 30", 2230 rpm (it's  smoothest and quietest there), 18 gph, 1550 TIT (ROP obviously) 

I misspoke on book speed. Book would be about 201 KTAS (not 198) so I'm about 4 knots slow

Looking at the grid, seems you're right on the money for ~65% "economy" power, no?

I'd be fast if I was at 12,000', but I was at 16,000. AT FL180 should be 208 KTAS.  Really ought to be around 201 KTAS at 16,000 I think...roughly. But hey--within 4 knots of a book number, what's to complain about?

[FloridaMan]

On 5/6/2020 at 12:31 PM, louisut said:

Also, consider that the Rocket AFM specifies 34" / 2300 RPMs for normal climb, not 35" / 2500 RPMs. Full power--38" / 2650 RPMs--is specified for Vx or Vy climbs.

I'm trying to find a copy of the TSIO520 operators manual. The -NB variant, which is in the Rocket, does not have a limitation for how long you can run at 100% power. 

[aviatoreb]

1 hour ago, FloridaMan said:

I'm trying to find a copy of the TSIO520 operators manual. The -NB variant, which is in the Rocket, does not have a limitation for how long you can run at 100% power. 

I would be interested to see if that is true for the TSIO520NB in a Cessna 340 or 414 - where the TSIO520NB might be rated at 335hp.  Ours is limited at 305hp, and I presume that is in part because for the airframe 335hp would just be too much.  But then the side benefit is that at 305, this is 91% of 335 in other applications, so our 100% is not as stressful as 100% in other applications.

[N231BN]

I would be interested to see if that is true for the TSIO520NB in a Cessna 340 or 414 - where the TSIO520NB might be rated at 335hp.  Ours is limited at 305hp, and I presume that is in part because for the airframe 335hp would just be too much.  But then the side benefit is that at 305, this is 91% of 335 in other applications, so our 100% is not as stressful as 100% in other applications.

The stock -NB is rated at 310 hp. RAM Aircraft offered several improvements to increase the rating to 325 or 335. In both cases, I believe they were rated at 325 continuous.

Does the Rocket have an intercooler?

[aviatoreb]

1 hour ago, N231BN said:

The stock -NB is rated at 310 hp. RAM Aircraft offered several improvements to increase the rating to 325 or 335. In both cases, I believe they were rated at 325 continuous.

Does the Rocket have an intercooler?

Hi - ah - I don't know the original rating of the NB.  And there was an N before the NB and I don't know what changes were made, or how that might have changed the hp rating.

Yes, we have an intercooler which seems to be a very large unit.

As I have written, my particular engine seems to be running cooler than others, and it is running very nicely cool.  I am not sure what to point at as to why, but as for mods, I have several and they seem maybe to have collectively made a cool running engine.  These are, balanced injectors, which seem to be between 0.3 - 0.4gph  peaking, fine wires, 4 blade prop, and electronic injection.

[carusoam]

Depending on the day.... Continental has been very helpful with posting engine manuals on line...

Some creative MSers have been able to build a relationship with Continental...   

+1 on getting a copy of the manuals for the engine... they are usually the basis of our POH...

The POH typically cuts down much of the important detail that is in the docs... while specifically cutting things out that don’t apply to our airframes....

Best regards,

-a-

[louisut]

7 hours ago, FloridaMan said:

I'm trying to find a copy of the TSIO520 operators manual. The -NB variant, which is in the Rocket, does not have a limitation for how long you can run at 100% power. 

 

3 hours ago, carusoam said:

Depending on the day.... Continental has been very helpful with posting engine manuals on line...

Some creative MSers have been able to build a relationship with Continental...   

+1 on getting a copy of the manuals for the engine... they are usually the basis of our POH...

The POH typically cuts down much of the important detail that is in the docs... while specifically cutting things out that don’t apply to our airframes....

Best regards,

-a-

I have a copy of the Aug 2011 revision; it's attached. Page 2-4 indicates that the NB's redline is 2700 RPM while the Rocket's manual specifies 2650 RPMs. That's probably where the 5 HP difference is.

TCM TSIO-520 Operator's Manual X30044.pdf

Edited May 19, 2020 by louisut

[FloridaMan]

4 hours ago, louisut said:

 

I have a copy of the Aug 2011 revision; it's attached. Page 2-4 indicates that the NB's redline is 2700 RPM while the Rocket's manual specifies 2650 RPMs. That's probably where the 5 HP difference is.

TCM TSIO-520 Operator's Manual X30044.pdf 7.99 MB · 1 download

Compare the table on 5-32 for the -NB with the one on 5-35 for the -P variant. Note that the -P has specific limits for takeoff power whereas the -NB has "max continuous" specified. 

[Yooper Rocketman]

On 5/19/2020 at 3:15 PM, louisut said:

 

I have a copy of the Aug 2011 revision; it's attached. Page 2-4 indicates that the NB's redline is 2700 RPM while the Rocket's manual specifies 2650 RPMs. That's probably where the the 5 HP difference is.

When I had my Rocket Engine OH'd they had trouble getting the max RPM set for a bit.  I had 2700 RPM for a while (would have been really tempted to leave it there had I not been selling it).  That IS why the H.P. was dropped to 305.  I will tell you, that extra 50 RPM felt like a lot more than 5 more HP !!!!!!  I was blown away how much more power it had.  Could have been a new engine vs. a 500 over TBO old one too.  Almost as impressive as 724 HP on my 2500 pound (empty weight) Carbon Fiber garage built experimental. 

Tom