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F1 Rocket upgrade

sailvi767

Well Known Member
I purchased Jim Winings F1 about 18 months ago. The decision was driven mostly by his reputation in the community and on the forum. I am sorry I never had the opportunity to meet him. He built a great aircraft. The aircraft was a amazing flying aircraft with none of the Rocket vices others kept warning me about. (Do Rockets have vices?) The aircraft had changed hands twice since Jim before I purchased it and was showing its age in places. The more I flew it the more I realized it probably would be my last aircraft so the decision was made to upgrade the aircraft but try and keep to Jim’s concept of a lightweight aircraft with handling a priority.
The first and heaviest upgrade was the seats. I went with Oregon area and they have been fantastic. Weight gain was however about 15lbs. Cant say enough about the comfort.
We followed that with a basic IFR Dynon HDX panel with a Garmon 175 GPS and kept the Dynon D10A as a backup.
I was very happy with the aircraft at this point but in the back of my mind felt a bit more power would be nice. The engine was a base C4B5 IO540 with a 1000 hours and a slight nagging vibration when run at lower RPM’s. I had mentioned that to Kent Gorton in Atlanta. A few months late he called and said he had a Barrett IO540 that he wanted to sell with 300 hours at a price point that got my attention. It had all the MB bells and whistles and Dyno’d at 310 HP. It was a low time older engine built by Monty himself. After a careful inspection and Kent agreeing to a great price including performing the swap the change was approved.
Dropping the motor in would prove a bit more difficult than expected as we worked around the tight F1 cowl. As expected the Barrett CAI was not going to fit. A decision was made to go with the Raven CAI and their recommended exhaust supplier. (Aircraft Exhaust Systems Specialist). The Setup fit the stock F1 cowl as advertised. Adapting the RSA10 servo to the inlet took a bit of work but Kent came up with a great solution.
At this point and concerned about weight a EarthX battery replaced the existing battery behind the rear baggage area. To try and avoid shifting the CG to far forward we switched to a B&C 40 amp pad mounted alternator. I was concerned how this setup would function with the Amp load but after replacing the initial VR that had infant mortality it’s been great. The hoses were all beyond my comfort age level and replaced by TS flight line hoses. They did their usual great job with fast service.
The weight and balance turned out interesting and I still can’t quite account for the change. The original 2004 weights were 1215 total and 58lbs on the tailwheel. I expected to be around 1225 and about the same on the tail. It came in at 1248 with 78 on the TW. We are going to recheck the weights as it seems odd the CG went aft with the battery swap. I did not expect the alternator shift to have that much impact. We will also look at options to move to newer lights and strobes and get the tail strobe power pack removed when my bank account recovers!
The engine swap was a challenge but the new engine is dialed in and performing great. It is sewing machine smooth and when dialed back to 2200 RPM at cruise is producing great fuel burn numbers. We do need some injector balance to explore LOP. The power appears excellent but since It’s been nothing but really hot hard to make a comparison from last winter. I am looking forward to the fall. Can’t weight for a 30 degree morning with 18 gallons of fuel! Cruise speeds seems about 5 knots faster. We had one pleasant surprise. We expected cooling to be a problem. The original engine struggled in the southern heat and it was difficult to keep the CHT’s below 415 or so in a long climb unless using 140kts and full rich through 5000. Oil temps in the pattern would reach 225 and about 190 cruise. We made no baffling changes and are using the exact same sensor package. Oil is now 180 to 185 in cruise and hard to push it above 205 in extended pattern work. CHT’s stay below 380 and we are leaning much sooner. This is with 90 plus ground temps. It’s been suggested the CAI system is the reason for the lower temps. Not sure on that but not complaining! I will post a link to some pics later.
G
 
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We need some pictures!!

How well does that alternator keep up with amp draw at idle or lower RPM? I've considered it but wasn't sure what to think about idle RPMs and the lower draw.
 
Glad to hear about the improvements, that sounds great.

For the weight changes, there are a number of things that could account for that. The likely suspects might be if it was painted after weighing, or if previous owners swapped or added equipment.

A long time ago, I bought a C180 to replace my C170, and had an opportunity to reweigh both airplanes. The C170 was 50 pounds lighter than the logbook, but unfortunately the C180 was 50 pounds heavier. It does happen.

Dave
 
I have one of those:

How well does that alternator keep up with amp draw at idle or lower RPM? I've considered it but wasn't sure what to think about idle RPMs and the lower draw.

I have one of those on my ship (550 Continental), and in my case, it works great. The 550 has higher gearing in the accy section, so I can get usable juice at around 800 RPM. The LYC has slower gearing, so you might need to go to 1000RPM - a bit high for taxiing. All else about the unit is the same as any other - except it has no belt to wear out and break. You might need to set the alt controller to a higher voltage if you have the Odyssey battery - piece o cake.
 
My experience is exactly what Mark is stating. The Lyc does spin it slower. I show zero amps at 800 RPM but have a positive 8 to 10 amps at 1000. Even with extended cranking and ground time it recharges the battery quickly once airborne. I see 37 Amps at 2700 RPM and 32 to 33 Amps at 2400 cruise. I have a EarthX900 so it will suck Amps up fast but even with multiple ground starts trouble shooting some issues it quickly recharges the battery and my Amps drop to my normal 14 sustained. As I mentioned moving the alternator 3 feet back and getting rid of the weight of the brackets and belt brought the CG further aft than expected.
 
Here are some pictures, better late than never!
 

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All modifications granddaughter approved!
 

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5 F1 Rockets..........

Here's 5 F1 rockets


Why-are-We-Still-Using-Rocket-Engines-for-Space-Travel-2.jpg
 
I tried to fit that F1 engine into my Rocket. I decided reinforcing the tail for VNE issues was going to be to much of a hassle! It does scoot with the new 540. I was not going to bother with Oxygen as I felt the sport wing was not suited to higher altitudes but after doing a bit of testing at high altitudes think it will be nice to have a permanent system for xcountries. The 9.5 to 1 pistons might account for it liking being high.
G
 

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I did a bit of impromptu comparison testing with my buddy and his MT 3 blade F1. In a side by side test at WOT, my airplane and it's Hartzel 2 blade would outrun him at 2500, but dialed back to 2300 he was faster. Weird.

Today I spent some time at 12.5k and I made some interesting performance measurements with this new prop. Stabilized at my normal LOP fuel flow setting I did an RPM sweep from 2300 to 2600 RPM to see what it did for FF and TAS. Note I changed ONLY the blue knob - the throttle remained against the stop and the SDS ECU did the rest. Numbers: RPM/GPH/KTAS

2300/9.7/193
2400/10.2/197
2500/10.6/201
2600/11.0/201

Looks like the prop hits a wall at 2600 at this TAS. More experimentation needed
 
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Those are very impressive speeds LOP. I am hoping I can run LOP with a little work on the gami spread. I probably need to add a EI and am considering the 6 cylinder PMag but out of aviation money at this point! Did you by any chance record the MAP with those results? With the old engine LOP at 2500 RPM I was around 190 TAS.
G
 
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Different design points

I did a bit of impromptu comparison testing with my buddy and his MT 3 blade F1. In a side by side test at WOT, my airplane and it's Hartzel 2 blade would outrun him at 2500, but dialed back to 2300 he was faster. Weird.

Hey Mike:

I spec’d that prop for MT to build - set up to cruise at 10k-12k at WFO and 2100 on a stock 540, so that shows up as faster at a lower RPM. The MT kinda lays down around 2600 or so. A prop with a bit less blade twist would do what your test shows, of course.

I did not tell Hartzell how to set up the prop in your case, and I recall asking for a higher cruise RPM at 12.5k - I think 2400 was the number? Prop cert testing was done with my ship: 550-N in front, so it has a bit more oomph at the higher altitudes. The testing did show that re-clocking the prop works on this design, so it is also set up that way for a smoother ride.

Then there was this crazy Reno thing going on every year - that had some influence on the design of the blades too...:D. I was able to pass Maj. Nelson in the Valley of Speed, even with his slippery ship and modified engine.

My plan is to test the MT 3-blade on the RG - results will be very different due to the forced induction and SDS controlling the fuel and spark. I have asked Hartzell to look into a different twist on the BA blades for altitude - COVID cancelled that for some reason..
 
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