Subaru back and running

[StanFoster]

My SparrowHawk is back and running. It started right up.....idled perfectly. I am going to cautiously work the air out of the sytem,,,but I can tell you already my cooling system already is acting differently. I can actually keep water in my overflow now.

I wont be flight testing till the end of the week while I get some other things done. I have to dump the sacrificial oil and put in my Royal Purple...:whoo:

Heres a couple pictures from tonights start up. You can see my red valve covers.

Stan

 

[cgmg]

Stan,

Your Sparrowhawk definitely looks better with the nice new red valve covers. Looks like it's brand new again!

Hope all goes well with the test flights.:yo:

 

[StanFoster]

Mark: Thanks.....I cant wait to see what how it performs with the new cam grinds.



Stan

 

[CLS447]

Good Stan ! That was educational, for sure.

I hope that you have no further problems & get right back to doing your favorite thing...... Flying & testing!

I'm ready for your report.

 

[M. Pearce]

Stan,

Whew, I'm glad for you getting it together.

Something like that woulda took me six months or more.

Not that I'm lazy, just family matters always sidetracks me from my projects.

I have a feeling you are gonna have a lot better and safer engine to fly with.

It all adds up to a more enjoyable flight experience when your not worried about something going wrong.

Thank you for keeping us posted and thanks for the pictures you provide us!!!

 

[barnstorm2]

Congrats!

That did not take long!


.

 

[StanFoster]

Tim: It really doesnt take long at all to actually remove the heads.... 3 hours total. A lot of this was figuring what to disconnect to slide the engine back one inch so the crankshaft pully can be removed.


Reassembly total time was 6 hours. Not a record by no means...but not really a big deal after having gone through it.


I did hire a Subaru mechanic for this time as I wanted to see how a true professional does it.

I started it up and did some taxi work. My cooling system is behaving perfect. I am going to have to deprogram myself for the little quirks I no longer have.

I did a real quick full throttle burst with the rotors up to speed. When my Ivoprop is set to minimum pitch...5400 was the max rpm. The quick throttle burst saw 5620 on my engine tach. Hard telling what climb out will be. I will have to monitor the rpm's and with this extra horsepower....may have to put another pitch limiting washer in it.

Tomorrow I will do some real flight testing...cant wait.


Stan

 

[dragonflyerthom]

Stan Foster-Man with a Mission. LOL

 

[Arnie Madsen]

Glad you are up and running again Stan. However my mind has been on your cooling system for a while.
I'm sure you know most of this Stan (and everybody) there is a proper sequence to bleed all the air out of the system and Subaru could provide it. Except that your rad and all your plumbing is placed completely different than the automotive set-up. All "air pockets" would now migrate to the top of your water jackets (cylinder heads)and could remain there instead of moving to the overflow bottle which I assume is at the top of the cooling system.

Any small air pocket will turn into a steam pocket and remain there continually and allow a hot spot , especially if it is close to an exhaust valve. It is surprising how hard it can be to purge all the air out of a system , even with the thermostat full open , high rpm and a good flow of coolant a stubborn pocket of air can remain.

If anyone gets bored and wants proof of this , find some clear tubing hooked to a garden hose with a bit of air trapped in the top of a loop. You can pump water through it all day at a medium flow and the air will remain at the top .

Im sure you and others have considered every angle when purging your cooling systems of air but what came to my mind and the reason for my comment has to do with the original heater core outlets Subaru used in the factory car cooling systems. Are they now plugged ? Are they plumbed in a closed loop ? Is this where your overflow bottle is connected ? When purging an automotive system the heater core outlets will flow even when the thermostat is closed and usually are plumbed to the highest points of the cooling system.

By way of experience in a small car factory setting we produced a 3-wheel parking patrol car which used a Mazda 1.6 liter engine. Production runs were about 20 per month .The sequence to purge the cooling system was quite complicated and frustrating. These were brand new components , thousands of gallons of antifreeze available , and some days it took over an hour to finally get all the air out of the system.

In summary air (or steam) will collect at the highest point in a cooling system unless there is a direct vent to an overflow bottle or rad or heater core etc that is placed higher than the engine.

Good to hear you are up and running again Stan .... now for a bit of humor .... I have seen some of your pictures ..!!!.. your machine is almost sideways in the air ..... how could any air remain in your cooling system ??? Please explain ......ha....

greetings from Canada
Arnie Madsen

 

[OzyRuss]

Where now in your rev range, have you set your torque curves etc.

And where were they originally.

Your yet to be reset of your desired cruise, compared to the original cams settings, interests me.

Lastly...........is your engine the "active" valve model [ variable cam ]

cheers............

 

[StanFoster]

Russ: I dont quite understand your question, except are you asking what I want to cruise at?

Let me just say this. I have hard data that has been posted in my Ivoprop thread.

Basically heres what my SparrowHawk did before at various prop pitches and rpm's. These are actual GPS averaged readings 180 degrees apart starting with a direct headwind course...and ending with a direct tailwind course.

My minimum prop pitch would yield 5400 engine rpm on full throttle climbout.

While full throttle....I add pitch to the prop until the engine pullls down to 4900 rpm. This gave me my best cruise numbers.

With this prop pitch setting if I throttle back to 4600 rpm, my GPS average was 86.5 mph. If I went to 4700 rpm..it was 88.5 mph.

If I cruised at 4800, my actual GPS averaged ground speed is just shy of 90.

Full throttle top end was 94.0 mph.

4800 used to be my max cruise rpm with my warp drive prop and that would give me 80 mph actual groundspeed. The IvoProp lets me improve this a lot as my above numbers reveal.

I am expecting the above engine settings to have more pitch in the Ivoprop due to the fact that I am pulling down a more powerful engine to those rpm figures. More pitch should mean more mph.

My main cruising speed is the 4700 rpm at 88.5 mph. I am very happy with that speed as it is so much better than I had with a fixed pitch prop set at a compromised pithc.

I am hoping to still cruise at 88 mph but with a lower engine rpm. Maybe 4600? or even 4500?

My tests will soon tell.

However, I will be flying with my doors off right now because of the heat. But to be actually fair, I need to put my doors on as that was what the above cruise numbers were obtained with.

Stan

 

[barnstorm2]

Sounds like you did things right Stan. Good luck on the flight tests, looking forward to the report!

.

 

[OzyRuss]

Thanks stan.............sorry for being confusing

the original cam.........soob, set the torque curve at ??????????

you mentioned the reason for this regrind, was to reposition that torque band to a different rev range area etc . Was interested where your best torque to rev area now was.
You will now be remapping your best cruise / fuels etc........interested to know

 

[StanFoster]

OZY: I cant honestly say what the original torque figures were at....but I was told by a few individuals that the torque curve is more geared for a car coming off a stop. The guy at Delta Cams told me my torque curve for my cam grind was in the upper 4000 range on up to 5500.

I can feel the difference,...but want to back this with averaged GPS figures. I am making sure everything is running perfect...which it is so fa....before I start gathering some performance data.

I do not want any more horsepower....I am at my personal limits for my redrive. I can tell you that I throttle back on takeoff....I dont need all that power for that unless I am hauling a passenger. I want my mid range cruise figures to be even better than the numbers I was tickled with before.

This will end my quest for more horsepower..


Stan

 

[OzyRuss]

Thanx for the info..........keep it coming

 

[OzyRuss]

"RAF" conversion.........ozy style.

Should be flying today.......ej25, 2.4 box,76" prop

My build is identical, with Ivo inflight adjust prop, should be completed end of year.

 

[OzyRuss]

My ej25.............has the variable cam stuff [ active valve ]
We got our engines direct soob. $2 grand each, brand spankers. The boxes are "Autoflite" @ 2.4 ratio

The completed gyro [ Allans ] 600 Lbs plus of thrust, at 5200revs, tweak it, run it in, etc etc, will be pulling more. Thats swinging 76" prop, wideish chord. Also useing soob computers.

 

[CLS447]

Russ, did they sell you complete engines ?

Stan, most guys that run the 2.5 usually run a 4 blade Warp.

I guess the 3 blade magnum Ivo is just as good ?

What are your thoughts on this ?

 

[StanFoster]

Chris: I cant see any fixed pitch prop having the same range that a variable pitch prop has. If the four blade was adjustable pitch....then maybe it would pull even more, I dont know. For now. I am enjoying having a "variable transmission" to shift. It really makes a difference.

Stan

 

[OzyRuss]

Russ, did they sell you complete engines ?

Stan, most guys that run the 2.5 usually run a 4 blade Warp.

I guess the 3 blade magnum Ivo is just as good ?

What are your thoughts on this ?

Even had alternator...............the bleedin lot. [ no pewtar ]

Guy down here has contact at soob........hence we got em. Can get more.

$2 grand, landed oz.