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Honda 1.8L on RV6A Now Flying!

Throttle Body install with throttle cable route

I have made quite a bit of progress getting things ready to run.

Besides installing the panel, I installed the Throttle cable to the TB. Fortunately it worked out quite well.

Of course I had to match the travel of the throttle cable to be appropriate with the rotation of the TB butterfly plate so it was close while the knob was pulled and precisely wide open relative to the airflow while the cable was pushed all the way in.

There was certainly a bit of trial and error. Fortunately the throttle arm has several holes on the arm which was very valuable in matching the rotation (of the throttle body plate) to the throttle cable travel ratio. I hope that makes sense, if you have questions let me know.

This is an after market TB. I think it is 70mm. The OEM is a non-mechanical unit which added complexity that just did not make sense to use.

On a side note, the vacuum ports/tubes on the TB have not been capped yet, but will be before runup.

ofe.jpg


Other tasks completed are:

1) Putting on a new (better} bypass hose.
2) Installing the PSRU (prop gearbox).
3) Wiring the various sensors. I decided to add another water temp sensor as well as a water pressure sensor.
4) Wired up the PSRU oil temp sensor
5) I added coolant.
6) Added the oil pressure sender for the HOBBS.

I am not going to bore you with the "to do" list, but it really is not bad.

Charlie
 
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Engine running on the airframe, works great.

I did my first run up of the engine on the airframe. It worked great. (and made it during OSK week!)

Here is a very short video.

https://youtu.be/VWT8bYB8tdM

With no prop on it yet, it quickly ran up to 4000 rpm with very little throttle movement. I will have to get used to that. I suspect it will work through those RPMs a bit more gradually with a prop.

I am surprised to see no pressure on the coolant system, even though I pushed it up to 230 degrees. This was easy to do with no air through the radiator at all, it did not take too long to get up to temp at 4000 rpm. I am suspicious the pressure gauge is not accurate at these low settings. I have to do more bench testing. I may need to find a more sensitive low pressure gauge and sender.

I have 3 water temp senders. One dedicated to the ECU. One on the engine outlet and one on the inlet. Right now I am running without a thermostat. I certainly do not need any help getting the engine up to running temp.

The PSRU temps were quite low, I think around 160F. But again with no prop that is probably about right.

You will notice some pretty shabby loose wiring if you look close. This will all change soon, now that I have the engine up and running again. I just did not want to spend a lot of time making is sanitary if things did not go well and more changes had to be made.

Many of you have PM me with support and comments and I appreciate that. One person asked about support for the throttle cable. I am not sure how well that came through with the picture, but I am using the stainless steel eyeball to capture the cable as it passes through the firewall. This allows the cable to be free to rotate about the (Z?) axis while still keeping the exterior of the cable very secure from moving in or out. I got this one from ACS Aircraft Spruce.

I have the plane on dolly's so I can push it around in my shop at home. I need to secure these before adding the prop. It would not be good to get airborne in my 60 foot parking lot. That would be a real bad idea.

I am not sure what else to share. Let me know if you have questions or comments for the good of the order so to speak.

P.S. You will see in the video I have an external fuel tank (jerry can) with fuel delivery system that is a stand alone unit. Since the fuel tanks are normally in the wings, and of course they are in the rafters of the shop, i just rigged up a fuel tank, pressure sender, and fuel pressure regulator and fuel pump on a roll cart. All the wiring is quickly attached using those CPC connectors and of course the Honda fuel rail is OEM quick disconnet fitting anyway so fuel hose connection is literally, well, a snap. Hope that all makes senses.

Charlie
 
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Congrats Charlie. Runs really nice.

The gearbox temps sound a bit high with no load though, keep an eye on those with the prop in place.

Always good to verify the accuracy of temp and pressure gauges. Erroneous readings can lead you down the wrong path. Coolant pressure may not always follow what you think, you can have negative pressure under certain running conditions.
 
Charlie, sounds like great progress,what year body didy you use, as my 2013 is
electric throttle. Thanks Tom (Tomcatrv4)
 
Congrats Charlie. Runs really nice.

The gearbox temps sound a bit high with no load though, keep an eye on those with the prop in place.

Always good to verify the accuracy of temp and pressure gauges. Erroneous readings can lead you down the wrong path. Coolant pressure may not always follow what you think, you can have negative pressure under certain running conditions.

Ross,

Thank you. Yes, I agree on the sensors. I did quite a bit of bench testing with the temp sensors and they were pretty accurate. But if things don't look right I will check them again before chasing that rabbit.

As far as the coolant pressure goes, that is one that I plan to change. I just ordered a manual (direct 1/8 line) gauge that I plan to install in the feed line to the header tank. I want to make sure I completely know what is going on there and if that the cheap cap that they make now days is working properly. I am concerned it is not, as the water in the overflow tank did not budge at all during the high temp run up.

I was actually thinking of using a MAP gauge just to be able to watch the suction side of the system, but those of course are not liquid filled and would not survive long with water/moisture getting in the port. I think once I get that new direct line gauge going things will become clear.
 
Charlie, sounds like great progress,what year body didy you use, as my 2013 is
electric throttle. Thanks Tom (Tomcatrv4)

Tom,

Yes, I had the same electric TB on mine. I opted to swap it out for that Aftermarket TB you see in the picture so I could have direct cable control on the throttle. It was quite a simple change.

Thanks for the kind words.

Charlie
 
RV-12 - Viking 130 engine

I'm installing a Viking 130 engine and need any help or advice that anyone has on safely installing and running the engine.

Currently I'm trying to find out if the standard RV-12 fuel system is a 45psi system?
 
I'm installing a Viking 130 engine and need any help or advice that anyone has on safely installing and running the engine.

Currently I'm trying to find out if the standard RV-12 fuel system is a 45psi system?

Sounds like an interesting project, good luck to you.

The engine set up that I talk about in this thread does use a Viking PSRU but the engine, ECU, etc are not provided by Viking. So I am not sure I can be of much assistance.

Charlie
 
Congrats Charlie. Runs really nice.

The gearbox temps sound a bit high with no load though, keep an eye on those with the prop in place.

Always good to verify the accuracy of temp and pressure gauges. Erroneous readings can lead you down the wrong path. Coolant pressure may not always follow what you think, you can have negative pressure under certain running conditions.

The vid showed 110F for the PSRU, and 82F OAT, so not much rise for the temp on that box. It may depend on where the sensor is located.

Where is the coolant pressure measured? It is really dependent on top tank temp where partial pressure at temp is established. A cavitation test measuring temperature to the coolant pump is in order, then you can measure that temp as a leading indicator of cavitation and system cooling collapse. It should be done w/o a cap and with pure water. Blocking the radiator and running the engine at a relatively high speed - one appropriate to takeoff. It does not take a long time to test, so raising the temps then increasing engine speed would suffice. It is a basic liquid system performance evaluation. It is a good static test for any new installation.
 
The vid showed 110F for the PSRU, and 82F OAT, so not much rise for the temp on that box. It may depend on where the sensor is located.

Charlie said he saw 160F. Mine never gets this hot 3 hours into a flight.

With maybe 20ish hp going through it without a prop, this is hot in my experience if the probe is in the oil.
 
I will watch that PSRU temp closer on the next run up to try to get a firm grasp of that temp. (I was really more focused on the water temp.) The PSRU temp sensor is at the top of the unit, as the manufacturer suggests. I would suspect it is being splashed with oil that is slung off the top gear, but really that is just my guess based on the location.

My next step is to install that mechanical water pressure gauge. While it wont measure the suction that does occur like Ross said, it will tell me if the system is developing pressure and whether or not the cap is working as it should. I believe that when I hit 212F that I should have seen a rise in the overflow tank as the cap opened. But there was no rise in the level of the overflow tank. Ummm.... The gauge I am using now is a 0-90 psi gauge I had on the shelf. The mechanical one is liquid filled 0-15 psi, which should give me more accurate readings.

Like Bill said there may be air pockets causing cavitation at the pump but Since all 3 sensors are within 10 degrees of each other at any given time my guess is that the flow is probably doing OK. One is on the exit of the head, another at the inlet thermostat housing and the other just prior to the radiator.

Charlie
 
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PSRU only 104 AT 4000 ( But no prop)

I did more extensive run up today. I ran it for about 4 minuts at 2000, and at 3000 and at 4000RPM.

I did some quick videos of the testing. My apologies to Ross. When I said the PSRU temp was 160F I probably misspoke, as I verified today it was only about 104f after several minutes at 4000rpm. By the way. My senses tells me the engine is the smoothest, and happiest at 4000rpm. I think you will agree when you hear it run on the video. It is also super smooth between 1000rpm and 2000rpm. There is some minor vibration between 2000 and about 3200 rpm. Nothing scientific at all. Just a seat of the pants interpretation.

Here is a 33 second clip at 4000rpm.

https://youtu.be/V1DIdcTlTz0


The good news is that oil pressure gauge I have serving as my temporary coolant pressure gauge actually got up to 11psi. You will see it in the video. The part that still seems odd to me is that the overflo coolant did not rise. So I suspect the cap is something higher than 11psi. I wish it was about 5 psi.

All three coolant sensors are typically with 10-12 degrees of each other.

Of course the real testing will begin when I put a prop back on and load up the engine. I need to build some real good chocks for that.

If that goes well I will then put the turbo back on.
 
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more temp testing at 4000 RPM

I did more testing for several minutes each at 2,000, 3,000, and 4000 RPM.

My apologies to Ross when I said the PSRU temp got up to 160F I must have been mistaken, as it never got above 103F today. My mistake.

The good news is that the oil pressure gauge you will see in the video that is actually temporarily serving as my coolant pressure gauge got up to 11 psi. The overflow tank still did not rise, so I suspect the cap is at least an 11 psi ca. I wish it was more like 5 psi.

Here is the link to the new run up to 4000rpm. Its only 33 seconds.

https://youtu.be/V1DIdcTlTz0

All three coolant sensors were usually within 10-12 degrees of each other at all times.

The engine seems the smoothest at 3800-4100. It settles down in to a very sweet hummmm. Just my seat of the pants feel. You may also get that impression when you watch the video.

Again, I do not have the prop on the plan so it is really not working at all. The radiator has zero flow over it as well.

Once I get sometime to pull the panel and change out that faulty volt gauge and add the mechanical coolant pressure gauge Ill build some sterdy chocks and start testing with the old prop I have. See what things look like at 4500 rpm with 20 degrees pitch on the prop.

I am also going to watch the reference voltage on the GM map sensor I have and see it compares to the EOM integral map sensor. If I can use the OEM one, it makes plubming the MAP lines much easier. It will be interesting to see if it either of them gets up to 5.0v at 25-30 inches.....if so Ill have to go to a 2 bar map sensor when I start adding boost. but that will probably be some tweaking on the programming in the ECU. Oh well, that is actually fun to me.

Charlie

Charlie
 
I just got back from OSH and see I missed the intial engine start.

Congratulations on this accomplishment. I'm following your efforts with keen interest.

Just a thought... sometimes when building an airplane a pilot lets his air skills deminish and then when the time comes to fly new creation the pilot may not be up to the task. With your engine now running on the airframe it may be time to tune-up and polish the pilot. It would be good to have recent time in same model prior to fist flight so memory items, sight picture, etc. become very familiar and attention can be focused on new engine while flying performace of airplane remains safe.
 
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I just got back from OSH and see I missed the intial engine start.

Congratulations on this accomplishment. I'm following your efforts with keen interest.

Just a thought... sometimes when building an airplane a pilot lets his air skills deminish and then when the time comes to fly new creation the pilot may not be up to the task. With your engine now running on the airframe it may be time to tune-up and polish the pilot. It would be good to have recent time in same model prior to fist flight so memory items, sight picture, etc. become very familiar and attention can be focused on new engine while flying performace of airplane remains safe.

Jim (sorry I first wrote Bill).

That is funny that you mentioned getting current. My wife just said the same thing tonight! I absolutely am going to do that. I have been putting it but I am getting closer to that point. I do need to get a few more things done before I feel I can commit to flying part of this hobby but it is not too far off.
 
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cooling suprise

Well I installed my "test" prop. It is a used 68" (corrected typo was 60) warp drive prop that I bought for a very good price. (I love the prop and I wished they may a higher HP version I would buy it in a minute.)

I ran it up to 4000 RPM and got a very good surprise. While I was only pulling 20-25 inches of MAP, I could not get it warmer than about 175 degrees. I was very surprised that the prop wash provided that much cooling effect on the radiator. I do not have the plenum around the radiator. Before, with no prop on it; no load, no cooling prop wash, the coolant temp would get up to 230F in about 10 -15 minutes. I have the prop at max pitch, 20.5 degrees. I can't make it work any harder. I the last time I had it running on the test stand, 5000 RPM would get me close to 30" MAP. In the end, I would like to see 40" - 45" of MAP at 4500-4800 RPM with the turbo on it.

I need a bigger prop. I just started to look at other props. I do have a limited budget so I am looking at a 72" two bladed whirlwind, and the 3 bladed 72"-74" IVO Magnum and the 72" DUC Flash-R.

I think with a 72" or 74" prop, especially if it was a 3 blade, I would see 40+" at 4500 which I believe translates to an output of approximately 170+HP at that speed.

Comments welcome.

Charlie
 
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Increased run up to 30" MAP at 4800

I ran the engine with the prop on it up to 30" MAP which was 4700-4800RPM. Of course since I do not have the turbo on it right now, this was the limit for this engine. I also had installed the thermostat to see how that would change the temps.

Here are some notes. Please know these are rough notes and may not be spot on. It is a bit harry to be running at that RPM on a ground test tethered to my truck. Note taking was not my priority during that 6-7 minute period at that RPM.

My notes....engine ran up to 4800 RPM. 30 in of manifold at 4800 RPM. Water coolant temperature at 225F on hot side of system, and after about 6-8 minutes the temps were rising fast enough that I needed to throttle back.
This is no suprise to me considered we were on the ground. Water temperature on cool side 209. At 4000 RPM I saw 24 in manifold pressure. PSRU temperature 110 -115 degrees at 4500 RPM. OAT was about 76F. Throttle was at 95% at 4800 RPM. Increase throttle did not increase RPM after 4700-4800 RPM.

The Thermostat did its job but I am not convinced it is really a benefit, except for maybe in the very coldest period of the year. The temps without the thermostat are closer on the hot and cold side and lower over all. It is important to know that this is all based on ground run up with no radiator shroud. Flight with a shroud, will be completely different.

I believe that with my current set up I could run at about 22"-25" of MAP and the system would run all day with no problems of over heating.

The Prop is a 68" WARP drive 3 blade tapered tip.

Here is a link to the run up.

https://www.youtube.com/watch?v=gXo-FL7-Xzw

I am very happy with these numbers. My plan is to get a 72" prop to get the static "limit" down to about 3800, then add turbo to be able to get about 40" at 4500-4800 RPM. I really just don't like working the PSRU faster than that. That is not a limit the manufacturer has, it is just me.

The engine is probably putting out about 130-145 HP at 30". I believe 5-7 lbs of boost will get me close to the 160-170HP I desire. Of course it will also help considerably at higher altitudes.

Charlie
 
Details on cooling and general update.

I have been out of state for a few weeks which is why I have not been posting the progress of the project.

At this point I can not be happier with the performance of this engine set up.

The last challenge I had to overcome was with the cooling problems. I believe that most of the high temps I saw were caused by a poor fitting radiator cap. It was not properly pressurizing the system. I installed a mechanical 15 PSI pressure gauge in the panel and learned a lot about how the cooling system was working. In short things work very well. I have to run the engine over 22 inches MAP before it overheats now and the cap releases between 10-15 lbs which seems to be a good pressure. I am not entirely happy with the cheap feel of this radiator cap but it is working well. (keep in mind this is all happening static on ground run ups and I am not flying it).

But I have to wait until I get a larger prop before I can load the engine more, especially to do testing with the T3/T4 turbo.

Another interesting thing is that I learned that LED gauges are great, in low light, but easily get washed out in direct sunlight, but LCD displays work great! LCD has sort of disappeared and are considered "outdated" technology but I am switching my LED gauges to LCD gauges so I can read them in sunlight. Which is another reason why I still like analog (steam) gauges.

The next step is to modify the cowl to fit the engine installation which is going to take me a few weeks (at least). I suspect that this part is a bit too off topic for this thread so I don't really plan to post on that part of the build. If you have questions feel free to ask, or PM.

I have ordered all the parts to install the dual Walbro 155LPH fuel pumps and that will be after or during the cowl mod.

Lots more to do! But all is well.

Charlie
 
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cowling mod

As I slave away with moding my cowling and remembering that I said I was not going to post about this, I got to thinking that anyone who may decide to venture off in to installing a "Alternative" engine will probably have to do some cowl modification, hence it makse sense to share a bit about this.....

I had to modify my cowling to fit this set up. I had built this cowl to fit a different engine set up. With the R18 Honda, it need to be dropped about 5/8 of an inch and lengthened about 1/2 an inch.

Looking at this photo you may think you see "bondo". Not the case. I use West Systems epoxy and lots of micro balloons with some sillica (cabosil). You will see green foam. This is what I call "flourist" foam that is readily available at any hobby or craft shop. Plus it is very easy to sand and shape. It is excellent and inexpensive when you want add volume and it is NOT structural. So for me it was an excellent choice to add 1/2" to the nose. Then cover with epoxy/micro.

o50.jpg


The next photo is a rough fit of the spinner. I have actually done a lot more filling and sanding after this, but it is coming along nicely.

o5X.jpg


There is a lot more work to do. I will be adding more to the lower cowl and sanding to the correct profile and then cover it all with a layer of glass before painting.

Feel free to ask questions if you want.

Charlie
 
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Cowl update

Just in case anyone thought I had been relaxing on some far away place - not the case at all! I have been slaving away building up the cowl to fit the engine/prop better.

Here are two photos of the progress. It needs more buffing and polishing but it did turn out fine with me.

o5b.jpg


Here is one more...

o5t.jpg


I will be glad when is done, fiberglass is certainly not my specialty, but I would rather do it myself and put up with all the cosmetic flaws than hire it done. To me that is what Experimental Aviation is all about.

I should get my new (72") prop in a few weeks and I am real anxious to do some testing with it....

Charlie
 
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Getting close now. Remember to brush cobwebs off flying skills. A lot will be happening on first flights and pilot will need to be very familiar with flying the airframe while sorting engine info. Very interesting to follow this thread with approach and decision making involved.
 
Jim,

I wish it was close. But honestly is not. I have probably at least 6 months to go. ...and quite a few non aviation tasks to work on.

But yes. I will get be proficient in type before the first flight.

Charlie
 
Pics on new Turbo downpipe

While waiting on the new prop to arrive and I am working on a variety of small tasks. I have decided to make some changes in the turbo exhaust as well as beginning to upfit the pipes that will go from the turbo to the intercooler to the TB (Throttlebody).

Here are two photos of the new turbo down pipe. It will be attached to the Turbo with a V Band clamp and will have a M14x 1.5tp O2 sensor as well as a bayonet mount EGT probe.

oFz.jpg



oFI.jpg


There are a lot of wires and other pipes and tubes that are not yet connected. But over all, I do like the set up of the turnbo down pipe. I was going to bend and route it farther aft, but after more thought, it seems to make more sense to keep it simple. It is about 1" from the silicone coolant lines but I believe this can be protected with a cuff off the downpipe. I know many wrap their turbos and downpipes with ceramic wraps, but I have never been a fan of that, but I will consider it.

Charlie
 
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boost or normalized?

I plan to have it boost 5-7 lbs, (40-45 in Hg). The plan is to keep that level up to 10K. This is quite mild (less than half) compared to most boost pressures used on Hondas over all. This will put me somewhere in the neighborhood of 160-180HP. There are factors that may change this once I actually get to flying, but so far this is a conservative set up.

I was very happy with how my intercooler performed on the test stand but on the airframe will be a whole new ball game. Can't wait!!

I did rough in the intercooler today. It actually "sits" quite nicely between the engine and the firewall. I even have a few inches to get a scat duct in there from the front left cowl inlet. I think I will have to fabricate a plenum out of fiberglass and aluminum.

Charlie
 
New fuel pumps

I am continuing to migrate engine systems and components over to the airframe that were functional on the test stand.

Below is a pic of my dual walbro fuel pump system.

oFB.jpg


I am happy with the set up. For those who may not want to build this piece by piece SDS EFI has a dual pump system that is very compact unit.

I did get my prop today. Very excited to test the engine with this. Unfortunately things are in limbo until I get the fuel system functional and with another trip out of state soon, it may be awhile before I can test the prop.

Ill keep this thread updated as long as there seems to be interest. And since it past over 60k views, I think for now its worth sharing what I am doing.

Charlie
 
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I am continuing to migrate engine systems and components over to the airframe that were functional on the test stand.

Below is a pic of my dual walbro fuel pump system.

I am happy with the set up. For those who may not want to build this piece by piece SDS EFI has a dual pump system that is very compact unit.

I did get my prop today. Very excited to test the engine with this. Unfortunately things are in limbo until I get the fuel system functional and with another trip out of state soon, it may be awhile before I can test the prop.

Ill keep this thread updated as long as there seems to be interest. And since it past over 60k views, I think for now its worth sharing what I am doing.

Charlie

Making progress. Cool.

It looks like there are 2 fuel inputs; one with a filter (the black thing?) and one without. Are you running the return fuel straight back to the fuel pumps? if so, the prevailing wisdom is to run the fuel back to the tank. It's even suggested to run the return line in the tank far from the fuel pickup. This is primarily because the return fuel is warm/hot. I don't know how much of a difference it really makes, my return fuel dumps into the tank right above the pickup tube.

I'm also imagining having the return fuel going back to the fuel pumps would create a problem with regulating the fuel pressure. Fuel would be pumped to and sucked from the regulator, and maybe not suck from the tank.

(Just raising a concern; I don't mind being wrong.)
 
Fuel return lines....

Jeff,

Good to hear from you.

Comments and suggestion are always welcome. I am pretty familiar with the discussion and debate on the returns lines. While I hate to crack open that debate...here are are my thoughts.

I agree that most of the concerns regarding the return line usually is tied to two thoughts. One, like you mentioned is tied to concern about the temperature of the fuel. (which leads to the second concern). High pressure systems like this sees most of the return at idle. While I don't have hundreds of hours of testing on this, I can tell you that the return lines during my testing are not perceptibly warmer than the supply lines, and those, even in the hottest time of summer. The second and actually more common concern is "vapor lock". Many people do not understand that this is a concern for the suction side of the system and virtually a non-issue for the pressurized side of a fuel system. The risks associated with what is commonly called vapor lock are prevalent on a carburetor systems and especially older systems that have mechanical pumps with limited fuel flow, low pressure and long supply lines. The problem occurs when a particular system is unable to move the fuel due to being "stalled" (sometimes called cavitation) with air that that particular system is unable to handle, for a variety of reasons.

When I do my test runs I hook up the system with an external fuel tank. (I don't have wings mounted on the fuse). As you can imagine the lines are nothing but full of air - absolute worse case of risk of "vapor lock". Right?! it takes a few seconds for the air to pass the injectors and then it runs absolutely perfect.

Some even think the return lines are to allow bubbles to return to the tank - not realizing of course that once they pass the pump, the are a non issue. (in a relative sense).

Now, should we be mindful of the value of keeping air out of our supply lines, especially in low pressure carburetor systems. You bet. Will I continue to do testings as the systems evolves? Absolutely.

Sometimes we take information that is applicable to one kind of system and then believe that is applies to all systems even though they are significantly different and that appears to be happening on this topic as well.

In short. Yes, I have thought about it. I have read every tech article I can find and I am basing my decision on credible information, backed by testing.

I appreciate you sharing your thoughts and concerns.

P.S. On a somewhat humors note, I am tempted to put a schrader valve on the suction side and inject very low pressure air in to the system just to verify how it would handle. Any one want to take a $100 bet it handles it fine? I need lunch money.

Take care.

Charlie
 
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The biggest concern would be if you run a tank dry, you'll have a lot of air in the system and it will take many seconds to process that through the injectors. The engine will be too lean to run. Maybe not a big deal with lots of altitude but would be down low.

Returning to the pump inlet has caused running issues on the dyno in one instance I can recall during a test.

Any air entrained, going through the pump gears is unfriendly to them.

Returning to the tanks is the safest and most proven. Worth considering IMO.
 
The biggest concern would be if you run a tank dry, you'll have a lot of air in the system and it will take many seconds to process that through the injectors. The engine will be too lean to run. Maybe not a big deal with lots of altitude but would be down low.

Returning to the pump inlet has caused running issues on the dyno in one instance I can recall during a test.

Any air entrained, going through the pump gears is unfriendly to them.

Returning to the tanks is the safest and most proven. Worth considering IMO.

Ross,

Always I good to hear from you.

I should add that my comment about air in the system was certainly not to suggest that it is a good thing, and running a tank dry is definitely not good in any situation, IMHO (Although I have read folks who routinely do that before switching to a full tank - not my idea of good fuel management.)

I mentioned the part about my start ups with air in the line just to help people have a real world perspective and to understand in an unlikely chance an air bubble develops in a system like mine it is (IMHO) not going to cause vapor lock, like in the older low pressure systems.

My testing continues. While the system I had on the test stand was functionally similar, I have not done testing on this particular set up. I hope to get going on it very soon and I will post all my experience, good and bad.

I appreciate comments like yours and Jeff, even while they might be different from my plan they are respectful, and helpful to us all. Your knowledge and experience is something I respect.

Take care.

Charlie.
 
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New prop

Below is a pic of my older 68" Warp Drive Prop that I used for testing, with the new 72" prop.

oFO.jpg


There are a few things worth mentioning here. Notice the new prop hub. Much "beefier" than the older prop. Warp calls this their HP hub.

Second, notice that the 72" prop blades are full width cord the whole way out to the tip, as compared to the tapered blades on the 68".

Last, you may be wondering why I chose Warp Drives. Really several factors. One, they have been in business for decades with a very good reputation for support and reliability. I have always received great customer service in my dealings with them. That counts a lot to me. I also think the 3 blade 72" full cord set is going to be a good match for my project. They are competitively priced. This prop with stainless steel leading edge, HP hub, crush plate, and bolts and pitch protractor was less than $1700. While it would probably not be a good fit for a IO-360 LYC, I think its going to work out good for me.

I did a real short run up today but I ended up with a coolant issue so I was not able to run it long. I will post a follow up on that issue later.

Charlie
 
filling and burping the coolant system

In my last post I mentioned the cooling issue again.

I saw excessive high temps on my last short run up. I suspected that it was due to a rather large air bubble near the water pump.

I decided to take more caution on how I fill the coolant in the engine and after doing so I am back with the correct temps and function of the cooling system.

Below you should see a picture of the engine with two reinforced silicone tubes that point straight up in the air. These two tubes are temporarily attached to two ports that just happen to be at the ideal high point of the coolant system on this engine. It is important to note these are on both sides of the water pump and filling them and porting them ensures that the water pump is properly immersed in coolant. The one on the left that has a yellow arrow pointed to it is on the the top of the thermostat housing. The one on the right that has orange arrow pointed to it is on the coolant outlet of the cylinder head where the OEM water temp sensor used to be. (After the filling procedure I attach a a line over to the catch can on the firewall so it can evacuate any remaining air bubbles that may exist as the system is running. That line is marked by a green arrow and is not attached at the time the pic was take.

oFu.jpg


You can see the bottle of antifreeze that am am pouring in to one of the tubes. As I pour in the coolant, I squeeze the larger sections of silicone in various places in the system to force coolant to move and fluctuate to "burp" the system which encourages bubbles to travel to the high points in the system where those two vertical tubes are temporarily placed.

Unfortunately the last time I filed the system I did not do this process and as a result there must have been a sufficient amount of air trapped near the water pump to cause it to cavitate enough so the coolant would not be properly pumped through the system.

This just highlights the importance of making sure your system is completely filled and no air is trapped in the system. Some engines have bleed ports to release trapped air. I do not believe this system as a port like this.

When I did another run up today the system worked very well. After the engine was properly warmed I ran it up to 4000 rpm.

Much more testing to come.

Charlie
 
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Yup this is super important. Trapped air in the system is the #1 cause of overheating issues on liquid cooled conversions that I'v seen and helped people with.

My suggesting to avoid the long filling process is to run a -3 line from one or both of these high points to your coolant tank. This way, any air in the system is automatically bled out when you run the engine. I usually call these active or dynamic bleeds. Saves time and is even better than trying to purge air during the filling process.
 
Active bleed line

Ross,

Yes I do have that dynamic or active bleed line. I may not have explained this well in my post but it is the line in the photo with the green arrow pointing to it. This line goes to the radiator catch can which is the highest point in my system that evacuates any air bubbles that may have been trapped. I only have to do the water bottle fill method if I completely drain the coolant which i did last month when changing the locatiom of one of the two coolant temp sensors.
 
Pressure testing the Air Intake Plenum

Now that I have the coolant system functioning properly I was able to do a run up to 4004 RPM. Everything seems to be working well. Even after about 4-5 min at 4000 RPM and 33 in Hg I was only at 185 degrees on the hot side of the radiator. I think the cool side was about 165. The water pressure was creeping up quickly though, I think it was at 14lbs. About the point the overflow gets some coolant.

The one think that bothered me though is that was only getting 33 In Hg. I was expecting more with the turbo. After serious contemplation here are some causes that ran through my mind

1) Need to bleed off more air out of the compressor line that goes to the waste gate.
2) Not enough preload on the waste gate arm?
3) Leak or too low BOV setting?
4) Leak in the the intake system somewhere?

For those that may consider a project like this, you need to be the kind of person that is comfortable with dealing with these types of grelims. They will happen. You - at least - have to put up with them, and if you are lucky and you are wired weird like me, you actually like these kind of challenges to conquer.

I decided to hook up a low pressure regulator to the intake plenum. You can see the pic below.

oFE.jpg


You can see the gauge at the base of the photo connected to my pressure gauge. You can see it feeds in to the intake, the BOV, Intercooler and around the corner that you cannot see is the TB and intake manifold.

I ran it up to 4 lbs. I did not find one leak. I found THREE!

1) One from an abandoned Air Temp sensor. ( I removed this)
2) Some air coming from the current active air temp sensor.(I did my best to seal this using Permatex ultra black)
3) An obscure port on the TB. (I plugged with with foam, Ultra Black and a new cover plate.

It will be set up enough to test tomorrow. First will be to test the BOV to see if it still opens at 12-14 lbs. If that is good I'll do another run up to 4000 may be 4500, may be 5000 rpm

I am hoping to get 40" at 4000 rpm and maybe 45" at 5000 rpm

That would be a mile stone on this project and I would be very happy.

Ill keep you 'all posted. Feel free to ask questions. I even welcome constructive critique, we all need to learn from others. All I ask is the comments are respectful and not denigrating to any person in particular.

Charlie
 
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Good results on hard run up to 40" hg MAP

After closing up all the air leaks in the intake system and calibrating the BOV and Waste gate release pressure I was able to do two hard run ups to 4400 rpm.

I am very please with the 72" 3 Bladed warp drive prop. It seerms to be a very good match for my set up. The prop had enough resistance when set at 20 degrees pitch that it held at 4400 rpm. It held at 4400 RPM at about 35 inches MAP. I increased to 40" hg, and the prop held firm at 4400 RPM static. These runs are of course on the ground.

Temps were real good as well. I started the run up at 170 degrees on the coolant and while on the ground with no radiator shroud, I can get several minutes above 30" MAP before it overheats. I can run at 25" MAP all day and it stays at 185 degrees. Very Happy with the radiator performance.

Unfortunately I regret I forgot to look at IAT. I sure wish I had looked but I was much more interested in MAP and RPM and Coolant temps. Running at that RPM in your parking lot is very nerve wracking.

After two runups, I pulled the plugs and they all looked very nice. I also did a compression test. The engine was still slightly warm . All cylinders were between 220-235 lbs. I am very happy with that.

This is really a good milestone for this project. The success it motivation to push forward.

Charlie
 
how can you have 2 runs at the same rpm but different MAP? This is a fixed pitch prop right? I don't know of a CS warp drive but I suppose nothing is impossible. Different MAP means different power being produced, so the RPM should be higher at the higher MAP. Something is strange here.
 
how can you have 2 runs at the same rpm but different MAP? This is a fixed pitch prop right? I don't know of a CS warp drive but I suppose nothing is impossible. Different MAP means different power being produced, so the RPM should be higher at the higher MAP. Something is strange here.

Prop blades could be partially stalled during the static run. Seen this many times on test stands so clubs are preferable.
 
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Prop and MAP limitsq

Ross,

Yes, that is what I believe is happening at about 4100 RPM when the RPM no longer increases with the MAP in lockstep.

I will drop the pitch a degree or two to move up the static RPM to 4400-4500 with 5-7 lbs boost and call it good. I believe that would be ideal for this engine, PSRU and this airframe. My target max rpm in flight is 5000 RPM and cruise will be 4200-4600 rpm with about 5lbs boost.

With all the other systems.... Coolant, ECU, PSRU, etc all performing well, I plan to move on to some more mundane tasks like finishing the panel, pitot systems, control rigging, interior work etc.

Thanks.

Charlie
 
testing prop pitch and map and boost

I dropped the pitch to about 18.5 degrees and did a couple of short run ups.

As you would suspect I gained 300-400 RPM but the MAP was down a bit. At 4600rpm and about 36" map. This time I saw about 115*F IAT. EGT was 1200*F. PSRU was about 105*f.

I am still very happy with this set up. I believe 20* with 4100-4200 ish static RPM is a good place to start. RPM will increase some when the plane is air borne. From there, it will be time to do more testing.

I did expect (and hope) to see slightly higher MAP with this prop at that RPM and that pitch, but I am very close to those ideal numbers that I see nothing to change.

I did wonder if my turbo compressor reference line might have been pushing my waste gate actuator open a bit too early? Since I am only doing ground testing, I disconnected it to see what the system would do with no reference signal. Since the waste gate is set to move at about 9 lbs, I doubted this was happening but I just had to test it. My guess was correct. No change at all. Since the BOV is set to release at 10 lbs I am confident this is not limiting the boost as well.

The only other logic I can see would be that the turbine trim of this T3/T4 turbo is tad too large to produce boost as early as would be ideal.

But at this state I am still very happy with it and I need to move on to other tasks. One will be to build a shroud for the intercooler to take advantage of ram air once in flight.

Charlie
 
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What turbine wheel and housing are you running?

The prop won't be stalled once you're moving so you can expect quite a bit more rpm in flight. You're likely to find the FP prop won't be the best compromise in cruise flight, especially up high with the turbo since power doesn't drop off.

I have to add a lot more pitch when I level off up high, even at moderate MAP levels.
 
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Cavitation

The prop won't cavitate once you're moving so you can expect quite a bit more rpm in flight.

Let's get one thing straight. Air propellers can not cavitate. EVER. Cavitation is specifically a phenomenon that occurs in liquids when localized pressures drop below the liquids' vapor pressure and gas bubbles form.

The phenomenon the you are calling "cavitation" is more likely aerodynamic stall of the blades which can occur during static run-up due to the high relative angle of attack of a propeller blade moving at high speed in still air. Forward motion of the aircraft reduces angle of attack of the propeller blades.

Skylor
 
Ross,

Here are the numbers for my turbo.

The Compressor is .60 A/R IN: 54.3mm EX:71mm
54.3 x 54.3 = 2950 71 x 71 = 5041
2950/5041 = 58 Trim on the compressor with a .60 A/R
Turbine is .63 A/R IN:65.25mm EX: 56mm
65.25 x 65.25 = 4257 56 x 56 = 3136
3136/4257 = 74 Trim on the Turbine with a .63 A/R


Charlie
 
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