Rebuilding an EG33.

Forum,

I'm looking seriously at building a EG33 engine for a Bearhawk (I know it's not an RV, but I live in Alaska for Pete's sake) because I would much rather have a liquid cooled setup for comfort and reliability in cold weather.

I don't much like the complete kits from Egg or others so I was thinking about buying an overhauled engine and a PSRU. I found this engine on ebay and like what the guy is doing:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33615&viewitem=&item=130225289996

ECUtune engines are built to exacting specifications and fully documented. These engines are built to happily run high torque at high rpms.

Click to expand...

High silicon aluminum bearings further enhanced with the same ct1 anti- friction coating used by nascar teams are used for both the mains and rod bearings. All bearings are caged and each crank pin and journal is machined to achieve exactly the desired oil clearance within a tolerance range approximately 20 times more acurate than factory specifications. Each bearing bore, journal or pin diameter, and resulting oil clearance is included in the documentation provided to the purchaser. Sets of highly ballanced H-beam rods with ARP 2000 rod bolts put together especially for ECUtune are used.

Click to expand...

You get the idea.... The rods and pistons are shown on his website:

http://www.ecutune.com/svx_rods.htm
http://www.ecutune.com/svx_pistons.htm
http://www.ecutune.com/svx_bearings.htm

These engines are designed for high rpm racing under boost.

Now I know that building a racing engine with race engine ports and camshaft timing is not a good idea for aircraft usage, but I think building racing engine rotating assembly is a good idea because it has much better tolerances, oiling, and balance. I called the guy and talked to him about it and he said he would run a totally different porting and cam timing package in an airplane engine. He said he would put the peak torque around 5000-5500 rpm. He also seemed to know this engine very well.

Now for my questions:

1. Is this engine worth the money to get the tighter tolerances, stronger/lighter rods/pistons, arp studs, grooved deck etc?

2. How complex is it to add a small turbo to the engine for a couple of lbs of boost? I don't want anything crazy, just want a little more torque and perhaps economy.

3. Is expecting 230hp for take off and 175hp continuous over working this engine?

4. Which PSRU do I run? I've heard good things about the autoflight one out of New Zealand.

5. What is the fuel economy like compared to a lycombing? Can I expect to see a little better GPH given that I'm not cooling the engine with the fuel?

6. Which is the best engine computer to use? Real world or SDS?

That is enough questions for now....

Thanks,
schu





"

Matt, welcome aboard

Guy in Canada, named Ross, should be chiming in on this-------also, Egg is a member here, and he should also have input.

For me, I totally agree with your comments about using racing technology to make the engine smoother, and more reliable. Just resist the temptation to get every last HP out of the engine, reliability is king in this arena.

Good luck

akschu said:

Now I know that building a racing engine with race engine ports and camshaft timing is not a good idea for aircraft usage, but I think building racing engine rotating assembly is a good idea because it has much better tolerances, oiling, and balance. I called the guy and talked to him about it and he said he would run a totally different porting and cam timing package in an airplane engine. He said he would put the peak torque around 5000-5500 rpm. He also seemed to know this engine very well.

Now for my questions:

1. Is this engine worth the money to get the tighter tolerances, stronger/lighter rods/pistons, arp studs, grooved deck etc?

2. How complex is it to add a small turbo to the engine for a couple of lbs of boost? I don't want anything crazy, just want a little more torque and perhaps economy.

3. Is expecting 230hp for take off and 175hp continuous over working this engine?

4. Which PSRU do I run? I've heard good things about the autoflight one out of New Zealand.

5. What is the fuel economy like compared to a lycombing? Can I expect to see a little better GPH given that I'm not cooling the engine with the fuel?

6. Which is the best engine computer to use? Real world or SDS?

That is enough questions for now....

Thanks,
schu





"

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Given the work required to do all this, it is a bargain.

Use stock cams though, you want the power band to stay down where the factory has it for aviation use and you should not mess with the valve train without proper validation in aircraft IMO.

You need to add a properly matched turbo to get good altitude performance. It is somewhat more complicated but the difference in performance will be substantial and cruise fuel economy may be better by permitting lower rpms for the same power. If 230/175 hp is all you ever want, you don't need the turbo.

For PSRU units, I like the Marcotte and Autoflight due to the prop/ crank offset for cowling clearance.

The fuel economy will be in the ballpark with an O-540. I would not expect it to be much better if any.

I build the SDS stuff so I may be biased. We have sold hundreds of systems for Subarus and several for the EG33 specifically. We have a lot of experience with these engines on the ground and in the air. We have some specific parts to make installation easier like crank sensor, wiring and ability to drive the OEM coils.

Check what RWS can do for you too though. Tracy is a good guy.

If You really want the right auto engine......

You need to look at Bud Warren's LS1, it would fit a Bearhawk perfect, weighs less than a IO540, fuel burn is about 11-12 per hour, 350hp. Generally cruise at about 2900. Bud really wants to do one for a Bearhawk and his drive is super smooth, has about 700 hrs. flight time, now. Many drives have been bought and are in preparation for flying. Check out Geareddrives.com. You won't be sorry.

rv6ejguy,

Thank you for taking the time to answer my questions, I'm still gathering information, but so far the EG33 looks like a good setup.

CNEJR,

Thanks for your response.... yes I have looked at the geared drives unit, but have some concerns with it:

1. It's very expensive. He wants $30k for a FFW when the engine is $4600. I'm really only able to toss $20k at it.

2. The system does weigh less than a angle valve o-540, but it is at least 50lbs heavier than a parallel valve o-540 which the bearhawk specifically requires because of the weight. The designer states that you need to keep the engine weight down to 400lbs, but some people are putting in o-470s which I figure are about 435lb. I have looked at the weight and balance and it doesn't mess up the CG that bad, so its certainly possible, but I'm not sure that it's worth 100lbs of weight over the subie when the airplane isn't supposed to see more than 260hp and flies very well on 170hp.

3. Testing. The LS1/geared drives/GM computer combo is for the most part untested. From what I understand the wheeler had a Bud built 383 with a carb.

Perhaps your right that the geareddrives setup is the better solution, but it does add a bunch of weight and it is very expensive. Keep in mind that many builders are running o-360s in this plane.

Perhaps I'll call Bud in the morning and talk to him about it.

Thanks,
schu

Yes, weight is the big thing here, the LS engine alone is almost 100 pounds heavier than the EG33 and the V8 redrive will certainly be heavier than ones for the Subaru. The Warren packages would be nice for a big Lancair but will demand some empty weight and C of G alterations for RV10s or the Bearhawk.

A new 3.2L V6 Honda package is in the works for the Titan T51 replicas. This may fill the gap in the 200-225 hp range with a fairly lightweight package using a widely produced, respected engine. Two PSRU options are being developed- a chain drive and a new offset gear drive from the experienced people at Autoflight in NZ. I'm not sure why the Honda engines have never caught on much in aircraft until now. We've just done some testing on the coil on plug ignition to be sure these will be reliable when driving them with our ECU. Looks good so far. Development is proceeding in both the USA and NZ on this one.

Ross,

I agree that the honda may be more comparable to a parallel valve o-540, and Jason Day at Vesta has the 3.5L and the 3.7 which are around the same weight as the subaru.

My primary concern with the honda is that it's untested. There aren't really any of them flying. Also, I just don't think that the rotating assembly has the strength of the subaru. Take a look at this:

Engine Bore Stroke RPM Piston Speed
Lycombing 0-360 5.125 4.375 2700rpm 1968fpm
lycombing o-540 5.125 4.375 2700rpm 1968fpm
Subaru EG33 3.815 2.95 5000rpm 2458fpm
Honda 3.5L 3.5 3.7 5000rpm 3051fpm
Chevy LS1 3.90 3.62 4000rpm 2413fpm

Because the Honda is an under-square engine, but still needs the RPMs to make it's power you have very high piston speeds and you are doing it with 2 less main bearings. Also, as you know the subaru engine has a large amount of crank journal overlap which makes things very strong.

Another interesting thing is that the subaru and chevy have similar piston speeds at takeoff rpm. Setting the chevy for 3000rpm cruise and subaru at 4000rpm cruse the piston speeds are still fairly similar at 1810fpm for the chevy and 1966fpm for the subaru.

This information basically tells me that the subaru is a better aircraft engine than the honda because it's setup for high rpm torque, where the honda engine is more built for low end torque, which is nice in a car, but doesn't do me any good in an aircraft when I still need 5000 rpm to get rated hp. It also tells me that the chevy and subaru are fairly similar when it comes to piston speeds the difference being that the chevy gets me another 100hp for another 100lbs.

Another factor is that there is a guy that lives within an hour of me putting a EG33 in his bearhawk which means I have someone to share notes with and he also has the mount all figured out. As with any conversion, the installation is everything and I think I will have a better installation with a EG33.

Anyway, I'm not totally decided yet, but I'm not really thinking I'll go honda, so the real question is whether the v8 is worth the 100lbs and the CG problems it will likely impose.

schu

AKSCHU,
Im curious if you've looked at the Mazda Renesis engine. From your requirements, it sounds like it might be the perfect fit. It is significantly lighter than the Lyc 540's and Subi's (abt the same as the 320/360 series), and it can provide 250+hp as long as you want in a small, durable, and smooth running water-cooled package. It also has affordable redrives and engine mgmt systems available.

My understanding of the rotary engines is that they need a turbo to make the HP I want and that they run real hot.

Being that a subaru is a AWD car, they are extremely popular in AK so I can get parts anywhere, where the rotary is a bit more difficult to come by.

I'll take a look at them, but so far I'm inclined to stick with what I know and rotaries are uncharted waters for me.

schu

Jason Day seems to have many projects on the go simultaneously with props, drives, engines and mounts. I can't think that any of these will have accumulated any significant flight time any time soon as he seems to be years behind delivering product. Not to cut down his efforts, just reality in this business getting reliable, proven designs into the air. I personally prefer conversions where the people doing them have their own test mule. That's what I like about Tracy Crook and Bud Warren. That speaks volumes in my book.

Schu, You have researched this well. I too like the EG33 for its short stroke, robust design and good power and peak torque numbers at relatively low rpm, only 1000 rpm apart. The engines are not plentiful but there are a number flying and we are helping the other fellow in Alaska a bit plus a couple others here in Canada with ex Crossflow engines..

Ross...unrelated to this topic, but check your PM's...

Chad,

Replied to your PM this morning.

That's weird...I never got it. Can you resend it? I haven't had a new PM arrive all day today...

akschu said:

My understanding of the rotary engines is that they need a turbo to make the HP I want and that they run real hot.

Being that a subaru is a AWD car, they are extremely popular in AK so I can get parts anywhere, where the rotary is a bit more difficult to come by.

I'll take a look at them, but so far I'm inclined to stick with what I know and rotaries are uncharted waters for me.

schu

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You will likely have more heat problems with the Subi, and the Renesis only needs a turbo if you want 300-400hp. A recent test of a peripheral ported Renesis, with carbs, gave 265 hp on Mazdatrix's dyno. The RX-8 OEM rating is 210 or 240 hp depending on which port arrangement you pick.

FWIW, Id guess the rotary engine, with its light weight and only 3 beefy moving parts that do not break in normal service, would be a real advantage in AK. Check out Tracy Crooks website at http://www.rotaryaviation.com/

I don't want to get into a Wankel vs. piston debate here but the Subies are not breaking in service either and the Renesis has not had the best longevity reviews by people in the Mazda servicing, racing/ rebuilding world like Rob at Pineapple Racing and Paul Yaw at Yaw Power. They both say the earlier engines last a lot longer than the Renesis in hard use. Paul should know, he had pre-production engines from Mazda for technical review before they were released.

I've dynoed my share of 13Bs and you are not going to see over 200 hp on any mildly ported atmo one running under 6500 rpm. High sound levels, consequent required muffling with the high EGTs are other drawbacks. A turbo gets them quiet and gives you a lot more power at very low boost without running the rpms up past 7500. Same as on a Subaru, which is why I'm an advocate of turbos on auto conversions.

The Wankel is an engine with small volume and relatively high power to weight ratios. Makes it a good choice for those needing 160-180 hp. The EG33 is 230hp stock at a low 5400 rpm and the long block weighs just over 250 pounds. It is more in the hp/ weight class of a 20B.

Cooling is just a matter of getting the right heat exchangers installed and properly ducted- irregardless of engine type.

Servicing the Wankel in Alaska won't be quite as easy either IMO but if nothing goes wrong with it, it is a moot point anyway.

I too don't want to make this a Mazda vs Subaru argument. I am bothered a bit when critics continue to confuse old with new Mazda technology. We are not locked to 1970s technology today; Mazda has made great improvements on the engine in the last 30 years, as has Subaru, not so sure about Lycomming.

I really like the Subaru engines. Mazda and Subi are both excellent alternatives for our use, each has strengths. Both are extremely smooth running compared to the air-cooled options. The power to weight advantage is clearly rotary, Id give sound issues to the Subi, though the Renesis side port exhaust is much better than older designs. I also like the mechanical stress advantages of the rotary's continual motion over any reciprocating piston/crankshaft arrangement.

I mentioned the heat thing only because the Subi engine envelope is larger and generally requires small front mounted heat exchangers in an RV cowl- a system that is not working out very well (same problem with that arrangement with Mazda, btw)- I agree that a good cooling system should work just fine, it is just that most of the Subi's Ive seen are not cooled all that well at full power... The small rotary package allows radiator mounting either on the side or under the engine where "better" layout options exist.

Id also have to take an issue with Ross's comment about Renesis longevity- it has been reported in a few RX-8's on the road, but not in the air. Breaking it down, the problems Ive seen reported are related to engines that use the OEM oiling system that uses crankcase oil to cool/lubricate the rotors- the detergent oils eventually gum up apex seals. The aviation guys mix clean burning 2-cycle oil with fuel, or install a separate oil reservoir for the rotor pump, which solves the gumming problem.

You can see the actual dyno video and data sheet on PL's website if you want to take issue with the measured 265 HP numbers on the initial P-port intake Renesis experiment. The Rotary loves a turbo if you want more than 250, up to 400+ if you want to push it, but not really needed in RV service. The Renesis is good for an easy 180 hp @ 6000 or 165hp @ 5500 rpm (the torque peak and best efficiency range). Just goose the throttle if you want more speed (and higher fuel burn) for as long as you want- no operating limits up to the 8500 rpm peak.

I have no idea why you would want to limit rpm to 6500 on your Renesis motor comparison, though it might make some sense with earlier 13B's limited by intake design. Intake system capacity has been the power limiting factor with Rotary engines historically, since they were compromised to maximize low end torque in road use. Rotary output rises linearly with rpm until breathing cuts it off. The huge Renesis side ports breathe much better than earlier designs (intake p-ports even better), and particularly so with tuned intakes that target aviation engine speeds. The 6-intake port OEM Renesis engine is rated 250hp @ 8500 rpm; the discontinued 4-intake port version 210hp @ 7500rpm.

IMHO, it appears to me that redrive ratio offerings have been the big problem with the Subi's so far; it hinders them from delivering rated hp levels to the propeller. I'm sure the increased torque from turbocharging helps a lot with that problem. The Renesis aviation guys are using Tracy's 2.85:1 redrive to take advantage of its extended rpm and power capability to actually deliver full power to the prop.

rtry9a said:

I too don't want to make this a Mazda vs Subaru argument. I am bothered a bit when critics continue to confuse old with new Mazda technology. We are not locked to 1970s technology today; Mazda has made great improvements on the engine in the last 30 years, as has Subaru, not so sure about Lycomming.

I really like the Subaru engines. Mazda and Subi are both excellent alternatives for our use, each has strengths. Both are extremely smooth running compared to the air-cooled options. The power to weight advantage is clearly rotary, Id give sound issues to the Subi, though the Renesis side port exhaust is much better than older designs. I also like the mechanical stress advantages of the rotary's continual motion over any reciprocating piston/crankshaft arrangement.

I mentioned the heat thing only because the Subi engine envelope is larger and generally requires small front mounted heat exchangers in an RV cowl- a system that is not working out very well (same problem with that arrangement with Mazda, btw)- I agree that a good cooling system should work just fine, it is just that most of the Subi's Ive seen are not cooled all that well at full power... The small rotary package allows radiator mounting either on the side or under the engine where "better" layout options exist.

Id also have to take an issue with Ross's comment about Renesis longevity- it has been reported in a few RX-8's on the road, but not in the air. Breaking it down, the problems Ive seen reported are related to engines that use the OEM oiling system that uses crankcase oil to cool/lubricate the rotors- the detergent oils eventually gum up apex seals. The aviation guys mix clean burning 2-cycle oil with fuel, or install a separate oil reservoir for the rotor pump, which solves the gumming problem.

You can see the actual dyno video and data sheet on PL's website if you want to take issue with the measured 265 HP numbers on the initial P-port Renesis experiment. The Rotary loves a turbo if you want more than 250, up to 400+ if you want to push it, but not really needed in RV service. The Renesis is good for an easy 180 hp @ 6000 or 165hp @ 5500 rpm (the torque peak and best efficiency range). Just goose the throttle if you want more speed (and higher fuel burn) for as long as you want- no operating limits up to the 8500 rpm peak.

I have no idea why you would want to limit rpm to 6500 on your Renesis motor comparison, though it might make some sense with earlier 13B's limited by intake design. Intake system capacity has been the power limiting factor with Rotary engines historically, since they were compromised to maximize low end torque in road use. Rotary output rises linearly with rpm until breathing cuts it off. The huge Renesis side ports breathe much better than earlier designs (p-ports even better), and particularly so with tuned intakes that target aviation engine speeds. The 6-port OEM Renesis engine is rated 250hp @ 8500 rpm; the discontinued 4-port version 210hp @ 7500rpm.

IMHO, it appears to me that redrive ratio offerings have been the big problem with the Subi's so far; it hinders them from delivering rated hp levels to the propeller. I'm sure the increased torque from turbocharging helps a lot with that problem. The Renesis aviation guys are using Tracy's 2.85:1 redrive to take advantage of its extended rpm and power capability to actually deliver full power to the prop.

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Since this is a Sube thread, I'm gonna defend the honor here:

The Renesis has not demonstrated superior durability to the earlier Gen engines. More power, yes, life before extreme oil consumption and low compression takes hold, no. While the Wankel is never likely to suffer a catastrophic failure in aviation use at the lower rpms, they don't offer the lifespan that most modern Japanese piston engines do. They are inexpensive to freshen up however so that makes it really not much of an issue. No Renesis engine has accumulated even 500 hours of flight time yet, so we don't know how they will actually hold up. Perhaps the pre-mix oil negates this problem entirely- only time will tell.

I think we can say that all liquid cooled engines have suffered poor cooling when saddled with a poorly designed cooling system- not a particular engine's fault here. The Wankel also demands a good oil cooler setup. Under engine rad setups are generally superior to cheek setups. In this respect, the flat Sube is about the same height as a Wankel.

If you want to spin the Renesis up to 8000-8500 it will produce the power, the question is for how long and at what noise and fuel consumption level. It is completely unproven in aviation apps at this time and power levels. Breathing ability affects the power bands of all engine types. We have a number of factory piston engines with redlines above 8000 rpm as well and race piston engines rev far above where the best Wankels run.

There are many different PSRUs available for Subes with ratios from 1.64 to 2.20 so this has never been a limitation for DIYers.

As far as power to weight ratios go, the modern Subes are not too far off a Wankel. The EZ30 is better than 1 pound/hp of long block weight and the new EJ25 is at about 1.14.

It really comes down to what you like. I personally like anything that is innovative and different and I'm intrigued by rotary powered aircraft and how they perform.

Ross,

I have several more questions if you don't mind:

1. What boost levels do you run on a single turbo EG33 with the stock 10.1 compression.

2. Is the ECUTune engine at 9.3:1 compression going to be a much better setup when running a turbo? I suspect it will be a much better setup.

3. Which turbo do I need to run and how do I know it's sized up correctly. In other words how can I match up the engine to the correct compressor wheel, etc.

4. How do you deal with the waistgate? I saw that the egg engines use a servo actuated waistgate and a computer controller. Does your ECU have provisions for turbo control?

5. What kind of HP should I look for at sea level or normalized? Is 250hp reasonable?

6. What will my cruise rpm be? Do you think I can get it under 4k rpm given the lower compression and higher boost levels?

7. How do I verify that I'm not overboosting the engine? Will that show up on a knock sensor?

8. Last, but certainly not least, are there PSRUs that run the prop the correct direction? The bearhawk uses an offset vertical stab to handle the left engine torque, so finding a PSRU that turns the correct direction would save me from some cutting and welding on the fuse.

I think that's it for now.... I'm just trying to get my hands around what it will take to build my own system since I really like the ECUTune/turbo setup.

THANKS!!!

schu

akschu said:

Ross,

I have several more questions if you don't mind:

1. What boost levels do you run on a single turbo EG33 with the stock 10.1 compression.

2. Is the ECUTune engine at 9.3:1 compression going to be a much better setup when running a turbo? I suspect it will be a much better setup.

3. Which turbo do I need to run and how do I know it's sized up correctly. In other words how can I match up the engine to the correct compressor wheel, etc.

4. How do you deal with the waistgate? I saw that the egg engines use a servo actuated waistgate and a computer controller. Does your ECU have provisions for turbo control?

5. What kind of HP should I look for at sea level or normalized? Is 250hp reasonable?

6. What will my cruise rpm be? Do you think I can get it under 4k rpm given the lower compression and higher boost levels?

7. How do I verify that I'm not overboosting the engine? Will that show up on a knock sensor?

8. Last, but certainly not least, are there PSRUs that run the prop the correct direction? The bearhawk uses an offset vertical stab to handle the left engine torque, so finding a PSRU that turns the correct direction would save me from some cutting and welding on the fuse.

I think that's it for now.... I'm just trying to get my hands around what it will take to build my own system since I really like the ECUTune/turbo setup.

THANKS!!!

schu

Click to expand...

The boost level needs to be kept low with 91 octane fuel and 10 to 1- maybe 34 inches to be safe. With 100LL, you can run up to 50 inches.

The forged pistons are a really good idea when turbocharging this engine as it does not have under piston oil jets like the factory turboed engines do. The lower compression would allow you to run maybe 36 inches on 91 octane which should give you well in excess of 260hp for takeoff.

I can help match a turbo for you if you know the hp and typical altitudes you operate at. Be aware that the turbo system with intercooler will add a good 40-50 lbs.

We don't control the wastegate actuator but you can use a standard pneumatic actuator and integral wastegate or an external wastegate. Advantages to both. I like the integral stuff but we are limited in turbine housing choices a bit with these.

With a turbo, you should be able to get cruise rpms below 4000-depends on how much power you need for cruise. Without a turbo, you'll have to spin up at least 4500.

I'd monitor MAP to be sure you don't overboost, but the wastegate will control max boost automatically. Just shove the throttle up. You can have a knock sensor as a backup to control detonation but there are some limitations to be aware of.

The Marcotte will retain the correct prop rotation direction and give you about 2 inches of prop hub offset which helps with intake manifold clearance from the cowling. The newer RWS drives maintain direction too I think. Autoflight, I'm not sure but you can ask the other guy up there in AK as he uses a special high hp version of that PSRU.

The turbo will require an oil scavenge pump unless you can mount it very high under the cowling. This can be engine driven or electric but it is a critical system. I'm using a new, lightweight electric gear pump now.

rv6ejguy said:

The boost level needs to be kept low with 91 octane fuel and 10 to 1- maybe 34 inches to be safe. With 100LL, you can run up to 50 inches.

Click to expand...

I'm not at all interested in 100LL so it sounds like lower compression pistons are the way to go.

rv6ejguy said:

The forged pistons are a really good idea when turbocharging this engine as it does not have under piston oil jets like the factory turboed engines do. The lower compression would allow you to run maybe 36 inches on 91 octane which should give you well in excess of 260hp for takeoff.

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That makes this ECUTune engine even better. It has the forced oiled pistons.

rv6ejguy said:

I can help match a turbo for you if you know the hp and typical altitudes you operate at. Be aware that the turbo system with intercooler will add a good 40-50 lbs.

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Sure, but I'll be into a muffler at least 10lbs and I am looking for something a little quieter than a lycombing. You think the total weight will be less than an o-540?

rv6ejguy said:

We don't control the wastegate actuator but you can use a standard pneumatic actuator and integral wastegate or an external wastegate. Advantages to both. I like the integral stuff but we are limited in turbine housing choices a bit with these.

Click to expand...

That sounds reliable, what kind of money will I be into one of these?

rv6ejguy said:

With a turbo, you should be able to get cruise rpms below 4000-depends on how much power you need for cruise. Without a turbo, you'll have to spin up at least 4500.

Click to expand...

I suppose it depends on how fast I want to go. Remember many people are flying this with 170hp so I really only need 150hp to go which should be fairly low.

rv6ejguy said:

The Marcotte will retain the correct prop rotation direction and give you about 2 inches of prop hub offset which helps with intake manifold clearance from the cowling. The newer RWS drives maintain direction too I think. Autoflight, I'm not sure but you can ask the other guy up there in AK as he uses a special high hp version of that PSRU.

Click to expand...

Is the marcotte worth it to not move the stab or should I just get an autoflight, and move the stab and be happy with reverse prop? Where do I buy a marcotte?

Thanks,
schu

Ross,

The ECUTune guy said he would build the engine for $5500 if I omit the head porting and aftermarket camshafts. So here is the question:

Is $5500 worth having it professionally built, turbo specific pistons, better crank tolerances, way better rods, arp fasteners, balanced, and 2lb lighter rotating assembly?

I figure I could get a SVX engine pretty cheap and rebuild it for $1500 so I'm really looking at a $3000 premium for this stuff.

Is this way overkill or reasonable? Should I just do this instead:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=330239962930

I have a bad habit of way over doing things so just looking to see if I'm going overboard.

Thanks,
schu

Yep, if you are going to run a turbo with 91 octane, much safer to drop the CR into the high 8s.

I think forced oiled pistons means either the rod column is gun drilled (unlikely) or he is referring to the pins being oiled from the oil ring groove/ scraper, probably the latter. A good idea but it does not cool the piston like the turbo engines. Probably no need with forged pistons however.

With a turbo, I think weight will be 20-30 lbs. heavier than an O-540, but you'll have a lot more power, especially at altitude. It will be much quieter than a Lycoming and much smoother.

I'd guess the turbo will be just under $1K with all the bits. Add a few hundred for an intercooler and a few hundred more for some 321 stainless tubing.

If you only need 180 hp or so, I would not bother with a turbo unless you are flying in high terrain. You will certainly be lighter than the Lycoming sans turbo system, even with a serious muffler.

The PSRU is as important as the engine. If either takes a dump, you are going down. Best to compare total cost of this to a fresh O-540, then it seems like a bargain. I can put you in touch with Marcotte. They are based in Quebec, Canada. Slow to deliver unfortunately.

If you have engine building experience and access to a GOOD machine shop who understands Subarus, then the JDM core would save you a lot. The stock rods are fine, you just need forged pistons and the rebuild parts. Be aware that these are a relatively complicated engine and don't tolerate mediocre assembly. If you are not experienced with DOHC Japanese engines, I'd be very careful. $5500 for the engine, trick parts and labor is a good deal IMO if the work is truly quality.

A few notes on pistons here: In my experience over the years, the custom piston makers can turn out beautiful parts, just not often to your specs. They often have "better" ideas how to do things. Beware of that one- about 50% of the pistons I have had custom made by JE, Wiseco and Venolia have had to be done again. Secondly, you can choose between alloys either a high silicon/ low expansion 4032 or a 2618 higher expansion tougher alloy in the JEs. For your application, the 4032 would be a better choice but you still have to open up wall clearance a bit over the OEM cast pistons. You will either have to hone or get the pistons made slightly smaller than stock.

Subes have an innovative way of extracting the piston pins and what the aftermarket guys supply for pin locks makes installation a nightmare.

The EG33 uses a tabbed oil rail so be sure this is incorporated into the new ones if using OEM ring sets. Get a straight bore pin or your life will be miserable when it comes time to pull them out.

You can get pin offset or not. Center seems to work ok. OEM is offset.

The pin boss to crank counterweight clearance is minimal on these engines as is clearance to the block webs. Be sure the piston maker does not add material below the stock pin boss dimensions- or it won't turn over.

Now are you seeing that all this takes a lot of time? This is just the piston part. You should see the heads!

Good news is that you don't need the forged pistons if you go atmo (no turbo). In fact if the JDM has good compression and leakdown, clean oil and good oil pressure, you might choose to use as is. Many people have.

Marcotte Info

Schu,

I PM'd you with contact info for Marcotte.

Matt showed me this thread and suggested I join up and post here since he was asking me questions spawned from this thread.

My 9.3 compression pistons are from 4032 forgings and use rings from the same manufacturer as OE with the tabbed oil rails. They are also (as all my pistons are) specially machined to use the OE Subaru pin locks. The force fed oiling is as suspected--the pins are force fed oil from the oil ring groove. This does not cool the piston it prevents pin hole wear and friction by forcing oil onto the top of the pin at the same time pressure is being exerted on the piston trying to force oil out. The thermal coating on the top of the piston is important to the piston fitment. It helps keep the piston cooler making it possible to use smaller sidewall clearances. The anti friction skirt coating is also important to fittment. If the piston should ever get hot enough to cause scuffing it will wear off the moly friction coating instead of the actual piston swelling into the bore. Engine builders often use larger sidewall clearances than are best with forged pistons because forged pistons do change in size while operating more than cast pistons do and they don't want to risk the piston swelling into the bore. It is also correct that pistons are rarely actually the diameter specified. For proper piston fitment I have the pistons made first, then measure them, then hone the block to the necessary bore for each piston to have the exact desired sidewall clearance. Doing this and machining to tight tolerances allows the sidewall clearance to be set dead on to ensure the piston will never swell into the bore while maintaining quiet operation and improving cylinder seal thus increasing MEP. My 9.3CR pistons also have light anti-detonation grooving and a v notch between the 1st and 2nd compression rings. If I end up building an engine for Matt I will set the sidewall clearances to .0025" for the coated pistons.

I favor this piston for Matt's application because it will provide excellent performance both naturally aspirated and with forced induction. If the engine is run naturally aspirated he will be able to use all pump gasolines including regular unleaded. I suggested he might consider supercharging and using two bypass valves--in which case even if his supercharger completely seized up the engine would still function reasonably well.


The rod and main bearings and oil clearances are even more critical on these engines. The OE tollerances are quite sloppy and some engines have what I consider grossly unacceptably small oil clearances from the factory. The OE rod bearings are tri metal bearings. I have moly coated high silicon aluminum bearings made for both the mains and rods. All bearings are caged (that means the block is assembled with the bearings but without the crank and the rods are assembled with the bearings and not installed on the crank and the bores of the bearings are measured with a brown and sharpe intrimik) The crank is then machined according to the caged bore measurements to obtain the exact desired oil clearances. With my coated bearings I favor 15 tens for both the rods and mains except the bearing with the thrust surfaces which I give a few more tens to increase the oil flow.

Welcome!!!

Mike, welcome to VAF.

Good to have you on board.

Enjoyed the tech info. Thanks.

Welcome to VAF. This is the proper way to assemble and check these split case engines and I'm impressed by your attention to detail. As I said, with these parts and method of assembly, your prices are more than fair.

How is your supply of these engines from Japan?

thanks Mike, thanks Ross,

The US and JDM engines are the same. I use US engines for cores. They are readily available. These engines are all of the age that they have bad head gaskets no matter what country you get them from. Between bad head gaskets, cars with blown transmissions that cost more than the car, cars crashed by high schoolers, and cars that have been driven on salted roads their whole life without maintenance of the undercoating there seems to be plenty of good engine cores around.

LAN,

You mentioned that these have the bad head gaskets, which you also mentioned on the phone where the gaskets only last 10 years then fail. Can you tell us aviation guys how this translates to safety at annual? Can you easily detect the failed gasket with a compression test, and does it cause sudden failure or is this something detectable early on? If it's sudden then how do we deal with this in the aviation world? Replace the belt and head gaskets every 8 years? Also, does your step deck machine work and a good gasket like a cometic solve this?

As far as me buying an engine, the current plan is to purchase one from you. The parts and knowledge are worth the money, but after parting with a very large chunk for the airframe I'm still catching up. The order will probably come in at the end of the summer.

Thanks,
schu

First let me explain what a step deck is so that others reading this will know what were talking about. Cylinder heads bolt to the cylinder block. That much I'm sure anyone interested in this conversation will know. The block side mating surface..flange if you will..is called the deck. The cylinder head mating surface is normally resurfaced perfectly flat and the deck on the cylinder block is normally resurfaced perfectly flat in most engine builds. A step deck is when we cnc machine off a very small amount of the deck everywhere except for right around the cylinders. In this case the area around the cylinders is slightly higher than the rest of the deck. When the heads are torqued down the head gasket is compressed more and a greater percentage of the clamping force exerted by the head bolts/studs is exerted directly around the cylinders. This allows us to hold in greater cylinder pressures with the same amount of tension on the head bolts/studs. We don't need a lot of pressure on the head gasket around the oil passages or coolant passages. Coolant and oil are under very little pressure as compared to combustion pressures. So while a step deck is beyond the abilities of most automotive machine shops it can be very beneficial.

Most head gasket failures in performance applications are actually head bolt/stud failures. Bolts or studs have a yield strength. When stretched beyond that they don't spring back to their original length thus clamping force is lost and then the head gasket leaks. By doing a step deck we can contain the higher cylinder pressures of performance applications without torqueing the head bolts/studs so tight that they are in danger of being stretched past yield due to thermal expansion if the block runs hot.

The OE head gaskets are very good. In fact I use all OE seals and gaskets in my engine builds. The cars that these engines are coming out of were made in 91-96 though. It's just to be expected that the head gasket will go bad after that much time. 12 to 15 years isn't a bad run for a head gasket.

I don't have a private pilot’s license and ground school was a long long time ago for me so I don't really know anything about annual requirements.

When the head gaskets fail they are actually very hard to detect by normal means. The engine just likes to overheat when the head gasket is bad. It's never a massive failure so you don't see steam out the exhaust or have a noticeable loss of coolant until your radiator boils over. I've block tested engines exhibiting these symptoms and they never test out bad. Then I rebuild the engine and there's always a cylinder that I can tell had coolant leaking into it.

akschu said:

LAN,

You mentioned that these have the bad head gaskets, which you also mentioned on the phone where the gaskets only last 10 years then fail. Can you tell us aviation guys how this translates to safety at annual? Can you easily detect the failed gasket with a compression test, and does it cause sudden failure or is this something detectable early on? If it's sudden then how do we deal with this in the aviation world? Replace the belt and head gaskets every 8 years? Also, does your step deck machine work and a good gasket like a cometic solve this?

As far as me buying an engine, the current plan is to purchase one from you. The parts and knowledge are worth the money, but after parting with a very large chunk for the airframe I'm still catching up. The order will probably come in at the end of the summer.

Thanks,
schu

Click to expand...

A remote oil system would be a big plus for you guys wouldn't it? I have a vertical machining center with .00005" resolution and 50x20x6 travels--plenty big enough to machine pans for a remote oil system.

Most aircraft engines are wet sumped and they work just fine because we are usually under positive G with a straight vector- simple, reliable and light. I personally don't like remote oil systems on aircraft like the Rotax 912 uses. Just a PITA in so many ways.

Now if you wanted to put your CNC machine to good use, come up with a stronger nose gear design for the RV A models. You'd have plenty of sales for that piece!

Do you have one? Someone with an RV A would have to help me develop it.

rv6ejguy said:

Now if you wanted to put your CNC machine to good use, come up with a stronger nose gear design for the RV A models. You'd have plenty of sales for that piece!

Click to expand...

longassname said:

Do you have one? Someone with an RV A would have to help me develop it.

Click to expand...

Oh boy! Dude, this is a can of worms that you don't want to open. I looked at doing this for about a year on and off. Liability aside, there are just too many configurations of RV-A nosegears to make a one-size-fits-all solution. For instance, Ross has a engine mount that has a Subaru on it, there are three different styles of RV-A lycoming mounts that I'm aware of, besides ALL the different dash number lycomings that are mounted on those three, with accessories hanging off all different places. You'd need at least 5 different examples of RV-A's before you could even think about finalizing a design, and even then, once sold, it would be a nightmare to support all the different installations.

I'd just start with the 7A, then do the 9A and then maybe the 8A and 6A later. Forget the alternative engine guys as they are just too few at the moment to make it commercially viable. If you cover the Lycoming powered 7A and 9A, you'd be rich.

The liability part would be the sticky part in the US unfortunately. Get some good legal advice before starting. Many vendors make clients sign a release/ waiver before shipping parts. Opinions vary on how much protection that offers.

I bet if you did it right you'd have a market for 1000-1500 kits within a year or two and a constant supply after that the way RV kit sales are going.

I didn't say it would be an easy path but many people would be grateful.

I did some editing of my website. There's a page for the EG33 engines now and a page of some pictures from the assembly of one. If anyone is interested it is: http://www.ecutune.com/svx_longblock_photos.htm

If anyone knows anything about ports I think you'll be pretty impressed with the porting.

Very nice! What kind of flow numbers do you see before and after on the bench?

well, I almost hate to admit it but I bought a lycoming. I really wanted a subaru, and have full confidence in Mikes ability to build a subie, but I just could not get comfortable with the psru options, and lack of prop choices that had any amout of time with this engine/psru combo.

When this io-540 came up for an exceptional price (poor guy getting a divorce) that made up my mind for me.

I would like to thank Ross and Mike for answering my questions. You guys are great and I'm sad I didn't get to work with you.

Thanks,
schu

No worries. When A deal comes up on a 540, that is about the only way you can afford one! Glad that came by for you. Hope it works out well for you and you get your bird flying. Don't forget the pre-heat.

Is this still the case? What kind of #'s of RV A models are being built? Are they common enough that I'll find an RV A owner in my local EAA chapter?

This comment just came back to mind because I'm begining the research to build an aircraft myself. I've got it in my head I want to build a two seat gyroplane.

rv6ejguy said:

Most aircraft engines are wet sumped and they work just fine because we are usually under positive G with a straight vector- simple, reliable and light. I personally don't like remote oil systems on aircraft like the Rotax 912 uses. Just a PITA in so many ways.

Now if you wanted to put your CNC machine to good use, come up with a stronger nose gear design for the RV A models. You'd have plenty of sales for that piece!

Click to expand...

RV-10 with 3.6 liter Eggenfellner Subaru

I am building an RV-10 in the Netherlands powerred with a Eggenfellner Subaru 3.6 liter 220 hp (2008 model).

Now we are reaching completion we have to start up the certication proces. That proces differs from what has to be done in the USA. But to smooth the process in the Netherlands it will help us a lot if we can produce copies of certificates and airworthiness test in the USA or Canada of the combination Vans RV-10 airframe and 3.6 liter or E6T 3.0 liter engine. So I wonder if anybody has a RV-10 certified with one of the Eggenfellner Subaru's and is willing to give us copies?

Thanks

Rob van Spaandonk

PH-RVX

As far as I know there was only one with a Subaru and it is not with us anymore. Ross should be getting close though.

Robair said:

I am building an RV-10 in the Netherlands powerred with a Eggenfellner Subaru 3.6 liter 220 hp (2008 model).

Now we are reaching completion we have to start up the certication proces. That proces differs from what has to be done in the USA. But to smooth the process in the Netherlands it will help us a lot if we can produce copies of certificates and airworthiness test in the USA or Canada of the combination Vans RV-10 airframe and 3.6 liter or E6T 3.0 liter engine. So I wonder if anybody has a RV-10 certified with one of the Eggenfellner Subaru's and is willing to give us copies?

Thanks

Rob van Spaandonk

PH-RVX

Click to expand...

You might pose this question to the EGG Yahoo group.
http://groups.yahoo.com/group/subaruaircraft/
Good Luck.

subenews yahoo group

Another group to visit is http://groups.yahoo.com/group/subenews/ - lots of good people there.