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Lycoming vs. Chevy 4.3L V6

EchoCharlie1

EchoCharlie1

Active Member
I'd like to know of experiences in using the marine grade Chevy 4.3L engine (designed for long-term WOT usage) in the RV-7A or similar airframes (-6/-6A, -7, -9/-9A) along with a Belted Airpower Firewall forward system.

To help with reducing the long responses, I am an experienced pilot, Apache helicopter repairer, engineer, and more (including over 25 years of mechanical experiences with engines)...so, I don't need a grade-school introduction the horizontally opposed 4 cylinder or the V-6 Chevy engine.

In advance, thank you for your input and assistance.

Cheers,
Frank
 
The Chevy installation is about 100 pounds heavier. This extra weight really screws up the weight and balance of your RV.
Charlie Kuss
 
No matter how much you love the idea, and plan on keeping the airplane forever, and because of your background it proves to be a trouble free perfect precision install work of art that makes the cover of kitplanes..............

The insurance company will be hard to convince,

and not if but when it comes time to sell you will be disappointed at the low ball tire kickers with few if any real offers above the value of the airframe with NO engine!:mad:
 
I looked at the Belted Air setup from Jess Myers while I was based in Las Vegas. Very nice setup & well tested but I ended up going with the Superior IO-360. Now they are in bankruptcy. Go figure.
My concern was related to any maintenance I would need if I happened to be away from home. My engine knowledge was weak at the time and felt I was not capable of servicing it myself.
 
Seems the poster is asking for first hand experiences of actually using this powerplant. He makes it clear he does not want to read a bunch of the usual drivel.

Anyone with performance, fuel burn and reliability feedback?
 
Chevy V-6 vs. Lycoming

I appreciate the information and understand that the resale would be disappointing, but I'm thinking more along the lines of fuel burn rate, reliability, maintainability, harmonics, weight and balance, etc.

The question is: Why are we still relying on 1940's engine technology in this new millenium, when everything else has evolved? Is there a better way of doing things or are we just doing it because "someone" says it's better or that everyone else is doing it, so it must be good?

Yes, there are statistics out there and many years of proving the reliability of the H-4 air-cooled engine, but can we do it better, cheaper, and with greater reliability? Can we have a safer engine from a different application?

I'm not for or against either option, but just wanted some data points from which I can make a sound decision.

Thanks again...
 
Stats

EchoCharlie1 said:
The question is: Why are we still relying on 1940's engine technology in this new millenium, when everything else has evolved? Is there a better way of doing things or are we just doing it because "someone" says it's better or that everyone else is doing it, so it must be good?

Yes, there are statistics out there and many years of proving the reliability of the H-4 air-cooled engine, but can we do it better, cheaper, and with greater reliability? Can we have a safer engine from a different application?


Thanks again...
Click to expand...

To answer the first question, because it works.

To answer the second question, the success rate of using alternative engines is dismal. Only a very small percentage of those using alt engines have had only marginal success. Personally, of the 10 people I know that chose alternative engines, only two fly consistently but have trouble with cooling and are extremely disappointed with the performance not coming close to advertised and promised, 2 have switched back to a conventional engine after years of tinkering, off field landings and lack of consistency. Three are not in the air yet after years of issues and finally 2 have crashed.

That's 10 for 10 with problems. Conventional engines are not without issues either but the success rate far exceeds the alt engine crowd.

Good luck. I will just be blunt and say, don't do it.
 
EchoCharlie1 said:
... but I'm thinking more along the lines of fuel burn rate, reliability, maintainability, harmonics, weight and balance, etc.
Click to expand...

Considering the current state of piston engine technology for our little aircraft, it sounds like you are describing a Lycoming installation. :)
 
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<<fuel burn rate>>

Much potential to be lower.

<<reliability>>

Obviously the base engines as delivered are very good. Most troubles are with aux systems.....PSRU, fuel, cooling, electrical and computers. You break the engine by doing one of them wrong.

<<maintainability>>

Again the base engines are fine, but you'll spend a lot of time on systems.

<<harmonics>>

Overall, the auto conversion folks have a dismal record in that area.

<<weight and balance>>

So far, the whole package is almost always heavier.

I note you're both an engineer and a gearhead, so you're a lot better prepared than most. You'll need both skill sets. Do it if you really like designing, creating, and finding solutions. It can be done, and it can be very satisfying. Examine fundamentals, believe nothing you're told, in particular regarding torsional vibration and cooling. Heck, don't even believe me.

Don't do it if your prime motivation has anything to do with saving money, or is based on a belief system about "modern engines". Engines are easy. Drive systems and support systems are hard.
 
High torque w/ low RPM

A good aircraft engine puts out high torque at low RPM's.

Most auto engines make their torque at RPM's higher than you can efficiently spin a prop, thus the need for a PRU.

Although the basic design of aircraft engines have not changed in many decades, neither have auto engines.

What has changed with auto engines is the fueling and ignition systems. Also, the metallurgy in the manufacturing of both engines has changed for the good over the years.

We are lucky in that we can run some very radical electronic ignitions. (Radical for aircraft anyway.)

You can also add automotive style electronic fuel injection to Lycoming engines, if that is what you are looking for. There was a good article in the March 2009 issue of KitPlanes by Marc Cook titled "The Egal Takes Off" which describes Prescision Airmotive's electronic fuel injection system.

The down side of the thing is price. At $8935 it seems a bit costly but remember, it provides all of your fueling and ignition needs. So figure $3500-$4000 for mags and a carb, the true cost is only $5K more.

That is a $5K premium to have your engine run like a car. BTW, that $5,000 will buy 1,666 gallons of 100LL @ $3.00/gallon.

Is it worth it? That is up to you. If I had the extra coin laying around and my engine could accept this, which it can’t, I would do it. But then I’m kind of a geek that way.
 
Responses

Thanks to all that have responded, however the insulting email that I got was NOT warranted. I am neither "dumb", nor an advertiser for any auto-engine conversion to aircraft, I was seeking information from those that have experienced the aforementioned and all the problems that have been experienced.

As for "P mag" usage, I have no idea what the difference is between a P-mag and a regular mag, so that insulting email didn't make any sense. Perhaps electronic ignition would be something to consider, as most have already. :confused:

So, although I may have stated that the H-4 is a dinosaur, I was NOT condoning the use of anything else...I was ASKING about options. Pros and cons, ying and yang, black and white...get the picture? Most importantly, if I was only worried about costs, I wouldn't be an aircraft owner. It's like having a child...if you have to wait until you can afford one...it'll never happen.

Thank you for your time and thank you for explaining the experiences that others have had.

Now, if they could only stop wasting those jet engines on trucks at the race track, we'll be back to that balance in the universe. :D

Cheers and safe flying to all...
 
Lyc. Vs Chevy V6

Okay,
sounds like EchoCharlie1 has had enough of input from the listers.....but I have to just add one thing.

Javelin V6

ask Dave Blanton about spending, what, 30 years of his life trying to make the Ford V6 the new powerplant in light aircraft.

he's been thru it all; I think even patented some of his better solutions,
still advertises this conversion packages, I think!?!? Chevys aren't much different I'd hazard.
 
No V6 experience but

Have a lot of experience with a 1.8 litre soob in a Zodiac..apart from the fact it tried to kill me three times it was great..:)

It basically comes down to the fact that in reality the engines are the same, i.e based on the same technology...will be about the same fuel burn per unit of horsepower..its just pistons going up and down turning a crank.

Mordern autos are very nicely machined, better in fact than the average Lycoming..But now add the required gearbox and cooling system and it will likely be as expensive and history has proven auto conversions to be far less reliable on average.

The Pmag you describe is an electronic ignition, with variable timing and like all the EI's does better than the old 1940's mags, (more efficient).

FI systems are also as much as you need in an airplane motor and run lean of peak gives very low fuel burn for HP produced.

This may sound like ranting..it isn't meant to be but there is a perception that Lyc's are ineeficient old clunkers when in reality they are not at all. They are designed purposely for the job and do it very well.

Add an EI and FI and they won't be beat by anything..Except maybe rebuild costs will be less..

Where airplane engines fall down is the persistent use of mechanical fuel pumps, but managed correctly this is not a huge issue. Cost of parts is not to be discounted either.

Frank
 
EchoCharlie1 said:
I appreciate the information and understand that the resale would be disappointing, but I'm thinking more along the lines of fuel burn rate, reliability, maintainability, harmonics, weight and balance, etc.

The question is: Why are we still relying on 1940's engine technology in this new millenium, when everything else has evolved? Is there a better way of doing things or are we just doing it because "someone" says it's better or that everyone else is doing it, so it must be good?

Yes, there are statistics out there and many years of proving the reliability of the H-4 air-cooled engine, but can we do it better, cheaper, and with greater reliability? Can we have a safer engine from a different application?

I'm not for or against either option, but just wanted some data points from which I can make a sound decision.

Thanks again...
Click to expand...

Frank,

The data points and assurance it will work is not out there.

It takes guys like you to bite the bullet and do it. Find those data points and others will appreciate the effort. If you fail some will say at least you tried to make it work, others will say, I told you so.

You have the interest, go for it.
 
alternate engines

Of the several people I've known over the last 20 years that experimented with alternate engines,there are 2 that stick out. Those 2 men both very talented,had the same agenda. These men were experimenters. They both had their ups and downs and you can take downs literally. They both had the same objective, to see if they could make an alternate engine work as well or better than an aircraft engine. The first gentleman, back in the 80's had a forced landing due to engine failure (no airframe damage). Afterwards I asked him how he felt about the engine problems and the ultimate failure. He said "all I wanted to do was to prove one way or the other whether this engine would workout". The test to him was successful. He promptly re installed his Lyc.. My other friend put a subie in a tailwind. He never flew it anywhere he just tested and loved it. My point is if you want to fly, get an aircraft engine. If you love to experiment go with alternate engines.
 
One last word

Peace!

I got it, I got it...only takes one or two lumps to the back of the head with that 2x4! :(

Okay, so there is more than just "one word". For the record, I like the Lycoming engines, but I had seen a very nice RV-7A for sale in Canada that has the Chevy V-6 engine and I just wanted to know what people were experiencing.

I am convinced...Lycoming it is and shall be.

Best regards and thanks to all that assisted me in this research.
 
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flyboy1963 said:
Okay,
sounds like EchoCharlie1 has had enough of input from the listers.....but I have to just add one thing.

Javelin V6

ask Dave Blanton about spending, what, 30 years of his life trying to make the Ford V6 the new powerplant in light aircraft.

he's been thru it all; I think even patented some of his better solutions,
still advertises this conversion packages, I think!?!? Chevys aren't much different I'd hazard.
Click to expand...

The senior Dave Blanton has not been with us for some time but he was a real pioneer in this field. The 3.8L Ford engines had plenty of issues in stock form with head and valvetrain problems even in ground use. The early examples were not a good starting place for an aviation conversion. The Blanton belt drives were not a great design either with plenty of problems. Other questionable engines mods created additional problems. Others who have pursued the Ford 3.8 and learned from the experiences of others such as Dave Sharples in Oz, finally got excellent performance, reliability and longevity from the Ford V6. It took some persistence for sure.

The modern Chevy 4.3 is a MUCH better engine than the early Ford V6s and the drives offered by Belted Air apparently perform well from the few reports we have (I wish more people would weigh in here). Just as many people have stated here though, fuel burn vs. speed and weight compared to an O-360 probably won't be there but I'd think cost would be less.

For most, Lycoming will suit their needs best. Alternatives are there for people who just don't want a Lycoming for whatever reason.
 
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GO-300

Regarding Chevy's,

I've had fun thinking about this over the past few years, here's my thoughts:
A stock 4.3L V6 with PSRU is nearly 500lbs(!) See: http://www.kitplanes.com/magazine/engines/155-1.phtml

This is just too porky for me to consider viable, living as I do so close to Van's home field. Plus, a stock 4.3L is less than 160hp at 2700 prop rpm (4000 engine rpm).

So, aluminum block and heads would be mandatory, IMHO. I'm guessing the weight would still be probably 50lbs porky. I've not been able to find exact weight deltas for the aluminum bits, does anyone down in NASCAR land have solid data?

GM performance parts Al block: $4500.
Brodix heads: $2300.
Forged rotating assembly,
all the good stuff: $2500.
Dry sump system, required
by the Al block: $1000.
Custom exhaust, carb, ignition,
electrics: $2000.
Custom Al radiator: $ 500.
Machining: $1000.
BAP PSRU: $5600.

So, for (very) roughly $19,500 I (you) could have what amounts to a erzatz Continental GO-300. :eek:

If done by someone with a heck of a lot of mechanical, electrical, and engine systems expertise, it could work as well as a GO-300, perhaps even a bit better?!

It would be a ton of fun for me, but I'm not sure the ROI is there. ;)

I like building Chevy engines, if someone wants to fund this experiment just give me a holler. :D
 
My Chevy Vortec powered RV-7A

I do own an RV-7A powered by a chevy vortec 4.3. Honestly, it is a good aircraft and the specs are good. At cruise speed, I burn 7.3 gal/hour. I recently had to replace a small rubber gasket on the oil pressure sensor. It costs 20$ and 30 minutes of work to get the job done. The belted air power forward kit is really well designed. The only thing I still can't figure out is why they replaced the fuel injection system with a carburator.

One more thing, there are no mecanical fuel pumps with the BAP setup. I'm using 2 electric fuel pumps instead and some people might think that it is not a good idea to rely on the electric system only. Of course, the electric system is also redundant (2 batteries, etc) but still...
 
fducharme said:
I do own an RV-7A powered by a chevy vortec 4.3. Honestly, it is a good aircraft and the specs are good. At cruise speed, I burn 7.3 gal/hour. I recently had to replace a small rubber gasket on the oil pressure sensor. It costs 20$ and 30 minutes of work to get the job done. The belted air power forward kit is really well designed. The only thing I still can't figure out is why they replaced the fuel injection system with a carburator.

One more thing, there are no mecanical fuel pumps with the BAP setup. I'm using 2 electric fuel pumps instead and some people might think that it is not a good idea to rely on the electric system only. Of course, the electric system is also redundant (2 batteries, etc) but still...
Click to expand...

Fred,
What is the empty weight of your 7A?
Charlie Kuss
 
fducharme said:
I do own an RV-7A powered by a chevy vortec 4.3. Honestly, it is a good aircraft and the specs are good. At cruise speed, I burn 7.3 gal/hour. I recently had to replace a small rubber gasket on the oil pressure sensor. It costs 20$ and 30 minutes of work to get the job done. The belted air power forward kit is really well designed. The only thing I still can't figure out is why they replaced the fuel injection system with a carburator.

One more thing, there are no mecanical fuel pumps with the BAP setup. I'm using 2 electric fuel pumps instead and some people might think that it is not a good idea to rely on the electric system only. Of course, the electric system is also redundant (2 batteries, etc) but still...
Click to expand...

Tracy Cook of Real World Solutions makes a control unit for the V8 which you can keep the electronic fuel injection. I have about 128 hours flying behind it.
 
Well I didn't know Ross was up in the air with his system. Last time we chatted he was going to stick to the ground.
 
I had a Chevy a few years back, I had so much trouble with it that I pulled the engine and installed a Lycoming in its place. It saved me $$$ in the long run when you account for the towing, or lack of it as a result.
 
I wrote the series of articles in Kitplanes referenced in post #20 by Ted Johns. Glad to see it is still useful as a reference.
When I was researching the articles, I tried to put myself in the position of the designer of an aircraft engine. Given the operational requirements and limitations, what would it look like? The most obvious requirement is to turn the propeller at less than sonic tip speed, for up to about 200 hp this is about 2700 rpm. So this sets the max torque speed. This means relatively long stroke and large bore pistons. The next requirements are light weight, so you end up with good useful load (which includes fuel weight by the way), and maximum reliability. Light weight is addressed by not including anything not absolutely necessary, and then using the lightest materials that will do the job. Then packaging in the most compact layout. Obviously ferrous materials for crank and rods, aluminum for crankcase and heads. Maximum reliability is addressed by redundant systems (ignition) and well tested (dyno and field) components.
If you go through this process it becomes pretty clear why most small aircraft engines are direct drive air cooled horizontally opposed 4 or 6 cylinder engines.
By the way, it is crucial that the engine and propeller are analyzed and tested for torsional vibrations. If these occur in the operating speed range they can result in a very short service life. I have never talked to an alternate engine supplier who did the analysis and testing, some didn't even know what torsional vibrations were. And I don't subscribe to the notion that a toothed belt "absorbs" the torsionals.
So as some of the previous posters have noted, what you are fighting with most automotive conversions are weight, operating speed and systems. The core engines are very good, but the architecture, materials and systems are not optimized for aircraft use. In order to make these work as an aircraft engine, you need a PSRU, a water cooling system and integration with the aircraft electrical system. Generally converted automobile engines, even those with aluminum blocks, are going to be heavier than direct drive aircraft engines for these reasons.
The final point is economy of operation. The magic number is brake specific fuel consumption which is a term that allows comparisons across a wide variety of engines. This is a measure of efficiency in turning fuel into torque and is measured on a dynamometer (brake). For aircraft engines at cruise this is about 0.37-0.42 lbs/brake horsepower hour. So a Lyc O-360 of 200 HP at cruise (75%) would burn say 0.37 x 200hp x 0.75/6 lb per gallon = 9.25 gals/hour. (Figures from memory, close enough to illustrate the point). You can compare this to published numbers for marine or industrial versions of your alternate engine of choice and I think you will not find any advantage. This is because aircraft engines are optimized for their operation conditions.
Unfortunately the certification process is so expensive and the market (don't underestimate this one) is so small and conservative that features that may improve performance or fuel specifics (FADEC, electronic ignition, electronic fuel injection, water cooling) take a long time to come to market. And sometimes the market rejects them, for example the Voyager water cooled engines.
So go ahead and experiment if you wish. Just be aware that you are the installation and systems engineer and test pilot. If you don't possess all these skills yourself, make sure you know where to get the help you need.
After considering the alternatives I will be using an IO-320 with mags in my RV-9A.
 
Well

EC,
Now that you've had a go at alt engines, try asking about priming. :D
Just duck first!



EchoCharlie1 said:
Peace!

I got it, I got it...only takes one or two lumps to the back of the head with that 2x4! :(

Okay, so there is more than just "one word". For the record, I like the Lycoming engines, but I had seen a very nice RV-7A for sale in Canada that has the Chevy V-6 engine and I just wanted to know what people were experiencing.

I am convinced...Lycoming it is and shall be.

Best regards and thanks to all that assisted me in this research.
Click to expand...
 
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