Overwhelmed by engine choices

I'm completely overwhelmed by the choices for engines. Tappets and cams and induction direction, oh my! I don't even know where to start. I see spec-sheets on the manufacturer websites and a few of the choices that were made on builder websites. But I'm still super confused. Everyone in this forum section seems to know what they're talking about. I'm clueless.

Where do I learn all of these terms and how they'll affect my engine choice?

Can somebody please point me to a getting started guide for Lycoming-like engines?

guidoism said:

I'm completely overwhelmed by the choices for engines. Tappets and cams and induction direction, oh my! I don't even know where to start. I see spec-sheets on the manufacturer websites and a few of the choices that were made on builder websites. But I'm still super confused. Everyone in this forum section seems to know what they're talking about. I'm clueless.

Where do I learn all of these terms and how they'll affect my engine choice?

Can somebody please point me to a getting started guide for Lycoming-like engines?

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Don't feel bad, I'm in the same boat. I haven't really started to dig into engine choices yet--still have an airframe to build! Engine choice seems to be one of the easiest places to get lost down little roads that diverge at subtle choices.

You came to the right place. We have a variety of opinions, just ask.

Building an RV8? What do you plan to do with it? What is you mission profile?

Engine choices

You may want to start with Vans.http://vansaircraft.com/cgi-bin/store.cgi?ident=1431131973-248-297&browse=engines&product=lycoming2

Choices
Constant speed vs fixed pitch. CS must be specified when ordering and which governor.
Horizontal vs Vertical induction. One uses the traditional cowl. Other requires a modified cowl. Horiz is standard. I think.
Compression. Lower is less HP but also less wear. You can burn lower octane fuel. Higher is HP but requires higher octane. Overly simplified.
Parallel vs angle valve. Higher performance with angle at greater weight and cost
Injected vs carburated. FI is easier to balance injectors for LOP and inverted ops. Carb requires heat. Overly simplified. Also which fuel injection and if so which fuel pump and does it require return line plumbing.
Roller tappet vs non roller. Lycoming added the rollers to eliminate the wear point on the cam. On Lyc engines a cam or tappet problem requires a complete tear down for replacement. The jury is still out as to the success. Most engine builders don't use roller. Lyc rollers are standard.
Mag vs EFI. Traditional mags or PMags. Pmag is basically a mag with the capabilities of electronic ignition. EFI is more like auto ignition.
Spark plug bosses. You can specify auto plug bosses if you want to use auto plugs.

I'm getting edumicated but not quite there yet.
For now
IO360, low compression, parallel valve, p-mags, Airflow Performance FM-150 FI and pump, auto plug bosses

This or that for all the other stuff, but roller follower cam actuation is 4x longer life than a slipper, at least. That is based on data seen in the lab, first hand. Anything can be poorly done, but a mediocre roller is better than the best slipper.

Roller

BillL said:

This or that for all the other stuff, but roller follower cam actuation is 4x longer life than a slipper, at least. That is based on data seen in the lab, first hand. Anything can be poorly done, but a mediocre roller is better than the best slipper.

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That's one choice easier to make. Thanks.

It is you.

There is not a good answer here with out knowing what you want, need or can get, for what type of aircraft and flying you will be doing. I can tell you that both the two after market suppliers in Texas have very good web sites that do answer a lot of what you are asking for. A lot of picking out a power-plant is what that person likes or what they see as their dream engine. Some guys like a 10,000 Hp. dragster and others like a Mo-pad engine.
It can and dose take many years, in some cases two or three generations to pass down most of what you ask for. Just don't get frustrated it may be slow in coming, but start with what your expectations are out of your pick of aircraft and what you want it to do. Then call some of the good engine builders and tell them what you want. Call and talk to as many as you can, not just one or two. Then be realistic with yourself. Do you need a fire-breathing dragon to do a humming birds work? Most every thing we get in our little toys is a compromise. The ideal is not often what you get. Keep asking question and looking up parts tell you are comfortable with your knowledge of the facts. You too may be a gear head in the making. Good luck. Yours as always. R.E.A. III #80888

brad walton said:

You came to the right place. We have a variety of opinions, just ask.

Building an RV8? What do you plan to do with it? What is you mission profile?

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I know what my mission profile is right now but I'm not quite sure what it will be in 5+ years when I finished with the plane.

I'm still years away from needing to make a decision on anything firewall forward, but what I'd like to do at this point in the build is become educated about engines and their options. As a renter I never really got to know much about the engine underneath the cowling. I want to understand.

I want to read. But my googling and amazoning hasn't turned up an obvious place to start.

How did y'all learn about these engines?

Should I start with the powerplant book in an A&P course or is there something more specific for Lycomings that would be a better start for me?

27 years of the RVator

The book "27 years of the RVator " has a lot of info in the first few pages of the firewall forward section. It's far from a comprehensive guide but has much of what you may want to know in one place.

BillL said:

This or that for all the other stuff, but roller follower cam actuation is 4x longer life than a slipper, at least. That is based on data seen in the lab, first hand. Anything can be poorly done, but a mediocre roller is better than the best slipper.

Click to expand...

Just curious, what lab did that data come from and was this some kind of "predicition"?
Real world numbers have not proven that to be the case to my knowledge, and I've never heard an engine builder (the guys who see this stuff everyday) make any such statement.

guidoism said:

I know what my mission profile is right now but I'm not quite sure what it will be in 5+ years when I finished with the plane.

I'm still years away from needing to make a decision on anything firewall forward, but what I'd like to do at this point in the build is become educated about engines and their options. As a renter I never really got to know much about the engine underneath the cowling. I want to understand.

I want to read. But my googling and amazoning hasn't turned up an obvious place to start.

How did y'all learn about these engines?

Should I start with the powerplant book in an A&P course or is there something more specific for Lycomings that would be a better start for me?

Click to expand...

You are as I see it correct, get the tail kit, be putting it together and doing all the study and home-work you can while you are building. Don't take much at face value till you have investigated it and it has ben tested and proven to be correct by more than two independent reputable sources. Just like Walts post. Ask do roller lifters help a low R.P.M. air cooled engine or do they help a water cooled Hi-R.P.M. engine? Do roller lifters help with an engines wear or dose regular starting and running of an engine with either type of lifter wear just the same as the other? Is spalling of a mushroom lifter do to its old stile desinge or lack of regular lubing and running of the power plant that they are installed in? And on and on. One of the things that I enjoy about Aveology is there are so many things to and questions to be asked that it is hard to get them all addressed in one life time. You have the will, you have the questions, you took the step in the right direction. That is clear from your first post. Welcome to the real world of frustration of ones self into getting the answers you want. It is worth it, for as you will hear often the principle tenants of our little hobby are education and recreation. Keep it up you are doing good. Yours as always. R.E.A. III #80888

Walt said:

Just curious, what lab did that data come from and was this some kind of "predicition"?
Real world numbers have not proven that to be the case to my knowledge, and I've never heard an engine builder (the guys who see this stuff everyday) make any such statement.

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Email sent, Walt. It was bench, engine and analyses for various combinations of materials etc. Extreme conditions of used oil, limit temperatures and speeds. It was on diesel engines with an expectation of 8000 hours life. Analysis showed that very high contact stresses. ZDP was very important, so for Lycs, additives are quite important. Chilled iron followers are the most difficult to obtain consistency. Maybe with follower replacement at 2000 hrs, the results would be much different for a long test.

The results were so contrasting, I have chosen rollers ever since.

My understanding fom reading the Superior Engines website info is that they were able to incorporate a steeper cam profile with roller cam followers than with old style. Thus the valve remains fully open for a longer time period. If I recall correctly, all the Lycomings now come with roller cam followers.

Induction

Can someone please expand on the horizontal vs vertical induction pros and cons?
Edit
I found an excellent write up.
See post #6
http://www.vansairforce.com/community/showthread.php?t=298

So now my question is what comes standard on the Vans Lyc M1B?
I would like Aerosport FI, P-mags and auto plug bosses don't believe there are options so the engine would have to be modified and no doubt the warranty would be invalidated.

Larry,
The Lycoming stock experimental classified YIO-360-M1B has a horizontal forward facing sump and Precision RSA-5 style fuel injection servo. It comes with roller tappets, slick mags and is set up for constant speed prop including the SS line from the pump pad to the crankcase nose.

this means you need the smooth bottom cowl and you do not need a fuel return line.

rzbill said:

Larry,
The Lycoming stock experimental classified YIO-360-M1B has a horizontal forward facing sump and Precision RSA-5 style fuel injection servo. It comes with roller tappets, slick mags and is set up for constant speed prop including the SS line from the pump pad to the crankcase nose.

this means you need the smooth bottom cowl and you do not need a fuel return line.

Click to expand...

Thanks Bill.
How difficult is the swap to auto plugs? Inserts from Emag or can the plug bosses be removed and changed?

Information

Start with a Lycoming Operators manual for one of the more popular engines. Then Lycoming Overhaul Manual. The next step would be the Lycoming Engine School, but that is beyond what most builders would need, unless you wish to assemble and engine on your own.

Genuine

Pretty hard to beat Van's show special for a Hartzell and Lycoming IO-360-M1B. Roller cams and injection would definitely be on my list if I bought new. Mags can be sold later and PMAGs added.

It just doesn't seem right to me that non-genuine is more. That was not the case when Mattituck, ASP and others got going assembling kit engines....

Another issue is if your engine will be built from all PMA'ed parts. This gives you some protection as any AD's would be issued for the certified fleet. Newer experimental engines are not being made with all PMA'ed parts, and to some extent it is unknown how they will perform and there may be no vibration testing with your chosen propeller.

ECI Titan cylinders are more resistant to corrosion. That's probably a good thing for anyone who doesn't fly regularly. Pitting in the cylinder bores is at least as big an issue as cam failure. ECI cylinders are prompted by engine shops for this feature. The ECI cylinders also come pre balanced to 1 gram and ready to install on the engine. Perhaps this might have something to do with the engine shop's interest in using them as well.

I haven't had great luck with my ECI cylinders. I replaced a set at 350 hrs due to an ECI AD. To be fair ECI looked after me well, despite the fact that the engine shop I bought from walked away. I was really happy with the replacement cylinders ECI provided.

From observation the ECI cylinders run hotter and take a lot more to run in. They tend to be less repairable that their Lycoming counterparts due to the harder bores.

For what it is worth, I just bought 6 new Lycoming cylinders for my next project. I bought plenty of other parts from ECI and Superior as well. In future I plan to build my engines locally from good cores, as opposed to buying new from Vans or an engine shop.

Engine Choices

First determine your mission / requirements. After that chaos will start to seem logical.

My RV-8A requirements: cross country, some acro, mostly solo (wife refuses to get in the plane - but that's another story), reasonable speed, reasonable weight, reasonable operating expense, proven reliability to compensate for my admitted lack of engine expertise. Sufficient excess power to handle Sierra Nevada mountain flying out of homebase of Inyokern, CA, on eastern side of Sierra.

Decision: Aerosport IO-360 180 HP Horizantal Induction with one mag and a Lightspeed EI. Hartzell CS prop. B&C 40 amp alternator with SD-8 backup.

Aerosport was great to work with; felt the additional performance of 200 HP wasn't worth the cost, weight or operating expense.

425+ hrs in four years. No problems, no regrets. It's a magic carpet.

TCDS

Type Certificate Data Sheets for the certified Lycoming are available on the FAA's website. This should provide a start on letter designations/differences. Don't know if these letter designations carry over to the kitbuilt engines. Anyone?

Optionitis

Optionitis is a disease that commonly infects homebuilders. First time builders are particularly prone to infection, as like most diseases, immunity is developed by prior exposure. It manifests itself as a mania for not missing out on any and all optional improvements to airframes, engines, and devices already known to be serviceable and reliable.

Additional symptoms include eyestrain from too much internet, thinness of checkbook, and the agony of indecision. Many patients become aware of their condition, develop partial immunity, and proceed to a favorable outcome. However, if left unrecognized and untreated, the patient slowly becomes paralyzed, eventually resulting in a unfinished project.

Dr. Dan's presription? Buy an M1B and a constant speed Hartzell from Vans when they run a special. Install it bone stock...highly proven, no worries, plenty of guidance, good resale. Get flying, wring it out, and change whatever you want later.