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I need an education

Av8torTom

Well Known Member
Hey folks,

It's time for me to start thinking about an engine. I know I want an O-320 160HP FP, but beyond that are there any variants that are to be avoided? Where can I find out about engine mounts, narrow vs. wide deck, induction systems etc? What are folks' recommendations for a O-320 160HP FP???

Thanks,

Tom
 
Not sure how true this is, but I tend to remember various amounts of disdain (from general grumbling to outright hatred) for the H2AD. They're plentiful, but are generally disliked because of the single-gear-double-magneto case setup, among some other things? Someone more knowledgeable can chime in, but that sticks out in my head.

Oh, and for a general listing of what's what, there's always Wikipedia. :) http://en.wikipedia.org/wiki/Lycoming_O-320#Variants
 
There is also a complete guide in the back of the preview plans/instructions that is handy.

the D2G is the O-320 engine sold by Vans so you know it will plug and play. The E2D (150 HP) also seems to be popular as it is widely available, although some do not have an engine driven fuel pump, which can usually be added.

The H2AD seems to be a red-headed stepchild but with some work a number of people are using them with no issues.

In general with a carb you are looking at vertical draft, and if you are planning a FP you don't need to worry as much about solid vs hollow crankshaft, although hollow gives you the option to upgrade and also may add some resale appeal.

Another issue is the mount type, I have Dynafocal 1 engine mount which restricts my options, but if you haven't ordered yours yet you can expand you search to the A and B series engines that have conical mounts, which are fairly common, usually with lots of hours though...

Chris
 
Tom,
Sun'n Fun is just a few months away, and the Mothership usually offers great engine/prop combo sales. By doing your research now, you shpuld have yourself properly armed to make a great purchase this spring depending on what they offer.
 
I'm deep into looking at the right engine and am allover the map. That said, I started with this article http://www.avweb.com/news/maint/best_aircraft_engines_208683-1.html

and went on the research journey. I can't remember all the stuff I've read in the past 6 mos, but as I remember its getting harder if not impossible to get new cylinders for O-320s, but don't quote me on that - might be cases I can't remember. Anyway, IO is pretty much the way to go if you want to manage your engine CHTs/EGTs ie health for the long term. For me IO360 angled is just a bit too heavy, and jugs are way way expensive. 390 or 400 nah. So it seems I gradually centering on a IO-360 parallel wide deck (pretty much all you can get now) and all are Dyna1. Good resale value, seem cheapest to rebuild (ie parts), plenty of power, tweakable if you want to increase HP by changing compression ratios or go the other way and run cargas. You can stuff a turbo on them if you want, theres plenty of different exhaust options, and go good with a CS or a fixed prop (like a catto or whirlwind).

Oh BTW Sean Tucker uses a 360 para in his plane - not an angle because the hotrodders can pull more power out of them than any other motor and still be reliable and light weight....

Now why was it you wanted a 320?
 
O-320H2AD for me..

I'm used to the usual comments,but I will put my H2AD up against the best. I run one in my-4, and its the "best bang for the buck hands down. Sure its "different", but its not a bad engine as given by the comments and "AD" designation, which ironically has nothing to do with "Airworthiness Directive". Unique issues are easily forgotten, and the 160hp/fixed pitch set-up is a natural for it. The Vans mount, Vetterman exhaust, and cowlings are all compatible. It has a single drive dual mag, but keep in mind so do many certified aircraft. The H2AD was designed by Lycoming as a semi-automated MFG process along with Cessna, and it worked well for the mission. For an RV, its basically a C-172 FWF install with a different fuel pump arrangement. Doesn't get simpler than that.
 
0320

Hi Tom. The 0320 160 hp has slightly taller pistons than
The 150. Dynafocal 1 is a common mount. Used on Cessna
E2D for example. It's what Vans sells as standard. Wide decks are newer models than the narrow decks. E stands for 150 hp. D for 160. Forward, middle or aft sump is Where the carb attaches on the sump. Mine is in the middle and was easy To hook up the air box to the cowl. It's not difficult to rebuild
engines with an experienced AP. In fact it's very fun. Find a TBO engine
And go for it. Call me if you have any questions.
 
SkyRanch

Best book out there "Sky ranch engineering manual". I reference mine all the time. As a budget builder I've been asked, What engine do I want on my 7a?The Answer is, "Any Lycoming that will get me into the air". The H2AD had a lot of teething issues,Spalding lifters,cheap automotive rockers,different parts,single mag,fuel pump in the nose(requires a bubble in the top cowl). These have been worked around over the years and most run OK but still not the first choice engine.If your going to roll your own,spend a week or two at the Lycoming school,money& time well spent.Its an education but will drain time from the project.Best bang for the buck is still Vans SNF deal.If you want duel Pmags forward induction&fuel injection,Stroker crank,roller lifters...all the good stuff and a Catto or WW200 prop.Talk to an independent builder about the IO-340,small,light,packs a punch up high where the 9 shines.IMHO:)
Rhill
 
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I have a friend who has been running the h2ad in a 6 for 10 yrs. He told me there were serious issues with them at first, but with some mods the issues have been dealt with and his runs well. Those issues have driven the price down on that model of engine making them a good value.
 
In general with a carb you are looking at vertical draft, and if you are planning a FP you don't need to worry as much about solid vs hollow crankshaft, although hollow gives you the option to upgrade and also may add some resale appeal.

Chris

Keep in mind that a hollow crank does not necessarily mean that you can use a constant-speed prop. There are other things to consider; mainly the front main bearing. There are many hollow crankshaft engines that will not accept a constant-speed prop.
 
Given your stated requirements a D2G or a D3G would be great, but AFAIK both utilize Slick mags. You'll get a lot of opinions on ignition systems, but I'd select a D2G or D3G with one Bendix mag and (choose one) P-mag or LSE Plasma with a direct crank trigger. D2G uses 7/16"Ø drive lug bolts; 3/8" on the D3G. Both of these carb'd engines are easily converted to FI, but there are thousands of O-320's pulling 172's and Warriors around just fine.

Although E's are easily converted to 160 HP, I "think" the nose main bearings are shorter than those on the D's.
 
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Bearings

Some of the E's use the four piece 0 235 front main bearing. Some use the standard two piece bearing. The 0 235 bearing engine cannot be converted to constant speed prop.
 
Thanks all

This has been helpful. Other than the H2AD, are there any other variants to be avoided? Any ADs to be aware of?

T.
 
This has been helpful. Other than the H2AD, are there any other variants to be avoided? Any ADs to be aware of?

T.

It seems most of the demons in the H2AD's have been exorcised by now, so if you find a great deal on one I wouldn't summarily dismiss it. The D2G and D3G are the preferred engines for the EZ's too, so many have been snapped up in the 80's/90's heyday of the EZ's. There are still many first run O-320 B's and D's out there as great candidates for overhaul. If you are considering an overhaul have your shop find the core for you; I had Mattituck do that 4 times after buying my own core on the first plane.

There's a series of SB's on oil pumps (don't think it hit AD level of problems) but the parallel valve 320's and 360's are mostly bullet proof. If I were looking at a brand new motor the stroker 340's would be a contender for a FP prop.
 
9A Sump carb placement

Tom your building a 9A,there is another issue with carb placement on the sump on some 0-320 models that will interfere with the nose gear.You haven't stated if your inclined to "Roll your own" from a core,mid time used,hang it as is,buy new from Vans or aftermarket?
RHill
 
I'm still undecided as to what I'll do. First I want to identify the type of O-320 that I want, then I'm open to options, new, rebuilt, mid-time, etc...

I'm quite accomplished working with fiberglass, so whatever needs to be done to the cowl will be no problem. My understanding is that the middle sump location will work find with the 9A.

I see you're in Valley Forge - I'm in Bucks county. We should get together sometime.

Best,

Tom
 
Keep in mind that a hollow crank does not necessarily mean that you can use a constant-speed prop. There are other things to consider; mainly the front main bearing. There are many hollow crankshaft engines that will not accept a constant-speed prop.

Mel,

Can you point me to a description of exactly what the differences are with each O-320 model?

Thanks,

Tom
 
H2AD w/ crank triggered ignition

What would be wrong with taking the discount on a H2AD engine and using the money to buy EFII from Robert Paisley? That set-up could care less what used to be in the plane.

Larry Tompkins
544WB -6A
W52 Battle Ground WA
 
What would be wrong with taking the discount on a H2AD engine and using the money to buy EFII from Robert Paisley? That set-up could care less what used to be in the plane.

Larry Tompkins
544WB -6A
W52 Battle Ground WA

It would depend what has been done/what you were willing to do about the cam lifters. The original lifters have a smaller contact area with the cam, and are famous for spalling. Lots of fixes over the years, but some engines no doubt still have the original removable lifters.
 
H2AD lifters/mags

The H2AD lifters are simply "drop in" based on the small block ford design. They can be installed after the engine is fully assembled, so the lifter diameter is the same size as the lifter body. In all other series of engines, the lifter is installed before the case is assembled from the inside, and the lifter face is slightly larger in area than the body. The spalling can occur on virtually all engines, but the H2 is only slightly more prone usually after periods of non-operation. There was a mandated oil additive required (via an airworthiness directive), which is now days blended into many oils. I use Aeroshell "plus". As far as the dual mags that scare many people because of one drive....well, the other engines split the drive to seperate mags inside the accessory case, and the single drive mag splits the drive outside the accessory case. it can still function on one side alone.
 
0 320

O 320's using 0 235 front main bearing. These cannot be used "as is" with constant speed prop. They can be converted to 160 hp, but there is little if any experience with higher horsepower conversions.
0 320 E2B Cessna 172
E2D Cessna 172 and 177
E2G Grumman American
E2H not used in production aircraft
E3D PA28, Beech Musketeer
E3H not used in production aircraft

320E series using standard front main bearing:
0 320E1A Grob
E1F Monsun
E2A PA28 140/150
E2B not used
E2C Beech Musketeer III
E2F Monsun

The Piper PA30 and PA39 Twin Commanche engines are type II mounting. These can be converted to type I mount by crankcase overhaul shops if you are overhauling. They are also rear mounted fuel injection.
IO 320 B1A
B2A
C1A

Many O 320's do not have provision for engine driven fuel pumps. I do not consider this a major issue. Accessory case can be machined or traded for a machined case. Special idler gear and pushrod are not high cost items.
There are some very rare 320's with provision for front mounted governor. The disadvantage is camshaft cost, somewhere around 3k.
Also some fairly rare solid crankshaft engines. Again, these could probably be traded for hollow crankshaft if you are overhauling.

On the top aft crankcase split is a flat surface with engine serial number. If the serial number has a two digit dash number folloed by and A, it is a wide deck engine. The narrow deck/wide deck transition occurred around 1964-65, so it is generally a good idea to avoid the narrow deck engine.
 
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