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Lycoming 360/320 combo...thoughts?

Av8safe

Av8safe

Well Known Member
It looks like I will soon be buying a beautiful RV7 that has an engine build that I would like some thoughts from the gallery on how best to care and feed it to ensure many happy hours. The plane will be in an un-heated hangar in a four season climate. Specifically looking for thoughts on winter protection including pre-heaters (tanis, hornet, home made), moisture protection (hope to fly at least every couple of weeks), and anything else that comes to mind about this engine.

Appreciate the input!
Mitch

ENGINE DESCRIPTION:​ Lycoming Direct Drive Engine was modified in the following way, during overhaul in 2003, by Engine Components Inc (ECI). They built the engine originally to fit into an RV-4 or RV-6. In order to place an angle valve engine into these two aircraft types the engine had to maintain a thin profile. Therefore, this engine is built up from an IO-360-A2F crankcase, O-360-A sump, an O-320-D2J hollow-bore crankshaft, O-320 connecting rods, O-320 cylinders attached to IO-360 angle valve heads with O-320 pistons giving a compression ratio of 8.7 : 1. The combination of these components results in an engine 1" thinner than a standard IO-360-A model. The engine was dyno tested with a MA4-5 SPA carburetor and 2 Slick magnetos and produced 193HP on a dyno test stand. Further modifications done by the aircraft builder and included the replacement of the MA4-5 SPA carburetor with an Airflow Performance Fuel injection system, a high pressure engine driven fuel pump and the replacement of the right side Slick Magneto with a P-Mag electronic ignition system.
 
I hope the O-320 crankshaft is strong enough to transmit that much power.

My bet is that the IO-360-A crankshaft was beefed up some?
 
None noted in engine log

There are no specific modifications to the crankshaft noted by the engine builder in the engine logbook. The first sentence states that it was modified for use in the RV.

-Mitch
 
Lake Elmo

Thanks Shark,

I am originally from MN and cut my teeth at downtown St. Paul airport long ago. Used to go to Lake Elmo often. Any thoughts on controlling moisture if you are not flying as frequently in the winter?

-Mitch
 
My concern would be using O-320 crank and connecting rods on a 180+ HP engine. This engine would certainly be considered "experimental".
 
Angle valve

How do you put angle valve heads on O320 cylinders? Would love to see a picture of this thing..
 
Taltruda said:
How do you put angle valve heads on O320 cylinders? Would love to see a picture of this thing..
Click to expand...

Since the bore is the same, and the stroke is different, I would imagine that heads would screw right on, same as on a O-360. Correct me if I'm wrong.
 
Jpm757 said:
My concern would be using O-320 crank and connecting rods on a 180+ HP engine. This engine would certainly be considered "experimental".
Click to expand...

Yes, this is my concern. Some beefiness that was added to the crank for the -360 is not there. Perhaps even additional beefiness for the angle valve.

Since the stroke has been shortened to O-320 stroke, it is hard to imagine that it is capable of the power quoted with a CR of 8.7:1. At what RPM on the dyno did it produce 193 hp?
An O-360 has a hard time getting that power at that compression. The IO-360-A1A "barely" makes 200hp at 2700 rpm. probably more typically 195.
 
Hope to get details from ECI

Steve,

Good questions that I hope ECI will be able to answer. Am also trying to contact the builder to see what they have to say. The current owner has provided logs that do not answer your questions. Pre-buy (Vic S.) is a few weeks away so there is time to research. On paper, Vic was not concerned.

-Mitch
 
What do we really want from an engine?

For me #1 is Reliability, #2 is Longevity will this motor go 2000 hours + ? Cost of service and installation? We use a 70 year old design that has been perfected by Lycoming for its intended purpose, what is known industry wide as a mature product. In my Porsche days we would play swap parts between the 2.2,2.4,2.7 engines these engines had to be built with clay&plastigauge then taken apart to check clearances.Some of these engines ran strong,just not long. the IO crank has counter balance weights not standard on a 0320. Is this a solid flange or lightning hole flange? Connecting rods and rod bolts are completely different Angle valves require a different sump.Not all sumps will work with the A gear,new or old. Different baffle+cowl ? Once you go off track you have to keep going further off track to compensate. For me this sounds like a cobble of used parts,I don't matter but what will a potential buyer say?IMHO
RHill
 
rhill said:
For me #1 is Reliability, #2 is Longevity will this motor go 2000 hours + ? Cost of service and installation? We use a 70 year old design that has been perfected by Lycoming for its intended purpose, what is known industry wide as a mature product. In my Porsche days we would play swap parts between the 2.2,2.4,2.7 engines these engines had to be built with clay&plastigauge then taken apart to check clearances.Some of these engines ran strong,just not long. the IO crank has counter balance weights not standard on a 0320. Is this a solid flange or lightning hole flange? Connecting rods and rod bolts are completely different Angle valves require a different sump.Not all sumps will work with the A gear,new or old. Different baffle+cowl ? Once you go off track you have to keep going further off track to compensate. For me this sounds like a cobble of used parts,I don't matter but what will a potential buyer say?IMHO
RHill
Click to expand...

All this is really is an O-320 with angle-valve heads. An interesting idea really. So it is not as odd a cobbling of parts as one might image. Honestly I doubt that it would make the stated Hp at 2700 rpm, since the displacement is still 320 and the compression is 8.7. So the loads on the crank are probably not that far out of line from other O-320's, especially ones where someone has played with compression.
 
This sounds like something the T18 builders were doing in the '60s. I remember reading in their newsletter about 'hot' rod engines that used cylinders from different engine.
 
ECi

Since ECi is no longer is business ( the assets were acquired by Continental Aerospace Tech ), I will reply. I was employed there for 23 years. We did quite a bit of innovative engineering and modification work there and the angle valve 320 was one project. ECi manufactured new replacement barrels so the custom fitment and manufacture of the 320 barrel ( which is simply about 1/2" shorter than the 360 barrel ) on an angle valve head was accomplished but their standard, manufacturing processes. ECi would certainly have manufactured a new solid propeller flange 320 crankshaft for that engine. The main journal diameter is the same on both the 320 and 360 engines. The rod journal diameter is the same on most 360's too although the 360 angle valve engines that are rated at 200 HP have a larger diameter connecting rod journal diameter. Much of the increased HP comes form the design of the angle valve cylinder head. Since it's essentially a "hemi" combustion chamber and intake system the air flow volume that is achieved is greater than a parallel valve cylinder design.
 
James Ball said:
Since ECi is no longer is business ( the assets were acquired by Continental Aerospace Tech ), I will reply. I was employed there for 23 years. We did quite a bit of innovative engineering and modification work there and the angle valve 320 was one project. ECi manufactured new replacement barrels so the custom fitment and manufacture of the 320 barrel ( which is simply about 1/2" shorter than the 360 barrel ) on an angle valve head was accomplished but their standard, manufacturing processes. ECi would certainly have manufactured a new solid propeller flange 320 crankshaft for that engine. The main journal diameter is the same on both the 320 and 360 engines. The rod journal diameter is the same on most 360's too although the 360 angle valve engines that are rated at 200 HP have a larger diameter connecting rod journal diameter. Much of the increased HP comes form the design of the angle valve cylinder head. Since it's essentially a "hemi" combustion chamber and intake system the air flow volume that is achieved is greater than a parallel valve cylinder design.
Click to expand...

Good info, thanks.
 
James, perhaps you could comment on the likely horsepower of a O-320 with angle valve heads. Putting angle valve heads on the O-360, along with a modest increase in compression ratio, raised the rated power from 180 to 200. An 11% increase. Much of the increase is presumably from better breathing, and a small amount from the modest compression increase.

So, doing the same thing to an O-320, wouldn't we expect the horsepower to increase in about the same way? 1.11 * 160 = 177. So my guess would be in that range. If it dyno'ed at 193, I would guess that was at a higher RPM.


James Ball said:
Since ECi is no longer is business ( the assets were acquired by Continental Aerospace Tech ), I will reply. I was employed there for 23 years. We did quite a bit of innovative engineering and modification work there and the angle valve 320 was one project. ECi manufactured new replacement barrels so the custom fitment and manufacture of the 320 barrel ( which is simply about 1/2" shorter than the 360 barrel ) on an angle valve head was accomplished but their standard, manufacturing processes. ECi would certainly have manufactured a new solid propeller flange 320 crankshaft for that engine. The main journal diameter is the same on both the 320 and 360 engines. The rod journal diameter is the same on most 360's too although the 360 angle valve engines that are rated at 200 HP have a larger diameter connecting rod journal diameter. Much of the increased HP comes form the design of the angle valve cylinder head. Since it's essentially a "hemi" combustion chamber and intake system the air flow volume that is achieved is greater than a parallel valve cylinder design.
Click to expand...
 
Thank you James Ball

James,

Thank you so much for that information, it is very helpful indeed!

Aviation, including this forum, is such a small tight- knit community it is amazing what comes back from posting a simple question. I found out I also have networking ties to the builder and will be able to connect soon for more of the backstory of the specific engine purchase history.

Thanks again!
Mitch
 
Cylinders

In the 60's?? some were installing Lycoming angle valve cylinders from the GO series engines on 0 290 and 0 320 crankcases. These were all narrow deck components. After the 0 360 became available interest in the angle valve conversions diminished.
A GO 435 is essentially a six cylinder 0 290 with angle valve cylinders and gearbox. GO 480 is six 0 320 cylinders but angle valve.
The GO series engines were used on Aero Commander, Twin Bonanza and other aircraft. They were high r/m engines-3500 r/m range.
 
Horsepower increase

scsmith said:
James, perhaps you could comment on the likely horsepower of a O-320 with angle valve heads. Putting angle valve heads on the O-360, along with a modest increase in compression ratio, raised the rated power from 180 to 200. An 11% increase. Much of the increase is presumably from better breathing, and a small amount from the modest compression increase.

So, doing the same thing to an O-320, wouldn't we expect the horsepower to increase in about the same way? 1.11 * 160 = 177. So my guess would be in that range. If it dyno'ed at 193, I would guess that was at a higher RPM.
Click to expand...

Your point is well taken. I cannot say why the engine got rated at 193 HP if the RPM were just 2700. At that time, ECi probably used a test club with a torque spool and then calculated corrected HP from that data. Later ECi built a water break dyno that was much more accurate.
 
James Ball said:
Your point is well taken. I cannot say why the engine got rated at 193 HP if the RPM were just 2700. At that time, ECi probably used a test club with a torque spool and then calculated corrected HP from that data. Later ECi built a water break dyno that was much more accurate.
Click to expand...

Well, the volumetric efficiency with the shorter stroke is the same a the 360 running at 2400 rpm. This might allow a touch better breathing and better power. 193 seems a little much, more than 180 seems likely. Quite an interesting component combination. Now, run it at 3000 (if the valve train will take it) and she's a winner.

Cooling should be outstanding.
 
Great Info!

James Ball said:
snipped We did quite a bit of innovative engineering and modification work there and the angle valve 320 was one project. ECi manufactured new replacement barrels so the custom fitment and manufacture of the 320 barrel ( which is simply about 1/2" shorter than the 360 barrel ) on an angle valve head was accomplished but their standard, manufacturing processes
snipped

Since it's essentially a "hemi" combustion chamber and intake system the air flow volume that is achieved is greater than a parallel valve cylinder design.
Click to expand...

James,
Use of GO-480 cylinders would be limited to the older "narrow" deck engines. Did ECi also manufacture "angle valve" cylinders for the wide deck 320s? I've always found the easiest way to differentiate a 320 cylinder from a 360 was to count the number of fins on the steel cylinder. A 320 will have 15 fins, a 360 has 19. This only applies to genuine Lycoming cylinders, as I don't have any experience with either Superior or ECi cylinders.
Does this hold true for the ECi units?

Is the concave in the angle valve heads deeper than on the parallel valve models?

Perspiring minds want to know

Charlie
 
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The EZ community has been mixing O-360 angle valve heads with O-320 wide deck cylinders for decades instead of using the heavier O-360 parallel valve engines - keeping the narrower width across the cylinders. D series (D2J and D3G in particular) are preferred for the longer nose main journal and solid crank.

I have personal knowledge of 2 such engines, but there were/are quite a few others. Seem to be exceptionally reliable;EZ's turn 2,900+ rpm down low and "cruise" WOT 2,700 rpm at 17,500'. I don't doubt 190HP; such EZ's will run 210 KTAS all day long.

The EZ guys also found a way to fit cross-flow heads (up exhaust) ; I think they were liberated from a Navajo (?)
 
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Barrel Fin Count

chaskuss said:
James,
Use of GO-480 cylinders would be limited to the older "narrow" deck engines. Did ECi also manufacture "angle valve" cylinders for the wide deck 320s? I've always found the easiest way to differentiate a 320 cylinder from a 360 was to count the number of fins on the steel cylinder. A 320 will have 15 fins, a 360 has 19. This only applies to genuine Lycoming cylinders, as I don't have any experience with either Superior or ECi cylinders.
Does this hold true for the ECi units?

Is the concave in the angle valve heads deeper than on the parallel valve models?

Perspiring minds want to know

Charlie
Click to expand...

Yes, ECi installed the angle valve cylinder heads on wide deck ( wide cylinder flange ) barrels.
Yes, since the ECi barrels were direct replacements for the OEM barrels, they had the same number of cooling fins.
 
As a hotrodder at heart with tons of hot rod engine background I have as many questions as Charlie.

How much different are the port locations on the parallel vs angle valve heads? Are the intake tubes the same diameter from 320 parallel vs 360 angle. Will the 360 sump fit on a 320 case, or is this even necessary to align the tubes to the angle valve port locations?

Are the combustion chamber specs different as far as volume is concerned?

I guess these questions may be better answered on the EZ forums as alluded to earlier in the thread.

That's just a small sampling of where I want to go with my education on this subject. The goal is MAYBE....180 true HP in a package the weight and size of the 320 narrow deck. Maybe even a shorter prop with a 2900 RPM speed in mind and making 190 HP........Fun to dream.

Probably not wise or feasible, but fun to think about none the less.
 
Some [but not all] answers

rackley16 said:
snipped
Are the intake tubes the same diameter from 320 parallel vs 360 angle. Will the 360 sump fit on a 320 case, or is this even necessary to align the tubes to the angle valve port locations?
snipped
Click to expand...

The angle valve heads [and parallel valve IO-360-M1B] have larger diameter intake tubes. The 360 sumps will fit onto 320 crankcases. Unlike the 320 & most parallel valve 360 engines, the "cold air"" sumps used on the angle valve engines do not have intake "stubs" on them. The intake tubes slide into machined holes in the sump. Sealing is done via O-rings on the tubes, to seal between the sump and tube. With this design, there is no problem getting the tubes to align with the 1/2" shorter 320 cylinders. The intake tube simply slides 1/2" deeper into the machined holes in the sump. If you'd like, contact me via PM with your email address. I can then send you some drawings that will make it easier to understand the differences.
Hopefully, James or perhaps Dan can respond to your other questions.

Charlie
 
320 ?Hemi?

I built a wide deck 320 with angle valve heads for a buddies RV-4 and had good luck with it. It?s still flying and doing great the last I heard. Basically I was just trying to replicate what the old ?hotrodders? did by putting GO-480 cylinders on 320?s but using modern wide deck architecture. We ran a basic 0360 Sump with custom intake tubes built by Larry Vetterman. It was originally setup with a carb but latter changed to AFP fuel injection. ECI built 5 custom cylinders for us (1 spare). I had custom pistons made that as I recall were 9.2-1 compression ratio and had the cylinders portflowed. We used an older part # cam that the hotrodders know about which makes a few more horsepower and with those mods it dyno?d in the mid 190 horsepower range. We wanted it to go into a stock RV-4 cowl but even though the width worked out we had to modify the top cowl because the angle valve heads are taller. We ran the piston cooling nozzles required on angle valves which resulted in a larger custom oil cooler installation. It was a lot of work which resulted in a unique set up. Those that question the strength of the crank and rods should note that the GO-480 uses the same journal size basically the same Rod (beams are polished) and same rod bolts. They spin 3200 rpm with the gear box slowing the prop down. The one cautionary note I would offer is that we did not use a metal constant speed prop due to the unknown torsional resonance characteristics.
In answer to the OP questions I wouldn?t shy away from the airplane based on its unique engine.
 
320 Hemi Dyno Sheets

I found the old dyno sheets and the results were better than I remembered.
It averaged 196 hp at 2700 rpm on several blasts.
It also pulled over 200 hp on a couple of 2800 rpm blasts.
 
theduff said:
I built a wide deck 320 with angle valve heads for a buddies RV-4 and had good luck with it. It’s still flying and doing great the last I heard. Basically I was just trying to replicate what the old “hotrodders” did by putting GO-480 cylinders on 320’s but using modern wide deck architecture. We ran a basic 0360 Sump with custom intake tubes built by Larry Vetterman. It was originally setup with a carb but latter changed to AFP fuel injection. ECI built 5 custom cylinders for us (1 spare). I had custom pistons made that as I recall were 9.2-1 compression ratio and had the cylinders portflowed. We used an older part # cam that the hotrodders know about which makes a few more horsepower and with those mods it dyno’d in the mid 190 horsepower range. We wanted it to go into a stock RV-4 cowl but even though the width worked out we had to modify the top cowl because the angle valve heads are taller. We ran the piston cooling nozzles required on angle valves which resulted in a larger custom oil cooler installation. It was a lot of work which resulted in a unique set up. Those that question the strength of the crank and rods should note that the GO-480 uses the same journal size basically the same Rod (beams are polished) and same rod bolts. They spin 3200 rpm with the gear box slowing the prop down. The one cautionary note I would offer is that we did not use a metal constant speed prop due to the unknown torsional resonance characteristics.
In answer to the OP questions I wouldn’t shy away from the airplane based on its unique engine.
Click to expand...

^^^ Very similar to the cylinders that Jay Wickham (Mattituck) built up for us. We used pistons that gave us a true 9.3:1 CR, and a "Mattituck special" cam.
 
Questions

theduff said:
I built a wide deck 320 with angle valve heads for a buddies RV-4 and had good luck with it. snipped
We used an older part # cam that the hotrodders know about which makes a few more horsepower. snipped
Click to expand...

David,
Can you give any more info about the camshaft you used? Hopefully a part number? If not, did it have a separate cam gear? Or was the cam gear integral to the cam? Do you know what model engines used this cam?

Charlie
 
The answer

chaskuss said:
David,
Can you give any more info about the camshaft you used? Hopefully a part number? If not, did it have a separate cam gear? Or was the cam gear integral to the cam? Do you know what model engines used this cam?

Charlie
Click to expand...

David was kind enough to contact me by private message with the answer. The camshaft in question is Lycoming part number 76097. I believe this is one of the first generation of Lycoming cams to have the integral camshaft gear. This part number is used on quite a few O - 320 engines. 76097 replaces part number 74167. 74167 is the older version of this camshaft that has a separate camshaft drive gear. This information is per page 2 of service instruction 1218a. Just thought I'd add this for the benefit of anyone reading this thread in the future.

Charlie
 
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