Lightest weight O320

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Dominic Eller

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Hi all, What is the lighest realistic total weight of an O320 160hp. This is for Jungnster 1 which is a small all wood aerobatic bi plane so nothing needs to be certified.
I am looking at;

EFII system with light weight fly wheel System32 - FlyEFII

Skytech XLT starter 6.5 lb Lycoming XLT Aircraft Starters | Sky-Tec

Fly safe FS1-14 Alternator PLANE-POWER FLYSAFE ALTERNATOR FS1-14 | Aircraft Spruce

If any one has sound knowledge of the good the bad and the ugly of any of these or know of lighter options and perhaps other light weight items such as sumps etc.. I would love to hear from you.

What are the lightest O320 you know exist with an electrical system?

Cheers all

Kind regards

Dom
 

Victor Bravo

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There are also potentially lighter weight internal reciprocating components that can be used, from the auto racing world. Possibly better designed or better manufactured rods, pistons, valves, etc. Save weight and have stronger components for acro work, at the cost of a modest wealth transfer.

I'm guessing a couple of pounds of dead weight can be removed by cleaning up the crankcase castings with a die grinder. Jon Sharp did that on his O-200 cases for racing.

Klaus Savier built a carbon composite oil sump for his engine, and saved several pounds over the aluminum casting. He re-shaped his to fit his Long-EZ fuselage, but you could just polish your existing sump and lay up carbon on the inside, vacuum bag it, and have a perfect fitting light weight oil sump.

A properly done and customized electronic ignition system can allow you to remove even the light weight starter, saving 10-12 lbs. This ignition would have to be set up so that you can hand start the engine - some EI systems have that adjusted to not be possible for ground handling safety. They don't want you to bump the prop accidentally and have the engine fire. Making it fire at the correct realistic RPM (not too easy but achievable with your hand strength) will enable this weight savings.

Definitely choose the B&C product over any other product, Bill Bainbridge (B&C) is a very very high quality guy.
 

Dominic Eller

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All good stuff guys, thank you.
Victor bravo, I like the idea of the carbon sump. The B&C is 4LBS is heavier than the Skytec, quality is important ....but if the Skytec is any good I'd go the lighter weight option.
I might ask the FlyEFII guys about the hand swinging options..... kind of wanted a simple push button start but if the EFI system can produce a very reliable easy start by hand it could be an option...

cheers again all
keep it coming :)
 

Victor Bravo

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Small wind generator can power a low-drain radio and low drain transponder. Removing starter, engine mounted alternator, and 2/3 of the battery will add up to a lot of weight saved.

ALL of the EI manufacturers have the technical capability to set the minimum "force" or "RPM" for a hand start. They can build one so sensitive that you just barley move the prop with your pinky finger very slowly and it will catch.

But they try not to do that for safety and liability reasons.

However, you can work with them to rig up a separate safety that prevents the type of accident that they are trying to prevent. A small circuit with a 20 second timer, where you push the button on the panel to start the timer, and you have 20 seconds to flip the prop, but after that 20 seconds it can't start. Like setting the burgular alarm in your house and have to close the door within a certain time for it to arm.

That way, when you are pushing the airplane to the tiedown, and you forgot to turn off the master when you landed, you still can't put yourself through a meat grinder.

This is a little more compelx than just "bolt on and fly" equipment, but you said you wanted to save weight for acro. That's the kind of thing the acro people do... get rid of large heavy parts and commit to being more cautious.
 

BJC

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.... an O320 160hp. This is for Jungnster 1 which is a small all wood aerobatic bi plane so nothing needs to be certified.
Even the lightest, no starter, composite prop, any -320 will be heavier, and provide more HP, than the Jungster was designed for. Have you looked at the airframe’s capacity to stay together, avoid flutter and still handle nicely with the added weight and power? Also, if for aerobatics, keep in mind the deleterious effect of ballast weight in the tail on the pitch and yaw axis moments of inertia, particularly on recovery from flat spins.


BJC
 

Dominic Eller

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Cheers for input BJC :)
The plans say the Jungster 1 is designed for the up to the O320 at 150 hp Ill take a 160hp and be sensible with it. I've heard from others running 150 and 160hp and are happy but would have liked to have a little less weight.
For me, the weight issue is all to do with handling and stall speed, light fly's better every time and if I can have the lightest O320 and the extra HP available for great climb and for shorter take off then that's great. I'm not interested in going fast in it.
The original had an O290, so I'm expecting an O320 to cause a potential nose heavy issue and I certainly don't want that as shortening the mount is not an option and I am loath to put weight in the tail!
 

BJC

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The plans say the Jungster 1 is designed for the up to the O320 at 150 hp
That is good. Just based on looking at the airplane - a friend built one many years ago - I would have thought that the -320 would be too heavy.

VB mentioned a carbon sump. There were composite sumps (not sure of the chemistry) developed by one of the Lycoming clone companies that were weight savers, but they had problems with them, and quit providing them. I don’t recall the details.

A carbon prop and no starter, as others have said, would be weight savers too.

Let us know what you end up doing. There needs to be more actual data on FWF as-built weights.


BJC
 

TFF

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A 320 is just a bored out 290. Just a few pounds different. Mainly a stronger crank. You can make a 290 into a 320 by boring the case so the cylinders will set in. About a 1/8”. The kind of light weight 320 you are talking about is going to be heavy on the pocket. Might match airframe cost in mods. Plenty of people have taken a die grinder to any nub and extra barb off the case. EFI is cool, you can have a independent sump and cold air intake, lighter weight exhaust. Just don’t give your plane a thick shiny paint job. That 15 lbs extra right there. Pick the right tires, retreads are heavier by a good bit. Make a nice carbon cowl.
 

speedracer

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Yes, you can build a (cheater) 320 using a 290 D2 case with the cylinder holes bored out 1/4" (not 1/8"). I've done that. Two things: It has to be a D2 case, not a D or G because you need hydraulic lifters which the D and G do not have. Wide deck cylinders won't bolt on, only narrow deck ones. Some of the airboat guys use 290 G (narrow flange) crankshafts to save 3 pounds. I believe that the G crankshafts are actually 235 crankshafts. I have a rebuilt G C/S if you're interested. For building a carbon sump you need to use special hi temp epoxy of course. When you paint, only 1/2 the weight of the paint stays on whatever you're painting. The other half is lost through evaporation and out the exhaust fan.
 

Dan Thomas

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VB mentioned a carbon sump. There were composite sumps (not sure of the chemistry) developed by one of the Lycoming clone companies that were weight savers, but they had problems with them, and quit providing them. I don’t recall the details.
The O-320 sump has the oil pickup tube and suction screen socket cast into it. That complicates things. Aside from that, plastics generally don't do well under high heat and hostile chemicals. The max oil temp you see in the TCDS is the oil inlet temp, after the oil has come from the cooler. It gets a lot warmer than that in the sump. Blowby gases contain some harsh stuff, too. The last thing anyone needs is a carbon fiber sump that comes apart in the air.

A skilled guy could cut the parts for a sump from sheet aluminum, like 1/16", 1/8" and 1/4" 6061, and a bit of 6061 bar stock, to form and weld up a light sump that would last well. The mounting for the fuel servo or carb needs to be there, as does the induction tubing. A 320 sump looks simple from the outside. It's not. One could move the induction stuff outside entirely, I suppose.

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TerryM76

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For that kind of money be sure and buy two of them!

In all seriousness, could there be a weight savings found in 3D printed parts that could withstand the rigors of recip engine operation? Is it possible to 3D print parts that could be used in a Homebuilt aircraft engine?
 

dog

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For that kind of money be sure and buy two of them!

In all seriousness, could there be a weight savings found in 3D printed parts that could withstand the rigors of recip engine operation? Is it possible to 3D print parts that could be used in a Homebuilt aircraft engine?
If you mean printing useing a plastic fillament,then probably no.
If you are refering to 3D printing useing laser sintered titanium,then probably yes.
 

Mcmark

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I have a modded GPU that is 320 ci currently. The guy that built it also built a cold air induction and a custom alum sump. I have the sump off as I'm modifying for inverted oil ops. It's deeper than a stock sump but shorter. One of my things to do while apart is to measure the quantity. You can see the front lip is longer than just a gasket flange.
The intake is based on Tunnel Ram tech. The plenum is large, don't have exact measurements but it appears to be sized to a cylinders volume. It's smoothed but not polished.
I was given one of the Superior plastic sumps. A friend had tried it on his Pitts and he could not get it to stop leaking for inverted ops. He thought it might work as a standard sump ok, that's why I kept it.
 

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