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Angle Valve O-320?

eskimo77

Registered User
Kenai, Alaska
Has anyone on here had any experience with an angle valve O-320 built using GO-480 jugs/pistons on a narrow deck O-320 bottom end? I have access to the parts to create such a Frankenstein but am curious as to the end results and feasibility. Compression ratio of the 480 is 8.7:1. Apparently there are some airboat guys down south that have done this and are guessing about 170hp is the result. Just thought I'd throw it out there and see what you guys might now.
 
About 2 years ago a guy called up that got eci (I think) to put angle valve heads on 0-320 barrels. He was putting it in an RV-4 and had us build custom exhaust and intake pipes. He said that it dyno'd really well, something like 190 hp and he was hoping to offer a conversion kit for people trying to get more out of their 0-320's. I haven't heard much about since then but it was an interesting concept that only added 10 lbs.
 
My eyeball measurements look like the intake tubes will fit, but the exhaust appears to be a little wider than the parallel head location.
 
We use to call that the "Newburg Special" ! Here's a shot of one... it's nothing new and works just fine. Picture is from 2001 after I rebuilt this airplane... not sure when the engine was first assembled.

DCP01684.JPG
 

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A friend of mine built an angle valve O-320 a few years back for his RV-6. Went to Crane Cams in Ft Lauderdale and had them grind a hot rod cam for it. He can't post on here, but says "that the only difference from O-320 to O-360 is a little longer barrel. The heads are the same. Figure 20 more HP either O360 or O320, due to heads breathing that much better" Check out his latest creation on the cover of last month's Sport Pilot magazine. Yellow scratch built Bucker.
 
Is there anyone running higher compression pistons (I'm considering 10:1) in one of these engines? How does performance compare to a parallel valve 160hp o-320? Just wondering what to expect? Thanks for the interest guys, just a reminder that there is nothing new under the sun.
 
I talked to a Pitts guy this last week and the discussion of the go-480 cylinders on an o320 came up. He claimed that this engine would do slightly better than an 0-360.
Im now curious to try to learn more about doing this as I've got an 0-320 due for an overhaul. If any of you could pass along any info I'd appreciate it.
 
Sounds interesting however remember that the GO-480 and it's parts is long out of production so that it will be necessary for you to scrounge in the market place, with the quality of any available parts being an unknown. Also your "new" engine will be a bastardized engine and thus be of diminished value. I also suspect that if you should ever desire to exchange the "new" engine as a core with Lycoming, that they may refuse to take it. This is not telling you not to do it, just something for you to think about.
 
Sounds interesting however remember that the GO-480 and it's parts is long out of production so that it will be necessary for you to scrounge in the market place, with the quality of any available parts being an unknown. Also your "new" engine will be a bastardized engine and thus be of diminished value. I also suspect that if you should ever desire to exchange the "new" engine as a core with Lycoming, that they may refuse to take it. This is not telling you not to do it, just something for you to think about.

AERO has them as well as several other places so it would appear that Lycoming still makes them or there is a lot of new old stock. At 2000$ plus a pop im just a bit reluctant to dive in head first.
If the power is there as friends have stated and cooling is better it seems like an interesting and perhaps viable option...at least when compared to throwing 30k at a 340 stroker
 
As far as cooling is concerned the original unmodified engine will cool properly IF the baffles, air inlet and outlet are correct. That is an entirely separate topic from modifying the engine. If you do decide to alter the engine be sure to install a full engine EGT/CHT/OIL temperature instrument because you need to know that this information is correct. Do not ruin your "new" engine.
 
I think it sounds like a great project. I have an 0-320 narrow deck sitting around. I'm interested to hear any and all experience reports.

http://www.airpowerinc.com/productcart/pc/cylinders.asp?catid=70&subcat=78

I see 435 cylinders on the list, too. Wouldn't those be the same as 290 cylinders?

I'm pretty sure you're correct on that. I was just having a talk with a friend working on a 435 on a Stinson L-5. It needed new cylinders, and I guess it was quite an ordeal getting 6 of them.
 
Sounds interesting however remember that the GO-480 and it's parts is long out of production so that it will be necessary for you to scrounge in the market place, with the quality of any available parts being an unknown. Also your "new" engine will be a bastardized engine and thus be of diminished value. I also suspect that if you should ever desire to exchange the "new" engine as a core with Lycoming, that they may refuse to take it. This is not telling you not to do it, just something for you to think about.

Pete,

Last I heard, Lycoming still overhauls 480s, and all overhauled engines coming out of Lycoming are equipped with brand new cylinder assemblies. Might not be cheap, but I'd bet Lyc will sell you cylinders and parts.

MTV
 
As far as better cooling goes, I was referring to the tendency of the stroker engines to run hot. If a guy could get 180 hp or near that with the 480 jugs I would think that they would run cooler.
 
I have 4 GO435 engines as spare parts for a Super Widgeon just sitting around. I overhauled another pair for that plane and Lycoming even had new cylinders at $3500 a piece. Went with chromed from Gibson instead. Anyone want 435 parts I have lots of them.

Jim
 
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