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  #11  
Old 01-18-2018, 09:21 AM
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N941WR N941WR is offline
 
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Location: SC
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Scott,

I know you don't usually deal in "what-if's", but can you indulge me this one time?

How much longer would the engine mount for the -14 need to be to put the CG where it would work for the parallel valve (I)O-360 and what would you expect the performance hit to be?
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Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
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  #12  
Old 01-18-2018, 10:29 AM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
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Quote:
Originally Posted by N941WR View Post
Scott,

I know you don't usually deal in "what-if's", but can you indulge me this one time?

How much longer would the engine mount for the -14 need to be to put the CG where it would work for the parallel valve (I)O-360 and what would you expect the performance hit to be?
I think the weight delta is about 40 lbs.

Assuming that is correct, a quick W&B calc shows that for the lighter engine to have the same moment it would have to be 6" further fwd. This would not be accounting for the fact that the prop weight was pushed further fwd as well, so the actual required might end up being about 5".

If it was an unmodified 180 HP parallel valve engine, cruise speed diff. would probably be in the neighborhood of 10 kts slower compared to the 200 HP IO-360 and a little bit more, compared to the IO-390.

The difference that would be more directly noticeable would be take-off and climb performance.
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  #13  
Old 01-18-2018, 10:55 AM
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N941WR N941WR is offline
 
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Quote:
Originally Posted by rvbuilder2002 View Post
...

The difference that would be more directly noticeable would be take-off and climb performance.
And the look. A long nosed RV-14 would look kind of funny.

I suspect most people are asking about sticking an IO-540 up front, not a smaller engine.
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RV-9 (Yes, it's a dragon tail)
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Build the plane you want, not the plane others want you to build!
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  #14  
Old 01-18-2018, 11:18 AM
rv7charlie rv7charlie is online now
 
Join Date: May 2006
Location: Pocahontas MS
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Default alt engine heresy

It's a shame that RVers are so Continental-averse. A C--IO360 is 210 HP, no heavier (usually lighter) than an angle valve Lyc 360, and smoooooth.....

Yes, shorter TBO & more cylinders to purchase, but...
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  #15  
Old 02-25-2018, 10:49 PM
Bernard Hartnell Bernard Hartnell is offline
 
Join Date: Jul 2013
Location: Grand Junction, CO
Posts: 61
Default Be careful with each change you consider , TIME in building increases!

Every mod to the Vans plans has cost me. Considerable TIME! If you love building and are young and donít care she you fly next, then mod al you like. My # of 14A is very low so while waiting for early kits I built up an IO360. No changes needed to fit right in the IO390 spot. So with electronic ignition, Lycon port and polish and 10-1 I have far more than the 10 hp goal. BUT there are down sides; increased build time, research time, sending off parts for reman etc.. and resale someday is an unknown but cold cost. Then while you have a spank-in new REBUILD it is not a spank-in new engine with zero hours! I would likely not do it again. Good education but longer time building when my goal is to fly the xxxxxx thing !!
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  #16  
Old 02-25-2018, 10:53 PM
Bernard Hartnell Bernard Hartnell is offline
 
Join Date: Jul 2013
Location: Grand Junction, CO
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Exclamation

Remember, ONLY the forward mount governor will work for both tric and tail !!!!!!!!!!!
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  #17  
Old 02-25-2018, 10:56 PM
Bernard Hartnell Bernard Hartnell is offline
 
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Location: Grand Junction, CO
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Exclamation Caution!

Remember, ONLY the forward mount governor will work for both tricycle and tail wheel 14s !!!!!!!!!!!
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  #18  
Old 02-26-2018, 07:56 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by Davoakes@att.net View Post
I was told that a 360 could be increased to 200-210 HP I do not know the truth. I know about 200 hp 360's but what would a 10HP decrease do to the performance.
Angle valve 360's average around 195HP stock, despite the 200 horse label. Monty Barrett developed the 390 in an attempt to deliver 210+HP without loss of TBO, which was was indeed down to 1000 hours or so among performance-oriented customers. Classic formula; add cubic inches, and not so much CR.

BTW, just for fun, do a little math.

390 / 360 = 1.08
195 HP x 1.08 = 210 HP

The originals were built on modified 360 cases. The buzz was good enough to interest Lycoming, who undertook design of a new 390 case and put together a kit for assembly by independent shops. The deal gave Barrett an exclusive for several years, followed by expansion to (IIRC) five other vendors. Things rocked along nicely until Lycoming suddenly ended the kit engine program. Today 390's are sourced from Lycoming only.

Quote:
Originally Posted by Jared_Solomon View Post
The price of the IO-390 and Angle Valve IO-360 are about the same. The angle valve will run hotter (possibly less longevity) and not climb as well for very little savings in money.
There is no notable cooling difference between the 360 angle valve and the 390 angle valve. Same basic cylinder, slight bore difference, 5.125 vs 5.319. FWIW, any angle valve Lycoming will indicate lower CHT as compared to a parallel valve cylinder.
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  #19  
Old 02-26-2018, 08:23 AM
mturnerb mturnerb is offline
 
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"FWIW, any angle valve Lycoming will indicate lower CHT as compared to a parallel valve cylinder.
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Dan Horton
RV-8 SS
Barrett IO-390"

Regarding the difference in CHT's between angle valve and parallel valve, does this change the acceptable operating temperatures or is it a "freebie"? In other words, is it just as acceptable to run an angle valve at 380-390 CHT in climb on a hot day as to do so on a parallel valve?
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