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03-03-2015, 04:03 PM
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Senior Curmudgeon
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Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
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I suspect Kevin meant that the peak torque is lower RPM wise------(but your are still the eagle eyed one)-------even if what he said was ????
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011 
Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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03-03-2015, 04:20 PM
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Join Date: May 2005
Location: Tuttle, Oklahoma
Posts: 2,563
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So, someone define this term so we can know what everyone is saying!
What are you saying? Are you saying that I can run X HP in this engine and in so doing the "torque curve" peak at that X HP is at a lower or a higher number ( lets call that number - Y) than from another engine that is running at that same X HP?
If I have: - Engine A - R409 engine that runs at 230 HP (or 235, or 250, or whatever number. . . you pick one)
- Engine B - standard engine that runs at 230 HP (or 235, or 250, or whatever number. . . you pick one, but it must be the same as Engine A)
Are you saying that the peak torque of Engine A will be higher than the peak torque of Engine B at the same HP reached? Please give some details.
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03-03-2015, 04:42 PM
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Join Date: Oct 2005
Location: 08A
Posts: 9,500
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Quote:
Originally Posted by Dan Langhout
I suspect he means peak torque occurs at a lower RPM.
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Could be. I'm sure a standard torque and horsepower graph will explain everything.
Better yet, plain 'ole dyno data corrected to Standard Day. Here's an example from Sky Dynamics:

__________________
Dan Horton
RV-8 SS
Barrett IO-390
Last edited by DanH : 03-03-2015 at 04:49 PM.
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03-03-2015, 04:53 PM
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Join Date: Aug 2010
Location: San Luis Obispo
Posts: 199
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Quote:
Originally Posted by Mike S
I suspect Kevin meant that the peak torque is lower RPM wise------(but your are still the eagle eyed one)-------even if what he said was ????
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What I was trying to say is that a stroked engines peak torque is lower in the rpm range. Meaning it pulls harder at lower rpm than say a stock 360. This is why Carbon Cub loves the 340 with their fixed pitch prop. At 2200-2300 the engine produces more torque than a 320. Right where they want it. 409 similar.
Clear as mudd.. 
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03-03-2015, 04:56 PM
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Join Date: Sep 2007
Location: Central IL
Posts: 5,516
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Quote:
Originally Posted by DanH
Each injector assembly is supplied at the same pressure, and they are (in this batch fire system) opened and closed with the same electrical signal. However, that does not mean they deliver the same fuel quantity. In the end analysis, an electronic injector is still just a body with a hole in the end. Unless a vendor runs a great many injectors on a test bench in order to assemble a flow-matched set, the match is dependent on the manufacturer's flow tolerance. Plus or minus 6% (a 12% range) is a common specification, brand new, although the typical random set will be better. How much better does it need to be? Assume 8 GPH. A good GAMI spread has all cylinders passing peak EGT within a 0.2 GPH window, so 0.2/8 = 2.5% range.
With use, an electromagnetic injector is subject to dirt and deposit issues, as is a mechanical system's nozzle. 'Nuff said.
Let's assume you get a perfectly matched set, and they never get dirty. Will all cylinders reach peak EGT at the same time? Probably not. Identical fuel/air ratios for all cylinders is also dependent on air delivery. Again, unless somebody took great care to flow match cylinder heads, air delivery may or may not be identical.
The SDS controller has a rich/lean panel control knob. It works pretty much like the familiar red handle, but with less range. With it, an Efii owner should be able to determine a GAMI spread, just like with a mechanical injection. Some installations will be good out of the box, and some won't. If poor, you'll need to swap injectors, just as we do with nozzle restrictors.
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Yep, I wrote the same thing and then figured was a waste of time to engage in that discussion and deleted. Thanks for posting. It is more likely that variation of airflow to each cylinder is greater than the fuel. Even more reason for individual injector control.
I am still waiting on the BSFC numbers. Until then it is just flag waving.
__________________
Bill
RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
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03-03-2015, 05:21 PM
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Senior Curmudgeon
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Join Date: Sep 2005
Location: Dayton Airpark, NV A34
Posts: 15,420
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Quote:
Originally Posted by Relentless
What I was trying to say is that a stroked engines peak torque is lower in the rpm range.
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Yep, that is what I interpreted it as.
__________________
Mike Starkey
VAF 909
Rv-10, N210LM.
Flying as of 12/4/2010
Phase 1 done, 2/4/2011 
Sold after 240+ wonderful hours of flight.
"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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03-04-2015, 10:38 AM
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Join Date: May 2005
Location: Tuttle, Oklahoma
Posts: 2,563
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Quote:
Originally Posted by Relentless
What I was trying to say is that a stroked engines peak torque is lower in the rpm range. Meaning it pulls harder at lower rpm than say a stock 360. This is why Carbon Cub loves the 340 with their fixed pitch prop. At 2200-2300 the engine produces more torque than a 320. Right where they want it. 409 similar.
Clear as mudd.. 
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Actually it is much clearer than mud. That is the info I was expecting to hear. So, since you brought up the O-340 going into the Carbon Cubs, do you have any information on the performance difference between the O-340 and the IO-340? Can you provide any HP/Torque curves for these two engines?
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03-04-2015, 11:04 AM
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Join Date: Aug 2010
Location: San Luis Obispo
Posts: 199
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Quote:
Originally Posted by RVbySDI
Actually it is much clearer than mud. That is the info I was expecting to hear. So, since you brought up the O-340 going into the Carbon Cubs, do you have any information on the performance difference between the O-340 and the IO-340? Can you provide any HP/Torque curves for these two engines?
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Now that I am no longer working for Titan I think it best you contact them for actual data on the 340. It is a solid 180hp with warm sump and carb. Pushing 190hp with efii and cold air induction.
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03-04-2015, 12:38 PM
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Join Date: Oct 2005
Location: 08A
Posts: 9,500
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Quote:
Originally Posted by Relentless
What I was trying to say is that a stroked engines peak torque is lower in the rpm range. Meaning it pulls harder at lower rpm than say a stock 360.
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The 320, 340, 360, 370, and 409 all have the same 5.125" bore.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
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03-04-2015, 01:00 PM
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Join Date: Jan 2014
Location: Ollon Switzerland
Posts: 78
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Kevin working for Titan or not anymore??
Hi Kevin!
You said in this thread that you are not working for Titan anymore but you said in another thread that you resigned your position by Titan.. What is the true?? I think you did a great job on this forum and I was looking forward to meet you for a lot of question at Oshkosh!
Cheers
Nicolad
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