izitbrokeyet?
Well-Known Member
- Joined
- Apr 5, 2003
- Messages
- 1,908
Has anyone in here ever calculated Brake Mean Effective Pressure for a Typical Modified .21 sized motor (Bmep)?
Norm, Marty, Rod, (Brian?)?
Norm, Marty, Rod, (Brian?)?
Yes, we used BMEP as our standard. We also did compare another propriatary indicator that Brian came up with which measured launchability. Since we have so much reliance on the ability to launch props, it is critical to have HP in the area where that is based.izitbrokeyet? said:Has anyone in here ever calculated Brake Mean Effective Pressure for a Typical Modified .21 sized motor (Bmep)?
Norm, Marty, Rod, (Brian?)?
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Kurt- Very interesting link, was good reading except for this part-Kurt Tedford said:Our 25.7 cc engine is between 7 and 8 bmep.
check this out for an explanation of bmep.
BMEP Explanation
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Lighten up dude! Nothing directed at you, just said hope they are cool with it.Kurt Tedford said:I did read the webpage, before I included a link to it. I was respectful of their statement and did not copy their web page, I only provided a link to others in this community to go too and read for their personal benefit. I guess I will go crawl back under the rock I came from.
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Very interesting thought. It could be the smaller bore. Or it could be that they can be made more efficient.TimD said:I can't see why wouldn't they be cool with it. The page is an advertisement for their software that they are trying to sell commercially. They have just got some exposure.
So is BMEP a suitable method of comparing engines? And does the results mentioned mean that 21 engines are particularly efficient in comparison to larger engines?
VERY interesting thread really. B)
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They were running those numbers at around 29K on some pulls. Some a little higher. Yes they built an inertial dyno. I know Brian Calihan, Marty, Ackerman, Norris Sparks , Joe Kramer and Tom Grannis all had a role in building this thing I believe, I hope I did not leave anyone out. It is quite the neat little machine.TimD said:Norm,I don't suppose there would be any test results for a smaller capacity engine than a 21 in your data?
The other possible difference could be the operating rpm range is higher on the smaller engines.....
I did some backward calculations on the figures you listed - either they are making very high rpm's around 40K or they were making some decent ponies at lower rpm.... closer to 4hp than 3.
How were the HP figures established? Inertia Dyno?
Tim.
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That would be all Marty, Brian and Ackerman. I have not a clue. They did all the testing. I am just the lucky guy to have all the data and the machine to test new stuff on.izitbrokeyet? said:Heya Norm.....thanks for the Info!
you guys have always been very helpful with the data you pulled. No doubt you went through a lot of trouble (fun) to get it and it's appreciated.
can you verify that you guys were using PSI as units for your Bmep calcs. It appears I have a bust in one of my formulae
I wanted to rule out unit math as the source of the bust.
Thanks again
Happy Thanksgiving
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Norm Doerr said:That would be all Marty, Brian and Ackerman. I have not a clue. They did all the testing. I am just the lucky guy to have all the data and the machine to test new stuff on.izitbrokeyet? said:Heya Norm.....thanks for the Info!
you guys have always been very helpful with the data you pulled. No doubt you went through a lot of trouble (fun) to get it and it's appreciated.
can you verify that you guys were using PSI as units for your Bmep calcs. It appears I have a bust in one of my formulae
I wanted to rule out unit math as the source of the bust.
Thanks again
Happy Thanksgiving
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All I know is that the thing works really good and is very accurite. LOL
And yes they did A LOT of pulls on the thing. I have found nothing on smaller engines. As I am sure you can imagine, most of the pulls are on 21 engines.
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Gene:Slideblues said:Hi Marty,So break it down for a country boy, who's formula is pie are round cornbread are square :lol:
Which 21 engine was the best overall from these tests?
Gene
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