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P-70 in BVM bypass

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Old 02-16-2006 | 12:01 PM
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Default P-70 in BVM bypass

This is a very snug fit. Hoping that someone has done this and has some input as to turbine position in the duct. I'm afraid that the obvious (easy) position is too far forward.

DC
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Old 02-17-2006 | 08:58 AM
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Default RE: P-70 in BVM bypass

Is that a P-60/RAM 500 size bypass? It looks a bit small for the P-70.
Old 02-17-2006 | 09:34 AM
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Default RE: P-70 in BVM bypass

Hi DC,

I think JohnV set up a P-70 in a RAM 500 bypass just a few months ago. Maybe he can take a look on yours.


Good luck,
Old 02-17-2006 | 11:40 AM
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Default RE: P-70 in BVM bypass

That might be the better question. Since it seems that few have actually put a P-70 in a bypass, what is the recommended bypass dia.? These were sold to me as P-70 size but they do seem a bit small. Normally you would want the exhaust approx. 5/8" in front of the bellmouth. In a bypass situation, the 'front' af the bellmouth becomes rather vague. Even with a Funsonic in the same duct, you gain a great deal of room, but the exhaust is even further from the 'front' of the bellmouth.

Thanks for responding.

DC
Old 02-17-2006 | 01:05 PM
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Default RE: P-70 in BVM bypass

DC, I have two P-70's in BVM by-passes. One in a Bandit the other in a T-33. They are a very tight fit. So tight in fact that they prevent you from running a FOD screen if it extends beyond the cowling at all. They do how ever perform very well in the duct.
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Old 02-17-2006 | 10:23 PM
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Default RE: P-70 in BVM bypass

BV makes a specific bypass for the P-70 which is a bit longer than the Ram 500 bypass. The diameter is the same, however. I used the Ram 500 bypass/P-70 combination in my BVM F-16 since the longer bypass did not fit as well. The combination works fine and the engine runs cool. I did use BV's P-70 pipe in this application as well. The RAM 500 tailpipe setup has smaller diameter inner and outer pipes than the P-70 setup. and it seemed to be somewhat restrictive. With the P-70 pipe you can trim about 1/4" to 3/8" off of aft end of the bypass. This will open up this area a bit more and allow more air flow for cooling between the inner and outer pipes.

Mike Danchak
Old 02-19-2006 | 11:45 AM
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Default RE: P-70 in BVM bypass

Hey Sled, I am running a P70 in the Ram500 bypass in my bvm fury, I have the p70 bvm bypass here, and it is bigger.
Old 02-19-2006 | 12:04 PM
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Default RE: P-70 in BVM bypass

I am debating whether or not to put a bypass in my jet. I would like to know the weight of the bypass and cover. If someone has a bypass out of their airplane, could you let me know the weight and brand. I am interested in a bypass for a p60 or p70 or 54mm class turbine.

Thanks,
Greg
Old 02-19-2006 | 03:12 PM
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Default RE: P-70 in BVM bypass

My scales are not real precise at these weights, but this BVM bypass is approx. 6oz. with cap and velcro straps.

DC
Old 02-19-2006 | 04:07 PM
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Default RE: P-70 in BVM bypass

worse thing that will happen is the P70 will run cold if the bypass is too small... Tail pipe
size is far more important..

Even if it does run too cold, you may not notice, thrust and fuel burn will be down a bit..

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