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Horsepower loss with Dry Sump?? #1441295
05/24/13 09:14 AM
05/24/13 09:14 AM
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Greensburg, Pa
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Mpetros Offline OP
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I just Dynoed My Engine Yesterday..Lost 24 Horsepower from last Year.
We freshened it but changed nothing from last Season..
Same Dyno,Carb, Heads, Cam,same set up as last Year.
The only thing different for this Season is a 4 stage dry sump.
Can a Dry Sump loose Power?
I ran 12" of Vacuum last Year with My wet sump.. This Year We bumped vacuum up to 20"..
Any Tips would be appreciated..

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441296
05/24/13 09:31 AM
05/24/13 09:31 AM
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Romeo MI
MR_P_BODY Offline
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While the dry sump does take power to turn it so does
the stock style pump... I've never tested a back to
back between them .. but the dry sump tend to make more
power because it is pulling vac.... were the conditions
the same as you dynoed last time.. remember that the
number you get is for the conditions that day(even on
the same dyno)

Re: Horsepower loss with Dry Sump?? [Re: MR_P_BODY] #1441297
05/24/13 10:54 AM
05/24/13 10:54 AM
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Greensburg, Pa
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Conditions where about the same.. Maybe 5deg cooler Yesterday from last Year

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441298
05/24/13 11:22 AM
05/24/13 11:22 AM
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Romeo MI
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Quote:

Conditions where about the same.. Maybe 5deg cooler Yesterday from last Year




Temp is only one aspect... was the humidity up...
pretty hard to burn water(the outside air coming in)...
but its hard to say where you lost 24 hp... even with
the added vac(which I wouldnt run 20"... too high and
can draw the oil off the wrist pins) the pump is
still pumping the same pressure ... unless you turned
up then it would require more power to turn the pump

Re: Horsepower loss with Dry Sump?? [Re: MR_P_BODY] #1441299
05/24/13 11:25 AM
05/24/13 11:25 AM
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Greensburg, Pa
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Mpetros Offline OP
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I had 60 psi with wet sump at 7800..
I now have 85 psi now with dry sump at 7800 Rpm

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441300
05/24/13 11:28 AM
05/24/13 11:28 AM
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Quebec, Canada
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Something doesn't seem right. IS the pan you are using specific for the Dry sump system? There really should be no power lose. You are getting better oil control in the pan and and more vacuum. Power should be increased! Did you use a different velocity oil?

Re: Horsepower loss with Dry Sump?? [Re: Diablo] #1441301
05/24/13 11:32 AM
05/24/13 11:32 AM
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Greensburg, Pa
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Same Oil, Brad Penn Break in Oil..
Charlies Oil Pan.. He custom built it for the 4 Stage Dry Sump from scatch

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441302
05/24/13 11:32 AM
05/24/13 11:32 AM
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Romeo MI
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Quote:

I had 60 psi with wet sump at 7800..
I now have 85 psi now with dry sump




The higher pressure will suck a bit more power(greater
back pressure)... so now you have changed the test
parameters and I would expect different results

Re: Horsepower loss with Dry Sump?? [Re: MR_P_BODY] #1441303
05/24/13 11:47 AM
05/24/13 11:47 AM
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Greensburg, Pa
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So do You think 24 is about right for the pressure change?
Just wanted to make sure I wasn't missing something

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441304
05/24/13 11:55 AM
05/24/13 11:55 AM
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Romeo MI
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Quote:

So do You think 24 is about right for the pressure change?
Just wanted to make sure I wasn't missing something




Your asking something that is a unknown.. with your
engine it MIGHT be, but like normal... all engines are
different.... I dont have a curve/graph to say what
power it takes to turn the pump with different pressure
points... I set my dry sump so I have 75 pounds at
rev and change the oil viscosity to keep the hot idle
pressure to what I want

Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441305
05/24/13 12:15 PM
05/24/13 12:15 PM
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LONG ISLAND
fishy340 Offline
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The track and mph will be ur dyno.I dyno mine for breakin and leak checks.Good Luck

Re: Horsepower loss with Dry Sump?? [Re: fishy340] #1441306
05/24/13 12:51 PM
05/24/13 12:51 PM
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Las Vegas
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Yeah somethig sounds a little odd. I would not necessarily expect more power form a dry sump over a good wet sump but I see no reason for it to loose that much either.

Who's pump is it? Also I think that is probably a lot more oil pressure than you need and the extra pressure will cost a few HP.

Lastly as MrP points out weather can have a huge affect on HP numbers. Temp is actually the variable that will affect it least. Humidity, and barometric pressure will have a larger affect. Where these corrected or uncorrected numbers?


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Re: Horsepower loss with Dry Sump?? [Re: Mpetros] #1441307
05/24/13 05:54 PM
05/24/13 05:54 PM
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Delray beach, Florida
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I'd get that vacuum setting under control first. as mentioned, 20" of vacuum is too much.
You said you freshened the engine, but there are a lot of unknowns about that part of it.
It could be as simple as not having the rings seated fully yet. I've never seen a dry sump engine make less horsepower because of the pump.
What are the bsfc and bmep numbers from before and now?


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Re: Horsepower loss with Dry Sump?? [Re: Performance Only] #1441308
05/24/13 07:16 PM
05/24/13 07:16 PM
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SW Ohio
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Same dyno as last year?
Been calibrated or abused?

Re: Horsepower loss with Dry Sump?? [Re: AAR-B4] #1441309
05/25/13 05:01 AM
05/25/13 05:01 AM
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IN
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The main benefit of the dry sump (beyond vacuum which you already had) is to prevent windage loss from splashing oil. On the dyno, you won't likely see it if you were starting with a deep pan. Different story when the car is accelerating and the oil is sloshing around a wet sump. Hopefully you will see the benefit in race conditions. Still I think 24 HP loss on the dyno doesn't sound right.

Re: Horsepower loss with Dry Sump?? [Re: ahy] #1441310
05/25/13 09:24 AM
05/25/13 09:24 AM
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Lynchburg, VA
Leon441 Offline
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20" vacuum too much? Really?
At what RPM.

When I had my W8 at BES we could not get but 12". They found some leaks and got it up to 20" with a wetsump. That is what they wanted.

How much oil pressure do you have at idle? You only need around 20 psi. So you can change you pulley to slow the pump down. Also 50 psi is really all you need at full boogy. There is a regulator on the rear of the pump to adjust pressure. But, slowing the pump down is the first step if you have plenty of pressure at hot idle.

Leon


Career best 8.02 @ 169 at 3050# and 10" tires small block power.
Re: Horsepower loss with Dry Sump?? [Re: Leon441] #1441311
05/25/13 09:40 AM
05/25/13 09:40 AM
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Romeo MI
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Quote:

20" vacuum too much? Really?
At what RPM.

When I had my W8 at BES we could not get but 12". They found some leaks and got it up to 20" with a wetsump. That is what they wanted.

How much oil pressure do you have at idle? You only need around 20 psi. So you can change you pulley to slow the pump down. Also 50 psi is really all you need at full boogy. There is a regulator on the rear of the pump to adjust pressure. But, slowing the pump down is the first step if you have plenty of pressure at hot idle.

Leon




According to Reier/Morrison(sp) they did testing and
seen that above 14"hg that it could cause problems
and waste power to go higher... yes higher vac does
help seal the rings better but that was all... it would
start pulling oil off the pins at the higher points

Re: Horsepower loss with Dry Sump?? [Re: Leon441] #1441312
05/25/13 11:04 AM
05/25/13 11:04 AM
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Quote:



...Also 50 psi is really all you need at full boogy. There is a regulator on the rear of the pump to adjust pressure. But, slowing the pump down is the first step if you have plenty of pressure at hot idle.

Leon




Joe mondello (rip) always said that you need 10 psi per 1000 RPM, to overcome centrifugal force. Has that changed? I sure would want more than 50 psi at 7800 rpm.


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Re: Horsepower loss with Dry Sump?? [Re: Hemi_Joel] #1441313
05/25/13 11:17 AM
05/25/13 11:17 AM
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Romeo MI
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Quote:

Quote:



...Also 50 psi is really all you need at full boogy. There is a regulator on the rear of the pump to adjust pressure. But, slowing the pump down is the first step if you have plenty of pressure at hot idle.

Leon




Joe mondello (rip) always said that you need 10 psi per 1000 RPM, to overcome centrifugal force. Has that changed? I sure would want more than 50 psi at 7800 rpm.




You really dont need the 10psi per 1000 revs in the
upper RPM.. remember pressure is a by-product of flow
vs restriction ... if you have good flow its getting
lubed... alot of guys run above 7000 rpm with 70si max
and some even run as high as 9000 with that same 70psi
but that 10 per 1000 was a standard number for YEARS

Re: Horsepower loss with Dry Sump?? [Re: MR_P_BODY] #1441314
05/25/13 02:21 PM
05/25/13 02:21 PM
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Lynchburg, VA
Leon441 Offline
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Been sharing notes with a guy who worked at Arringtons shop where they built engines for Craftsman truck. They turn 9,700 with only 50 psi and ran 15" of vacuum. Some teams would seal every bolt and thread to get 17" but saw no power.

I ran 20" and never had any pin wear problems that would suggest lubrication issues. But, I would assume I was running a smaller pins and piston bore than what Reher Morrison was testing with.

My newest project has forced oiling to the pin through the rod. But, if your oil control ring and piston are working properly you should have plenty of oil at the wrist pin no matter what the crankcase vaccuum. Just my opinion.

Leon


Career best 8.02 @ 169 at 3050# and 10" tires small block power.
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