Yep..........I've found an average of about 10 hp is lost, perhaps less,
due to the extra effort need to turn the pump drive...and the windage the
oil pump creates in the crankcase.
I found this on a 360 I built a few years back, the machine shop recommended
a hi-volume oil pump be installed on final assy.
So I went along with it, (and they never mentioned changing the pump drive)
My grandfather and I got the engine home to his garage, spent the weekend
installing it.
We got it running, I drove it to a local Cruise-in, and on the trip home
that evening the oil pressure gauge went
nuts...........2 blocks from home it lost all
oil pressure.
The next evening after I got home from work, I got ready to pull the 360
again.
(getting very tired of this by now) so I can get the oil pan off...no room
to do it under the car...............I get the pan off and remove the pump
only to find the pump drive twisted and snapped off in the pump body......I
have to rip the intake off to get the pump drive out and replace it.
I installed a stock volume pump and a new MP drive.......
I reassembled everything, got it running and much to my surprise it rev's
nicer, and smoother........and feels much more stronger than before......
I asked the shop why it happened and how come a proper drive wasn't
installed.
They apologized for the problem and rechecked the car and said that the pump
must have been creating windage
inside the crankcase creating some drag on the crank due to the high amount
of oil being moved thru the engine.
This had cost the engine about 5-10hp!
I'll never use a hi-volume pump again,
and I don't recommend them for stock
or near stock engines.........just my.02
sorry this is so long.....
Ron-
"Bernd D. Ratsch" <bernd@texas.net>
To: <dakota-truck@dakota-truck.net>
Sent: Thursday, July 24, 2003 8:53 PM
Subject: DML: RE: Re: High Volume Oil Pump?
>
> Huh??? Cost HP?
>
> - Bernd
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