Non A*E* Roots Numbers

[Lawrence E. Mayfield]

No, no real solutions. No matter what kind of idler you add, the crank is
still the dohickey that has to pull that belt around and that's what causes
the funky crank problems. I suspect that the aftermarket blocks like the
big boys use in their top fuel and funny cars has extra strength to help,
but I suspect that a lot of blown engines result from crank flex. A
solution for 6-71 or similar blowers would be those old inline crank gear
driven units that stuck out in front. The only car I have seen one of those
in lately was a land speed car with a blown chevy. Nice but sure add to the
length of the motor system.

mayf

At 11:46 AM 6/21/99 -0700, you wrote:
>Sounds like a valid issue mayf,
>
>However, you didn't state any solution, like runnin an idler pulley or
>such in between the crank pulley and the blower pulley or somethin, any
>ideas?
>
>Thanks,
>
>Todd....
>
>------
>
>Lawrence E. Mayfield wrote:
>> 
>> Been lurking around and listening to the talk of crank driven blowers. One
>> of the things that strike me is the damage potential caused by driving the
>> pump from the crank snout. Taking a 100 horsepower out the crank snout puts
>> a tremendous side load on the crank which causes flexing of the crank. I
>> know it is hard to visualize a big stout crank flexing but they do. What
>> happens then is that this stresses the block's main bearing webs and
>> subsequent cracking through the web to the cam bearing races. This is
>> probably the cause of many blown Ford 302 engines which have split the
>> block. Just a thought or two...
>> 
>> mayf
>> 
>> At 06:20 PM 6/20/99 -0700, Walter Sherwin wrote:
>> >
>> >
>> >>One of the more significant things to observe in the numbers posted
here is
>> >>how LOW the VE for a Roots is at low engine/blower speed--these low VE
>> >>numbers at low speed translate to not much boost there until the revs are
>> >>up a bit!! A VATN turbo will actually get the boost up a LOT SOONER
than a
>> >>Roots or a Screw huffer!! Get it up rates for VATN turbo/
>> >>Roots/conventional turbo are prolly sorta comparable to the same rates
for
>> >>a 15 year old boy/ 30 year old man/50 year old man!
>> >>
>> >>Another point to consider--Don't even THINK about running a Roots or a
>> >>screw in "blow thru" configuration!
>> >
>> >
>> >
>> >
>> >
>> >I agree completely with your comments regarding the "Roots" blowers.   On
>> >the other hand, "Screw" compressor technology has come a long way over the
>> >years.  You might be surprised by the performance figures for an optimized
>> >screw unit, no matter whether you want to examine  1)Dry Discharge
>> >Temperature   2)Adiabatic Efficiency   3)Volumetric Efficiency
4)Parasitic
>> >Power   5)Internal Compression Ratio...........etc.  Sized correctly,  a
>> >screw(s) can nearly match the peak efficiency of a good turbo system,
but do
>> >so over a much broader range, with near instant response (wet or dry).
>> >
>> >Do you have a URL for the VATN turbos?
>> >
>> >
>> >
>> >Walt.
>> >
>> >
>> >
>> 
>> L.E. Mayfield
>> 124 Maximillion Drive
>> Madison, Al. 35758-8171
>> 1-256-837-1051
>> 
>> http://www.hsv.tis.net/~mayfield
>> 
>> DrMayf at AOL.com
>> mayfield at traveller.com <<<<preferred
>> 
>> Bonneville Land Speed Racer, '66 Hydroplane Drag Boat (390 FE)
>
>
>



L.E. Mayfield
124 Maximillion Drive
Madison, Al. 35758-8171
1-256-837-1051

http://www.hsv.tis.net/~mayfield

DrMayf at AOL.com
mayfield at traveller.com <<<<preferred


Bonneville Land Speed Racer, '66 Hydroplane Drag Boat (390 FE)