<VV> Re: PG RAMPY POWER QUEST 110hp/140hp torque the same

[Dan & Synde]

Hi Bob, 

As I understand it, in a stock 140hp the extra horsepower is from the better
breathing and thus higher rpms, not from increased torque.  The 110hp and
140hp have the same max torque output, the difference is where it develops
that torque.  The 110hp max torque of 154-160 Ft-Lbs occurs around 2800 rpm
whereas a 140hp reaches 154-160 Ft-Lbs at 3600 rpm.  The formula for
Horsepower vs Torque vs RPM is HP=((Torque x RPM)/5252)).  The increase in
HP for the 140HP is thus due to RPM only.  You get a whopping 10HP at
4400rpm with the 140HP engine, way above where you really need it for a PG
FC with a 3.55 rear end and tall tires.  The better breathing heads means
loss of port velocity in the lower RPM range and loss of torque.  The
retarded crankgear used on the "140HP" PG engine was an attempt to regain
some of the lower RPM torque at the expense of some of the top end. I put
the "140HP" in quotes because it doesn't breath as well at the top end and
thus doesn't develop as much gross horsepower, actually around 120HP if I
remember correctly.  

Just got done figuring out what engine to put in our UltraVan and  after
much consideration for tire size, rear end gearing, desired cruising speed
and max torque range, max HP range and reliability I ended up with what most
of the UltraVan guys and many of the FC guys told me to begin
with....164Cu-in, 95HP 889 cam, PG crankgear, 8.75:1 compression, small
valve heads, SafeGuard ignition.
 

Dan Kling

1961 Greenbrier Deluxe, 4spd, 3.89  On the Road Again,  yeehaw :)
1963 Spyder, restored   4spd Saginaw
1967 Ultravan #299  Newest of the herd!! Almost killed me already!!


http://photos.yahoo.com/duchesskyra
A few pictures of the Greenbrier, UltraVan, engine and tranny tear down with
more to come! 


Bob Helt said:
>BUT  from 2600 rpm and UP, the 140 outshines the other two greatly in
torque 
>and thus  horsepower.