Wilpower (Wildcat) Vs. Huffaker Intake
Posted: Wed May 23, 2007 7:48 pm
This is excellent info from Dan Jones
Spent a little time evaluating a couple of Rover V8 single plane intake
manifolds on Dave McLain's flow bench in Cuba, Missouri. I wanted to
know which of the intakes would flow best when bolted to my 1964 Buick
300 aluminum heads. The heads are ported and use larger Stage 1 Buick
V6 intake and exhaust valves (1.775" head diameter for the intake and
1.5" for the exhaust):
http://www.bacomatic.org/gallery/album1 ... ambers_001
http://www.bacomatic.org/gallery/album1 ... take_ports
http://www.bacomatic.org/gallery/album1 ... ust_ports2
The two intakes tested were a Huffaker:
http://www.bacomatic.org/gallery/album13/Huffaker_front
http://www.bacomatic.org/gallery/album13/Huffaker_side
and a Willpower:
http://www.bacomatic.org/gallery/album13/Willpower_1
http://www.bacomatic.org/gallery/album13/Willpower_2
Note the Willpower intake pictured is not the actual intake tested. I've
not yet taken pitures of the intake we tested but it differs from the one
pictured in that it has EFI injectors bungs in each port but the injectors
were not installed for these tests. The Huffaker has larger ports which
better match the Buick 300 heads:
http://www.bacomatic.org/gallery/album1 ... aker_ports
The Willpower has smaller Rover-sized ports but has a better radius on
the end runners than the Huffaker. An end port and a center port of the
head were first flowed without an intake attached to get a baseline, then
flowed with the intake bolted in place. Also, a Holley 780 carb body
with the throttle plates at full open was bolted to the intake to
represent the pressure drop across a carb or fuel injection throttle body.
I'll be using an EFI throttle body later but have not purchased it yet.
When the heads were ported, they were tested on a Superflow bench at a
28" H2O pressure drop. The head had a clayed intake radius but no exhaust
pipe stub was used on the exhaust. Those numbers are shown in the 2nd and
3rd columns. The 4th and 5th columns are the same head flowed on Dave's
bench which has a 10" H2O pressure drop. The numbers were converted
mathematically to 28" to be on a consistent basis. Note the numbers are
somewhat lower than those of the 28" bench. We're not sure if this due
in part to the conversion or is simply bench-to-bench variation. In any
case, it doesn't influence the results of the intake manifold tests.
On both single plane intakes, the center runners are short and straight
while the end runners are long and curved, so one center port and one end
port were tested. The Huffaker was bolted to the head and tested first,
followed by the Willpower. The results are shown below and are best
viewed in a non-proportional font like courier:
Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench center runner center runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" Int Exh bare bare
1.775" 1.5" head head
Int Exh
center
port
0.050 -- -- 26.3 22.6 26.1 99.2 27.6 104.9
0.100 66 47 56.3 51.6 55.1 97.9 56.4 100.2
0.150 99 82 86.8 75.0 87.8 101.1 89.0 102.5
0.200 129 104 115.1 98.4 117.2 101.8 119.1 103.5
0.250 155 119 140.4 114.1 141.4 100.7 142.8 101.7
0.300 174 130 158.1 125.4 160.6 101.5 160.0 101.2
0.350 187 139 171.7 134.4 169.9 98.9 167.9 98.0
0.400 191 146 179.8 140.2 170.5 94.8 172.2 95.8
0.450 194 150 181.3 143.2 172.6 95.2 174.3 96.1
0.500 196 152 182.1 144.3 173.9 95.5 175.3 96.2
Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench end runner end runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" 1.775" 1.5" bare bare
end head head
port
0.050 -- -- 25.5 22.6 26.8 105.9 26.9 105.5
0.100 66 47 55.0 51.6 56.6 102.9 55.4 100.7
0.150 99 82 87.0 75.0 88.2 101.4 88.6 101.8
0.200 129 104 116.9 98.4 114.1 97.6 119.8 102.5
0.250 155 119 143.4 114.1 132.5 92.4 144.6 100.8
0.300 174 130 157.8 125.4 146.5 92.8 164.8 104.4
0.350 187 139 171.6 134.4 155.6 90.7 173.3 101.0
0.400 191 146 178.3 140.2 156.9 88.0 175.0 98.1
0.450 194 150 180.8 143.2 156.6 86.6 176.0 97.3
0.500 196 152 182.9 144.3 157.6 86.2 175.3 95.8
Despite the smaller runners, the Willpower is the better flowing manifold.
The center ports on both intakes are quite close to the head flow but
the Huffaker end ports are not as good. I think it would be worthwhile to
port just the ends of the Huffaker intake end runners with a better radius
to see if the flow loss could be recovered. There's a slight drop off in
flow as lift increases on the Willpower intake that may be due to the small
port size. The Willpower could be ported to a larger size but given how
close the intake is to the bare head flow, it's probably not worth the
trouble. The worst flows are at 96%. As a point of comparison, we've
recently flow tested a couple of (non-Rover) dual plane intake manifolds
and they were in the mid seventy % flow range (unported).
The exhaust-to-intake flow ratio on these heads is excellent. Dave thought
a bit larger itake valve, at the expense of exhaust valve size, might make
more power if it were practical. During our tests, a 4" diameter tube was
used to simulate the effects of the cylinder wall. To see if shrouding
might be a problem, the tube was moved around (closer to the valve) but
little effect was noted.
Dan Jones
Spent a little time evaluating a couple of Rover V8 single plane intake
manifolds on Dave McLain's flow bench in Cuba, Missouri. I wanted to
know which of the intakes would flow best when bolted to my 1964 Buick
300 aluminum heads. The heads are ported and use larger Stage 1 Buick
V6 intake and exhaust valves (1.775" head diameter for the intake and
1.5" for the exhaust):
http://www.bacomatic.org/gallery/album1 ... ambers_001
http://www.bacomatic.org/gallery/album1 ... take_ports
http://www.bacomatic.org/gallery/album1 ... ust_ports2
The two intakes tested were a Huffaker:
http://www.bacomatic.org/gallery/album13/Huffaker_front
http://www.bacomatic.org/gallery/album13/Huffaker_side
and a Willpower:
http://www.bacomatic.org/gallery/album13/Willpower_1
http://www.bacomatic.org/gallery/album13/Willpower_2
Note the Willpower intake pictured is not the actual intake tested. I've
not yet taken pitures of the intake we tested but it differs from the one
pictured in that it has EFI injectors bungs in each port but the injectors
were not installed for these tests. The Huffaker has larger ports which
better match the Buick 300 heads:
http://www.bacomatic.org/gallery/album1 ... aker_ports
The Willpower has smaller Rover-sized ports but has a better radius on
the end runners than the Huffaker. An end port and a center port of the
head were first flowed without an intake attached to get a baseline, then
flowed with the intake bolted in place. Also, a Holley 780 carb body
with the throttle plates at full open was bolted to the intake to
represent the pressure drop across a carb or fuel injection throttle body.
I'll be using an EFI throttle body later but have not purchased it yet.
When the heads were ported, they were tested on a Superflow bench at a
28" H2O pressure drop. The head had a clayed intake radius but no exhaust
pipe stub was used on the exhaust. Those numbers are shown in the 2nd and
3rd columns. The 4th and 5th columns are the same head flowed on Dave's
bench which has a 10" H2O pressure drop. The numbers were converted
mathematically to 28" to be on a consistent basis. Note the numbers are
somewhat lower than those of the 28" bench. We're not sure if this due
in part to the conversion or is simply bench-to-bench variation. In any
case, it doesn't influence the results of the intake manifold tests.
On both single plane intakes, the center runners are short and straight
while the end runners are long and curved, so one center port and one end
port were tested. The Huffaker was bolted to the head and tested first,
followed by the Willpower. The results are shown below and are best
viewed in a non-proportional font like courier:
Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench center runner center runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" Int Exh bare bare
1.775" 1.5" head head
Int Exh
center
port
0.050 -- -- 26.3 22.6 26.1 99.2 27.6 104.9
0.100 66 47 56.3 51.6 55.1 97.9 56.4 100.2
0.150 99 82 86.8 75.0 87.8 101.1 89.0 102.5
0.200 129 104 115.1 98.4 117.2 101.8 119.1 103.5
0.250 155 119 140.4 114.1 141.4 100.7 142.8 101.7
0.300 174 130 158.1 125.4 160.6 101.5 160.0 101.2
0.350 187 139 171.7 134.4 169.9 98.9 167.9 98.0
0.400 191 146 179.8 140.2 170.5 94.8 172.2 95.8
0.450 194 150 181.3 143.2 172.6 95.2 174.3 96.1
0.500 196 152 182.1 144.3 173.9 95.5 175.3 96.2
Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench end runner end runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" 1.775" 1.5" bare bare
end head head
port
0.050 -- -- 25.5 22.6 26.8 105.9 26.9 105.5
0.100 66 47 55.0 51.6 56.6 102.9 55.4 100.7
0.150 99 82 87.0 75.0 88.2 101.4 88.6 101.8
0.200 129 104 116.9 98.4 114.1 97.6 119.8 102.5
0.250 155 119 143.4 114.1 132.5 92.4 144.6 100.8
0.300 174 130 157.8 125.4 146.5 92.8 164.8 104.4
0.350 187 139 171.6 134.4 155.6 90.7 173.3 101.0
0.400 191 146 178.3 140.2 156.9 88.0 175.0 98.1
0.450 194 150 180.8 143.2 156.6 86.6 176.0 97.3
0.500 196 152 182.9 144.3 157.6 86.2 175.3 95.8
Despite the smaller runners, the Willpower is the better flowing manifold.
The center ports on both intakes are quite close to the head flow but
the Huffaker end ports are not as good. I think it would be worthwhile to
port just the ends of the Huffaker intake end runners with a better radius
to see if the flow loss could be recovered. There's a slight drop off in
flow as lift increases on the Willpower intake that may be due to the small
port size. The Willpower could be ported to a larger size but given how
close the intake is to the bare head flow, it's probably not worth the
trouble. The worst flows are at 96%. As a point of comparison, we've
recently flow tested a couple of (non-Rover) dual plane intake manifolds
and they were in the mid seventy % flow range (unported).
The exhaust-to-intake flow ratio on these heads is excellent. Dave thought
a bit larger itake valve, at the expense of exhaust valve size, might make
more power if it were practical. During our tests, a 4" diameter tube was
used to simulate the effects of the cylinder wall. To see if shrouding
might be a problem, the tube was moved around (closer to the valve) but
little effect was noted.
Dan Jones