Inline Cylinder Head Flow
Here are 3 flow tests, first on stock head with 1.72 intakes, second on bolt boss removed with 1.84 intake valve, third is same port with a bolt in HI-FLOW lump added.
stock head 1.72 intake
.050" lift 27.3 cfm
.100" lift 52 cfm
.200" lift 103 cfm
.300" lift 149.5 cfm
.400" lift 164.6 cfm
.500" lift 168.5 cfm
This is a head with 1.84 intake valves . It has had valve unshrouding done to it and the guides have been coned shaped.
First port is a intake that has had the bolt boss removed and has a cap screw sitting in the bottom, like it would be in use.
1.84 intake @28" on a superflow
lift flow
open port no lump
.100 62.1cfm
.200 115.3cfm
.300 168.7cfm
.400 184.3cfm
.500 195.6cfm
.600 202.0 cfm
same port with bolt in lump
.100 lift 59.3 cfm
.200 lift 112.9 cfm
.300 lift 166.9 cfm
.400 lift 203.9 cfm
.500 lift 215.6 cfm
.600 lift 226 cfm
Engine planning
Head flow #'s are in!
Bolt in lumps work! Even with what some people say are small valves, these heads flow very well. Flow tested at a reputable performance shop. This head shows excellent flow at midlift and full lift values. The I/E ratio is 72% which is also nice to have in a naturally aspirated engine.
Here are 3 flow tests, first on stock head with 1.72 intakes, second on bolt boss removed with 1.84 intake valve, third is same port with a bolt in HI-FLOW lump added.
stock head 1.72 intake
.050" lift 27.3 cfm
.100" lift 52 cfm
.200" lift 103 cfm
.300" lift 149.5 cfm
.400" lift 164.6 cfm
.500" lift 168.5 cfm
This is a head with 1.84 intake valves . It has had valve unshrouding done to it and the guides have been coned shaped.
First port is a intake that has had the bolt boss removed and has a cap screw sitting in the bottom, like it would be in use.
1.84 intake @28" on a superflow
lift flow
open port no lump
.100 62.1cfm
.200 115.3cfm
.300 168.7cfm
.400 184.3cfm
.500 195.6cfm
.600 202.0 cfm
same port with bolt in lump
.100 lift 59.3 cfm
.200 lift 112.9 cfm
.300 lift 166.9 cfm
.400 lift 203.9 cfm
.500 lift 215.6 cfm
.600 lift 226 cfm
Engine planning
Head flow #'s are in!
Bolt in lumps work! Even with what some people say are small valves, these heads flow very well. Flow tested at a reputable performance shop. This head shows excellent flow at midlift and full lift values. The I/E ratio is 72% which is also nice to have in a naturally aspirated engine.
What does this airflow do?
So you want to really know what all this AIRFLOW does for your engine. Look at the chart to the right. The graghs are made up of real dyno runs made on a single 292 engine.
The Bolt in Lump Kit is equal change in power as a cam change. When combined with a cam change, gains of over 100 hp can easily be achieved with a mild cam.
To compare the blue lines(stock head) to the green lines (lump port head.
Stock head was 1.72/1.5 valves , no porting.
Lump port head was , 1.94/1.6 valves, ported and lumped.
Same cam was used on both runs. See the tq increase at low RPM? See how the HP was much higher and over a longer RPM?
The other graghs represent the same thing with a performance camshaft on the same 292 shortblock.
The 292 shortblock used had Our 18CC pistons and a balanced lower end. Compression was approximately 9.25 . Intake was a Offenhauser with Holly carb. Exhaust was long tube headers.
So you want to really know what all this AIRFLOW does for your engine. Look at the chart to the right. The graghs are made up of real dyno runs made on a single 292 engine.
The Bolt in Lump Kit is equal change in power as a cam change. When combined with a cam change, gains of over 100 hp can easily be achieved with a mild cam.
To compare the blue lines(stock head) to the green lines (lump port head.
Stock head was 1.72/1.5 valves , no porting.
Lump port head was , 1.94/1.6 valves, ported and lumped.
Same cam was used on both runs. See the tq increase at low RPM? See how the HP was much higher and over a longer RPM?
The other graghs represent the same thing with a performance camshaft on the same 292 shortblock.
The 292 shortblock used had Our 18CC pistons and a balanced lower end. Compression was approximately 9.25 . Intake was a Offenhauser with Holly carb. Exhaust was long tube headers.