SBM Edelbrock/Speedmaster Head Data
Some more flow test results on the Speedmaster - this time with a 39 degree pressure recovery 'cone'. As in the last test, clay was added in the combustion chamber to simulate a top cut to try to improve on the factory 15 degree top cut.
Three sets of flow numbers are included, all tests run with a 30 degree back cut intake valve. First is the stock 15 degree top cut (with sharp inside corner on the shrouded side). Second is the 35 degree clay top cut with 4mm radius on the shrouded side (this is the test from the previous post). Last is the 39 degree clay top cut with 4mm radius.
Again, I am not qualified to interpret the results, but for this head, on the flow bench, it seems that the stock 15 degree top cut angle is not optimal. It also seems that the 35 degree angle flows better at lower lifts and the 39 degree angle flows better at higher lifts.
Some more flow test results on the Speedmaster - this time with a 39 degree pressure recovery 'cone'. As in the last test, clay was added in the combustion chamber to simulate a top cut to try to improve on the factory 15 degree top cut.
Three sets of flow numbers are included, all tests run with a 30 degree back cut intake valve. First is the stock 15 degree top cut (with sharp inside corner on the shrouded side). Second is the 35 degree clay top cut with 4mm radius on the shrouded side (this is the test from the previous post). Last is the 39 degree clay top cut with 4mm radius.
Again, I am not qualified to interpret the results, but for this head, on the flow bench, it seems that the stock 15 degree top cut angle is not optimal. It also seems that the 35 degree angle flows better at lower lifts and the 39 degree angle flows better at higher lifts.