As most of you know, I am having the cylinder head ported so we can determine the maximum flow capability. The first step was to flow test the head with out the intake, then again with the new 4V intake. I picked up the results tonight and we spent an hour and a half talking about them. I have to say; I was surprised by the numbers.
When I took the intake over and asked him to flow test it, I expected the results to show a loss in flow, as it is difficult to design an intake which matches the capability of the cylinder head, especially when limited by size and shape as we are. Keep in mind; the test was done with 180 intakes rather than 184s. We also flow tested the exhaust, with and without the headers, and 150 valves.
Without the intake, the flow numbers were pretty close to the results we got when we flow tested the first proto type, which was encouraging. This time, we got a bit more flow at the lower lifts (100-200), about the same for mid range (300-400), and slightly less at high lifts (500-600). With the intake installed, the numbers were the same at 100. Then at 200, the flow numbers started increasing. That's right, INCREASING. From 200 to 500 the cfm numbers increase from 3-7cfm. However, the flow at 600 decrease by 5cfm, which means we have a little bit of work to do to the intake for top end power. It won't make much difference for most, as very few builds will ever see that much lift.
The flow numbers were much better than I expected. I was sure we'd see a loss of 10cfm or more across the mid and upper lifts, so this was a pleasant surprise. Tomorrow, he is going to make some modifications to the fins in the plenum chamber, add more radius to the top of the runners where they meet the plenum, and will swap the four hole adaptor to an open design with a slight radius. When he's done, he is pretty sure we'll see a nice improvement across the board, including the 100 & 600 lifts.
He also told me that when he ports the head and does the flow test with the modified intake, he expects to see a nice gain over our base line numbers. I sure hope he's right, as we would see flow numbers around 215-220 at 500, and that's with the 180 intake valves. The exhaust flow with our header and 150 valves, was 174cfm at 500, and 188 at 600. With the stock exhaust manifold, it was 160/172 respectively.
When I took the intake over and asked him to flow test it, I expected the results to show a loss in flow, as it is difficult to design an intake which matches the capability of the cylinder head, especially when limited by size and shape as we are. Keep in mind; the test was done with 180 intakes rather than 184s. We also flow tested the exhaust, with and without the headers, and 150 valves.
Without the intake, the flow numbers were pretty close to the results we got when we flow tested the first proto type, which was encouraging. This time, we got a bit more flow at the lower lifts (100-200), about the same for mid range (300-400), and slightly less at high lifts (500-600). With the intake installed, the numbers were the same at 100. Then at 200, the flow numbers started increasing. That's right, INCREASING. From 200 to 500 the cfm numbers increase from 3-7cfm. However, the flow at 600 decrease by 5cfm, which means we have a little bit of work to do to the intake for top end power. It won't make much difference for most, as very few builds will ever see that much lift.
The flow numbers were much better than I expected. I was sure we'd see a loss of 10cfm or more across the mid and upper lifts, so this was a pleasant surprise. Tomorrow, he is going to make some modifications to the fins in the plenum chamber, add more radius to the top of the runners where they meet the plenum, and will swap the four hole adaptor to an open design with a slight radius. When he's done, he is pretty sure we'll see a nice improvement across the board, including the 100 & 600 lifts.
He also told me that when he ports the head and does the flow test with the modified intake, he expects to see a nice gain over our base line numbers. I sure hope he's right, as we would see flow numbers around 215-220 at 500, and that's with the 180 intake valves. The exhaust flow with our header and 150 valves, was 174cfm at 500, and 188 at 600. With the stock exhaust manifold, it was 160/172 respectively.