TwinCam head flow data
Posted: Mon Nov 22, 2021 10:12 am
There is very little published data on original or modified heads or new ( SAS QED Bean) heads flow testing. If your into Chevys there are literally hundreds of head builders publishing data not so with our engines
So I thought its time to collect some data on twink heads. I have started with the flow testing done recently on a McCoy modified racing head of mine that I am rebuilding for my spare race engine. Its an early McCoy modified race head at No 34.
Running McCoy 450 cams , TTR exhaust, 45 DCOE with 36 mm chokes and 12.5 comp ratio with Avgas the 1600 cc engine made 175 to 180 HP at 7500 to 8000 rpm based on rolling road tuning with great mid range torque . This matches well the estimated head HP capability based on flow testing of 180 hp with 0.45 lift. With a higher lift and longer duration cam and bigger carb chokes a bit more top end power of about 10 to 15 hp is possible at the expense of midrange torque with this head.
It would be good to see any equivalent flow data plus any resulting engine dyno data that people have for standard heads or for ported standard heads or for the new SAS or QED or Bean heads
cheers
Rohan
So I thought its time to collect some data on twink heads. I have started with the flow testing done recently on a McCoy modified racing head of mine that I am rebuilding for my spare race engine. Its an early McCoy modified race head at No 34.
Running McCoy 450 cams , TTR exhaust, 45 DCOE with 36 mm chokes and 12.5 comp ratio with Avgas the 1600 cc engine made 175 to 180 HP at 7500 to 8000 rpm based on rolling road tuning with great mid range torque . This matches well the estimated head HP capability based on flow testing of 180 hp with 0.45 lift. With a higher lift and longer duration cam and bigger carb chokes a bit more top end power of about 10 to 15 hp is possible at the expense of midrange torque with this head.
It would be good to see any equivalent flow data plus any resulting engine dyno data that people have for standard heads or for ported standard heads or for the new SAS or QED or Bean heads
cheers
Rohan