Posted By: gregsdart
572 on the dyno! Fun day! - 11/23/22 11:32 PM
A Moparts member, Larry Curtis, AKA lowflyingDart, built this 572 cu in iron block motor for a local racer.
4.5 bore 4.5 stroke, 14.5 compression, .043 top and 2nd rings. Comp roller with 284/296/112 cam in at 112, with . 836 gross intake lift, .824 ex lift. Intake lobe is a 24140b Comp, forgot the exhaust.Fuel ended up being VP c14+, which produced a few more hp (7?) Than c14. Timing ended at 37 degrees for best power. Carb is a 1250 Dominater, with a one inch high cloverleaf spacer on top of the Indy 3X. If there is a revised 3x, this would be it, new in 2022. Heads are 385cnc 572-13, with a minor touchup at the valve boss area to remove a small lip left by the cnc cutter. The final power pulls with 2 1/4 dyno headers are 962 hp. We tried my 2 1/8 step to 2 1/4 with merge collecters, and gained a few hp, to 967 hp and the increase was from 6000 rpm to 7200. I was very happy to see my headers produce more power than the dyno headers. Mine have a 4 inch collecter with 3 inch merge ( choke) and primarys are 30 inch. Larry was hoping for 950 hp, and considering leaks kept vacuum to a best of 4 inch, it is assumed this motor will make 980 hp when vacuum is up to 10+ inch. All in all, a very good result, IMHO!
I am happy to see this power level, as i have a similar build. Mine will be 550 cu in, but will have narrower . 9mm (.036) rings, ported 3X, methanol, terminater 2500 cfm injection, and the heads are cnc385 572-13 with extra port work by Larry Smith, and a similar duration @.050 cam, but . 032 more intake lift and more duration at . 200 lobe lift. My intake valves have no back cut, so it will be interesting to see how that works
4.5 bore 4.5 stroke, 14.5 compression, .043 top and 2nd rings. Comp roller with 284/296/112 cam in at 112, with . 836 gross intake lift, .824 ex lift. Intake lobe is a 24140b Comp, forgot the exhaust.Fuel ended up being VP c14+, which produced a few more hp (7?) Than c14. Timing ended at 37 degrees for best power. Carb is a 1250 Dominater, with a one inch high cloverleaf spacer on top of the Indy 3X. If there is a revised 3x, this would be it, new in 2022. Heads are 385cnc 572-13, with a minor touchup at the valve boss area to remove a small lip left by the cnc cutter. The final power pulls with 2 1/4 dyno headers are 962 hp. We tried my 2 1/8 step to 2 1/4 with merge collecters, and gained a few hp, to 967 hp and the increase was from 6000 rpm to 7200. I was very happy to see my headers produce more power than the dyno headers. Mine have a 4 inch collecter with 3 inch merge ( choke) and primarys are 30 inch. Larry was hoping for 950 hp, and considering leaks kept vacuum to a best of 4 inch, it is assumed this motor will make 980 hp when vacuum is up to 10+ inch. All in all, a very good result, IMHO!
I am happy to see this power level, as i have a similar build. Mine will be 550 cu in, but will have narrower . 9mm (.036) rings, ported 3X, methanol, terminater 2500 cfm injection, and the heads are cnc385 572-13 with extra port work by Larry Smith, and a similar duration @.050 cam, but . 032 more intake lift and more duration at . 200 lobe lift. My intake valves have no back cut, so it will be interesting to see how that works