Endured 300 miles of wind battering on the M1 motorway today, to visit John Sleath Race Cars in Doncaster, UK. He’s an old school knowledgeable engine guy. Has a good rolling road, but it doesn’t offer so called ‘corrected power’ readings, that is rear wheel data converted to flywheel or Dyno equivalents. He says it’s pointless because losses vary between min 20% and 35% and can’t be reliably ascertained. So all his graphs are at the rear wheels. Anyhow, after an afternoon of timing, distributor weight and jet adjustments we improved the low down running and unplugged the power. The new straight through (loud) glasspack exhaust has also made a big contribution. Final figures show car now produces, at the rear wheels, 412ft lbs and 380bhp, which clearly makes Michigan based engine builder and FE guru Barry Rabotnic’s originally dynoed 503 tq /532 hp beyond doubt and pretty good for an OE bore/non stroker, all aluminium 427. Car drove great and has taken me unawares by the seemingly bottomless acceleration into the 6000rpm area. With the old 302 it was all over by 4000. Anyhow, glad I made sure of a long accelerator travel. 😬 😁 😀 Also 17.3 mpg overall on the journey seems pretty amazing for a 7 litre and car ran faultlessly without any dramas. Taken me 3 years to complete the Autokraft Mk IV small to big block metamorphosis, so looking forward to exploring this fabulous combination 😀
PS The new 1/2” higher Blue Thunder air cleaner element gained us 20hp.
Here we are at a theoretical 156mph