MMX Is Building an 800HP, 7,000-RPM Street Hemi for a Drag Week Dart09/07/2019
Hidden in the hills above the famed NASCAR Martinsville bullring is Dave Weber’s Modern Muscle Extreme barn complex and workshop. A man of few words, Weber makes statements by building 1,000hp street Hemis for the general public using shelf and easily obtainable parts. To push the point, Weber and the crew at MMX have put together a doable 800hp Hemi recipe with a nutso plan to put it into a 1971 Dodge Dart and show up on HOT ROD Drag Week 2019 for some shakedown runs before trying their luck on the route. Will they make it? Will they wheelstand and backslap or go up in tire smoke?
The engine combo is based on a 6.4L SRT8 block with a 4.125-bore, a 4.250-stroke Molnar crankshaft, and majorly hogged Apache 6.4L cylinder heads. The cam is rowdy, but not crazy enough to confuse the EFI or smash the valvetrain on long freeway trips.
With the power numbers in the 800s, you might be thinking there is a small blower or a whiff off the bottle. The reality is 14.0:1 compression and good parts allow the engine to peak at 7,000 rpm yet use the factory rocker bodies and only a small tweak to the valvetrain geometry using custom lash caps. The cam is a custom solid roller with 250/260 at 0.050 and 650-ish lift on a 112 LSA. The block and heads are from Mopar, the intake is a shelf item that was worked a bit to fit in a Dart, and the rest of the parts carry part numbers you can find on the internet.
The Dart was stripped and put back together in four weeks with an NHRA-certified ’cage that connects through the floor to the rear subframe. Amazingly, the Dart is still on leaf springs with CalTracs plugged into the 9-inch. It’s a small tire combo with a 4.10:1 gear ratio, so it’s going to be dicey at the top on a 275 Drag Radial. Look for the car at Virginia Motorsports Park on Tech and Registration Day. Gates open at 8 a.m, and be sure to check out the Drag Week live stream Monday through Thursday (links will be available on the Drag Week events page on HOTROD.com).
Source: Read Full Article