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Noonan 4.9" Bore Space Hemi Engine Package

Driving Innovation.

We call it the Ultimate revolution of the Billet Hemi Engine Evolution. Laying down a jaw dropping world recording setting number on it’s first ever quarter mile pass, we’ll let the actions of the Noonan 4.9” powerplant showcase it's capability. Designed specifically for the NHRA and Extreme Promod categories and tractor pulling.



Engine package INCLUDED PARTS

  • Noonan 4.9" Billet Hemi Engine Block. 10.225" Shortdeck or 11" Big Dog Supertall (612 Ci).
  • MSD Pro Mag 44
  • GRP Rods
  • Bryant Racing Crankshaft
  • Trend Wristpins
  • CP Pistons
  • Clevite Coated Bearings
  • Total Seal Ring Pack
  • Jesel Lifters
  • Custom Bullet Camshaft
  • Dan Olson Oil Pan
  • Barnes Oil Pump
  • Noonan 4.9" Cylinder Heads
  • Noonan Billet Manifold (Roots, Screw or Turbo)
  • PSI Springs
  • Manley Valves
  • Noonan Billet Valve Covers
  • Reid or Manton Rockers
  • RCD Mag Drive
  • Noonan Front Cover / Gear Drive Assembly
  • RCD Fuel Pump Extension
  • MSD Leads
  • NHRA Promod, Outlaw Promod, Tractor Pull....


WHAT'S DIFFERENT BETWEEN THE 4.8" Hemi & the Noonan 4.9" Bore space Hemi?

The major differences between the 4.9 Hemi and the 4.8 Fathead style hemi is obviously the increase in the Bore Centre. This enabled the bore diameter to increase to max 4.600” where we were limited to 4.500” bore in current hemi applications. The increased bore diameter enabled the ability to run a larger intake and exhaust valve than we could with a 4.500 bore. Not only were we able to go bigger with the valves, we stood the valve angles up three degrees, to flatten the combustion chamber out and we raised the port up an inch on the intake and exhaust.

The 4.9 cylinder head changes then allowed for a better flowing cylinder head on both the intake and exhaust ports than we could have with the 4.8 bore centre. Another big change was the lifter spacing from 2” to 3.300”. Not only does it make the valve train geometry almost perfect as far as push rod angles to rocker locations, it allows us to not have any push rod bulges in the intake port. It frees up the opportunity for a lot more intake port development than we could have done with the 2” lifter spread in our current 4.8” hemi.

Other significant cosmetic changes on the 4.9 engine include the and 1.250” raised cam which shortens the push rods and stiffens the valve train. The cylinder head can be removed while leaving the manifold, blower and injector secured to the block. Thus reducing quick and easier turnaround times between racing rounds. The engine has shown extreme durability under adverse engine failures that have never been witnessed on a 4.8” Hemi to date. The engine also allows the use of a 5/8” diameter push rod on both intake and exhaust and is offered with a T&D individual shaft or Reid Dual Shaft Rocker Assembly similar to the normal 4.8 Hemi.