Racing Engines

JRPW Signature Series Pro Clone Engine Package

This is the ultimate in stock class clone engine Horsepower. JRPW has made the investment in research, development, and machinery to insure the highest level of performance.  JRPW uses its state of the art machine shop to precisely machine and massage the hand selected internals to the razor’s edge. The JRPW  “Attack Series” cylinder head and carb package tops it off. Here at JRPW, we believe in walking all over the line set by the technical regulations, but not across it. Every engine is painstakingly assembled, checked, and double checked to verify every aspect is perfect, then we test and tune on the dyno to quality control. This package is complete with all linkages, sleeved header/ muffler assembly, chain guard, all hardware. We only offer this top level package, nothing else is acceptable. The blower housing and recoil is custom powder coated in your choice of color, standard. JRPW engines set the bar in performance as well as appearance.

Signature Series Dual Bearing Flathead

Our quality machine work, testing, and experience set this engine apart from the competition. This engine is fully machined, with replacement valve seats and full length valve guides precision honed to size. We weld the lifter bore, angle deck the cylinder, and port and polish for max airflow. We align bore the cylinder and finish hone to exacting clearance. The valve seats are perfectly finished with our Rottler seat and guide machine. We add a pair of blueprinted valves, a pair of perfectly matched valve springs, and top off the cylinder with one of our machined heads. We complete the package by adding one of our signature “Attack Series Carbs”, with its precision machined body, offset throttle shaft, and hand picked internal parts to insure the highest possible airflow. Included in this are a pair of billet lifters, billet rod, and all the go fast goodies we can legally fit inside this powerhouse.  Each piece is hand selected to insure maximum horsepower. This engine comes standard with our billet header support, oil vent kit, and a lightweight filter adapter. Restricted class engines also include a max-size restrictor plate. Dyno tested and tuned to meet our highest standards of quality, this engine is ready to bolt on and win…. just add oil and fuel. Powder coating is also included at no additional charge.

Engine Kits


JRPW Big Block Level 10 Cylinder Head

JRPW is proud to introduce their cylinder heads to the big block market. Same expert craftsmanship as our small block heads, just on a larger scale. Fully machined and assembled, this beauty has a 40mm intake valve and a 33 mm exhaust. Includes dual valve springs, retainers and valve locks.$409.95

JRPW Clone Cylinder Head Level 5

For the smaller modified engines or the stock appearing engines with smaller carbs, this may be the best choice. An oversize intake valve seat is installed along with a 28.5mm stainless valve. Exhaust is a stock diameter stainless valve. Professionally ported and blended, it comes complete with spring package of your choosing, HD retainers and valve locks. $265.00

JRPW Clone Cylinder Head Level 5X

This head is a special model with factory 27/25mm valve seats. JRPW performs their magic to make this a significant upgrade, and tops it off with the valve job to make it all work. The head is fully assembled with stainless valves, your choice of springs, and hd retainers and locks. $235.00

JRPW Open Animal Cylinder Head

Beginning with the the improved Briggs RT-1 casting, we add the JRPW touch. Stock seats are removed and the pockets are machined to accept 1.25”/ 1.12” machined stainless valves. Ported, blended, and decked to our highest of standards, no stones are left unturned in our quest to provide you with the most possible HP. Includes springs and HD retainers, ready to go. $360.00

JRPW Open Clone Cylinder Head Level 10

When all out HP is the goal, this is the only choice. Precision machined with 32/28mm machined stainless valves. Valve bowls are machined and hand blended into the runners.  As with all our heads, seats are precision machined on our state of the art Rottler Seat and Guide machine, leaving a perfect 3 angle seat. Air, air, and more air, thats what this head is all about. Decked out and ready to bolt on, includes dual springs, HD retainers and locks. $295.00



JRPW 390 BP Carb

JRPW machines the internal components and properly jets the carb for your choice of fuel. Same as above but with stock bore size. $109.95