< Briggs World Formula Jr Sprint Race Prepped Engine – Krybaby Performance
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Briggs World Formula Jr Sprint Race Prepped Engine

$2,299.00 $2,500.00

Please provide your phone number on the check-out page.

It will take a short conversation to get the particulars of your goals so we can get you the best engine poissible.

You can also email us at: sales@krybabyperformance.com

Description

Briggs & Stratton World Formula without gear box and with starter for the Jr. Sprint Class.

Wait times on this engine can be anywhere from 10-15 days depending on time of year. We Build all year round any try to have engines in stock at all times.

Depending on the part of the country and the rule package this build needs the rule package summitted with the order. These are run on both Gas or Alcohol. Some tracks use the electric starter, others the pull starter and others have to be started with an external electric starter.  

Watch the video of it on the dyno - Briggs jr sprint running on the dyno!

We build each racing engine to spec per the class and organization you will be competing in.  Every Krybaby Racing Engine is given 100% of what the rules allow  –  we build each engine to peak performance. 

This is the Jr Sprint Engine - the most powerful in the Briggs line up. This is almost one of the most expensive engines to build. The parts list is long and the parts are expensive.  The engine is nearly $1150 and then you have to Add more.  Before you are done adding up the parts you are at just over $1500 and the built has not begun. The entire engine will come apart and be rebuilt piece by piece.  The deck and head will be milled before cam inspection and 20 other points of inspection to bring you the most powerful race engine around.  

If you little racer is built for speed they will love the power. Because of the expense of these engines most clubs don't have enough cars for a class race. At regional races or nationals these are the king of the track and when you get 12 of them out there at once its like rolling thunder. 

Briggs has been making these for many years so there are lots of old warn out ones at the tracks and they hold their value. We rebuild plenty of them but if you are serious about winning a brand new one will be king of the track.

Key Specifications

MODEL/TYPE(S)124335 8105-01/124335 8106-01 M.A.P. Price enforced horsepower/torque11.5 hp/13 ft. lbs. torque*
Displacement204cc Bore/Stroke2.6875”/2.6885” Compression Ratio9.5 to 1
Rpm–Digitally Limited7,100 RPM Factory Timing29 degrees BTDC Fuel Type91 Octane

 

  • Reinforced, cast iron sleeved, dual ball bearing racing cylinder
  • Single cast, custom aluminum alloy cylinder head with 'kidney bean'' combustion chamber, custom seat/guide material and CNC Machined Intake D-port.
  • 2024 Billet aluminum rod with reinforced I-beam
  • Carbon steel crankshaft with induction hardened micro-polished crankpin reinforced timing gear
  • Cam ground, barrel faced, eutectic alloy domed piston with 3-piece ring set with chrome faced top ring
  • .308 max. lift ground cam with stellite-faced lobes and built in mechanical compression release
  • Dual high silicon valve springs
  • High grade stainless steel, dished valves with nitrited exhaust
  • 3-piece automotive style keepers and reinforced rocker arm and lock ball
  • Digital ignition with built in rev limiter
  • Steel hub, cast aluminum flywheel
  • Walbro 26mm round slide, fully adjustable jet carburetor
  • Custom graphoil composition, fire ring head gasket
Description Wrench / Socket Size Torque
Air Guard 7mm 40-50 lb-in. (4.5-5.6 Nm)
Blower Housing 10 mm & 3/8” 60-110 lb-in. (7-12.5 Nm)
Carburetor (to manifold) 10 mm 80-110 lb-in. (9-12.4 Nm)
Connecting Rod 5/16” 125-135 lb-in (14-15 Nm)
Cylinder Head Bolts 10 mm 200-220 lb-in. (20-27 Nm)
Exhaust Brace Screws 10 mm 95-125 lb-in. (11-14 Nm)
Flywheel Nut 15/16” 55-75 ft-lbs. (74.5-101 Nm)
Flywheel Fan 10 mm 180-240 lb-in. (20-27 Nm)
Intake (to cylinder) 5 mm Allen 70-90 lb-in. (8-10.2 Nm)
Oil Drain Plug 3/8” 100-125 lb-in. (11-14 Nm)
PVL Ignition Module 7 mm 20-35 lb-in (2.3-4 Nm)
Rocker Arm Stud 7/16 90-120 lb-in. (10-14 Nm)
Rocker Arm Set Screw 1/8” Allen 50-70 lb-in. (5.6-7.9 Nm)
Spark Plug 5/8” deep 95-145 lb-in. (11-16.4 Nm)
Side cover 10 mm (patched, grade 8.8) 10 mm (unpatched, grade 8.8) 10 mm (SIMS patched, grade 10.8) 215-230 lb-in. (24-26 Nm) 160-175 lb-in. (18-19 Nm) 260-270 lb-in. (29-30 NM)
Top Control Cover 10 mm 70-90 lb-in. (8-10 Nm)
Valve Cover 10 mm lower & 3/8” 30-60 lb-in. (3.5-7 Nm
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