Hi John,
Archies boat was smokin fase at the nats. He was using a 45" rampage.
Below are the rules for the Supersport class.
Here is the link might be easier to read.
http://nebula.wsimg.com/8c830a8db2a22a8c64e2b0164cb5e3a8?AccessKeyId=ACA7381D2BFC72351748&disposition=0&alloworigin=1
F. Super Sport Class
1. Purpose The intent of the Super Sport class is to provide a LSG racing class that enables the contestant to compete with a factory stock engine.
2. Hull Specification The Super Sport class shall be offered as a Mono hull class. a. The Mono hulls will conform to current IMPBA “Technical Standards” section, Mono Hull Definitions and Restrictions.
3. Engine Specifications
a. Spec engines will be a Zenoah G260 PUM ONLY.
b. The Engine may run a stock unmodified 257 or the original 644 with choke carburetor.
c. No internal modifications are allowed. Replacement parts must be from the original manufacturer and the same type engine (Example: Zenoah 260 to Zenoah 260). No part swapping from other manufacturers or engine types is permitted.
d. The engine ignition coil may be moved to another location on the engine or hull.
e. Each engine must have a working throttle control and the engine must be set up to be completely stopped with the transmitter controls.
f. Recoil pull start must the primary method of starting. EZ Start and pulleys are acceptable.
g. The top 3 finishers at the annual IMPBA Gas Nats will be torn down and will be checked using the following Specs as listed below. If the engine & muffler is not legal they will be disqualified from the event.
h. All engines & mufflers are subject to inspection at any time during the event 2015 I - 8 Large Scale Gasoline
4. Stock Motor Inspection Inspection to include all parts of motor:
a. Fasteners: Stock or Stainless
b. Gasket Thickness: Carburetor .017 to 0.023; Manifold .017 to .023; Case .017 to .019; Base/Barrel .014 to .016 may be copper or fiber
c. Seals: Springs
d. Bearings: Stock
e. Flywheel: Thickness .800 - .810 – Keyway .121
f. Crank Rod Piston and Ring – Keyway .121
g. Intake Manifold: Thickness .690 to .702 (Allow to sand gasket sealing area only to make flat)
h. Ignition Parts – Color – Slotted Holes
i. Case to Crank Shaft Top .910 j. Barrel Depth 2.025 k. Must have original cooling cap -- painting, anodizing, and etching allowed. l. 34mm (1.338 inch) bore, 28mm (1.102 inch) stroke.
5. Muffler
a. All engines must have tuned pipe or canister type muffler. The exhaust must meet all current IMPBA noise regulations (no megaphones). Modifications may be made to the inside of the muffler if they will still meet the noise level limitations currently in place in the IMPBA Rule Book after modifications.
b. If a single hole or exhaust tube/stack out of the muffler is used, the inside diameter must not exceed 3/4 inches. If dual holes or exhaust tubes/stacks are used exiting the muffler, then the maximum inside diameter must not exceed 1/2 inch each.
c. The canister type can muffler must be mounted directly to the exhaust flange of the engine. If a spacer is used for cooling between the muffler and the flange, a maximum spacer thickness of one inch (1”) will be allowed.
Hope this helps,
Kevin
