As published on StartlineOnLine..
This notice is a clarification and does not make any changes to current regulations.
There have been queries from members considering using the Piedrafita engine in Mono F3.
Regulation 5(7).1 allow for the use of Standard Production Engines as specified.
Regulation 5(7).2 allows for the use of the specified “Piedrafita” engine without modification, with a restrictor as specified and with the original Piedrafita seals intact. Previously issued Championship Technical Bulletin MRC/2016/1 sets the air restrictor aperture size at 28.5mm for Piedrafita engines.
Engines used in Mono F3 must comply with Regulation 5(7).1 OR 5(7).2 OR 5(7).3 as specified in the regulations.
Standard production engine parts and components and Piedrafita engine parts and components cannot be mixed and used together to make a single engine. This would produce a hybrid engine which is neither a standard production engine nor a Piedrafita engine, and a hybrid engine is not allowed.
Please also note that it is not a straight swap to fit a Monoposto compliant Toyota 3GSE Gen 3 engine in to a Piedrafita car as the head is different and changes to manifolds and engine mounts will be needed.
Cars using either the 3S-GE Piedrafieta engine or other Formula 3 specification engines must comply with the current F3Cup regulations on induction vacuum, notably:
“The material for the air box is free providing that it is not porous. The total air box system must be capable of sustaining a vacuum of ‘3 inches’ of mercury when using a pump drawing a maximum of 0.9 cubic feet per minute of free air. In the event of a failure of the vacuum pump test the following secondary test will be offered to the competitor concerned. With the engine at tick over, when putting a plug on the air restrictor of the intake system, the engine shall be stopped in less than 2 seconds. Declining the secondary test will be considered as a failure to comply. Any device or construction that is designed to adjust or alter the size, shape or length of the inlet tract/trumpets, or improve airflow, operated by any manner (electrical, mechanical, hydraulic or pneumatic) whilst the car and engine are in use, is prohibited under all circumstances. The engine shall have no mechanism which is capable of adjusting the valve timing following a mechanical, hydraulic pneumatic or electrical input whilst the engine is in operation.”