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The oval port was never designed for a race application and was never sold as a short shaft version. Compared to the recreational 56 bridge port long shaft which it replaced in the early 1990’s, it is the better motor both in performance and fuel economy.
In 2000 the oval port was a legal engine in the Formula V PPR class. It is legal in T850.
It became very competitive in 2014 as more racers learned how to get improved performance from the engine.
It’s been a trial and error time consuming and costly learning process for those individuals trying to get super performance from the oval port to compete with a top running bridge port. It’s just easier to build the bridge port and you have a good idea as to the result because there is more information available.
BUT! The oval port has more potential! It produces more torque and has an acceleration advantage over the bridge port. SECOND BUT, the SST 60 Spec bridge port has more top end. THIRD BUT, if you raise the exhaust port on a 1986-7 production cast 56 to the SST 60 Spec, run an SST 60 Spec cylinder head and blueprint the other ports , that motor is better than the SST 60 on a T boat.
The problem the oval port guys generally have is they can improve one aspect of performance, but another aspect decreases at the same time.
Both bridge ports and oval ports are currently winning races in T850. Both motors can hold onto the lead provided they got the better start.
I don’t know what modifications make a superior oval port.
I do know that running 1 1/2 big bore carbs with 78D jets, boyesen reeds, 160 compression head, a Kevi billet base with the one inch longer tuner, raise the exhaust port to the SST 60 Spec and match port the other ports makes for a very strong motor.
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