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Bridge Port Rotary Engines



RAISON d'ETRE:

Design Specification: Build a high-performance rotary engine for high-speed aerodynamic testing

at the Bonneville Salt flats.

Design goal: Develop a series producible Bridgeport design for VRI use and for sale to the racing community

Sponsors: Mazda of America

First ran: 1975


PARTICULARS

ACTIVE

1974-1977


CONTESTS & EVENTS

  • Bonneville Speed Week 1976 with bridge port Mazda rotary.

HISTORY/COMMENTARY


Making a bridge port was a known technique for hot-rodding rotary engines. An enlarged port was machined in the side and center plates that included a metal "bridge" that allowed the rotor end seals to still travel as designed (without the bridge, the seals would fall out as they crossed a now enlarged port since the port enlargement removed material that would be part of their normal path).


The VRI had a good relationship with Mazda at the time, so parts were plentiful. Later it was determined that used engine parts could be used and resurfacing techniques for the center and side plates were developed.


This changed the timing of the intake/exhaust port and gave any bridgeport rotary a unique sound.


A surplus Bridgeport mill adapted with a Japanese milling head was bought for this purpose.


Students recall seeing various "mistakes" where the bridge was put in the wrong place that were preserved to warn newcomers of what not to do.


A VRI specification was developed without radical timing, a solid 200 "streetable" horsepower could be achieved.


This modification became less interesting when a peripheral port modification was developed.






Peripheral Port Rotary Engines



RAISON d'ETRE:

Design Specification: Build a better high-performance rotary engine for high-speed aerodynamic testing at the Bonneville Salt flats.

Design goal: Develop a series-producible Perhipral Port design for VRI use and for sale to the racing community

Sponsors: Mazda of America


First ran: 1978


PARTICULARS


ACTIVE 1978-84


CONTESTS & EVENTS

Bonneville Speed Week 1977 (Viking IV with Perhperal Port Mazda 13B)


HISTORY/COMMENTARY


The bridge port technique was available from many suppliers.


The "Holy Grail" of rotary engine go-fast technologies was the Peripheral Port. Mazda of Japan gifted the VRI with a series of special race housing were provided to the VRI. Motorsport teams wanted these, but Mazda limited the supply. So the VRI set about to find a way to engineer them on their own.


A peripheral port was a totally different porting system than used on standard Mazda rotaries. It is the most efficient way to provide a fuel/air mixture into the engine and get exhaust out. However, it provides poor emissions control and fuel economy compared to a side port. These are the key problems with production rotary engines, so side porting is used in product emission-controlled vehicles as this design provides better control.


A peripheral port uses ports that are through the rotor housing themselves. The center plates and side plates are not ported. So both special Mazda housing and side/center plates must be used.


The VRI figured out a way to modify stock side port side plates and housing to be modified with a peripheral port setup.


This involved using epoxy to seal the side plates (the standard ports are not required or used) and modifying existing housing to add peripheral ports.


Normal production rotary housings have water jacket channels where the required intake and exhaust of peripheral ports are required. The solution was to mill through the water jackets, and then install an aluminum plug that contained the actual peripheral port intake or exhaust port shape. These were resistance-fitted using a process involving liquid nitrogen to shrink them before press fitting into a prepared stock housing. The result was a full peripheral port housing and end/center plate set made from stock Mazda parts (or even from used parts).


For a short time, this provided a lively side business to local racing and rallying enthusiasts.


This did not last as expected due to a general downturn in interest in rotary engines and a freeing up of factory racing parts from Mazda.. Mazda stopped producing rotary engine cars in 1977 as the fuel economy and emission issues with rotaries seemed insurmountable for regular production cars. They would bounce back with the RX-7 in 1979, when there was again an uptick of interest in the VRI's home-grown solution.


The VRI slowly moved away from support from Mazda. Mazda had become a bigger company and the Northwest US distribution outpost had closed down. The gratis parts flow dried up. The VRI had moved to a closer relationship with Subaru who continued to be a good sponsor.







Single Rotor Rotary Engine



RAISON d'ETRE

Design Specification: For ultimate fuel economy with a rotary, build a single-rotor version

Design goal: modification of aerodynamic production car

Sponsors: NASA Lewis Research Center, Ohio

First ran: 1978


PARTICULARS


500cc SIngle rotor rotary engine, based on a 10A housing and a modified two-housing crankshaft.










Twin Cam, four valve-per-cylinder boxer update of boxer four for Subaru of Japan



RAISON d'ETRE

Design Specification: Improve performance of production Subaru boxer four with new twin-cam, four valve-per-cylnder VRI developed heads..

Sponsor: Subaru of Japan


More information about this project coming soon...






Natural Gas Engines



RAISON d'ETRE

Design Specification: Applications of Natural Gas Fuel to existing gasoline and diesel production engines.

Sponsor: Canadian Natural Gas (CNG)


More information is coming soon...





Minicars RSV Re-Engine for the U.S. Department of Transportation



RAISON d'ETRE

Design Specification: Re-engine the second generation Minicars Research Safety Vehicle (RSV) as built for U.S. Department of Transporation

Design goal: Replace existing 1977 vintage FIAT 130cc with 1980 specification Honda 1500cc, test and verify 1980 Federal emissions compliance

Sponsors: U.S. Department of Transporation


FUN FACTS

The VRI is likely the only have two efforts of the original ESV program under one roof and available as "daily drivers".


PARTICULARS

The 1980 Honda Civic was a modern, advanced engine design that used CVCC design, which added a third valve per cylinder; this introduced lean-burn swirl technology. This generation was available with a 1,335 cc ("1300") engine and with an optional 1,488 cc


EMISSIONS TESTING

Emissions Test performed at Honda North America in L.A

Criteria: PASS (1980 City/Highway)



HISTORY/COMMENTARY


The Mincars RSV arrived before the contact action plan was determined. So students had considerable time to play with it in its delivered form. It was popular for making beer runs late in the evening. I drove horribly due to its rear engine configuration and the multiple non-constantly velocity links used in the steering column.


When the contract was sorted out, it was determined the fastest and cheapest way to get a Honda engine was to buy a new 1980 Honda CIVIC. So the VRI did. The engine was removed and installed in the RSV without much difficulty. For the five-speed gearbox, the Honda transaxle was also used. The axles were spliced to keep the FIAT CV joints intact on the uprights. The shift linkage required some engineering, but since the Minicars system was so bad, it likely shifted better than before.


After emissions testing in California at Honda, the DOT wasn't in a hurry to get it back so it hung around for some months.


It is believed this is the hero car that Loren Green used for the DOT commercials. These were destroyed by the DOT in the late 1990s.


The brown 1980 doner Honda hung around outside the VRI for decades because it was unclear if it was owned by the VRI or the DOT. It was finally carted off the local junkyard - a 1980 Honda Civic with 24 miles on the clock, less engine.













V-12 Engine



RAISON d'ETRE

Design Specification: 2.0 litire V12 engine

Sponsor: Dr. Michael Seal


This was Dr. Seals "master piece", the culmination of 50 years of automotive engineering.


More on this project coming soon...




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