It7r
As many of you are aware, here in SEDIV there are a couple of really good though differing proposals floating around to try and save IT7. Both involve using the Renesis engine from the RX8. Both have pros and cons which can be debated.
One version, set forth by Blair Stitt, uses fuel injection and includes upgrades to brakes, etc. The proposed rule set for the injected version can be found here: http://www.ncrscca.com/it-7r-rules. I can't provide a lot of information about Blair's version, as I have not been involved in that one. Hopefully, someone with more information can contribute to this thread.
The other proposal, advanced by Estus White, is a carbureted version which utilizes the carburetor, front cover and distributor from the 12A. This version is intended to produce a car comparable to and able to race alongside the current IT7. An adapter is used to fit the 12A oil pan, as well as the intake. It makes use of only four ports to limit horsepower. Plus, using only four ports allows either the manual or automatic version of the RX8 to be a donor car. The Renesis engine is essentially used as a replacement “short block.” If the Renesis based engine is removed, you can reinstall a 12A and you have a fully legal IT7.
Several years ago, I bought an IT7 to run in track trials and hillclimb events, with the intent of eventually going road racing. I chose IT7 because, in my mind, it was a lot of bang for the buck and I had always heard that rotary engines were pretty reliable. The car was a pretty good car, and I managed to set the course record for IT7 at the Wolf Ridge Hillclimb and run competitive times at other hillclimbs and CMP. However, like so many others have experienced, I eventually broke the engine. When I started looking for a replacement, I discovered what so many others already knew – they were hard to find and expensive. I wasn’t prepared to try rebuilding a rotary motor, especially as expensive as the parts were. I’m a pretty fair backyard mechanic, but all my previous experience was with Ford V8s. I figured out I could buy another car for what a new motor would cost, so I bought one from Jim Hess up in Maryland (2 time MARRS IT7 championship winning car), and put the first car in the garage. I figured if I wrecked the new car, I’d have a spare chassis, but I really wanted to find an engine so I’d have two cars.
A mutual acquaintance told me that Estus was looking for an IT7 to use as a prototype IT7R. I offered the use of my spare chassis, and Estus pulled the broken engine out and put the Renesis in. A carbureted IT7R was born!
Recently, the carbureted version of the IT7R ran its first two events, first at the Chasing the Dragon Hillclimb in late June, and then again at Roebling Road June 30 - July 1.
At the hillclimb, the car (driven by Estus, who has tons of hillclimb experience including holding the course record at several sites in RX7s) posted a time of 2:21.817, compared to the course record of 2:20.922 (set last year). (The only other IT7 at the hillclimb this year broke on its first run. Another IT7 needing a new engine).
At Roebling, Estus' son Ess drove the car. After the race, Estus sent me an email saying "The car is dead even competitive with IT-7. Less than 1/2 second difference in lap times compared to the IT-7's. Not over competitive, not under competitive. We ran what would be 2nd place in IT-7 for most of the race...." A late problem with the fuel pump both days caused the car to begin missing, so the car fell back at the end of the race both Saturday and Sunday.
There have been a number of threads on here about IT7s and the motor replacement issues. A couple mentioned these two proposals, so I wanted to give everyone an update on the progress to date on the carbureted version. Hopefully, both versions will be represented at the upcoming MARRS / SARRC at Charlotte Motor Speedway in August.
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Originally Posted by tom_sprecher
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