About Our RX-8 Renesis Engine Rebuilding

When it comes to rebuilding Renesis rotary engines, it's similar to an RX7 though still unique nuances that must be addressed. We carefully inspect and measure many parts, some can be cleaned and reused while others need to be replaced because they're too worn out.

While it might seem cheaper to use lots of used parts, it doesn't guarantee great results. An engine's performance depends on the quality of its parts. That's why we focus on using new parts to ensure longer-lasting and more efficient engines.

At Known Motors, we build engines that are meant to last for years with proper maintenance. That's why we replace essential components like apex seals, corner seals, side seals, and more. We use only new seals, gaskets, and other parts to ensure top performance and durability

NEW PARTS & SERVICES INCLUDED IN THE BASE PRICE BELOW (this list represents approx. $1800 retail cost in parts):

  • Oem mazda apex seals 
  • OEM mazda apex short & long springs
  • Oem mazda corner seals 
  • Oem mazda corner springs 
  • atkins rotary side seals cut to length
  • Oem mazda side springs
  • Atkins rotary viton oil oring inserts
  • Oem mazda inner and outer coolant seals
  • Dowel pin orings, tension bolt seals, rear stationary gear o-ring, front/rear main oil seal
  • Front cover gasket 
  • Atkins rotary thermal pellet replacement for front of e-shaft
  • Main bearings
  • Rotor bearings
  • Spark plug holes threads are cleaned and retapped. OMP injector holes are drilled to remove clogged carbon.
  • Exhaust porting to remove casting shelf obstruction in the exhaust port to minimize carbon build up in the future in the exhaust port.


  • 2) rotor housings
  • 2) rotors
  • Eccentric shaft
  • 2) stationary gears
  • Front cover
  • 3) iron housings/plates
  • Oil pump, chain, sprockets, various small hardware
  • Rotor metal oil control scraper rings (8), cutoff rings (4), w/ springs (12)

Please Note: $1500 deposit is required before the project can be put on the books

Short Block Engine Rebuilds Estimate Pricing

04-11 Automatic     $3800+ core

04-11 Manual     $3900+ core

 ​Engine Rebuild with Installation

04-11 Automatic     $6000+ core

04-11 Manual     $5800+ core

Prices are based on your having a rebuildable core. Please call for pricing if you do not have a core. 

If required or desired, additional parts/services are available:

  • New rotor housings @ prevailing current prices, approx. $1900/pair(04-08) or $2000/pair(09-11)
  • New iron housings @ prevailing current prices, approx. $2000/set of 3 
  • New apex short/long springs $60
  • New metal oil control scraper rings, cutoff rings, w/ springs $550
  • New oil pump approx. $70 @ current prevailing prices
  • Streetport all intake ports and exhaust ports $850 (I do not recommend or offer bridge ports for renesis rx8 engines, it has never been proven to make additional power and can impact longevity of the engine)
  • OMP modification to use external oil feed and reservoir for premix oil $400


  • Shop rate is $100 per hour
  • Turnaround time for engine rebuilds is typically 2-4 weeks, depending on current workload.
  • You're encouraged to bring all engine cores or parts thereof. After inspection, leftover parts can be traded in for credit.
  • Located in McPherson Kansas, visits are by appointment only. Shipping via truck freight is available, with assistance provided upon request.
  • Upon receiving your engine, work begins after pending jobs are completed. Detailed photo documentation is provided throughout the process.
  • Payment is accepted in various forms, with a deposit potentially required upfront. A signed service contract is necessary prior to work commencement.