Donovan N.

Ok I plan to build an NA S5 that I got for $20 so im off to a good start already i guess, but I was hoping for some feed back. I plan to have the following done:

1. P-Port by goopy performance (any recomendations for port size or timing?)
2. balanced rotating assembly by RX7 specialties (I hear they have the most precise balancing, down to 0.1 grams)
3. I am not sure what apex seals to use (2mm, 3mm, 1 piece, 2 piece, ALS, NRS, Ianetti,...)
4. re-surface rotor housings by goopy or Cermet coat housings (any suggested shops for cermet?)
5. re-nitride irons or cermet coat? (again any suggested shops for nitride or cermet)
6. snap-ring mod for rotor drive gear (is this necessary)
7. modified stationary gears (again is this necessary?)
8. external water feed mod (is this necessary for NA engine)
9. external oil feed mod (if necessary, need more info)

any feed back about shops, parts, or mods you guys have experience with would be appreciated.

j9fd3s

iTrader: (3)

1. it depends on the power level, and rpms you intend to run (a little)
2. balancing is a great idea.
3. depends on the RPM level. if you're going over 8500rpm, carbon seals are better than the stock iron seals. ceramic would be even better, but its expensive.
4. i'd resurface
5. i'd renitride. or buy new. side irons aren't expensive, so by the time you machine and re nitride you might be able to just buy new, which is faster and a known quality
6. the S4+ engines added more pins to hold the rotor gear, so it not critical to do this, but it does depend on the RPM range you're looking at too.
7. the S5 has it, but it could use the FD/Rx8 bearings
8. dunno, probably not
9. its not a bad idea

IMO the engine can be pretty basic, you don't need a lot of fancy parts. the MFR engines in the 80's were just built with closer balanced rotors, carbon seals and higher oil pressure. can you build it using newer/better parts/specs? yes. do you need to? nope