I was wondering what would be better to build street port. I have 76 4 port plates, and housings. I have gsl-se rotors and 89 gtu rotors. The gtu rotors have new seals and springs, and gsl-se rotors have new seals and springs, but they are missing 3 apex seals. I wanted to know what combination would be better to use, and why it would be better. Thank's for any advice.

 

the 89 rotors are lighter but the 3mm on the se rotors are stronger.
i am building the same motor and am going with the se rotors.
you can sell your 89 rotors for a grip on ebay ($200-500)

 

i think u should use the entire rotating assembly of whatever u have, wheather it be from an se or fc.

 

What about the higher compression on the gtu rotors. Will that be better for street port.

 

Staying NA, yes, though I don't recall the difference between the 2. Lighter rotors, 2mm seals, and a lightweight flywheel should give you a quick reving engine. You might want to consider hardened stationary gears, 3 window bearings and upping the oil pressure if you plan on running above 8k rpm. Iirc, the S5 rotors came with the hardened stat gears.

 

yes, the S5's did come with hardened stationary gears. however, the 1976's did not, so you'd have to get them for yourself.

i guess the question is a matter of which "complete" rotating assembly do you have? having the rotors alone is not enough. which front counterweight and which flywheel do you have?

personally, if given the choice, i'd go with the Gen II setup. however, i've always been leary about mixing "old" and "new" - regardless of the fact that so many people have done so with good results. it's just something that i try not to do. so i'd probably go with the SE rotating assembly if i were you. however, with that said, the S5 rotating assembly would make a slightly hotter street package.

 

As others have said, the critical thing is the matched rotating assembly. With the lighter rotors, you must have the appropriate front and rear counterbalances. You can use the later crankshaft with any of the rotors, if you plug the front.

There are people who machine the apex seal slots on the later rotors to use the 3mm apex seals. This gives you the advantage of more robust seals with the lighter weight rotors. Personally, I think you will gain much more by sticking with the early parts and buying a RB aluminum flywheel. This has more benefit that a small reduction in rotor weight. This assumes you are not planning to run this thing at 8-9 thousand rpm on a regular basis. If you decide to go with the 2 mm apex seals, contact Atkins rotary and find out about their one-piece seals. People here in the Northwest have had good luck with them.

The longest life will be achieved with the 3 mm apex seals and the SE rotor housings with oil injection directly into the rotor housings. I am currently setting one up that way, using an RX-4 carb, with an SE front cover so I can use the 4-port oil metering pump, two lines to the carb and two into the rotor housings.

 

I have a complete 89 gtu motor. A complete SE motor, minus the housings. I also have the motor thats in my car now. It has 76 plates and housings, with 86 everything else. I don't know what is still good in that motor, until I pull it out.

 

bump^^^^^