The_7

I am going to be putting together a custom 4-Port 13B this summer for my FB. I was planning on using GSLSE Rotor Housings, 12A Side & Int. Plates, and S5 Rotors. What do you think of this setup? Are all the parts compatable? Are the S5 Rotors the lightest and highest compression? Any advantage of 12A side plates over 13B besides being cheaper? Disadvantages? What about GSLSE rotor housings? Maybe I should go for newer rotor housings for better wear. The side plates can be older because I am getting them resurfaced.

Elysian

the only 4 port 13B plates u'd find are either A) from the 70's or B) from TII's/FD's... the 12A intermediate plate would be nice because they have those nice big intake ports, and still plenty of meat to port...

The_7

ok so 12A side and int plates it is. are the GSLSE housings the only ones that will work with 12A sides? i remember reading that something doesnt line up with other 13B housings like the shape of the notch for one of the gaskets or something like that.

Elysian

S4 and up housings don't have the grooves for coolant seals, the coolant seal grooves r in the cast irons... the S3 and below have the grooves in the rotor housings... the RX8 went back to the grooves in the housings design

The_7

so i can use S3 and below then? whats the newest year for that?

Elysian

85

The_7

ok thanks, how about the eshaft - is there any particular year besides the S3 that has some advantage that would be compatible?

Elysian

not real sure... i think the 93 and up E shaft had better bearings, but really i'm not sure... to me an e shaft is an e shaft lol

The_7

ok, finally, just to make sure, are the S5 rotors the lightest and highest compression? what years is that?

Alex-7

S5='89-'92


And yes, lightest/highest comp.

Elysian

besides rx8 rotors, yes, but u wouldn't really want to run rx8 rotors in anything but an rx8...

The_7

ok thanks for the info and the quick responses

Dom_C

what intake manifold though? would the turbo intake mani's line up? I'm considering this but want to stay efi

The_7

hmm good question, hopefully someone knows. what about teh na s4/s5 manifold?

Elysian

i know the exhaust manifold will, i believe the intake mani requires minor mods to work, ie i think drilling a few holes for bolts...

The_7

are there any detrimental effects to flow? like are the ports lined up perfectly?

Dan H

Interesting setup. I plan on something similar but will be using TII irons, S4/S5 rotor housings, and possibly S5 rotors with a 12A front cover to mount it. The reason I didn't go with the other setup is because of the intake manifold problem. But I know for sure Mazdatrix has a TII intake manifold to use Weber carbs.

Elysian

port match if there is a prob, but the ports should still line up the same

kenn_chan

The_7,

you need to remember to use the same E-shaft, counterweights, and rotors as a set. different models/years have different counterweights for a reason, the rotors, and e-shaft have different static/dynamic balance points. for instance, the S-5 turbo rotors, and the S-3 e-shaft are not generally compatible without a rebalancing. do a search on counterweights, and rotor weights, and compare and research prior to purchasing, I personally don't rtemember the differences (all of them) off of the top of my head, but I do know that a custom rebalanceing will set you back a lot of cash, and there are only like one or two places in north america that could be considered competent in this area.

Heck even the rotors were different from engine to engine sometimes, and there is a stamping on the rotors detailing which it is. general rule of thumb IIRC was not to vary by more than one letter, IE: if you have a "H" rotor than the other one had to be a G, H, or I to keep the engine balanced.

kenn

Feds

I've been looking into this set up as well, so I will add a little more speculation and conjecture to this thread:

1: I HAVE HEARD (not tried) that the e-shaft doesn't matter. As long as you match rotors and counterweights, you'll be o.k.

2: The S3 e-shaft is the way to go. S4 and S5 had the thermo-pelet deal that can fail in the closed position and starve your engine for oil. You can bypass it.

3: Balancing is in the neighbourhood of $500. If you are spending the dough to do a ground up build, spend the extra dough for a little peace of mind.

http://www.nopistons.com/forums/inde...howtopic=50207

kenn_chan

Feds,

Not sure about the turbo e-shaft to NA, but I know for a fact that the early 12a's had differences the pre 1973, and the 1973 and up (JDM) had holes drilled in the journal that lightened it and it worked really well for high RPM engines, yuo had to rebablance your motor when you built it because the 73 and later rotors were better because they had the newer style apex seals (new at that time ) and the weights were different . I would uts a safe assumption that its the same for US versions jsut one year later was the pattern before.

kenn