How can I tell a 13B-REW iron (front, middle, and rear) from any of the other generations? Casting marks or numbers? Or are they all interchangeable?



Thanks,



Jeff

 

The intake runners on the REW come down at an angle, and the manifold flange is higher on the block than the other motors. I probably get you a pic if necessary.

 

I would really appreciate a picture if it's not too much trouble. Then I won't make a mistake.



It is my understanding that the only way to tell rotors apart is by weight (13B-REW weighs approximately 9.5 lbs. give or take the weight code and the weight of the bearing). Also 13B-REW rotor's bearings have a larger oil groove. I guess very early non-13B-REW rotors had 3mm apex seals too.



And as far as housings go - 13B-REW housings will have a port for a knock sensor and only one port for oil injection.



Is that about right? Any other means of identification?



Thanks,



Jeff

 

Rear REW plates are a dead give away as the mount holes are located there, as if you could miss the enormous intake port(s), and as mazdaspeed7 said, they angle downward fairly steeply as opposed to earlier 13BT plates



As I understand it, the REW bearings are multi-holed similar to the earlier three window bearing style from racing applications.



Housings are as you described but the front and rear are different by number and the housing are rumored to be stronger than the 13BT housings

 

All rotor housings only have one port for oil injection, the second location was in the manifold for 2nd gens. As for the knock sensor, it seems that the casting/machined hole for the knock sensor was randomly placed. Most of the S5 n/a's Ive seen and many S4 engines, both turbo and n/a, had the knock sensor location on the rotor housing machined.



I dont know if there is a good way to tell the rotor housings apart, but Ill take a look in a day or two.



The FD rear iron obviously has the motor mount bolt holes on the bottom, as well as an oil drain on the exhaust side of the engine. The center iron does not have the motor mount bosses the FC engines have.



Ill see what I can get for pictures, but it will be a few days.

 

the FD irons are easy to spot, they ALL have an N3A1, N3F1, or N3G1 cast into them. depending on when it was made, and which iron it is.



the rotor housings are harder too tell. all the S5 and newer engines have the knock sensor holes above the spark plugs, the s4 and earlier do not.



s5 vs s5-8? harder!



the FD has longer studs on the exhaust. they also DO NOT have the coolant ports for the turbo. the front housing i think is marked with a blue paint stroke and the rear is red.



oh easiest way to tell, is on the legs of the housing, its got a channel for sealant.

 

Thank you everyone for the information. So on the housings, if there is a groove for sealant on the legs is that all I really need to look for? Groove equals 13b-REW?



Is there anything else besides weight which you can use to differentiate the rotors?