What engine is PR3 from?

[Slvrwrx]

i have a ls vtec crx. its got a b18a bottom end, and a pr3 head. my question is, what engine did the pr3 originally come from? i think its either the 93 gsr or a b16. any information would help. thanks.
-Sam

 

[efhondakid]

PR3/PW0 is OBD0 B16. PR3 came from the JDM SiR EF, PW0 came from the USDM Integra XSi.

 

[cjvictoria]

i may be wrong so someone correct me if so... but PR3 is also the Type R head as well, correct?

Just with different valvetrain and a factory port and polish
(port on int, port and polish on exh)

 

[D15Beater]

LS camshafts have PR3 gears on them....

 

[Taco15]

LS camshafts have PR3 gears on them....

sure its not just the cam gears being switched? LS have pr4 on them.

and yes the type R head is also a pr3 stamped.

 

[FLounder]

i think its the type r head, the b16a head, and the b17a head that have pr3 on them

 

[D15Beater]

sure its not just the cam gears being switched? LS have pr4 on them.

and yes the type R head is also a pr3 stamped.

Not these LS cams. They came out of a virgin never modded once 92 Integra LS B18a. These are the gears that came on them.

As far ass why they dont have Pr4 on them I dont know....I found a starter in a LS once that had a bracket on the wires that was marked PR3 as well.

 

[Taco15]

wow thats pretty weird. it might just be me but uhave never seen and LS motor with a pr3 stamp on it. especially in the head.

starter, camgears and other stuff in the block i can understand since they are interchangeable. But from the factory they say pr3? hmmm

 

[D15Beater]

I assume that both the pr3 and the pr4 gears have the same number of teeth on them. Are the keyways in the gear at the same position to then? I asking because these are the gears/cams that came outta my old LS swap and i skunked b16s and gsr's. If the key ways are different that coulda thrown off the cam timing in my engine and resulted in more power than i would have gotten form stock pr4 gears. This is just a theory though, has not been proven or concluded in any way.

 

[xchipx]

Im pretty damn sure in saying all the cam gears are the same on the b series. All stamped pr3.
Same with the b16 and type r heads ( other b series heads not sure on ) all the same casting but then modified by honda ( type r )