gdupfromfeetup

Ok guys, here's the rundown. My friend recently aquired a 99 si. The motor setup is not the original, previous owner said he had the install done by a shop in PA. It's a b16a2 bottom end with a pr3-3 head.
After doing a lot of research I have discovered that the pr3 series heads have 4 different heads.
Pr3- 1 through 4 COULD be either a b16a, b17a, b16b, or a usdm b18c5 itr head. However, there is no way to distiguishvthe difference in them. I will say this, this car pulls substantially harder than another boys stock si. ( I do not condone street racing, I'm simply using this as a reference)
My question is, could this head possibly be a type r head? I've heard that you can tell by looking behind the distributor for blue paint marked from the factory to be sent out for port and polishing. I believe I see some, but honestly it's too dirty and all faded off that it's not credible at this time. Any input about any experience with this particular head would be great. I've looked a great deal into this and I'm trying to determine which head this is.

Thanks!

Fabrik8

All of those heads use the same base casting, which is why they're all marked the same. If you can't pull the head to check the valve sizes, you could pull the valve cover off and see if you can ID the cams. I can't remember what the visible differences are, but it's a possible starting point to see if there are any clear identifiers. Or remove the intake manifold and see what the intake ports look like. I'd research these things before doing any disassembly, just to make sure you don't waste your time taking things apart for no reason.

gdupfromfeetup

thanks fabrik8, also dont both itr and b16a heads come ported and polished from the factory? that would eliminate two choices but I think that the best way to determine the difference is to take a look at the cams. thanks for the input.

burnoutboy

THis may help.

http://www.ff-squad.com/tech/temp/VtecCams.htm

imcnblu

only the PR3-4 heads (ITR and CTR) were ported and polished from the factory. (Though, I've read posts on H-T that say PR3-2 heads are first gen ITR.)

As far as the other variants of the PR3 head (mainly the B16A's PR3-3) are basically the same. The only thing that REALLY changed over the years were the manifolds. The cams might be different between first and second gen B16, but I'm not positive on that. I believe they are, as Fabrik8 mentioned ID'ing the cams.

So, if it pulls harder than your other friend's Si, it might have had head work done. Maybe swapped to aftermarket cams?

gdupfromfeetup

This was really helpful! Thanks burnoutboy