Hi, I'm new to this board and I'm currently rebuilding my 13BT.



I just received RB intake porting template and I have some questions. Is this template only good for secondary ports or it's also good for primaries ? Is it too big for primaries ? Can I port bigger than this template or it's not recommended ?



Thanks all!



Alex

From what i have hurd the racingbeat templets are pretty mild compared to what you can do for a port job so going beond the templet is probaly ok, how far though i dont know



Im not sure if you can use them on the primairys, i dont htink so only because there is so little castin there. I know on my bridgeport templets the templet is atleast 60% larger than the primary port, and im 99% sure that it would bring me into the waterjacket

It's too big for primaries on fuel injected intermediate 'plates'. I think RB ought to mention that there is a difference. Several people have over-ported there intermediate plates because of this.



You're one of the luckier people. https://www.nopistons.com/forums/pub...IR#>/smile.png

Actually, you can port up as far as the template on the primary ports, just DO NOT port down with the template. Using that, makes a pretty nice port.

So I can port as far as the template for primaries, but is it good. I know it changes something on low end and stuff like that. I'm a little confuse about that. Can someone explains or give me a good URL.



Also I want something wild, I don't care about emission, so I can port more than the template as far as I let about enough space for corner seals ?



Thanks again!

No, you cannot port to the template on the primaries. What you can do on the primaries is port UP using the template. If you port down you will hit water. What are you doing for an exhaust port?

Ok, for primaries can I port everywhere to the template except down or juste up ?

I was thinking to keep exhaust port stock. Is it correct ?



Thanks guys!

If you want to make very little power then don't port the exhaust. The RB exhaust port is a good starting point if you don't feel confident in your ability to do your own. Put it this way. You can cram all the air in that you want, but if you can't get it out you aren't going anywhere. Go visit Judge Ito's exhaust porting thread.



Yes, you can go out and up on the primary, just don't go down.

On a side note, It would be great is someone could add some comments concerning exhaust porting. Timing related, by that I mean I would like to know what are the main effects of earlier exhaust opening/later closing, how far can you go (in degrees would be nice https://www.nopistons.com/forums/pub...DIR ) Etc. I've been looking for this kind of info but just can't seem to find it. As I am not rich and unfortunatly do not have many housings laying around to experiment, I would be VERY greatfull !



Sorry Alex for jumping in your thread https://www.nopistons.com/forums/pub...IR#>/happy.png

If you have time, Ito is doing an exhaust port thread that is pinned, and promises to get into exactly what you are asking.