I have a 6-port NA 13b that is getting a rebuild, but like everybody else I want to perform a street port. Originally I purchased the 13BfcNSP v2 "medium" street port templates for both the plate and housings from Pineapple Racing. Once acquiring the templates I found out the plate template was for the 4-port and not the 6-port. So I went ahead and purchased the 6-port template from Mazdatrix.

Right away I noticed the exhaust ports between both plate templates are vastly different. So I was wondering which template would be best to use for the exhaust ports, the Mazdatrix or Pineapple Racing template?

Is it even wise to use the Mazdatrix intake template on the plates, and use the Pineapple Racing exhaust ports? Or is it best practice to use both intake and exhaust from the Mazdatrix template and forget I have the Pineapple Racing template?

I did not order the housing templates from Mazdatrix, so is it okay to use the Pineapple Racing housing templates with the Mazdatrix 6-port template? Or is it best to match it up with the Mazdatrix housing template?

Not sure if this matters or not, but I'll be using the Atkins Rotary wrap around intake with Weber 48 DCOE side draft carb. Thanks for the help!

Mazdatrix vs Pineapple Racing templates:


In this picture the Pineapple Racing template is sitting on top of the Mazdatrix template for the exhaust ports. The Pineapple racing template is shorter and wider, where as the Mazdatrix template is taller and thinner.

 

Both of those templates are for the intake ports. The ports you are comparing in your bottom picture are the primary intake ports. These are on the center iron. The top ports on the Mazdatrix template is for the secondary and Aux. ports on the six port. These are on the front and rear irons. The exhaust ports are in the rotor housings. I'd use the Mazdatrix for the intake ports since you know it is for the 6-port. I would figure you can use whatever exhaust template you want. Read these links:

https://www.mazdatrix.com/faq/portintk.htm
https://www.mazdatrix.com/faq/port6p.htm
https://www.mazdatrix.com/faq/portexh.htm
https://www.mazdatrix.com/faq/6pexh.htm

 

Still got so much more to learn >.< at least I'm not new to porting in general....

 

OK, so I fully understand my own questions at hand now. I'll go ahead and use the Pineapple Express exhaust templates I bought for the exhaust ports, while using the Mazdatrix 6-port template on the intake ports. Thanks!

 

i do not like that the pineapple port template has you port into the oil seal tract, this is a REALLY bad idea.

 

Another noob question, oil seal tract? I'm going to guess you're talking about the Pineapple Racing intake templates? Or is there something about the exhaust port templates I should know about?

 

He is talking about the intake template. The pineapple racing template ports slight inwards toward the center of the side housings. The rotors have a oil control ring and if you compromise it sealing surface it can let oil thru causing the engine to smoke.(a lot)

 

Oh I see, thank you very much for clearing that up.

 

. You can port about halfway into the outer oil seal track with zero ill effects. This is well documented. Significant increases can be seen in port flow by using this technique.

That being said, we don't race flowbenches, and porting a 6-port intake is bit of a waste of time without changing the intake manifolds.

 

for an experienced person porting, yes. most people who need a template, are not experienced.

 

Yeah, I'm just following the templates.... No reason to risk getting fancy on my first rotary. And I'll be changing my intake manifolds for the Atkins wrap around intake for the 6-port.

 

I have a casual bystander question...
Seems like the timing/duration/volumn of the porting would have been worked out as a matched set by the two companies, is there a reason to suspect that the Pineapple exhaust port works better with the Mazdatrix intake shape?
Seems like you'd stick with one design all the way through unless you've experimented on multiple engines.

 

i think that pineapple template is for 4 port engine.... my 6port large streetport template looks like the mazdatrix template

 

dp

 

i've experimented a bit with different port shapes and sizes, and in all honesty none really make a big difference over the other.

it's only in places like bridgeports where you see a big noticeable shift in the power range. but even then, the power gains are still minimal, probably in the ballpark of 5-7% more peak power due to the ability to rev higher while keeping velocity up.

D shaped exhaust ports smooth the idle where rectangular make the idle a little lumpy, power is the same. longer ports versus wider, almost no change in the power band. porting is rather mysterious because no one realistically does back to back porting tests and all you can do is look at the average as a whole of how the engines seem to perform with a certain port type.

 

Good to know, I was actually wondering if using the PR exhaust port would be a bad idea with the MT intake ports...

 

The actual exhaust port template from PR I'm using.

 

That exhaust diffuser has to go. Either get a plasma cutter or source some Turbo exhaust sleeves.

 

Oh I know, I've not even started on anything yet. I'll be sourcing TII sleeves.