When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I am going to rebuild my engine and while I am in there I would like to get some more power. Of course buying a 6 port will give me the most power increase but that would involve swapping the dash and ECU too, so I would probably just sell my 4 port and buy a 6 port.
But there are no 4 port porting templates for sale.
I see 3 options:
1. Make my own porting template. I can figure out where the oil rings and corner seals ride and figure it out from there. But it seems risky.
2. Buy a racing beat 6 port template and use the template for the center irons for all the irons.
3. Buy a racing beat 6 port template and use the template as intended but just leave out the top ports since they are not there.
What would be the best way to go? Personally I am leaning towards option 2.
Other than cleaning up and smoothing things, DO NOT PORT!
I’ve made many posts about this. You can’t really make much if any power porting a Renesis, but you can lose power pretty easy trying to treat it like some other engine. So lucky for you there aren’t any templates to be suckered into wasting your money on.
.
Regardless, porting a 4 port has no business being posted in the Major HP Upgrade forum area.
Other than cleaning up and smoothing things, DO NOT PORT!
I’ve made many posts about this. You can’t really make much if any power porting a Renesis, but you can lose power pretty easy trying to treat it like some other engine. So lucky for you there aren’t any templates to be suckered into wasting your money on.
I will defenitely smooth out the ports too. I swear I saw people with 5-10% HP increase and a more powerful low end. Seemed maybe worth it for me. I have some 6 port irons lying around so I might at least steal the exhaust porting from that since it is bigger. I won't buy a template then but see what I can manage to do. I have a couple of irons lying around anyway so there's no harm if I mess up.
I'll report back if I have anything noticable to report.
Originally Posted by TeamRX8
Regardless, porting a 4 port has no business being posted in the Major HP Upgrade forum area.
The description of the sub is:
This is the place to discuss Super Chargers and Turbos, Nitrous, Porting, etc
I suppose it depends what your comparing it to. I see people post gains, but they’re so far down below what a good stock port results are that you can’t just claim it’s a different dyno. The pro builders that specialize in this engine and tried every trick in the book swore it was 5 - 10 hp at the flywheel at most (6-port) with less side seal life.
Porting was listed back before anybody knew there was little-nothing to gain, but I can’t really argue with it being listed and you not knowing different. So that’s on me.
A 4-port isn’t a 6-port obviously, but if you want to sacrifice one end of the powerband for the other, then ok. It doesn’t have APV ports to carry it up therel like a 6-port so you might put some more thought into that. But if you have 6-port irons then it’d make more sense to plug the APV and use those than put the energy into making 4-port ports to match. However anyone who ever ran a 6-port NA with the APV not functioning can attest that it makes less power than the 4-port.
Be careful what you wish for; you just might get it. Otherwise, have at it.
.
which it’s likely closer to 220 - 225 bhp at the flywheel. A really good unported 6-port hasn’t even opened up the APV yet at that same power point ...
.
Most people wouldn’t bother with a 4-port over a 6-port is a good place to start. Probably because it costs just as much to build one, more if stronger 6-port parts like stator gears and such are swapped in.
I understand that for some people my comprehension of an NA rotary engine isn’t any better than FI rotary, but in this particular case I’m not sure why 1+1 is hard to calculate. Why would anyone think there’s any more magic in a 4-port than a 6-port? The factory Mazda output graphs are posted above and the information on what a 6-port can achieve are known.
hand built 4-port; 222 bhp @ 7500 rpm and 180 ft-lbs @ 5600 rpm (my estimations based on dyno wheel numbers)
—————————
or wheel output numbers are roughly 230/150 6-port vs 186/150 4-port comparably.
which getting back to a Renesis 20B based on 4-port housings; it might theoretically achieve 280 whp based on these results if it were’t for the center rotor only having primary intake and siamese exhaust ports holding it back. How that’s going to then achieve 320 - 350 whp while being both fuel efficient and affordable with it essentially being an engine swap requiring intake, exhaust, fuel system, cooling system, subframe, and engine management mods at a minimum is going to be interesting.
.
Most people wouldn’t bother with a 4-port over a 6-port is a good place to start. Probably because it costs just as much to build one, more if stronger 6-port parts like stator gears and such are swapped in.
.
You are getting confused . This thread is about porting a 4 port engine .... nothing to do with comparing it to a 6 port. So why even mention a 6 port ? There are lots of people out there with 4 port engines that may want to modify them.
Transplanting a 6 port engine into a car that had a 4 port isn't a feasible option for most people either.
Originally Posted by TeamRX8
which getting back to a Renesis 20B based on 4-port housings; it might theoretically achieve 280 whp based on these results if it were’t for the center rotor only having primary intake and siamese exhaust ports holding it back. How that’s going to then achieve 320 - 350 whp while being both fuel efficient and affordable with it essentially being an engine swap requiring intake, exhaust, fuel system, cooling system, subframe, and engine management mods at a minimum is going to be interesting.
.
Dunno why you bring that up either ...wrong thread for it. But happy to talk about that in the thread I started if you want to cut and paste that over.
if it’s messed up, then please explain to us how a 4-port is going to have any difference in magnitude than a 6-port over the factory numbers? I didn’t put that link on there just to demonstrate and reference your intentionally sour comment when the dyno results were posted.
again, there’s no magic well of secret sauce in a 4-port Renesis over a 6-port. it has all the same porting etc. limitations and general configuration except for the 2 APV ports and VDI.
so no, your personal bias and general obstinance towards anything from me prevents you from seeing/accepting the obvious again.
they estimated it at 218 bhp = flywheel hp, imo it’s slightly higher around 222 bhp/flywheel for that wheel output
compare that to my recent 6-port engine dyno hitting the same bhp at ~6400 rpm; 1100 rpm sooner
.
So what you are saying is that ...because a hand built 6 port makes x power then it stands to reason a hand built 4 port will make .... 'y' power. You don't have anything to back that up at this point other than that logic ?
EDIT:
BTW ... I wasn't clear on what you meant above because you made it sound like you already had all the proven/tested numbers. The logic is reasonable but if it's not tried tested and proven ...it's not a forgone conclusion ....and you know it.
this is what I know that people with rocks for brains refuse to accept, which it must be at least the 3rd or 4th time I’ve expressed it to you now in one form or another:
So let me try this one more time. Somebody comes up with an idea; a triangle shaped wheel. Then says let me try a 4-sided square wheel, then a 5 sided, then 6, then 7 , 8 etc.
Somebody else sees the concept of triangle-shaped wheel and immediately deduces that a smooth circle is the obvious solution without ever getting their hands dirty.
If you have nothing better to do than squander resources getting your hands dirty reinventing the rotary engine wheel, then ok, but there’s no secret well of magic rotary sauce to be discovered and spring forth.
Let me get this straight .... I post an actual dyno of real life results. You postulate about what your engine builder could do (if he ever built one) and state it as fact..... And I'M the one with rocks in my head ?
the results are exactly as expected; the difference is spending $6000 or not
I already told you and everyone in another thread my conclusion that it made no sense to use/choose a 4-port over a 6-port with blocked APVs. Your “postulation” was that a 4-port could benefit from that. Best case it would just mimic a 6-port without the APV ports and VDI. Which is what I meant about trading off the slight difference of one for the other in my response to that postulation. Because the torque peak occurs below where the 2 extra ports have an effect; again obvious, if your mind is open and there’s a proper understanding of how the Renesis porting and timing works. Which you keep postulating against all my attempts to explain and help people finally understand why a Renesis is different than the previous 13B.
the only thing you fault me for is that I was able to deduce what you couldn’t even comprehend until your edited post when the lights finally came on.
which again there’s nothing much to gain from porting a Renesis, yet you egged another noob on with a false notion rather than attempt to educate him on that reality. because you didn’t even understand that yourself after all this time.
it was you who postulated that, you were wrong, and it took $6k proving the obvious to finally drill and blast through all those rocks.
.
A 4 port can definitely benefit from some extra port timing. Definitely more scope for improvement than a 6 port.
I'm gunna quote myself here because you either can't read properly or your head is too thick to penetrate.
This thread is about PORTING A 4 PORT !!!! What I said above is saying the 4 port has more scope for improvement than the 6 port. I'm not suggesting it can make the same power as a 6 ...just that it can be improved more.
The dyno I posted goes some way into proving that assertion.
Now if you want to argue that point then argue it and shut up about the 6 port !
Had a 4 port bridgeport on the dyno the other day . Showed some gains at the top end where the stock engine would fade. Would like to see where it ends up at 9000. Have never dynoed a strong stock 4 port to compare properly though.
and go play Lil’ Hitler with somebody else because I don’t take orders or give up my freedom of speech for anyone, let alone a guy with a head full of rocks.
.
I guess seeing dozens of rx8s on the dyno race prepped / ported,turboed whatever , doesn't give me the same knowledge that you get from doing a couple of dynos on your own car and brown nosing with your engine builder.
it only says you still don’t get it because outside it just being the particular reference point chosen to illustrate a point, your reference to me or him is irrelevant and certainly not an honest thing to say; I’m not surprised though.
a lot of people ZOMG’d over this 10 years ago, but failed to comprehend the text at the bottom and what made the actual difference.
You are right, it was a guess. Just kinda seems that way to me, listening to you go on about him
Anyway ...getting back to the 4 port.
To deny that the 4 can be improved upon , is kinda like denying the 6 even exists. The closer you can get the ports to the shape and size of the 6 port , the more power it will make. That is just ...logical.
The manifold runner size is a constraint but from the dynos I already posted it's obvious that there is extra capacity for flow there.
sure, if you ignore my latest assessment to just go with a 6-port and block the APVs and what you gain without the hassle and extra cost to try and take a 4-port there vs just doing that.
frankly, you’re just arguing to oppose me is the least of the possibilities over why it is that reflects negatively on your position over this.
Because I’ll say it again in clearer terms, if you have the ability to accurately comprehend and assess the results properly, then what little bit of torque gained at several hundred rpm lower improvement on the 4-port is more than offset by what a 6-port less APVs and VDI can produce. It’s not even debatable at all. IMO even Mazda came to the same conclusion 2 years later and went all 6-port. Let’s not forget who it was that proposed the 4-port potential several years ago with much resistance, and then also came to to conclude otherwise for this very reason. At least with regard to the secondary port timing assessment, which is the only real difference once APVs and VDI are eliminated.
it’s not even about who’s right or wrong because if it makes anyone feel better; I was wrong then, it’s just about what makes sense now.
.
09-23-2020 | 04:06 PM
