RETed

Nitrous...no wonder.
I don't think the original poster was sniffing the giggle gas?


-Ted

Asleep

No sniffing, no funny gas.

Asleep

Paul? Paul Yaw? If not then I think might just continue testing with those housings on at least one more engine. Maybe not the engine I put back in the car.

Those wacky exhaust ports DID make enough power to pull car lengths on quite a few fast cars around here. I just wonder how much more they could have been making or how much time I spent banging my head on the laptop wondering why the turbo was not matching my calculations.

Mr rx-7 tt

iTrader: (5)

Detonation is detonation...

Mr rx-7 tt

iTrader: (5)

Looks to me like they are wasted. Are they not gouged?

Mr rx-7 tt

iTrader: (5)

Your power didn't come from those exhaust ports my friend.

Asleep

Not gouged. Marked, but not gouged. Finger nail test shows no groove.

Asleep

And that fact is "paining" me. All that time and energy, not to mention $, wasted trying to overcome something that I assumed was "optimum." Because that is why you pay a professional...to get the optimum performance.

Latin270

Actually I've seen that type of exhaust port (shape/ size) used on BP and on PP motors, so they are a proven port. I just never seen that type of exhaust port used on a SP motor. The port itself isnt that bad, it just needs to be better finished.

rotarygod

iTrader: (1)

Nope I'm not Paul. I do have a flowbench though which I was inspired to build after many phone conversations with him. He's a damn smart guy.

sccagt3

I agree, if they pass the fingernail test you should be able to alter the port a little and see improvements. They are overkill on a street port motor. Ship them to me and I will do it for you---shoot me a PM.

samperry007

And I thought mine were bad, at least it was my first time.

RETed

Uh, no it's not.
There is such thing as mild detonation versus severe detonation.


-Ted

RETed

Ah, the flow bench rears it's ugly head again...

Something I came across poking around randomly...

I agree.

Full link:
http://www.pineappleracing.com/TechLinks.html

YMMV


-Ted

rotarygod

iTrader: (1)

That's because you've never used one. Fortunately, there are smart people out there (like Paul Yaw) that know better and share their knowledge for others to mooch off of! If you aren't testing, you are guessing. One test result is worth far more than a thousand expert opinions.

If you'd actually talk to Pineapple about it rather than just quote their website you'd realize that they do in fact have a flowbench and have in fact used in many times in the past on rotaries. They learned what they needed to early on and have no need in their eyes to use it for any further research. On a piston engine, each one is different. Things are changing constantly and you are always learning how to do things differently from engine to engine. Valve jobs are very different, valve sizes, total lift depending on cam selection, etc. It has nothing to do with being able to simulate internal flow inside a rotary vs a piston engine. A flowbench can't do this on a piston engine either. Any swirl you get in a rotary intake port is completely gone by the time it gets to the other side of the engine anyways so any claims you see of people making venturis inside their engines or having some new kind port job that helps suck on the other port are bogus. Complete crap. I asked them about this last year at Sevenstock and that was their answer. It wasn't to say that a flowbench is worthless on a rotary even though that's how it reads. The main point of it was to say that you need to know what to use it for and how to use it properly. Most people don't and this would make it worthless on any engine. Their logic was also that once they learned all they could on 1 engine, they were done with it and could for the most part copy it easily. Too many people won't use one properly so you may as well just tell them not to rather than trying to show them how to.

A flowbench is like a dyno. It is a tool and nothing more. Don't put all of your faith solely on the numbers it gives you. It is a reference point. You need to know other parts of the story. It tells you changes but as with any tool you need to know how to use the information that it gives you. Your ultimate goal on a flowbench is not to get as much ultimate flow as possible. In some cases you want less! You need to also understand what you need. More is almost always not better. Too many people just strap a housing on a bench and see how much it flows and then enlarge the ports until they flow more. This is definitely not the way to do it. This is like strapping a cylinder head on a flowbench with no valves to see how much it flows and then making everything larger. That would be worthless. Pineapple even mentions as measuring static flow rates being a futile exercise. It is! You need to understand what this means.

A flowbench is a great tool if you know how to use one properly. Go learn!

Mr rx-7 tt

iTrader: (5)

Wow thanks for the hot tip. Of course there is.

Your assertion is the exhaust and only the exhaust caused the apex seal to split which I can tell you from building engines for over 25 years and first hand experience wasn't the case.

Lasse wankel

Me and Mikael have had our rotary flow bench since 1997 and definately worth every dollar! We have some really interesting engine projects coming up this winter that shall be dyno tested. As Rotarygod said the flow bench is only a tool and you don't compare benches to each other! Any way an example: A stage 2 monsterstreetport flows nearly 30 % more air than stock FD REW, that is with stock height of port 51 mm to 61 and +2 mm of duration.

/Lasse

RETed

Ah, so why don't we qualify your claims?
That 30% was for just the port or did you set-up the whole TB -> intake manifold -> housing ?
It all still comes down to weakest link in the chain.

BTW, what application is this for?
How do you qualify the need for such prep work when you can just turn up the boost or run a larger turbo?


-Ted

RETed

Are you claiming that you can cause such breakage of the apex seal from non-nitrous applications?
If so, what where the operating parameters?


-Ted

GUITARJUNKIE28

yea man, who needs to do things right?? just turn up the boost!!

Mr rx-7 tt

iTrader: (5)

How about 22 lbs of boost on pump gas.

Asleep

And not having enough fuel for it, you mean.

RETed

So you're saying that you cannot run 22psi of boost or risk catastrophic failure of the apex seals like the pics?


-Ted

GoodfellaFD3S

iTrader: (213)

On 93 Octane **** water without some kind of auxiliary injection, no. Doing that long term will lead to some severe apex seal damage.

SPOautos

Obviously he is saying that detonation can cause a seal to split longways. He pointed out that he witnessed an engine fail due to detonation, pulled the engine apart and the seals was split longways. Then to help eleviate that the cause could have maybe stemmed from improper porting he mentioned that it was a reman engine with bone stock mazda ports in it. Basically demonstrating that seals can break long ways from some other method than poor exhaust porting.

Stephen