Keihin PD Super Pumper Carb/ TURBO

[mixxer]

Can't say enough how much I appreciate the back to back comparison info, jeffrow....

It's too bad the knock off carbs couldn't be copied a bit more faithfully to their Keihin blueprints....   Since the originals were designed specifically for mid size thumpers from day one... And they bolt right in with zero adapters... Even the original 230 throttle cables bolt right up...

That would have to be in line for the award for biggest engine personality change for least money and time I have ever spent...

My jetting is currently at 120main /42pilot.... May try a 45 pilot just to see if anything changes , but I don't really have anything telling me I need to besides popping on decel until fully warmed up...

When I add the BBR piston setup to Bunny, I'm going to try a 115 main...

Added displacement makes for a stronger vacuum signal / effectively pulling more fuel from the same size jet...

But something not often considered is so does higher compression....

Easy to illustrate with the syringe example....  If you started with the syringe plunger already 20% of it's way down the bore and then pulled it 100% of the way down.... And measured the negative pressure/ vacuum generated...  Then compared to a reading where the rubber plunger itself was a bigger/ longer one where it's top started only 5% away from the end of the syringe before being pulled to the same end point of 100% open...

It becomes intuitive to understand that to the one that started with less air space to begin with would pull a higher vacuum reading due to the lower "capacitance" afforded by the lesser initial trapped air volume...

=stronger vacuum signal...

Same lower capacitance is in effect when the higher compression piston is at TDC during the overlap portion of the cam timing (end of exhaust stroke, intake valve opening , exhaust valve not fully closed, one complete system from airbox to exhaust tip) ... That is the point where you have the exhaust system (hopefully) providing a strong vacuum if its own to help "scavenge" burnt gasses out the combustion chamber... Intake and exhaust valves are both open during overlap so scavenging across the combustion chamber CAN work beautifully,.. exhaust system vacuum can pull burnt gasses out, while it initiates a sweep of fresh intake charge across the combustion chamber through the opening intake...

The harmonic magic continues... The vacuum of the exhaust system can initiate momentum and velocity to the intake tract BEFORE the piston even begins travel down the bore!! (Also why I'm not interested in partial exhaust upgrades, too much magic to be had in a full system)

Back to compression....

Higher compression helps enhance all that harmonic magic that can be happening during TDC cam overlap (close lobe centers anyone?!?)...

If you had a very low compression setup, as far as the exhaust system vacuum wave was concerned, it would feel like the piston was part way down the bore... Added volume and capacitance to dampen and absorb that exhaust vacuum signal... Scavenging effect diminished... Intake charge momentum non existent... Booooo ... Hissssssss....!!!

And that, my friends, is how high compression and efficient exhaust systems , as a side effect of all their other magic... Can provide a stronger vacuum signal at your carb.... And need a smaller jet to have correct (not too rich) air fuel ratio...

All apologies in advance to Baja Rambler, who doesn't like it when I take the time and necessary words to illustrate engine dynamics....

 

Edited August 26, 2017 by mixxer

[VortecCPI]

2 hours ago, mixxer said:

Can't say enough how much I appreciate the back to back comparison info, jeffrow....

It's too bad the knock off carbs couldn't be copied a bit more faithfully to their Keihin blueprints...

 

If they can't adequately/properly copy a carb why do many think they can copy Honda's engines?

Edited August 26, 2017 by VortecCPI

[On2Whls]

If they can't adequately/properly copy a carb why do many think they can copy Honda's engines?

Ignorance?

[mixxer]

2 hours ago, VortecCPI said:

If they can't adequately/properly copy a carb why do many think they can copy Honda's engines?

BINGO!!

DING DING DING!!!

WE HAVE A WINNER!!!

?

[On2Whls]

I just picked up an authentic Keihin PD03A for a 78-81 XL250S. Won't be in till Wednesday.
I still think I'm putting the cart before the horse, but the HC piston and cam will come this winter and the acel pump sure does make a difference.
Anxious to see if the straight swap from knock off to Keihin will get rid of the cut out/stutter that I currently have.

[VortecCPI]

From a Spanish rider.  Another take on QM:

"To give you a real-life example of quality control we have a Thyssen sintered gearbox components factory here in my region. A lot of car makers use common components in things like gearboxes: Audi, Seat, Skoda, VW, etc but guess what? on final dimensional QC checks the absolutely perfect components are coated with a protective film, lovingly wrapped in special bubble bags and carefully placed in specially built boxes to be sold to AUDI. The ones that are not quite up to spec and are at the maximum tolerances are chucked in a pile and go to the likes of SEAT and SKODA...and the ones that are crap are usually bought by FIAT...but in theory all the components are made by the same people so they must be the same, right?...wrong!.
This could be the difference between engines produced by QINGQI for SUZUKI and the ones used in their own bikes."

[VortecCPI]

We couldn't get the carbs right so let's go on and try our hand at entire engines...

[Chuck.]

1 hour ago, VortecCPI said:

From a Spanish rider.  Another take on QM:

"To give you a real-life example of quality control we have a Thyssen sintered gearbox components factory here in my region. A lot of car makers use common components in things like gearboxes: Audi, Seat, Skoda, VW, etc but guess what? on final dimensional QC checks the absolutely perfect components are coated with a protective film, lovingly wrapped in special bubble bags and carefully placed in specially built boxes to be sold to AUDI. The ones that are not quite up to spec and are at the maximum tolerances are chucked in a pile and go to the likes of SEAT and SKODA...and the ones that are crap are usually bought by FIAT...but in theory all the components are made by the same people so they must be the same, right?...wrong!.
This could be the difference between engines produced by QINGQI for SUZUKI and the ones used in their own bikes."

Except that most of Chinese producers have a third, and largest pile to sell to Merica. And no 1st pile to ship in bubble wrap.

[adnohguy]

Except that most of Chinese producers have a third, and largest pile to sell to Merica. And no 1st pile to ship in bubble wrap.

And IMO:
True that...

[On2Whls]

We couldn't get the carbs right so let's go on and try our hand at entire engines...

Couldn't get the carbs right is al relevant to what one considers "right". Apparently their right is good enough for who it's for. As long as they sell then why change. Not my philosophy on what a product should be, but I/we do have a higher expectation for a finished product.

[adnohguy]

Yep good enough when you ride alone and your truck is parked 50 ft away from the practice track .
Not so much when your 40 miles away from your truck when riding 5 canyons away and you don't have a helicopter available.

[VortecCPI]

6 hours ago, Chuck. said:

Except that most of Chinese producers have a third, and largest pile to sell to Merica. And no 1st pile to ship in bubble wrap.

Right on Chuck!!!

[Oil Baron]

6 hours ago, Chuck. said:

Except that most of Chinese producers have a third, and largest pile to sell to Merica. And no 1st pile to ship in bubble wrap.

You guys do realize this could change overnight, don't you?

[adnohguy]

You guys do realize this could change overnight, don't you?

 

 

Yah, let's just go with that.

 

And if I ever play the lottery, I could be a millionaire over night.

 

The odds of me dropping my beer while watching the camp fire this weekend in Lake Tahoe are far more likely than the odds of both of the above.

 

[mixxer]

20 hours ago, VortecCPI said:

From a Spanish rider.  Another take on QM:

"To give you a real-life example of quality control we have a Thyssen sintered gearbox components factory here in my region. A lot of car makers use common components in things like gearboxes: Audi, Seat, Skoda, VW, etc but guess what? on final dimensional QC checks the absolutely perfect components are coated with a protective film, lovingly wrapped in special bubble bags and carefully placed in specially built boxes to be sold to AUDI. The ones that are not quite up to spec and are at the maximum tolerances are chucked in a pile and go to the likes of SEAT and SKODA...and the ones that are crap are usually bought by FIAT...but in theory all the components are made by the same people so they must be the same, right?...wrong!.
This could be the difference between engines produced by QINGQI for SUZUKI and the ones used in their own bikes."

This is only referring to dimensional tolerances....

Nothing mentioned of the quality of the material it's being made of, or anything about heat treating, deburring, stress relieving,  or any number of surface treatments or finish processes ....

Impurities (assuming correct material in the first place) , stress risers, improper or lacking post dimensional processes...

Many ways to look like a daisy, and yet not be a daisy....

Hard to believe that the whole concept of copy vs engineer is so difficult for some to grasp....  Truly amazing actually...

[VortecCPI]

36 minutes ago, mixxer said:

This is only referring to dimensional tolerances....

Nothing mentioned of the quality of the material it's being made of, or anything about heat treating, deburring, stress relieving,  or any number of surface treatments or finish processes ....

Impurities (assuming correct material in the first place) , stress risers, improper or lacking post dimensional processes...

Many ways to look like a daisy, and yet not be a daisy....

Hard to believe that the whole concept of copy vs engineer is so difficult for some to grasp....  Truly amazing actually...

We have had to copy software applications and that is incredibly difficult, though we have requirements and specifications, and even a full working example as a reference.  However, we don't have to worry about material chemical and physical properties, weld preps, weld fillers, weld procedures, NDT, PWHT and other post-build requirements such as those mentioned above.

We used to buy ASME heat exchangers from different sources to meet quantity.  Though they may all meet ASME, all have "U" stamps, all are registered with National Board, and all perform thermally equivalent, the methods used by the fabricators/manufacturers will be vastly different.  About the only thing the same is the ASTM specs on the base materials they started with.  Even when we have very specific guides such as ASME, TEMA, etc, we are still left with "Good Practices" which are left almost entirely in the hands of the fabricators/manufacturers.

I have been involved in CFD and FEA since 1997 and, to Mr. Mixxer's point above, two things that look very much the same can be very different.  A chamfer, radius, or weld configuration can make or break (literally) your design by way of one-time first-use failure or by way of cyclic/fatigue failure.  More and more customers are demanding cyclic/fatigue analysis and that is an entirely different animal.

Again we can put two engines on a dyno and get the exact same results by way of copying the original.  Now come back to the dyno in two or three decades and let's try it again.  Wait..  What...  The copy has been in a land fill for most of that time...  One thing we know for sure is that there are countless Honda XR engines that have been used and abused and they are still available for use by the owner.

I am all for third-world countries refining their products but not at the expense of American fabricators/manufacturers and all the good blue-collar and white-collar jobs that go along with it.  We haven't even begun to talk about copyright infringement and proprietary information and trade secrets that have been stolen by them...

Edited August 27, 2017 by VortecCPI

[Oil Baron]

There's nothing wrong with being patriotic but the crf230 is Japanese engineering manufactured in Brasil.  

And you can certainly be the men in the cave, but after WW2, Japan made boat loads of junk, started copying, the rest is history . . . .

There's nothing standing in China's way to do the same.

[mixxer]

27 minutes ago, Baja Rambler said:

There's nothing wrong with being patriotic but the crf230 is Japanese engineering manufactured in Brasil.  

And you can certainly be the men in the cave, but after WW2, Japan made boat loads of junk, started copying, the rest is history . . . .

There's nothing standing in China's way to do the same.

You really REALLY still don't have a clue ....

Hard to believe with how many ways it's been put of engineering vs copy...

Japan copied a bit.... Before they became an ENGINEERING AND MANUFACTURING JUGGERNAUT... that schooled the world on innovation and quality...

 

Stuff made for oems like HONDA ... When outsourced it is still specd with full engineering support and disclosure of Honda... Materials and methods and physical dimensions all specified and QA'd to oem ENGINEERED SPECS... All with OEM reputation , warranty, and profits tied to it...

 

Vastly different than look alike knock offs without any of that Engineering ...

I'm blown away that the concept is completely over your head...

You have to be just funning with everyone...

Look me straight in the eyes... Wipe the spittle off your chin... And explain what you don't understand about that...

No one gives a rats ass that it's "possible".... Not a new concept.... Anything is possible...

Probable NOW... Without engineering or oem support.... is the topic

Edited August 27, 2017 by mixxer

[VortecCPI]

45 minutes ago, Baja Rambler said:

There's nothing wrong with being patriotic but the crf230 is Japanese engineering manufactured in Brasil.  

And you can certainly be the men in the cave, but after WW2, Japan made boat loads of junk, started copying, the rest is history . . . .

There's nothing standing in China's way to do the same.

I was making a very generalized statement with respect to the impact upon America and Americans -- It was not in the context of CRF230...

Japan was taught by, and embraced the practices of, W. Edwards Deming...  A brilliant  American mathematician, among many other things...

[adnohguy]

There's nothing wrong with being patriotic but the crf230 is Japanese engineering manufactured in Brasil.  
And you can certainly be the men in the cave, but after WW2, Japan made boat loads of junk, started copying, the rest is history . . . .
There's nothing standing in China's way to do the same.

And your point is?

Your purchasing stock in Zongshen? Or everything China [emoji630] or your thinking about a second home over there or what?