Poly Quad Head - Anyone heard of it or tried it?
#1
Senior Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Azusa, CA
Posts: 1,407
Total Cats: 116
Poly Quad Head - Anyone heard of it or tried it?
I'm taking a head porting class at a local CC and my instructor brought up this article he read about Polyquad heads. Here is an article on it.
Polyquad Article - MotorTech Magazine
Long story short it is a method to help 4 valve engine's increase their low end torque output without sacrificing anything or gaining some on the top end. It uses 4 different size valves (in the article +1mm and -1mm on both the intake and exhaust) to introduce more swirl into the chamber. They claim about 7% gain on the low end.
I have +1mm intake valves and +2mm innconel exhaust valves for a 99 head I'm building. I was thinking about giving this a shot.
The plan would be to pick up a spare head and run 3 tests.
1. stock valves
2. both +1mm intake, both +2mm exhaust
3. Polyquad - 1 over sized and 1 stock valve for both intake and exhaust.
I'd be able to compare the valve lift vs flow charts, port velocity, and swirl between the 3 variations to make a decision before actually cutting the valve seats of my 99 head.
What are your guys thoughts on this from those with engine building expertise?
Polyquad Article - MotorTech Magazine
Long story short it is a method to help 4 valve engine's increase their low end torque output without sacrificing anything or gaining some on the top end. It uses 4 different size valves (in the article +1mm and -1mm on both the intake and exhaust) to introduce more swirl into the chamber. They claim about 7% gain on the low end.
I have +1mm intake valves and +2mm innconel exhaust valves for a 99 head I'm building. I was thinking about giving this a shot.
The plan would be to pick up a spare head and run 3 tests.
1. stock valves
2. both +1mm intake, both +2mm exhaust
3. Polyquad - 1 over sized and 1 stock valve for both intake and exhaust.
I'd be able to compare the valve lift vs flow charts, port velocity, and swirl between the 3 variations to make a decision before actually cutting the valve seats of my 99 head.
What are your guys thoughts on this from those with engine building expertise?
#6
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 407
Im familiar with a few Honda heads that have a different cam profile between the intake valves. Im not talking about VTEC, although these are VTEC heads, the "low cam" has a lobe for each intake valve and there is a difference in lift there to create swirl.
The "low cam" is for economy though, and as far as I know the "high cam" of all the VTEC engines, and the cam profiles of non-VTEC engines all use the same profile between valves.
It seems like most of the effort put into create swirl and tumble are for economy, not power.
The "low cam" is for economy though, and as far as I know the "high cam" of all the VTEC engines, and the cam profiles of non-VTEC engines all use the same profile between valves.
It seems like most of the effort put into create swirl and tumble are for economy, not power.
#8
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 407
I know one of the Ks did it, not sure of the engine code. Pretty sure its the one in the EP3 that doesnt make very good power.
All of the "VTEC-e" D series do it. Most people say that it switches between 3 valve and 4 valve, but the 1 intake valve isnt completely disabled, it just doesnt open very far. And then the D15B basically has swirl mode, then 1st stage VTEC where both intake valves open the same, and then finally real VTEC where they go "high cam".
The cam is pretty hilarious looking with all those lobes.
All of the "VTEC-e" D series do it. Most people say that it switches between 3 valve and 4 valve, but the 1 intake valve isnt completely disabled, it just doesnt open very far. And then the D15B basically has swirl mode, then 1st stage VTEC where both intake valves open the same, and then finally real VTEC where they go "high cam".
The cam is pretty hilarious looking with all those lobes.
#10
Senior Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Azusa, CA
Posts: 1,407
Total Cats: 116
I did not see this discussed anywhere on this forum. I'm in the rare position to test this theory on the flow bench and post the results for the greater good of the miata community. I'm just wondering if more knowledgeable people in miata engine building can chime in and say for sure it's not worth my time and efforts to do so with good reasoning.
I'm thinking that the same... Maybe some gains in the low end and some economy but this will be used mostly for track driving so I mostly care about the upper rev range.
But let's say I do give this test a shot in the name of science... Would a decent increase in swirl throughout the entire range of lift be worth some power gains?
Im familiar with a few Honda heads that have a different cam profile between the intake valves. Im not talking about VTEC, although these are VTEC heads, the "low cam" has a lobe for each intake valve and there is a difference in lift there to create swirl.
The "low cam" is for economy though, and as far as I know the "high cam" of all the VTEC engines, and the cam profiles of non-VTEC engines all use the same profile between valves.
It seems like most of the effort put into create swirl and tumble are for economy, not power.
The "low cam" is for economy though, and as far as I know the "high cam" of all the VTEC engines, and the cam profiles of non-VTEC engines all use the same profile between valves.
It seems like most of the effort put into create swirl and tumble are for economy, not power.
But let's say I do give this test a shot in the name of science... Would a decent increase in swirl throughout the entire range of lift be worth some power gains?
#13
Elite Member
iTrader: (1)
Join Date: May 2009
Location: Jacksonville, FL
Posts: 5,155
Total Cats: 407
We can. Not all Honda engines are like the K20A, F2xC, B1xC
The humble B18B from the LS integra is surprising similar to the BP. Port size is nearly identical, same sized valves, same rod ratio. The BP has an advantage in that its larger bore and shorter stroke that the B18B.
Here is a B18B with intake, header, and tune:
The humble B18B from the LS integra is surprising similar to the BP. Port size is nearly identical, same sized valves, same rod ratio. The BP has an advantage in that its larger bore and shorter stroke that the B18B.
Here is a B18B with intake, header, and tune:
#14
Senior Member
Thread Starter
iTrader: (8)
Join Date: Jan 2012
Location: Azusa, CA
Posts: 1,407
Total Cats: 116
I found this post on a different forum from a guy who does cylinder head development work. It sounds like different valve size alone will not make any difference from the tests he has run.
Vizard's polyquad.. valve size theorization.... ? Speed Talk
Vizard's polyquad.. valve size theorization.... ? Speed Talk
Honda, Nissan, Mazda and others have done 4-valve heads with ports that are angled relative to the cylinder bore centers to create swirl, and or superior low rpm mixture motion for more efficient burns.
Staggering valve size isn't very effective since the cylinder pressure is the same working on each valve and the mixture will always take the path of least resistance.
Honda makes 4-valve heads with only one active intake valve for low-range operation. The divider wall in the intake has an angled window in it so mixture from the entire port can access the single valve that's opening. The short-turns in these ports are also angled to "encourage" swirl. In situations where more power (air) is necessary, the 2nd intake valve becomes active and the flow is straight to each valve (albeit with some losses due to the window and associated increases in wall surface area).
Back as far as 1978, I worked with different size intake valves on the Cosworth DFV and X heads and we never realized any gains in torque or power (in both NA and turbocharged applications). We've played with staggered valve sizes on the Honda's since 1991, and once again, when you compare apples to apples, there was never anything positive that came of it.
For the last five years we've been analysing exhaust gasses on engines we've developed for improved fuel effiency and EPA compliance, and we've never realized anything positive with any combination except staggered valve opening on the intake-side.
On the exhaust-side, it's always best to open both valves at once.
Staggering valve size isn't very effective since the cylinder pressure is the same working on each valve and the mixture will always take the path of least resistance.
Honda makes 4-valve heads with only one active intake valve for low-range operation. The divider wall in the intake has an angled window in it so mixture from the entire port can access the single valve that's opening. The short-turns in these ports are also angled to "encourage" swirl. In situations where more power (air) is necessary, the 2nd intake valve becomes active and the flow is straight to each valve (albeit with some losses due to the window and associated increases in wall surface area).
Back as far as 1978, I worked with different size intake valves on the Cosworth DFV and X heads and we never realized any gains in torque or power (in both NA and turbocharged applications). We've played with staggered valve sizes on the Honda's since 1991, and once again, when you compare apples to apples, there was never anything positive that came of it.
For the last five years we've been analysing exhaust gasses on engines we've developed for improved fuel effiency and EPA compliance, and we've never realized anything positive with any combination except staggered valve opening on the intake-side.
On the exhaust-side, it's always best to open both valves at once.
#15
Hi folks ! I joined for the sole purpose of bumping this thread. David Vizard is one of my favorite small block Chevy modifiers. His tips and techniques allowed me to build the Vortec 350 in my Tahoe , which makes stupid power over the stock engine , with the smallest Comp Cams roller in their catalog. Mileage and drivability were both improved as well. But this Polyquad thing...while I like the theory, the initial test he did used a pair of 4 valve heads created for the small block Chevy. The manufacturer designed them to SPECIFICALLY MAKE MORE POWER than available 2 valve heads. At no point do we see dyno figures for the heads in unmodified form. In other words, we have no way of knowing if these mods increased or decreased their output. All we know is they performed better than 2 valve heads, which they were supposed to do anyway. I'm not accusing David of lying or misrepresenting his data, I am merely stating the fact that we cannot draw any conclusions from this original test. Then there is the whole " patent and royalty" thing. Mr. Vizard points out that it took 4 years and " great expense " to have the patent granted. No duh ! You can't patent a law of physics, this must have required multiiple attempts to find someone who misiunderstands the difference between a unique idea and the discovery of a physical property. If making these modifications creates more power, it is specifically because the laws of physics cause this to happen. Allowing a person to patent " modifications " to someone else's head design is a slippery slope. Do we patent the concept of raising compression, installing larger camshafts or power adders like turbos because someone discovered they made more power? NO! Because they are based on the laws of physics. Don't get me wrong, I admire and respect Mr. Vizard's R&D and excellent understanding of all things engine related. If he had designed and produced an actual, unique cylinder head, I would be all about protecting his right to patent it. However, the person who approved this patent was either smoking crack or doesn't understand the difference between intellectual property an immutable laws of airflow. The ability to transmit sound by converting it into electrical signals was not patented, the telephone was. Electricity was not patented, the lightbulb was.. Whether this idea makes more power or not may never be fully explored because a silly beurocratic mistake requires the payment of money to explore it. Mr.vizard, if you have not already done so, please surrender your patent , I believe you to be a man of integrity and I doubt you truly benefit from charging royalties. Your most beneficial contributions to motorsports have always been your books and articles revealing the results of your testing. We have all purchased a magazine or book from which you have profited. If the Polyquad modifications become common place because they make more power, we will all remember your contribution, something I believe will result in far greater financial gain for you long term. Ben Franklin didn't invent electricity, he mere showed proof of concept, as you have. Designing a device that generates or stores electricity, now that is a patentable idea. This is embarrassing for a man of your brilliance. Thank you.
P.S. The same goes for Singh grooves, this is the discovery of a property of airflow, not an invetntion. Design a head from scratch with Singh grooves and patent that. What have we become ? I believe something exists and improved it so it must be my invention ? Bull !
P.S. The same goes for Singh grooves, this is the discovery of a property of airflow, not an invetntion. Design a head from scratch with Singh grooves and patent that. What have we become ? I believe something exists and improved it so it must be my invention ? Bull !
Last edited by Pontiacivan; 06-25-2015 at 08:46 AM. Reason: Corrected references to existing patents.
#17
Yes...yes it is.
Well, it's a post about a topic that someone ( other than myself ) is interested in, so I guess I do care. Not my number one priority. David Vizard obviously cares. I'm sorry if it bothers you, I just can't stand the " I had an idea so pay me"' philosophy the world has come to. And yes, this is real life, it contains some of the most bizzare concerns you will ever see. Most people could care less about 99.99999% percent of the things other people find important,but let someone tread on a concept you hold dear and observe how you feel.
Said with the most matter of fact intent. Not looking to provoke. Thanks.
Said with the most matter of fact intent. Not looking to provoke. Thanks.
#20
Sigh.
P.S. I happen to think Miatas are pretty cool, why do you think I was lurking here? Not owning one personally doesn't invalidate my interest. Gotta go, my sex doll is calling.
Last edited by Pontiacivan; 06-25-2015 at 09:49 AM. Reason: Grammar, clarity