4AG discussion

**oldeskewltoy** · 10-07-2015, 03:07 AM

trying to keep inflammatory remarks to a minimum........ and not clog up others threads.......

Originally Posted by 101gze

You asked for evidence as to how the 20v can deal with duration over 16. I gave it to you as simple as it gets and you reply with:
1) 3 valves equal MORE, not less even though the individual valves are smaller, the total is greater.

That is EXACTLY THE ARTICLES POINT A larger valve area with LESS VALVE HEAD SIZE = better use of duration. The article explains that clearly.

2) the larger the lift, the more disturbance the 3rd intake valve suffers from do to too much influence of the other 2 valves that as lifts increase the total air charge actually begins to fail...

Really? See, now here your regurgitating unfounded crap from...gee..the year 2000?? yeah? I think thats when I first read that little ditty.
Firstly, did you actually write this yourself? or cutnpaste? because I dont know what the 3rd intake valve is...and I'm pretty sure the 3rd intake valve would not appreciate the discrimination.

Your one of the muppets that thinks that the induction of a charge is some perfectly organised, presented friendly little get together of an oxygen molecule and a precious mole of fuel...yeah? and to make the matrimony perfect, we have 1 valve on the left and one on the right.
And they work with each other to make a lovely swirl and invite everyone into the cylinder to be as one... oh how lovely

The induction and combustion of an intake charge is an ugly cacophony. If you watch that video, there is no evidence of the precious chorus you like to delude to.
Its an nasty place to be, the forces are such that they can melt the toughest hardest nastiest most clever metals in an instant.
Clearly by viewing this brilliant video, we can see that all you want in an engine is a set of valves that open and allow an avalanche of air to be inducted. I give you the 20V! The whole inlet side of the chamber can open up and flow an avalanche.

"I've got flowbench #s on a silvertop intake and although the low lifts are significantly better then a 16V, as lifts increase the flow begins to fall back toward 16V levels".

Show them. Was the head ported? was it flowed on the same machine as the 16V on the same day? If not, the #'s are pointless, but hell..humor me, show it anyway.

"If the 20V(5 valves per chamber) was better... why is it no longer available from any manufacturer that ever made one???"

Once again, as you always do, you make this a 20v vs 16v debate. Its a really simple answer as to why the OEM's dropped the 5 valve.
Emissions. Thats it. Government mandate. But whyyyy??? well, the head of Yamahas development team on the R1 said in Fast Bike magazine that the shape of the 5 valve chamber is a dirty burner.

that is, the requirement of the "centre" intake valve (3rd valve in your speak?) extended the flame propogation to the point that it created too much NOx to meet Euro 5 emissions laws, he further stated that whilst Yamaha had a great deal of development gains to come with the 5 valve, Europe was their largest market and it was dictated to them, by the boffins, to clean up there act and the 16v R1 was born.
That along with the extra cost and the fact that the oem performance world was beginning to be frowned upon, brought about the concepts demise.

Originally Posted by from Hot Rod article you posted

The type of heads typically used on domestic V-8s are much more responsive to lift than, say, a four-valve engine (5 valve too?).

There are two reasons for this. The first is that all two-valve V-8s are under-valved for the cubes those valves have to feed. Secondly, heads with a predominantly parallel valve design go through three phases of flow efficiency. The first, right off the seat, is a high-efficiency regime. As the valve lifts through the 0.100 inch (100 thousandths) to about 0.500 inch (500 thousandths), efficiency drops off considerably. Once the valve lift goes over a point equal to a lift of about a quarter of the valve's diameter, the flow efficiency starts to pick back up. The reason for this is that intake valve's shrouding starts to diminish because the valve is sufficiently far enough out of the seat's sphere of influence. For this reason, most of the V-8s we work with will benefit from valve-lift values equal to about 0.3 to 0.35 times the diameter of the intake valve.

much in there just doesn't fit either 4AG head... and if you do follow their recommendations the lift should be between .3 and .35 times the valves diameter... so a silvertop intake is 26.5mm, based on the article you quoted, the most lift should be 9.2mm. Not knowing blacktop valves, I can't say exactly how much lift, based on the article you posted, they would peak at, but I doubt anything over 9.5mm

please explain how I've said the intake process is anything but, " an ugly cacophony"?? My work tends to reduce the cacophony, as the flowbench reveals.

Flowed on the exact same bench @ 25", the heads were not flowed on the same day... but the flowbench room has set temp and humidity

unported silvertop intake #s
.050 - 44.6
.100 - 92.4
.150 - 130.5
.200 - 154.2
.250 - 175.3
.300 - 188.1
.350 - 195.2
.400 - 197.6

You'll note that in the low lift there is significant difference over a 16V, but as lifts get higher the gap shrinks back.

comparing stock 20V to "minor throat work" (my porting on a 16V) the .050, .100, and .150 lifts are all significantly higher, but the gap begins to narrow as lifts increase

Finally... not just Yamaha/Toyota... but all companies have dropped it, along with all the exotic makers (Ferrari), and all forms of racing........ as Formula One has no "silly emissions" laws you'd think it would be there if superior

By the way... as I've tried to do... please post a link, or some kind of actual evidence as a reference, and not "regurgitating" info.........

**trdee** · 10-07-2015, 09:24 AM

fyi 5v heads are explicitly banned in f1.

**jonathan yee** · 10-07-2015, 11:53 AM

yamaha still use a 5v head on their 450r quad.
http://www.yamaha-motor.com.au/produ...0r-hypersports

**101gze** · 10-07-2015, 09:53 PM

It appears you are trying to engage myself in a forum argument.

It appears that you relish the opportunity to "blow smoke up your own arse" as we say in Australia.

You critisised a forum member for making a statement you claimed was infactual. You have been given more than reasonable evidence as to why your rebuttal was not correct.

You have more than once contradicted your own information as to regards to valve diameter, lift, and duration.

You claimed that the 4AGE was capable of reving to 13000 Rpm ..no wait..14000RPM?? which was it?? bahh its only a 1000 rpm. This alone puts you in my phuqtard book.

You have previously claimed that dyno readings are a waste of time, because there are FAR too many VARIABLES and dyno figures can be fudged. Yet you claim that your dyno reading on your 16v PROVES BEYOND ANY DOUBT WHATSOEVER that a 16V can make more power than a Blacktop 20v.

unported silvertop intake #s
.050 - 44.6
.100 - 92.4
.150 - 130.5
.200 - 154.2
.250 - 175.3
.300 - 188.1
.350 - 195.2
.400 - 197.6

Your comparing ported 16V numbers to "unported" 20v numbers?

"much in there just doesn't fit either 4AG head... and if you do follow their recommendations the lift should be between .3 and .35 times the valves diameter... so a silvertop intake is 26.5mm, based on the article you quoted, the most lift should be 9.2mm. Not knowing blacktop valves, I can't say exactly how much lift, based on the article you posted, they would peak at, but I doubt anything over 9.5mm"

Exactly. 9.2mm I'll give you credit on your maths. Do you get it yet?

Can you explain why you, or your head flow grand master flowed the head at 25" if you really did? why didnt you as a typical BIG NUMBER YANK flow it at 28" 's ?? THE NUMBERS WOULD BE FAR MORE IMPRESSIVE!!!
And, how could you not know that the ST and BT valves are all the same diameter with your oracular knowledge of all things GE?

Typically, and consistently, you have by way of this thread, along with all others you have posted over the last decade +,leave more questions than answers,

It seems to all and sundry that you are persistently blinded by your own bias and therefore, shall never accept the light offered.

This point proves it:
"please explain how I've said the intake process is anything but, " an ugly cacophony"?? My work tends to reduce the cacophony, as the flowbench reveals"

Err... once again, you dont get it. The ugly cacophony I spoke of is, the combustion of the intake charge shown in that video. If your "work" increases flow...which is what I thought you were aiming at, (or should be) your "hopefully" proliferating the ugliness of the cacophony. More air, more fuel, more violence in the chamber, albeit controlled.

The more ugly I can cram into my chambers, the happier Iam.