Improving 4AGE Largeport head flow?

[oldeskewltoy]

Keep us updated

The port above was my very first attempt @ reconfiguring the splitter.

Below is my 2nd attempt. This one was just nasty.... note the pre splitter reconfiguration, the un-even shape of the splitter.





What is "special" about this port is this very port I had put on the flowbench last year to check how much my bowl work improved flow over a pre bowl work. Here are those numbers




Now I just have to get the head back to the flowbench for testing

[MWP]

You guys need to look up TK's (Tony Knight) posts on PerformanceForums.
He does some incredible port work (with the engineering/performance knowledge to back it up) and posts lots of photos of his work.

Bigport 4A-GTE: http://www.performanceforums.com/for...php?t=67258848
Gen3 3S-GTE head: http://www.performanceforums.com/for...php?t=67247264

He's working on two smallport 4A-GE's as we speak, one of which is Takai's.

[dangdang]

Thanks for the tip MWP

[abently]

The port above was my very first attempt @ reconfiguring the splitter.

Below is my 2nd attempt. This one was just nasty.... note the pre splitter reconfiguration, the un-even shape of the splitter.





What is "special" about this port is this very port I had put on the flowbench last year to check how much my bowl work improved flow over a pre bowl work. Here are those numbers




Now I just have to get the head back to the flowbench for testing

Here's a free tip, keep airflow below 200" at or lower than stock no's, and only increase it above that point. You will make more power. (It's not easy though)



Remember anyone can make a port flow more CFM just by enlarging the choke diameter, which is ok if you've increased the capacity, otherwise your decreasing port velocity which only works if the port was too small or had a too sharp of a radius causing fuel/air separation.

[oldeskewltoy]

You guys need to look up TK's (Tony Knight) posts on PerformanceForums.
He does some incredible port work (with the engineering/performance knowledge to back it up) and posts lots of photos of his work.

I'm not impressed - looking @ the roof of his exhaust port it does not look condusive to optimal flow. The bowls look fair enough, but the roof of the port appears to be less blended - pinching the flow down.




port on Left Loyning's, port on right TK's



Here is a very interesting thread measuring(flowbench) blacktop, largeport, and smallport heads..... http://forums.club4ag.com/zerothread?id=80960

[takai]

Actually that has more to do with the fact that the photo of the Loynings roof is so crap that you can see buggerall apart from JPEG compression, failure of the camera to focus and flash flare.

Flow figures speak volumes.

4AGE Big Port
Inlet

Lift 0.100 0.200 0.300 0.400 0.450 0.500 0.550
Inlet CFM Stock 74.0 147.0 183.0 190.0 190.0 190.0 190.0
Inlet CFM Ported 80.8 158.0 210.6 224.2 227.0 230.2 231.5
Improvement % 9 7 15 18 19 21 22

Exhaust

Lift 0.100 0.200 0.300 0.400 0.450 0.500 0.550
Exh. CFM Stock 59.0 107.0 115.0 117.0 118.0 118.0 118.0
Exh. CFM Ported 82.4 145.2 153.6 154.8 155.0 155.2 155.2
Improvement % 40 36 34 32 31 32 32

Inlet/Exhaust ratio

Lift 0.100 0.200 0.300 0.400 0.450 0.500 0.550
Ratio Stock 79.7 72.8 62.8 61.6 62.1 62.1 62.1
Ratio Ported 102.0 91.9 72.9 69.0 68.3 67.4 67.0

Average Inlet/Exhaust ratio Stock = 0.65 %

Average Inlet/Exhaust ratio Ported = 0.74 %

[oldcorollas]

how will all this improved "flow" affect engine output in midrange (or are we just thinking about max RPM screamers?)
isn't the bigport too "big" to begin with? (in terms of port velocity?)

Takai, has anyone else flowed TK's head on a different flowbench to the guy he uses?

[trdee]

isn't the bigport too "big" to begin with? (in terms of port velocity?)

according to another discussion we've had before, someone (duk maybe?) was saying the stock bigport ports were so big that you need to upgrade to oversize valves before you can even make full use of the volume that a stock bigport can flow.

[takai]

Yeah, that head which TK built is for a 4AGTE, so it can use the air that it gets.

As for flowbenching, i dont think anyone has done that 4AGE head, but people have done back to backs on some of TKs other heads. From memory they had to outsource Supercrowns 1FZ head flowbenching because it was flowing more than the bench supported, and i think they used a known head as a back to back comparison for reference purposes.

[abently]

how will all this improved "flow" affect engine output in midrange (or are we just thinking about max RPM screamers?)
isn't the bigport too "big" to begin with? (in terms of port velocity?)

Correct, but what do we know..

Maybe ask them also what the cam and pistons are doing at 0.100 and 0.200 and what improved head flow does in that situation.

[oldeskewltoy]

at 0.100 and 0.200 and what improved head flow does in that situation.

my head shows some boost in low lift situations.... as well as improving them @ higher lifts. I'm hoping the new numbers get even better @ low lifts




Here is some recent exhaust port work performed by me on a smallport head...
#1 on the left, #4 on the right

[oldeskewltoy]

The intake was the only change, so only new intake #s are supplied, the new flow #s are........ these are measured @ 25"

.050 - 39.1cc
.100 - 75.3
.150 - 114.9
.200 - 152.7
.250 - 171.2
.300 - 181.3
.350 - 186.0
.400 - 189.6
.450 - 191.4

I'm not impressed with the absense of change... what is there is incremental @ best

[abently]

I'm hoping the new numbers get even better @ low lifts

To increase reversion and amplify the negative effects of too much overlap?

[PrettyCoolWagon]

No fun in that! and some of us have heads to spare to play as is our pleasure

Rare as hens teeth pros cost rare as hens teeth dollars, I know my pockets are not that deep. Luckily I know one and he is happy to port just one inlet, chamber and exhaust for me so as I can copy and learn on the others...ace!

I don't have access to software but neither do some of the top engine builders I know of, a flow bench at least perhaps for some tangible evidence of an improvement.

I reckon good on you Oldskewltoy, if some of us don't experiment, try and learn this sort of thing it becomes a lost practice relegated to the memories of old men..fuck that!

I rekon you're both right - too many people seem to focus on air flow over & above velocity.

The truth is - you can't consider one without the other... & realistically you have to consider volume as well. (charged vs.n/a)

The problem with flow benches is exactly that... they're a constant flow..
Engines don't work like that. It doesn't take a rocket scientist to put his hand a few feet back from the exhaust at idle & feel the rythmic pumping nature of the exhaust gases coming out of the tail pipe.
So flow benches are only half the story - they don't really tell you what's happening in terms of velocity...

Which one has more to do with power through an accelerated curve???
Would a pee shooter or dart pipe be more effective in a larger diameter pipe???



But, anyway.. as for leaving it for only the pro's..., well c'mon..

If we all left it for the pros - there be no point in these forums.

I like his skills & what he's learning but aside from some de-burring I wouldn't port a bigport head - "IT'S ALREADY BIG!!"

Unless you're strapping on an enormous turbo for top end speeds - I believe you're actually likely to loose power.

Other wise ... Why would've toyota engineers created TVIS on the first gen 4age?
..It could've been an after thought once they realised they lost torque.

Then improved it by designing the smallport.

If I was toymodding a big port I'd head in this direction.

http://www.thumpertalk.com/forum/arc.../t-792548.html

http://www.mototuneusa.com/homework.htm

He does go on a bit but the theory's solid