Port and Polish?

[scmil95eg]

The the part "before" the head is the intake and fuel isn't mixing there. The injector is located at the flange of the intake, spraying directly into the cylinder head. The only time fuel (vapor) sees the intake is during reversion.

Ideally, with port fuel injection, you want to start the injection event long before the intake valves open. Maybe 360 crank degrees or so. Injector sprays fuel. Fuel hits back of hot intake valves. Fuel vaporizes. Then the intake valves open. Fuel vapor & air mix easily and are drawn into the engine with a lot less energy.

Getting back to the cylinder heads though; Kelford has been working with them quite extensively lately and being a fellow Honda-guy, he's told me the stock FR-S ports are really nice and very - Honda-like. No flow numbers yet, but from the info. I've been given, the throttle body, intake, and cyl. heads should move a lot of air quite easily. With a solid bottom end, er I mean center end, I suspect we'll be seeing 300+ whp N/A FA20s in the near future.

[Tansey86]

Originally Posted by scmil95eg

The the part "before" the head is the intake and fuel isn't mixing there. The injector is located at the flange of the intake, spraying directly into the cylinder head. The only time fuel (vapor) sees the intake is during reversion.

Ideally, with port fuel injection, you want to start the injection event long before the intake valves open. Maybe 360 crank degrees or so. Injector sprays fuel. Fuel hits back of hot intake valves. Fuel vaporizes. Then the intake valves open. Fuel vapor & air mix easily and are drawn into the engine with a lot less energy.

Getting back to the cylinder heads though; Kelford has been working with them quite extensively lately and being a fellow Honda-guy, he's told me the stock FR-S ports are really nice and very - Honda-like. No flow numbers yet, but from the info. I've been given, the throttle body, intake, and cyl. heads should move a lot of air quite easily. With a solid bottom end, er I mean center end, I suspect we'll be seeing 300+ whp N/A FA20s in the near future.

is he working on cams?

[scmil95eg]

Originally Posted by Tansey86

is he working on cams?

Indeed. Still too early to talk about though.

[oldeskewltoy]

Originally Posted by scmil95eg

Ideally, with port fuel injection, you want to start the injection event long before the intake valves open. Maybe 360 crank degrees or so. Injector sprays fuel. Fuel hits back of hot intake valves. Fuel vaporizes. Then the intake valves open. Fuel vapor & air mix easily and are drawn into the engine with a lot less energy.

hmmmm, typically... sequential injection times the fueling to occur @ peak cam lift on the intake valves.... not 360 crank degrees before.....




Concerning porting..... if they(Kelford) haven't cut up the head... they haven't done enough research....

[oldeskewltoy]

I see substantial flaws in both of these ports....

http://www.ft86club.com/forums/attac...1&d=1347583162

http://www.ft86club.com/forums/attac...1&d=1347583656


and I see quite a few machining marks.... that could get blended away.... to allow for even high compression

http://www.ft86club.com/forums/attac...1&d=1347583228


so... there is room for improvement... there ALWAYS IS... because these are MASS PRODUCED PARTS.

[scmil95eg]

Originally Posted by oldeskewltoy

hmmmm, typically... sequential injection times the fueling to occur @ peak cam lift on the intake valves.... not 360 crank degrees before.....

I'm talking about the start of injection event. And this must take place before the intake valve opens. If the injection event started at peak intake cam valve lift, you'd only be able to inject fuel for 1/2 of your intake cam duration, and at 7000 rpm, there wouldn't be enough valve open time to inject enough fuel. Anything beyond ~25-30% duty cycle would be used in the next intake event.

I found ~5 hp on a 200hp n/a engine simply by playing with injection offsets. You can easily witness the effect if you have a car sitting at idle at a stable afr. Start moving the injection offset and watch what your afr does. The leanest offset value is the most efficient for that rpm.

[oldeskewltoy]

I've done some digging around... I can almost guarantee that there is at least 10hp untapped in the FA20 head..... (correction... FA20 heads... not head)

I've adjusted lighting and size of most of these so they are a bit clearer











As with a 4AG head the exhaust port could use some re-shaping.... the intake port you can see suffers from a seat/bowl mismatch, along with casting flash along the walls... finally the short radius just before the valve seat is pretty good, but it can get better.

[andrew20195]

Originally Posted by oldeskewltoy

... finally the short radius just before the valve seat is pretty good, but it can get better.

I thought the short radius doesn't really matter, as inertia will force a vast majority of the air along the long radius?

[Dimman]

Originally Posted by oldeskewltoy

I've got a flowbench........

4AGE


7MG


I just need an FA20 head - http://www.ft86club.com/forums/showthread.php?t=47375



Oh... btw.... there is some inaccuracies.... the smoothness of the ports surface for one..... when you have a carburtor, or T/B injection where the air and fuel are mixed before the head... then I more or less agree that a "textured" surface (80 grit) helps keep the air and fuel atomized.... but the FR-S has a mixture of injection system...neither of which has the air and fuel mixing before the head.... so the ports in an FA20 head should be a lot smoother... (200 grit)

Exhaust ports should be as smooth and reflective as possible....

4AGE exhaust port - before and after.......

What were the cfm (@28" water) before and after on the 4AGE (old big port or later small port?).

As for the FA20 I've heard opposite opinions on how this thing flows, but not a single cfm number. Is there a degree of secrecy in the porting industry, or is it just BS? Will you post the FA20 numbers if you can get some heads?


(Someone get this man some heads, stat!)

[Tansey86]

Moving air is what makes power, if you can move more air while maintaining decent velocity in the engine then I cant see why it wouldnt be beneficial. Bigger isnt always better though.

[arghx7]

Originally Posted by scmil95eg

I'm talking about the start of injection event. And this must take place before the intake valve opens. If the injection event started at peak intake cam valve lift, you'd only be able to inject fuel for 1/2 of your intake cam duration, and at 7000 rpm, there wouldn't be enough valve open time to inject enough fuel. Anything beyond ~25-30% duty cycle would be used in the next intake event.

Typical port injection is set by the end-of-injection timing, while typical direct injection is set by the start-of-injection timing. That's on OEM controllers running in relatively steady-state conditions. On standalones it varies a lot.

I found ~5 hp on a 200hp n/a engine simply by playing with injection offsets.

I'm not sure what engine management you were using, but typically open valve injection will cause some cooling of the mixture under full load which can help output. Depending on how the injectors are sized, sometimes you really have no choice between open and closed valve injection at full load and high speed. It has to be open valve because there isn't enough time otherwise.

[/quote]You can easily witness the effect if you have a car sitting at idle at a stable afr. Start moving the injection offset and watch what your afr does. The leanest offset value is the most efficient for that rpm.[/QUOTE]

I know what you're saying, but really you can't do more than a very rough tune of injection timing (especially at low loads) without being able to read CO and O2 concentration, preferably on an engine dyno. The best mixture preparation tends to have very low numbers of both. A wideband can't tell the whole story.

[oldeskewltoy]

Originally Posted by andrew20195

I thought the short radius doesn't really matter, as inertia will force a vast majority of the air along the long radius?

In essence you are correct... but if we can also gently shape the short radius to aid in filling.... the more air flow, the better.... and that includes the short radius... by improving ALL areas we improve the ports function, and find more horsepower where there was less.



Oh... and I'm not talking about "hogging" anything out either... My goal in porting is to improve the casting... because the basic casting is a mass produced part.... and as such has flaws

small thread divert.... A TV show... on Ferrari's factory explained that Ferrari has highly skilled technicians porting the CASTING SAND before the metal is poured... because it was less costly to then perfect the shape in sand, then it was to pay someone to port the finished castings...

Back to Toyota/Subaru and the FA20... as advanced as this engine is... it still is a mass produced casting without any one porting/perfecting it... either before, or after casting.

Oh... and I'm not talking about "hogging" anything out either...

A lot can be done inside the port.... without hogging anything

exhaust


intake


As you can see in the above shots.... the bowl to port transitions have been blended to allow for added airflow in the same overall space.

See..... No hogging...

[oldeskewltoy]

Originally Posted by Dimman

What were the cfm (@28" water) before and after on the 4AGE (old big port or later small port?).

As for the FA20 I've heard opposite opinions on how this thing flows, but not a single cfm number. Is there a degree of secrecy in the porting industry, or is it just BS? Will you post the FA20 numbers if you can get some heads?


(Someone get this man some heads, stat!)

I've not yet mounted one of my smallports to the flowbench.... but I have done some extensive testing with a largeport..... btw I test @ 25".... don't ask.


EXHAUST -



Btw... for those who think gasket matching is port matching... you're WRONG...

this is port matching... below are the flow charts of all 4 exhaust ports... less then a 2% difference





Here are the 4 intakes... also within 2%




Good luck with that doing gasket matches....



You asked me about posting my numbers.... I've got nothing to hide

[oldeskewltoy]

Oh... let see how many smart people are looking at this thread.... Can anyone tell me why the "dirty" port in my first graph flowed better then the cleaned port up to .25" lift?


Hint: the valves used were the same - clean and smooth in both test