Port and Polish?
 

Hi all,

I was thinking the other day about getting the cylinder head, intake manifold, exhaust manifold (if not going to the aftermarket header route) and throttle body ported and polished?

This will free up some ponies for sure!!!

Has any one done it?

Subscribed for results. If you go ahead with this could you get them flowed befor and after?

The intake manifold is plastic so good luck with that one. :)

There are two heads, I don't doubt it will help but is best done when building the rest of the engine unless you like removing the engine.

I don't think anyone has done it yet.

It hasn't been done and for the work your going to do id just wait and get cams/valve-train goodies at the same time.

Still if you do try and get flow bench data of the before and after.

Several rs25.com members have done it in their cars... but tbh, you'll won't see much as you think you'll get... but I'm looking from EJ engine & not FA engine, so I could be wrong on this one.

If you gonna do it, I would recommend get some cams too. That's where you'll see more result w p&p

The throttle body on the FA20 is already pretty large. I doubt you will see much gains staying N/A.

You will probably need a tune to make the most of any head work also.

How about doing just the ports? cyl head - intake and exhaust, and intake manifold, and exhaust. The intake is plastic? WTF?

No doubt!

I guess if you do JUST that the gains will not be as significant as if you do the whole thing:
1. Exhaust - port and polish ports, header back system
2. intake - port and polish ports and full intake system.

No point in doing just one bit if you dont go all the way. My .2 cents. Just like the exhaust - what is the point in having a high flow axle back if the rest of the exhaust is 1.5 inch (not that it is but you get my point;)). Yes, it will free up some power but not a great deal of it. Same with the intake. Yes, the throttle body might be big enough although Greedy is making one with a bigger diameter...so more air in the intake plenum will need to go somewhere with the same proportional flow. But than again a true free flow system would include cyl head - back in both intake and exhaust!

And if we go into the cyl head..than I agree with @dabocx by waiting for cams/valve goodies to get it done properly.

And it is quite obvious that such mod will need a tune.

I read that the top end would become quite crazy...not as much as the bottom end and who knows maybe that 4000rpm dip would disappear FOREVER!
https://encrypted-tbn0.gstatic.com/i...q6stJbTPrX7eV5

Resurrecting this semi-old thread...

Has anyone given the porting/polishing idea a try? Any results?

I know there have been some gains shown on late model Chevy's with the plastic intakes. Seems like it would be easier to work with the plastic than the metal.

FBM and others are working on beefing up the heads(CNC, Valvetrain, Cams)

The TB is 70mm, more than enough for high horsepower.

JDL is making a billet intake manifold after they popped the top of their motor.

Thats all I know of as of right now.

I used to do custom head work on Ford and Chevy small blocks back in the day. Those old factory heads were built by cavemen when compared to the R&D and engineering that goes into heads these days. I don't think there would be much to gain from this work unless you were building a full-on race long block with cams, stroker rods and pistons, the works.

Also there are some big misconceptions when it comes to port polishing. You really don't want to make the runners "perfect" and smooth. The small casting bumps and imperfections aid in turbulence which helps keep the fuel-air mixture from separating.

If it were me, I would like to set the heads up on a flow bench to see where the restrictions are (if any). Its never a good idea to start grinding unless you are doing it with a specific purpose, otherwise you are just working "blind".

Scott

+1. A flow bench is critical. I think the heads are pretty decent on these cars in terms of flow, the cams will give the most gain in terms of beefing up the heads.

If you don't go ITB's or carbs then you're unlikely to have any gain by porting the heads further.

Every cylinder head I have seen has always had tons of room for improvement. I don't see why the FA20 would be any different.

That's a pretty broad stroke.

Do you now, or have you ever done head work for a living?

Scott

Could try milling the heads also while your at it for higher Compression Ratio if you plan on staying NA

That with some more aggressive cams (and supporting valve-train) would be nasty. It's just a lot more difficult compared to an inline engine because you have 2 heads and need to remove the engine. So it's going to be costly, but I'm waiting to see someone do this!

Yes I have done cylinder head work on everything from domestics to pro street drag bikes. I am also a lead machinist for a dev team that was recently blessed with the task of designing the worlds most efficient natural gas turbine.

Well, I was just a simple, part-time, "tuner" 20 years ago that worked in a small shop working on engines for drag cars. Nothing like your resume obviously.

I guess I will just shrug and walk off.

Scott

Porting and polishing will make obviously make the air flow more efficiently if done correctly. Just not sure you'll move a large enough amount of air to get the type of gains you're looking for. Cost vs. reward just isn't going to work out imho.

What would the horsepower gain vs cost be? Prohibitive!

There's heaps of cars being made recently with plastic manifolds.. i assume this is to prevent heatsoak from a metal manifold.

Cost and weight are usually the drivers with plastic. Cars will become more and more plastic base as fuel economy regulations take place.

Extrude hone.... assuming the runners are smaller than the ports of course.


@Hawk77FT you are talking about a huge investment of cash and down time. The motor has to be pulled out, torn down, put back together, and re installed.. not to mention the cost of the actual PNP work, which will cost a good bit if your going with a reputable head-work shop.

Probably the lest gains per dollar you could do at this point in time. If the motor were going to be out for some other reason and torn down... then sure go ahead.

You would be far better off (power per dollar) to just do a supercharger kit. Probably cost about the same or even less as well.

I'm sure it won't be long before we have aftermarket exchange parts available (pre ported and built heads, cams in various profiles, intake manifolds) as well as modified stock parts. At that point the whole idea becomes more feasible imo since the skilled and dedicated DIY guys could then pull the motor and have it back in and ready to tune in a single weekend.

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

4AGE
http://i79.photobucket.com/albums/j1...psa06e0441.jpg

7MG
http://i79.photobucket.com/albums/j1...ps203e2131.jpg

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.......
http://i79.photobucket.com/albums/j1...toOversize.jpg

I don't understand how a port injector isn't mixing fuel before the head.

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?

Indeed. Still too early to talk about though.

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....

http://www.ma70.ru/wp-content/upload...dsc00798rp.jpg

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.

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.

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

http://i79.photobucket.com/albums/j1...psc896f194.jpg


http://i79.photobucket.com/albums/j1...psfa3e01ce.jpg


http://i79.photobucket.com/albums/j1...psf8134eb2.jpg



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.

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

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!)

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.

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'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.

:D 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. :thumbsup:



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.



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

exhaust
http://i79.photobucket.com/albums/j1...ort32panel.jpg

intake
http://i79.photobucket.com/albums/j1...arison4to3.jpg

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... :D