I am very curious if it is at all possible to port the L15a. I have seen pictures of top fuel and noblesse fits and they are the only ones that i know of to actually open the head up and work with the cams. is it possible to take the head and give it a mild port job and then polish it up?

 

It's possible on every otto cycle engine out there as long as you make sure the guy who does it knows his job!!

Marko!!

 

Anyone have this done?

 

going by all info available, you really can;t open up the head any. just clean it up to reduce drag.

 

right!! but i bet you can gain some flow by polishing the ports and lower manifold just as you said!!! I would do them with some 200 grit papier on the intake side (to help keeping the fuel mist in suspention!) and the exhaust ports glass smooth to help flow!! I would also make the intake runners shorter to improve top end a bit!!

Marko!!

 

hmm.. tagged for interest.

 

i was studying the l15a and was wondering if it would be worth it to port and polish the aluminum part of the intake manifold? that would be cheaper than getting the weapon r mani.

 

the manifold is fairly thick and there's a good bit of meat you can shave from it. but you'll still be limited by the heads. Cleaning them up and porting a little is about all that is safe though. Due to the angles of the valves and how compact they made the heads there really isn't much room to work with.

 

supposedly the ports are thin and go into the water jackets easily. I think your best bet would be forced induction. force it to breath!!! a little bowl work and cleanup of the ports and a nice valve job would be the furthest I'd go on a stock head, unless you had a junk one to cut up to see how much material you can actually remove. isn't the lower intake some sort of ceramic? not sure how that would work with porting if it is.

 

If it is possible. It would really only be worth it under a FI condition. NA would probably only give 2-5whp (with other multiple bolt on's), if that even.

 

that 2-5 whp would at least be an imoprovement. the idea behind polishing is to help ai flow as smoothly into the head and smoothly out. the header im using is flawlessly polished to reduce any drag. now i just want to work on the intake side. wish we could swap the head of the l15a for one that has some more potential like the f22.

 

Yea but $$ to hp gain is not worth it.

 

that could be true but the f22 motors are fairly cheap. it seems like a better alternative than fi or k20 swap for the moment. i want to go as high hp with na as possible.

 

I think he means the amount of money used on porting the stock Fit heads isn't worth only gaining 2-5whp.

 

that many tuners advise against any porting. like mentioned above the walls are to thin. and if you open up your manifolds don't forget to port match them! the airflow is impeded otherwise. its got to be smooth sailing from one side of the cylinder chamber to the next. i'd shine up the whole intake side like a mirror. and get a decent header.
sayonara

 

yup, what this dude said.

 

that makes sense. but i have the tooling to do it in house. so anyone do anything with their head?

 

GIve it a shot, I'll keep watching for what you end up with.

 

If you have never done this before. I HIGHLY advise against doing it yourself. Just take it to a shop and have it done correctly

 

The only thing i would do by myself is to polish the ports with some sandpaper to prevent from messing up the head... Getting the intake side of the head glass smooth is a bad idea since the fuel would not stay airborne!! (Allready tried on a DOHC neon and ended up gaining 6Whp and way better driveability when we putted it back slightly rough with sandpaper...) I dunno what it could do for the Fit but i have polished the inside of that very same DOHC Neon manifold with really great results... Anytime the inside of a manifold is rough, there is something that could be gained or that is left on the table!!

Marko!!