anyone port and polish their STOCK ITR head? I know its already "hand ported and polished" or whatever from the factory, but I was wondering if anyone has tried to improve it with more porting and polishing? Did you notice any significant gains? Im particularly interested if there was much gain on a relatively stock B18C5.

 

me to , i wanna do mine , . im assuming a pretty nice gain .

 

Yes, you will see a good gain from a good port job.

 

Topspeed PnP
Look at the huge gain in midrange

Red line is B18C5 w/ AEM intake, AEM cam gears, DC JDM 4-1, Mugen Twin Loop and Apexi V-AFC. Cam gears were +3, -1.. VTEC@5100
Blue line is same motor. Topspeed ported head, Topspeed ported ITR intake manifold, head was only milled 5 thou to clean up. Compression is about 10.8:1 if I did my math right. New settings were +4, +2 on the cams, VTEC@4600, richened up on top after 6000rpm...

 

Do you think Honda would have only done a halfassed job of hand polishing/porting the head? Im sure they did it *perfectly* for the STOCK motor. Unless you have spent $$$ on internal mods and addressing the other areas of i/h/e, porting/polishing the head will be a waste of time and money, imo...

Edit: but what do I know?...


[Modified by Super7, 10:29 AM 6/18/2002]

 

haha what a joke

 

Do you think Honda has enough technicians to allow each and every port job that leaves their factory to be absolutely perfect and not able to be improved upon? I highly doubt it.

The quantity of ITR/CTR heads that are produced each year would not allow the time necessary to get each and every head perfect.

In no way does Honda do a 'halfassed' job on their heads. Actually, they do quite a good job considering the volume that they produce. But, there is always room for improvement when it comes to mass production.

I don't feel a port and polish on an ITR head would be a waste of time and money when done by a person who knows what they are doing.

-kenji

 

the key to making hondas go fast and making more power is to let them flow.

 

Yea, you're right. They did a terrible job.

Which isn't actually very many. And only the best techs are allowed to do it.

Which is why is said without i/h/e, it would be a waste...

 

thanks ladies

 

Not much.

 

on the topic of porting.. found an interesting link:
http://www.mototuneusa.com/think_fast.htm

 

That site is a load of bull...

When shops like JUN Japan port a head, they are not porting it just by flow bench numbers, they have ported hundreds if not thousands of heads, and have empirical data (how much of an increase in HP they see when the head is back on the motor), to back up their head porting technique. These guys have spent thousands of hours and test many of the possible permutations of port size.

When a Honda engineer designs a head, (especially one for a high output motor like the ITR) it is not just done from theory (mathematical modelling and fluid mechanics calculations), but it is tested in practice as well. So if that site convinces you, then I have the brooklyn bridge for sale, you interested?


[Modified by canuck-mx6, 7:11 PM 6/18/2002]

 

I WAS NOT CRITICIZING THE HONDA HEAD DESIGN!!!
If you had taken the time to read the site, you would have noticed that the technique is primarily used on MOTORCYCLES...
specifically Yamaha R6's, I just thought that it would be pertinent information to the topic at hand - specifically the risk of over porting the stock cylinderhead...jeez some people.
I personally think that the B18c5 is excellent in stock form, and port/polish would probably be the LAST thing I would do for normally aspirated tuning... lets not be so quick to judge people...

 

I doubt it.

 

.....I had considered this too a while back (and still am), but the interesting thing is that nobody guarantees any whp. They will guarantee better flow, but no guarantee of whp.

They said that you pretty much wanna max out your system before you do a p&p... this might involve raising the compression or building a 2+L bottom end (or both) first.

It's all in the tuning is the bottom line.....

 

Steve I love your 1 word answers, they are to the point. And funny as hell.

 

everyone stop bitching...this topic is very important to me!
I too like to know of the gains...I heard that you gain the most in combination with aftermartket cams...I was thinking of doing toda A cams and the P&P...would someone Pls tell me if it is worth it


[Modified by Type-Rare#1248, 1:04 PM 6/18/2002]

 

I did didnt I?

 

I am not judging you, and I did read the article. However, my logic is this: Since you posted a site with information pertinent to intake porting for motor cycles, you must have thought it relevant to Honda (B18C5) porting as this is what the original topic was about. Otherwise, there would be no reason to post a link to a site with yamaha R6 info.

There are manufacturers that have tried this idea. Spoon has the venturi plate which increases the intake air velocity, but only for the B16, not the B18.

 

We port alot of Heads Type R heads right out of the box any ? give me a call.

Thanks

 

There is more to the ITR than the US you know... In one year you have 1000 ITRs in the US, 500? in Canada. And in Japan its not really a limited production vehicle. So even if we exclude Japan. Thats 1500 P/P jobs a year. Working EVERYDAY. Thats 2.74 heads a day. Now take into accoutn Japan where the number is probably double that. You are lookign at 5.48 p/p jobs a year. Narrow out the techs that arent "the best" and you dont have a that much time to do a great job.


Oh silly me!!!! I forgot all about the CTR... and the NSX and I belive the S2K has a p/p job...

Even if I exclude the NSX and S2K becasue Im not 100% sure they have hand p/p... Thats still alot lof CTR and ITR heads to polish. Not everyone worls 365 days a year either....

 

With this infomation in mind then, what kind of gains can be expected with a mild port and polish on a b18c5 head anyway?
(back to the topic at hand)

oh, and I did not mean to miss-lead anyone with the link post, my buddy just sent it to me, and I thought it was interesting... probably off topic though.

 

I dont get it. We aall tell you that you can get good gains and someone even
posts a graph to illustrate the gains and YOU STILL ASK???

 

I think it's obvious that a good P&P and a VERY WELL THOUGHT OUT plan of what mods you're gonna do to your motor can be very beneficial. Sgt is like Mr. Miyagi (sp?) very short answers to questions, but if you listen carefully, you will understand... J/k. LOL...