Head porting
Head porting
So after my first boost experience last year. I have decided to fully build my engine, not due to any mechanical failure, but because I have been bit by the boost bug. So part of what i want to do is port and polish the head. My ? is do i port around the valve stems or take them out? IF take them out, How? I have read a couple people just grind them smooth with the runners. But it just didnt seem like a good idea to me. But what do i know. If anyone has any tips, tricks, or just some good ole advice. I would appreciate it. BTW i have 4 heads so im not concerned about messing something up.
-
idahotuner
- Posts: 10583
- Joined: Thu Jun 28, 2007 7:11 am
- Car: 2012 Dodge Ram 2500 6.7 Cummins
93 Nissan Sileighty
93 Honda Civic hatch
2011 Polaris Ranger - Contact:
Re: Head porting
they are easy to take out. you just need a valve spring tool. 
i used one of these to take every valve out of a vg30 and then put them back in. they are easy to use.
with an sr20 the head design was such that the normal air valve spring took wouldnt work. but i am not sure about ka24 the head , it is pretty narrow
i used one of these to take every valve out of a vg30 and then put them back in. they are easy to use.
with an sr20 the head design was such that the normal air valve spring took wouldnt work. but i am not sure about ka24 the head , it is pretty narrow
-
eazye2000
- Posts: 1880
- Joined: Mon Jun 27, 2005 9:42 am
- Car: S13 KA-DET
- Location: Inverness, FL
- Contact:
Re: Head porting
Yep, that tool makes it so much easier. I made a tool just like the one above, but it got stolen because it worked so well I guess.. lol
Or you can use an old wrist pin, and cut 1/4 of it out lenthwise, and use the old 'C' style spring compressor. I will elaborate more if you don't understand.
I ported my heads pretty good. I didn't grind out the guide, I ported around it. I measured the guide, and the length of the valve and determined I didn't want that little of guide 'guiding' my valve. That was a personal decision. But I've seen where people just grind them out.
My suggestion, is to do a basic port match, and take out some of the casting marks, and make the ports more even. Spray some of the machinist dye in there, and grind that out. Then spray another coat in there, and grind that out. Do it about 3 times, and you should be good. Don't go s*** because they flow pretty good in stock form, and only need a good port match to be effective.
Search around, there are a few threads around here about porting the KA head. I made one myself.
Or you can use an old wrist pin, and cut 1/4 of it out lenthwise, and use the old 'C' style spring compressor. I will elaborate more if you don't understand.
I ported my heads pretty good. I didn't grind out the guide, I ported around it. I measured the guide, and the length of the valve and determined I didn't want that little of guide 'guiding' my valve. That was a personal decision. But I've seen where people just grind them out.
My suggestion, is to do a basic port match, and take out some of the casting marks, and make the ports more even. Spray some of the machinist dye in there, and grind that out. Then spray another coat in there, and grind that out. Do it about 3 times, and you should be good. Don't go s*** because they flow pretty good in stock form, and only need a good port match to be effective.
Search around, there are a few threads around here about porting the KA head. I made one myself.
Re: Head porting
so you ground the guide out correct? Or did you take them out and install new ones
-
WDRacing
- Moderator
- Posts: 15983
- Joined: Mon Nov 25, 2002 2:00 am
- Car: 95 240SX, 99 BMW 540i, 01 Chevy Express, 14 Ford Escape
- Location: MFFO
- Contact:
Re: Head porting
I've never ground the guide on the KA, but I have on other engines. I've read mixed reviews on both, but IMHO, the point is to increase airflow, so having things poking out and in the way is a restriction to me. So I'd grind them bishez...lol.
When porting the stock head your main goal should be to assist airflow while maintaining high velocity of incoming and out going air. That basically means don't go nuts when porting. Each port has 2 interior ports where the valves are. The interior ports shouldn't be larger then 80% of the valve size to maintain velocity.
I'd gasket match as much as possible and smooth everything out. The intake side shouldn't be buffed or smoothed "to much", because the turbulence helps the air/fuel mix together. The exhaust on the other hand should be shined up like a mirror.
WD
When porting the stock head your main goal should be to assist airflow while maintaining high velocity of incoming and out going air. That basically means don't go nuts when porting. Each port has 2 interior ports where the valves are. The interior ports shouldn't be larger then 80% of the valve size to maintain velocity.
I'd gasket match as much as possible and smooth everything out. The intake side shouldn't be buffed or smoothed "to much", because the turbulence helps the air/fuel mix together. The exhaust on the other hand should be shined up like a mirror.
WD