Injector housing pull; Porting - ZR-1 Net Registry Forums

LGAFF · 01-12-2008

Pulled the injector housing on the passenger side as I will be finishing the plenum soon and going to port match to the IH.

I noticed that the secondary TB are 37mm in the head(stock), while the primary ports are 33mm. The IH itself follows suit with the IH to head ports on the secondaries running 37mm, while the IH port that mates to the plenum is only 35mm. Head ports on primaries are also 33mm.

It seems for the poor mans port job, you might be able to focus on opening up the secondaries only to 37mm all the way through and get a pretty good bang for your buck. This way you wouldn't have to worry about the port match to the head. With the small primary ports in the head, and the limited room I wonder if you get much return as it has to neck down pretty good at some point, although I assume that you might gain some velocity going from 36-37mm as it necks down to 33 in the head.

Just a few thoughts, might generate some conversation. I'm not a professional porter, I just play one on the Registry Forum.

LGAFF
92 ZR1
#234

PS: I am surprised at the smooth finish I got from hand sanding with 100 grit and then 400 grit in the plenum runners, its pretty darn close to the extrude hone finish it had before.

Pete · 01-12-2008

Lee, port the primary IH port to 36mm then match port the primary head port about an 1-2"s into the primary head port for now till you port your heads.

Pete

XfireZ51 · 01-12-2008

Pete,

The secondary head ports are 37mm stock from the factory? Does that mean there's no need to match secondary head port with the secondary port on the IH assuming you've ported all IH ports to say 36-36.5mm?

lbszr · 01-13-2008

Sounds like we're at the same porting steps, about two hours into the IH , not much. From what I've seen so far it might be hard to get 37 mm all the way through primary unless you have some ultrasound thickness gauger or a welder ready since the breather and coolant section are nearby, I was starting to shake while grinding, had to go get a beer and ready to go again.

Pete · 01-13-2008

Dom,yes you can,you can make the primary 37mm at the buttom of the port to match the secondary port where they meet the head.

lbszr1 take your time with them.
The way i do it i go with a 35mm ball first and then slowly work with the 36mm ball,just make sure you work the IH's evenly all the way around,i'm sure you already knew that, just a reminder

Don't worry if you go thru there are plenty of welders in America,if you don't know any welders let me know just in case you have an accident.

Pete

Sorry Lee, if i hijacked your thread,all this talk about porting gets me excited :-)

LGAFF · 01-13-2008

Thanks for the feedback Pete, learning alot as I move through the process.

LGAFF
92 ZR1
#234

Locobob · 01-14-2008

Keep in mind that the secondary ports at the top of the heads / bottom of the injector housings are oversized to make up for the butterfly valves intrusion - you won't actually get 37mm of air flow at this location. I gradually taper the primary ports from 36mm at the top of the injector housings down to near stock size at the head surface - unless of course the heads are ported.

XfireZ51 · 01-14-2008

Quote:

Originally Posted by Pete

Dom,yes you can,you can make the primary 37mm at the buttom of the port to match the secondary port where they meet the head.

Pete,

I think you meant I should "match port' the secondary IH port with the secondary head port to 37mm, am I correct?

01-14-2008

Robert,
Do you need to oversize the butterfly too?

bradslt5 · 01-14-2008

hadi, i think he is removing the secondary butterflies from the head

01-12-2008	#1
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Injector housing pull; Porting Pulled the injector housing on the passenger side as I will be finishing the plenum soon and going to port match to the IH. I noticed that the secondary TB are 37mm in the head(stock), while the primary ports are 33mm. The IH itself follows suit with the IH to head ports on the secondaries running 37mm, while the IH port that mates to the plenum is only 35mm. Head ports on primaries are also 33mm. It seems for the poor mans port job, you might be able to focus on opening up the secondaries only to 37mm all the way through and get a pretty good bang for your buck. This way you wouldn't have to worry about the port match to the head. With the small primary ports in the head, and the limited room I wonder if you get much return as it has to neck down pretty good at some point, although I assume that you might gain some velocity going from 36-37mm as it necks down to 33 in the head. Just a few thoughts, might generate some conversation. I'm not a professional porter, I just play one on the Registry Forum. LGAFF 92 ZR1 #234 PS: I am surprised at the smooth finish I got from hand sanding with 100 grit and then 400 grit in the plenum runners, its pretty darn close to the extrude hone finish it had before.

01-12-2008	#3
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,683	Re: Injector housing pull; Porting Pete, The secondary head ports are 37mm stock from the factory? Does that mean there's no need to match secondary head port with the secondary port on the IH assuming you've ported all IH ports to say 36-36.5mm?

01-13-2008	#4
lbszr Join Date: Nov 2006 Location: dayton,ohio Posts: 424	Re: Injector housing pull; Porting Sounds like we're at the same porting steps, about two hours into the IH , not much. From what I've seen so far it might be hard to get 37 mm all the way through primary unless you have some ultrasound thickness gauger or a welder ready since the breather and coolant section are nearby, I was starting to shake while grinding, had to go get a beer and ready to go again.

01-13-2008	#5
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,667	Re: Injector housing pull; Porting Dom,yes you can,you can make the primary 37mm at the buttom of the port to match the secondary port where they meet the head. lbszr1 take your time with them. The way i do it i go with a 35mm ball first and then slowly work with the 36mm ball,just make sure you work the IH's evenly all the way around,i'm sure you already knew that, just a reminder Don't worry if you go thru there are plenty of welders in America,if you don't know any welders let me know just in case you have an accident. Pete Sorry Lee, if i hijacked your thread,all this talk about porting gets me excited :-) __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage Last edited by Pete; 01-13-2008 at 02:08 AM.

01-13-2008	#6
LGAFF Join Date: Mar 2007 Location: Crystal Lake, IL Posts: 7,180	Re: Injector housing pull; Porting Thanks for the feedback Pete, learning alot as I move through the process. LGAFF 92 ZR1 #234

01-14-2008	#7
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,047	Re: Injector housing pull; Porting Keep in mind that the secondary ports at the top of the heads / bottom of the injector housings are oversized to make up for the butterfly valves intrusion - you won't actually get 37mm of air flow at this location. I gradually taper the primary ports from 36mm at the top of the injector housings down to near stock size at the head surface - unless of course the heads are ported. __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368

01-14-2008	#9
HADI-ZR1 Guest Posts: n/a	Re: Injector housing pull; Porting Robert, Do you need to oversize the butterfly too?

01-14-2008	#10
bradslt5 Join Date: Oct 2007 Location: lone pine and mammoth lakes ca. Posts: 544	Re: Injector housing pull; Porting hadi, i think he is removing the secondary butterflies from the head