Top end porting examples

[Locobob]

Some of you expressed interest in seeing my porting projects so here they are.
This set is my standard port job on a 94.

Plenum
http://www.pnwzr1.net/Robert/Plenum/PB090005resz.jpg

Air Horn
http://www.pnwzr1.net/Robert/Plenum/PB100044resz.jpg

Injector boss close up - 93+ style, finish is from bead blasting.
http://www.pnwzr1.net/Robert/Plenum/PB200028resz.jpg

[Locobob]

Set 2: standard porting job on a 91.

Plenum + Injector housing bolted together to show port alignment - looking down a secondary runner from the bottom of the injector housing.
http://www.pnwzr1.net/Robert/Plenum/PA100006resz.jpg

Side by side before and after injector housing pics (90-92 style)
http://www.pnwzr1.net/Robert/Misc%20Pics/BefAftinjbossresz.jpg

http://www.pnwzr1.net/Robert/Misc%20Pics/BefAftinjhsresz.jpg

[Locobob]

Set 3: Partial siamese job on a 94, close to completion but lacking final finish.
http://www.pnwzr1.net/Robert/Plenum/Nicks1%20036resz.jpg


http://www.pnwzr1.net/Robert/Plenum/DSC00007.jpg

Plenum + Injector housing bolted together to show port alignment.

http://www.pnwzr1.net/Robert/Plenum/Nicks1%20024resz.jpg

[Locobob]

This last set is my own 368. I had the underside of the plenum and backsides of the injector housings welded up so I could go futher with the partial siamese. Finish is from bead blasting.

http://www.pnwzr1.net/Robert/P7120021resz.jpg

http://www.pnwzr1.net/Robert/P7120032resz.jpg

http://www.pnwzr1.net/Robert/P7120042resz.jpg

[A1990]

Impressive work :thumbsup:

[Patton]

Anybody have $1000 dollars to donate to the Poor Ex-Soldier Trying To Make A Living foundation? :thumbsup:
Its worth a shot! :mrgreen:

But seriously, Robert thats great work! I am curious,... Does taking all this metal off have any plausible drawbacks? Does it pose any longevity/durability issues?

Also, what kind of performance would I see with your porting & headers/RTcats/B&B xpipe cat back/perf chip? This is with a 94 motor.

Now what performance increase would I see with siamesing done to that setup?

I have never had an explanation of what siamesing actually enhances... Anybody care to fill me in? I’m guessing it just combines the primary and secondary tubes and increases the overall volume dramatically. I.E. better air flow.

[Locobob]

Does taking all this metal off have any plausible drawbacks? Does it pose any longevity/durability issues?


No, these are non moving non wear parts.


Also, what kind of performance would I see with your porting & headers/RTcats/B&B xpipe cat back/perf chip? This is with a 94 motor.


Probably around a 50rwhp increase on a 94 with all of the above. The earlier cars (90-92) have more to gain from porting. The 93+ castings are much better flowing from the factory mainly due to the reduction in size of the primary injector boss.


Now what performance increase would I see with siamesing done to that setup?


Probably very little to none. I had planned on testing the difference on my own 368 which start out looking very similar to what you see in photo set 2 but I ended up doing some other things that will muddy the test so it wont be a good before and after comparison.


I have never had an explanation of what siamesing actually enhances... Anybody care to fill me in? I’m guessing it just combines the primary and secondary tubes and increases the overall volume dramatically. I.E. better air flow.

Airflow science is tricky business, not being a scientist I'll give you my basic laymans understanding of it. Think of it as going from a dual plane to a single plane carb intake. The dual plane design relies more on port velocity than volume and is better for low and mid range power. The single plane design allows a greater volume of air at high rpm but loses some port velocity and thus mid range torque. What I have done with the partial siamese would fall somewhere between these two designs. In practice on a 350 LT5 I've seen no loss of low-mid range torque from doing a partial siamese. Is it worth anything extra on the top end, maybe, maybe not. Now on a more radical/larger motor you should see some benefit just like a carbed race motor responds to a single plane intake.

[tomtom72]

[QUOTE=Patton]Anybody have $1000 dollars to donate to the Poor Ex-Soldier Trying To Make A Living foundation? :thumbsup:
Its worth a shot! :mrgreen:

I know this Federal Reserve bank in NYC, we could tunnel in from the subway....oh, that was a movie...yea, right. I'll go take my meds now! :mrgreen:

That stuff looks sweet Bob! :thumbsup: I'm saving my nickles because I think my 90 really deserves a present. Gotta keep up with those damn C5's & C6's!

Happy Thanksgiving everyone!! Hope everyone has a nice day with their family!

:cheers:
Tom

[Aurora40]

I don't know jack about jack. But just wanted to toss in, the SLP siamesed runners I put on my '87 L98 were what you are talking about. They were only partially siamesed at the top and bottom. Of course, those were runners to two different cylinders, so only one would be on intake at a time, thus I guess allowing more air volume into each cylinder. They were designed to be well-rounded, not a top-end gain with a bottom-end hurting. I thought they seemed fine, the car seemed a little more peppy, though it actually wasn't that dramatic, I was expecting more.

Edit: Oh, and that bead-blasting finish looks :cheers: How much would you say you are widening the openings?

[cuisinartvette]

Looks good, Bob! Awful lot of time spent there. I remember browsing that thread a long time ago, one of the things that really set off the bug for a Z. Now I'm ruined, thanks a lot :mrgreen:

[Patton]

Thanks very much Robert! That is very good to know. When I am ready you will be my first choice! :thumbsup:

[FU]

Nice work Bob :thumbsup: :thumbsup:

[Z Factor]

I took these quotes out of the other thread along with my post since it is more applicable here.

I'm offering porting and powder on the top end for 1K for the package. Nobody else can touch that cost period.



Jeff does the powder and I do the porting,

That is a great price.:thumbsup:

What diameter are you doing for the plenum/IH ports, and the TB? What do you do with the fuel injector bosses and air horn?

Not that you are competing with some of the better know tuners out there, but with prices like that, I cant imagine why anyone would not go with you guys. You should get the word out more.

:cheers:

[Locobob]

That is a great price.:thumbsup:

What diameter are you doing for the plenum/IH ports, and the TB? What do you do with the fuel injector bosses and air horn?

Not that you are competing with some of the better know tuners out there, but with prices like that, I cant imagine why anyone would not go with you guys. You should get the word out more.

:cheers:


Jeff and I have done a couple at that price but for future jobs I think it's going to be more like $1200. At 1K for porting and powder we are pretty much giving these away. I'm not really in the business (have a full time job) but I'm up for doing one every now and then.

Generally I open up the ports to 1.4in (about 35.6mm) measured at the plenum/inj. housing gasket surface. The plenum ports get larger from there while the injector housing ports neck down a bit toward the heads. I open up the secondary ports in the I/H's quite a bit more than the primarys. As for the injector bosses I take them down as much as possible and work the areas on either side to try and channel some air behind the spray pattern. On the air horn I knock down the protrusions as best I can and blend everything in. I also like to port match the air horn to the throttle body. On all the pieces I do I really put a ton of effort into the little details.

[Nick]

Also, what kind of performance would I see with your porting & headers/RTcats/B&B xpipe cat back/perf chip? This is with a 94 motor.

With Rob's porting work at the PNW ZR-1 group's "Q Branch," my '94 with Jeal headers, Random Tech cats and Corsa exhaust went from a baseline of 337 rwhp and 326 rwtq to 381 rwhp and 350 rwtq. :thumbsup: That's with a Haibeck header calibration as well.

[tomtom72]

With Rob's porting work at the PNW ZR-1 group's "Q Branch," my '94 with Jeal headers, Random Tech cats and Corsa exhaust went from a baseline of 337 rwhp and 326 rwtq to 381 rwhp and 350 rwtq. :thumbsup: That's with a Haibeck header calibration as well.

Sweeeeet!!!! "Now pay attention 007...and do try to bring this back in one piece!"

[Patton]

Now those are some numbers! I can dig it!

[blackjack]

put my name on the waiting list
blackjack
91/1735

[Locobob]

With Rob's porting work at the PNW ZR-1 group's "Q Branch," my '94 with Jeal headers, Random Tech cats and Corsa exhaust went from a baseline of 337 rwhp and 326 rwtq to 381 rwhp and 350 rwtq. :thumbsup: That's with a Haibeck header calibration as well.

I just want to clarify this a bit because it could be misinterpreted. I believe the case was that the car baselined at 337rwhp with the just the Corsa exhaust and it was the combination of the porting, headers, and calibration that raised the number to 381rwhp. Correct me if any of this is wrong Nick. It is not possible to gain 44rwhp with intake porting alone. Sorry if any of you got overly excited, no free lunch. The combination of intake porting, headers, exhaust, and a good prom is quite satisfying. The way the engine pulls in the upper RPM's just takes your breath away. As Ferris would say "If you have the means I highly recommend it".

[Nick]

I just want to clarify this a bit because it could be misinterpreted. I believe the case was that the car baselined at 337rwhp with the just the Corsa exhaust and it was the combination of the porting, headers, and calibration that raised the number to 381rwhp. Correct me if any of this is wrong Nick. It is not possible to gain 44rwhp with intake porting alone. Sorry if any of you got overly excited, no free lunch. The combination of intake porting, headers, exhaust, and a good prom is quite satisfying. The way the engine pulls in the upper RPM's just takes your breath away. As Ferris would say "If you have the means I highly recommend it".

Rob, you are entirely correct; sorry if there was any misunderstanding. :cheers: