ZR-1 Net Registry Forums - removing the secondaries a compelling story

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- - removing the secondaries a compelling story (http://zr1.net/forum/showthread.php?t=15601)

Re: removing the secondaries a compelling story

Quote:

Originally Posted by bobbyhi (Post 122895)

Hey Goldy - I had Marc take my secondaries off this last spring. Haven't notice too much difference as I screwed up my left leg last July and I cannot push the clutch in. She just sits in the garage waiting for the leg to heal. Real bummer:mad: BTW when you decided to get rid of the wing I want first chance at it...:) When do you think yours will be ready for the permagrin???

You are first in Line Bobby but I will be honest. Unless im smacked in the rear end it isnt coming off. The PO said it was actually struted to the frame. I hope you heal up soon. When im in town Ive been driving Pops 96 CE LT4 powered. NLT than 1 OCT is the target

Re: removing the secondaries a compelling story

Quote:

Originally Posted by rhipsher (Post 122897)

O:eek:M:eek:G:jawdrop: That would ruin my day. But aren't the throttle plate screws swedged just like the air horn throttle plates to make it impossible for those screws to back out? When I took my throttle body apart for powder coating the screws looked like they were screwed in through the rod then cut off and the tips of them looked like they had been melted. So if you back them out you will rip the thread out. And the screws were flush with the back of the rod so I could not just grind the swedged tip off and unscrew them without ruining the thread. That's why I had to tap them the next size up 8-32. I would think all the throttle plat screws would be the same. Unless of course some one had messed with them previously.

They are... which almost makes this impossible (right?) but its happened twice and they seperate right where the screw centers the rods (both times). The rods appear to break at their weakest point where is where the screw centers it. Its entirely possible they were over tightened at the factory and after 20 years or Heat cycles, Pressure, vibration whatever they failed. Believe me the Driver side head when it failed a year ago we all thought it was a fluke. Well im a believer. The secondary system is outta there. GC[-X

Re: removing the secondaries a compelling story

Frank a thought just occured to me. Should I increase the porting to the TB say 63MM. Help me oh racing obiwan.

Re: removing the secondaries a compelling story

Wow, Daryll... certainly not just a fluke, after having it happen twice on your motor. I'm glad my butterflies have flown away :)

Re: removing the secondaries a compelling story

I'd ask Pete about that D. He has probably forgot more than I know.

Re: removing the secondaries a compelling story

Quote:

Originally Posted by GOLDCYLON (Post 122870)

And Frank ought to know. BTW My heads are being ported, welded and Multiangled at this time. With Petes Intake Cams and a 380 bottom end with a Fidanza flywheel. OH Baby

I raised this question a month or so ago and Mark Haibeck said there was very little benefit in porting the heads. Did I miss something?

Re: removing the secondaries a compelling story

Quote:

Originally Posted by cvette98pacecar (Post 122960)

I raised this question a month or so ago and Mark Haibeck said there was very little benefit in porting the heads. Did I miss something?

according to his website head porting is worth 35 hp...http://www.zr1specialist.com/HAT%20W...20upgrades.htm

maybe mark can chime in here

Re: removing the secondaries a compelling story

Here is the link for full pocket porting. I think I need to get my car to Mark and see what is truly done to the engine.

http://zr1.net/forum/showthread.php?...Pocket+porting

Re: removing the secondaries a compelling story

Quote:

Originally Posted by cvette98pacecar (Post 122965)

Here is the link for full pocket porting. I think I need to get my car to Mark and see what is truly done to the engine.

http://zr1.net/forum/showthread.php?...Pocket+porting

FYI, "pocket" porting refers to porting just a small area of the head. Basically the area behind the valve.

The way I read Marc's reply was that there is little to be gained in this on the LT5, and that the real gain from headwork comes in porting the runners. In fact, in that post, he refers to it as the porting goldmine.

Re: removing the secondaries a compelling story

Quote:

Originally Posted by cvette98pacecar (Post 122960)

Did I miss something?

Yes ;) All heads benefit from porting. The real question does the cost = the potential gain. Your mileage may vary. Mine are being done at a local shop very cheap due to my sons friendship with the owner.