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Discussion Starter #1
Looks like we'll be seeing the new Bowtie Vortecs arriving at the end of the month for a future article in Chevy High Performance Magazine. One of the issues I brought up was that these new heads feature a raised runner design that may pose a problem mating up to my existing Vortec manifold. GMPP says they'll send the proper manifold, gaskets, hardware, and everything else. And I thought just getting the heads would be cool! At least you won't have to wait until the story comes out to find out what the outcome was. I'll just post here as things progress. I'm still curious about the d-port exhaust runners and how they'll mate to the hedmans that alot of us run for headers.Stay tuned- Dale
 

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Discussion Starter #2
A New Saga-

Well- these new Bow-Tie Vortecs are beginning to show their evil side. I guess that's why this is all one big test or experiment. After the head bolt issue, I thought we were home free, but alas, problems arise again. And with first generation Nova's, this may be a big one. I've stopped dead in my tracks. It seems that the machined exhaust head surface is milled at a slightly different angle then standard, as it has "flared out" my hedman hedders (mind you they're only 1 1/2" primaries) to a point where they come into major contact with things that had 1/8th to 1/4 inch before. I've some ideas to remedy this, but I don't care for any of them. It just should not have to be this way! Frustration is starting, and we all know that's the time to walk away from it for awhile. :confused: Dale
 

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Awe man! What a PITA!!! If I dont have to work Saturday Im gonna head up your way and help you out. Ill even bring my BFH just in case! ;)
 

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Makes me wonder what's going on with this whole thing. I'm wondering if these were some initial pre-production pieces. First, chamber volume was not as specified, second, intake and exhaust port runner volumes were not as specified in catalogs, third, head bolt alignment problems with a couple, and now, exhaust side machined surfaces not matching up to production tolerances. Leaves me with a head being scratched. :confused:
 

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That sucks. Its really odd that the castings or milling of the surfaces would be any different than any of the standard SBC pieces. I would definately be on the phone with your supplier trying to figure out what the problem is. These heads should be little more than just a bolt on affair and not much of an "experement" really. Heres hopin you figure it out. Let us know how it goes. Good luck.

Kasey
 

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I wonder if the angle the exhaust surface is off is the same as the angle the headbolt holes were off.

Before you spend time getting the headers to fit, verify the intake surfaces are not off as well. It would be a crying shame to have to angle mill the intake and run really thick gaskets.
 

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I've come this far, so for now there won't be any turning back. All this that's been going on will make for some good reading in CHP when it hits the stands.The heads came directly from GM Racing Division, so I'm trying to get some answers in the next few days. Only two bolt holes were slightly out of whack, but this "off angle" exhaust machine surface is inherent to both heads.Intakes all line up perfect,so angle milling will just create more problems I'm thinking.But in the mean time, until we get some more information through GM, We are going to try to get hedman hedders to send out an identical set to what's on the car now, only not ceramic coated. My theory is to make "pie cuts" of only a degree or so out of the bottoms of each primary tube, then squeeze it back together and weld up. That way, I'll butch these up and get the car back running to make the next set of dyno runs to show if all this was worth it or not. My gut tells me that I'm only having this problem due to the fact that we drive early Nova's,which have very small confined spaces to run headers to begin with. Camaro's, Chevelle's and other cars have bigger engine compartments and would hopefully not have an issue with this problem. BUT, we are. What I'm also trying to do is respectfully inform GM that what they have now is not what it's supposed to be. It may be a small amount, but it's enough to throw a big wrench in the gears. Boy, I'd love to have a detailed set of drawings on these heads?
 

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It's very possible that the first batch of heads were incorrectly machined. I would contact GM racing and tell them the problem. They may want them back to check.
 

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Hey Dale, I have my old set of Hedman's Ill donate to you if you want. Let me know...
 

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I read that these heads are good for vortec or standard intake manifolds - would that universal fit have any thing to do with changing the exhaust side?
 

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Discussion Starter #11
Chuck- it should not have anything to do with it. Paul- you are correct.I'm curently awaiting a call from one of the GM Racing's project managers. I sent an e-mail through Scoggin-Dickey (whom orchestrated most of this with GM) and got an immediate response. Seems they may have grabbed a set not destined for use. Hmmn? We'll know more as the day unfolds.
 
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You will hit the giant brick wall with GMPP, their "leader" is so self-protective that no info will get past him to R&D or the production staff unless it is complementary to him, and the products he states have no problems at all.

He posts on chevytalk.org, and getting any useable info from him is just plain next to impossible, but, he emphatically states that their products are dead on correct and it has to be some other aftermarket parts being the cause of any and all issues.

I don't remember his name or username on CT, but he shouldn't be hard to find there. He is the head protector of all things GMPP mis-machined.
 

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Well, I did receive call backs from one of their senior engineers,and they are interested in whats been happening. The guy I talked with was familiar with what I've been doing with these heads. He informed me that they were indeed pulled straight from production inventory, and was most concerned about the head bolt hole alignment issues. Asked alot about what we did to remedy it. Then he dropped the bomb. This new head is actually a "marriage" of the best parts from two different heads, the Vortec truck head and the aluminum fast burn head. They designed this head three years ago, so they were going to pull up drawings or diagrams to see the difference's.So there are two different design elements involved. I missed his second call back in the afternoon with some numbers, but will most likely hook up on Monday morning. Still trying to keep the faith, but this is not a true bolt on after all?
 
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"Gary" was the guy's name, never a problem with GMPP products always the aftermarket stuff that didn't fit. Real defensive on the GMPP stuff, even when proven he was covering something up.

It takes a bunch of lack of engineering to get a small block head NOT to fit, they've only been around for what....50 YEARS, now.

AFR, Brodix, other heads are available.
 

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heads

And the plot thickens!
Mike
 

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Discussion Starter #17
I put the word out I'm gonna cut into some headers, and a few people have come through. NOGO has stepped up with a donor set and another good friend has given me a beautiful new set of three quarter length Hookers from a Chevelle part number to try and squeeze around. Maybe we'll stumble on a good alternative that'll cross over with small modifications??? Thanks, guys for stepping up. Looking for an old set of Hooker headers in a Nova part number if anyone would maybe want to get rid of for a good price? (62-67)
 

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Is the problem the angle of the exhaust face of the head? Can you measure the angle with an angle finder? I wouldn't cut up headers if the problem is mis machining issue or a design issue.
 

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Discussion Starter #19
Paul- I just spent some time with their engineers and the answers I've been given are very disappointing- they've failed to let people know (this through the catalog and various suppliers including GM dealerships) that they have relocated the exhaust surface .250". Thats ALOT to move something and not let anyone know. I felt (and I told them) that this will have a huge impact on the consumer that will put forth the funds for a set of "bolt on" heads only to find out that the exhaust system will not even come close to being able to be installed. This is such a big design change that other GM model cars will experience clearance issues as well. I won't bore anyone with the specific's of why the changes were made, but nevertheless, they are what they are. I'm waiting on a call back from a header manufacture that tells us they do have a part number that will fit, but I'm skeptical. They still are very upset about the head bolt alignment issues, and wanted production numbers off the heads. Gee- I'm wondering how many people have already purchased these heads through suppliers like Jegs and others only to find out that Pandora's box has been opened? :(
 

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Actually you wouldn't bore me with those details AND you'd be doing a great service to others considering these heads. So the ports are raised 1/4" and that's why the bolt holes don't line up? Does this mean the collectors are closer to the floor pan by an equal amount or am I missing something?
 
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