Re: Q-jet Questions
For the newbies, please reread Danny's last paragraph. Its the core, the best builder, the best flow bench, the prettiest rebuild will not make a fast q-jet. Borrow a known fast q-jet, buy several cores, rebuild them, run them on the track. Then get the best one done by a good builder. Just my experience. I don't think the same process works for stocker heads any more.
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Re: Q-jet Questions
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Anybody who has ever put a stock size intake or exhaust gasket up to the head and checked out the port size, knows that the size and shape of the ports can vary greatly even with exactly the same spec heads. When you just do a simple gasket match, you will need to grind different amounts, in different places on each head. Therefore, not every 6x Pontiac head is created equal. Common sense says that some will flow slightly better than others. And since no porting is allowed, my thinking is that even the best valve job in the world can't make a worse flowing head, make more power than the better flowing head with the same valve job. Now this is just country boy thinkin. If I'm wrong, somebody please explain to me how the head builder can make the worse flowing head make more power than the better flowing head, without porting. Hey, I'm not talkin 50hp difference here. But it seems that class racers are always lookin for hundreths and even thousandths of a sec. Correct ? :) |
Re: Q-jet Questions
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For cores, yes you want the best cores....head, intake, or carb. What you start with affects what you end up with. Listen to Danny Ashley. He knows his stuff. |
Re: Q-jet Questions
Some good Q-jet info here for DIY people
http://racingfuelsystems.myfunforum....forum.php?f=26 |
Re: Q-jet Questions
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Hey I've done some dirt racin. I know all about racers running illegal stuff and getting by with it. So are we talkin several 10th's difference when using these "ported but legal" heads ? :confused: I'm just curious. For you guys who have been around this for a long time, have ya'll seen some racers disqualified for these "ported' heads ? Or have the top head guys gotten so good with it, that the tech guys can't detect it. Or do the tech guys know all about it and just let it slide ? :) |
Re: Q-jet Questions
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Swirl ? |
Re: Q-jet Questions
Anybody who has gone through the process of flowing a bunch of truly raw heads thinking that the ones with the best flow number in that state will be the best after legal prep only to find out that what really matters is the area from the top of the valve seat to about a half-inch below after the work is done can attest to the fact that you can go very fast without acid porting heads.
Long statement, I know. Digest it. |
Re: Q-jet Questions
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and...if you are flowing heads before that work is done....you are wasting your time gathering meaningless information |
Re: Q-jet Questions
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In other words, your saying that the shape and location of the stock ports will make very little difference to the power output of a stocker engine ? But the power is all gained from the valve job ? That is VERY interesting ! I'm glad I ask the question. You see, I've been living in the world of bracket racing, since there is no class racing close by, or wasn't until recently. All I've heard is that you always need to port iron heads or at the very least do a simple gasket match. But if what you guys are saying is true, then unless I'm shooting for #1 qualifier at Indy, I'd be wasting $ to pay "Heads Up" for their " better than acid porting" head treatment which they advertise on their website ? Next question: The Pontiac engine shops get nearly $2000 for a set of 6x Pontiac heads with their valve job and CNC porting. So aprox what would it cost to have one of the Stocker head shops do just their magic valve job on a set. I don't need an exact figure. But for some of you guys who have had this type of head job done recently, was it about $2000, $2500, $3000, OR ? Now for an opinion question. Do ya'll think it's possible to run just slightly under the index with one of the good Pontiac 350 or 400 combos, with just the usual 5 angle valve job that most Pontiac shops advertise ? Or is there enuff power difference in the real Stocker heads to make them a requirement to get you under ? Hey, ya'll will just have to excuse the dummy questions. :o I don't have any Stocker buddies to ask. So it seems to me that the best guys to ask are those who have been there and done it. OK ? If I decide to build a Stocker, I don't want to buy a $1000 valve job, only to later find out that I needed a $2000 job from somewhere else to get the car under. Thanks for all the info guys ! |
Re: Q-jet Questions
Not a problem to run well under the index with a budget Pontiac.
On our cars the difference between the best magical stuff and a set of stock heads ( with a decent valve job and CCd ) is only a couple of .10s of a second. You can learn a lot by a careful inspection of ports and valve placement just by eye. We used to go to a lot of swap meets and just look at the heads for differences. NHRA polices the heads and checks runner CCs much better and closer than it used to be several years ago. Heads Up races do not happen every race and I have seen very successful racers in Stock on a very tight budget. Give it a shot! |
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