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09-19-2021, 03:05 PM | #21 | |
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Re: 1967 Pontiac Firebird
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Knieper May 1968 SS/FA=9.50 class record, 12.16 at 113.92mph Pretty sure thats a RamAir at 335hp or 340hp factored. I'm still guessing on some of the factoring. I know at some point NHRA started to factor the Firebird engines same as the GTO, figuring that: 1. Everybody had figured out how to get the Qjet to fully open and 2. Everybody ran headers so the exhaust manifold differences were nil. So at some point, late 1968 or 1969, that 1967 Ram Air was factored to 360hp which bumped it up a class hotter. In the current class guide, the manual & auto cars are listed at the same weight. But for some reason, in my own edits for "back in the day" I'm adding 54 lb for the T400 trans, as NHRA sometimes does, & sometimes doesnt. Not sure which is right. BTW - is there a way to tell a RamAir car from a Non-RamAir car? Since they share the same hood it often isn't clear from the pictures. Last edited by DeuceCoupe; 09-19-2021 at 04:17 PM. |
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09-19-2021, 04:16 PM | #22 | |
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Re: 1967 Pontiac Firebird
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It has to be more than just the small hole (3.718" bore) that is the problem with the 326 ci Pontiac. People build the 305 ci SBC 3.736" bore and run well. Stan |
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09-19-2021, 07:17 PM | #23 | |
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Re: 1967 Pontiac Firebird
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Now this is my opinion of why nobody has/would build a 326 powered Stocker. (1) The 326HO carb is a an AFB. It seems that most all the popular Pontiac combos are Q-jet equipped. It has been proven that legal 750 Q-jets will feed even low 9 sec SS engines, & 10 sec Stocker engines. Therefore, a Q-jet would not be a choke point for a 326 engine. (2) The NHRA hp factor of 285 is just too high to make the 326HO competitive. There are later Q-jet equipped 400 cube engines that have a lower hp factor. The '68 Q-jet equipped 350HO has an hp factor of only 305. That would make it much more competitive than a 326 @ 285hp. Don't know how low the 326 engine hp factor would have to be in order for it to be competitive. But obviously, if you get the hp factor low enuff, you can make most any combo competitive. There have several very competitive 4-cyl cars. http://www.classracerinfo.com/Engine...0&MAKE=Pontiac (3) There are no legal replacement 326 pistons listed. So, anyone who wanted to build a 326 Stocker would have to get a piston made & NHRA approved. Adam Strang did this for the '68 Pontiac 350. (4) Not sure, but I assume that the auto trans equipped 326 cars came with the 2-speed. I think you can now run a 3-speed. But, this was probably a major consideration, back when you had to run what it came with. I'm quite sure that's why there were VERY few '64-'66 GTO Stockers which ran an auto trans. (5) Bottom line is that there are just too many other Pontiac combos that are much better choices, for a variety of reasons. Therefore, I don't expect there will ever be a 326 Stocker built. "...People build the 305 ci SBC 3.736" bore and run well." As to that statement: The '80 Bird I bought in recent years had a Q-jet equipped 305 in it. So, just out of curiosity, I just looked up the 305 powered '80 Pontiacs. For all Pontiac models except the Birds, the hp factor is 235. That's 50 hp LESS than the 326 Pontiac engine, plus it has a Q-jet. Hey, at 235hp, the 326 MIGHT be competitive. Don't know. http://www.classracerinfo.com/Engine...5&MAKE=Pontiac Last edited by oldskool; 09-19-2021 at 07:24 PM. |
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09-19-2021, 11:26 PM | #24 | |
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Re: 1967 Pontiac Firebird
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Otherwise, factoring the RamAir engine to 340hp and NOT adding the 56 lb for the T400 trans gives W/P=9.38. Either way, 1968 seems to be the only year that would fit, or 1973 & newer but the picture just looks "old". Since today's NHRA class guide does NOT add the 56 lb for the T400 in the Firebird, maybe it was never added. Manufacturers were inconsistent about this - sometimes they add 50 lb or so for an auto trans, sometimes they dont. That's in Today's NHRA Excel files. I dont have the old class guides so guessing a little. |
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09-20-2021, 12:15 AM | #25 | |
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Re: 1967 Pontiac Firebird
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Interesting. While it may have an AFB carb and not a Q-Jet. The Throttle and Venturi sizes listed on Class Racer Info for the '67 285 HP 326 are the same sizes as was used for the '66 335 HP 389 engine. Stan |
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09-20-2021, 12:22 AM | #26 | |
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Re: 1967 Pontiac Firebird
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Same with the Q-jet. Most of the Pontiac engines used the same size Q-jet, during the same model year. There were exceptions, such as the SD455 Q-jets. Also the rare 455HO Q-jets that didn't have the outer booster rings. Hey, some of the OHC Six engines had a Q-jet. http://www.classracerinfo.com/Engine...6&MAKE=Pontiac Some 301's came with an 800cfm Q-jet. http://www.classracerinfo.com/Engine...9&MAKE=Pontiac I suppose the main thing is that Q-jet equipped Pontiac Stockers are not power limited by the carb, since the Q-jets can feed low 9-sec SS Pontiacs. I suppose the quickest Pontiac powered SS pass may have been the 8.90, made by the GT/AA 428 powered Cobalt, raced by Robert Cruzen. That Q-jet had to be the 750cfm size. I suppose some refer to that size as the "small" Q-jet. Don't know. https://www.dragracecentral.com/DRCS...r2016#indextop Last edited by oldskool; 09-20-2021 at 07:29 AM. |
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