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He He He Hee....
Tom, Tom, Tom, I was just yankin' on your chain...Comment
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Re: Clarification on flow rates
Pretty interesting. I never knew two and four bbl ratings were done differently. So, if the tripower setup is evaluated in 4 bbl terms, we can compare about 906 cfm to 780 (is that what my 425 '66 carb is rated?)?
So why are the 425's always faster than the tripowers? Just a little joke guys, don't take it personally...Comment
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Re: CFM and the Renaissance Man
Duke,
Just going from memory I would have said the CFM to be 1100 to 1200 (out of the book), like motorman mentioned. But I can now appreciate the extent that you, Jerry, and everyone went to clarifiy the original question.
Additionally, my hat it truely off to you. You didn't miss a beat and can joke around with the best of them, a true modern day Renaissance kind of guy. TBarr #24014Comment
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Re: Da "Duke of Earl" strikes again.....
Guys, I am really finding this interesting, guess I had not looked into it much before. Maybe I am starting to get the picture - if any one of the 3 two bbls was rated against the total pressure drop across the intake, you might get the full 2 bbl rating? But when all 3 carbs are rated against the same total pressure drop across the intake, they become limited by the intake, and that is why the total actual flow is not the sum total of the 3 carbs? Someone out there please summarize it, in one clear sentence... and, I'll still put my 425 up against those 435's... nothing like a little friendly rivalry!Comment
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Re: I'm OK with that....
.....I began to worry that The Duke and Lord Jerry would banish me to some deserted isle (without the keys to my Corvette). TBarr #24014Comment
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Everett, you're on......
let's see....my 68 came from the factory w/trips, an' if I take on Everett's challenge, I could swap out my trips for a high rise and an 855 3418. That would work, after all Everett has an advantage with the high rise. Hey, anybody have 67 intake I can borrow, just long enough for me to dust Everett off? I I use the intake from a 67, the odds are even, yes?Comment
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They're not called pocket protectors anymore
Nowadays its the PDA, cell phone, and pager. Not in the pocket, but clipped on the belt. Gotta keep up with the modern "geekdom" guys and gals.
DonComment
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Re: Everett, you're on......
I'm confused, you are going to put the tripower setup back on? What's on there now? Anyway, I think I remember reading something about the rest of your motor, what have you got in there? Seems like you have a monster motor? My challenge was stock '66 425 up against stock '67 435... and, I wouldn't really thrash mine that hard anyway, it's old and tired... and it is a unrestored Bowtie car, so I don't want to break it. Was I close on the summary of flow?Comment
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Re: Everett, you're on......
George is into yanking chains today, Everett. Look further down the posting, I wouldn't race him until he can steer the car. But when he get's that fixed, you're right, watch out he's got a few extra ponies in there. TBarr #24014Comment
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Re: I'll Try a Summary
I believe what Duke said is for some reason the 2 bbl and 4 bbl carbs are flow tested at different standards of pressure differentials. The 2 bbls were tested using a vacuum of 3 inches and 4 bbl carbs were measured at 1.5 inches. The carbs are basically venturi meters and a higher pressure differential will flow more across the carb. To correct for the different standards of pressure differential, Duke intorduced a correction factor. If your tripower engine would pull a 3 inch vacuum across the carbs at wide open throttle and assuming the intake and heads would also handle the flow, your carbs would flow at the ratings that Motorman posted. If you only developed 1.5 inches of vacuum you would flow at the numbers Duke posted. Conversely, at 3 inches of vacuum the the 4 bbl would flow about 1.4 times its rating at 1.5 inches of vacuum. I assume the Holley tech said the tri-power carbs would not flow at their rated volumes because in actuallity, the engine would not develop 3 inches of differential across the carb at wide open throttle. I assume it is more likely to develop only 1.5 inches. Sorry it is not one sentence, but I think Duke enlightened quite a few of us on this thread.Comment
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Would that be...
The trust part or the never wrong part? :)
jerComment
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I Leave You Guys Alone For A Minute
Don't give Duke and I too much credit, we got together and , KNOWING that the Holleys CFM rate, (advertised) was in the neighborhood of 1275 CFM, (wrong), I suggested dividing this by the number of carburetors, 3, and came up with 425 CFM, after all the carbs LOOK the same.
This deductive reasoning is similar to the engineer on the Titanics maiden voyage. With the ship listing at 15 degrees, down at the bow by 30, he decides to save some weight and throws a deck chair off then stands back for five minutes to observe the effect, perfectly logical...
Now back to inches of Mercury
jer
P.S. Duke really wasn't involved, I just wanted to destroy his credibility along with mine, if there was any to begin with.Comment
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Everett, I'm just funnin' with ya.....
but to answer your question, Comp Cams solid lifter roller, .625 gross lift, TRW closed chamber +.030 12:1 pistons (L-88), Bow Tie open chamber Al. 077 (Casting) heads, ported, 2.25" intakes, 1.88" ex. triple grind. I was going to use the cold chamber hood and the 3418 (855 cfm) Holley, but decided TOO much ponies would break the Doug Nash 5 speed, so to detune it a wee bit, I decided to go with the factory trips. Haven't decided what to use for an exhaust system, either Hooker Supoer Comp under the chassis headers or Hooker side mounts, or stock exhaust, but stock would severly cramp the breathing of the heads and cam.
I might have to change the rear from my 3:55 to either a 3:336 or a 3:08, but I won't know till I get it on the road and see how the gears in the tranny work. The way it coms out is that in gears 1-4, I am running 5;13'S and 5th, 3:55. If I use a 3:36, that drops it down to 4:88's and 3;36, and with a 3:08, I would have 4:56 and 3:08.
Oh what a dilema, but it will be all sorted out within 3-4 weeks, as Godzilla will roam the streets of Cleveland once more.Comment
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Re: Would that be...
i guess it could be either. i believe i was wrong only once, that time i thought i was wrong but i was not!!
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