The Holleys I run hold their tunes that long too. When it seems one is "out of tune" the problem is rarely the carb, but an ignition problem causing it.
I'm not sure I'd be puffng my chest out about whupping a '79 ANYTHING.That wasn't exactly a peak of American car performance. But I gotta take exception with your theory about "needing" a large carb for the street. There's no such thing as a "6500 rpm carb", period. Ever see the kind of power a NASCAR racer gets out of a 390cfm Holley? Even your local saturday night circle track guys easily get 400hp out of 500cfm Holley two barrels.
Yes, there is....on a 289 a '6500' rpm carb is around 600-650 cfm rated.....on a 427 rectangluar port Chevy a 6500 rpm carb is around an 850 cfm rating.....it all depends on your cid and how well you use it.
Don't listen to people who tell you to run a smaller carb
God, please deliver me from the fools who konw more than people who have actually DONE something
Or how about Dan Perrin's Cross-Ram Dual 4-barrell Chambered exhaust 68 Z/28 that he turned into an 'f' gas 287 cid 13,000 rpm 10.2 1/4 cart in 1974?
so i guess the 850cfm carb used on nextel cup engines is a 9300rpm carb? sorry but carbs, for the most part, dont limit rpm, unless they are very small. even with a restrictor plate a nextel cup engine makes around 500hp above 7500 rpm.
as for the
1: look at his engine combination. it is quite mild, and he wants a daily driver, so he is going to want and need decent fuel economy.
2: most street engines dont need a 650dp carb, and most street engines like the one indicated dont need more than a 500cfm carb. putting a carb that is 100-150cfm larger MAY improve performance, but not by enough to warrant the loss of fuel economy.
as for the
d.hearn, zookeeper, and historic have earned my respect when it comes to dealing with cars, and that it tough to do. and dont tell me to get some real world experience, been there done that, got the T-shirt and ruined it with grease. i do have "real world" experience. things like crewing on a circle track car, and crew chiefing on a fuel altered. enough real world experience for you?
13k rpm? in 1974? sorry but i am callingon that one. even bob glidden was barely cracking to 10k rpm barrier in pro stock, and formula one didnt break the 12k barrier until the mid 80's. i would accept more like 9500rpm, but NOT 13k.
1. 289'S don't make more torque than a turbo 305
2. 4777...without a suffix, smart ass
3. Get some real world experience and get back to me.
4. 'Bought into the ad campoaings'????? right...like Shelby's "Cobra Kits" that were MATCHED componets....kind of like the Gurney-Weslake 305 I had in 68....you know.
everything in the engine was built for 8500 rpm. Ever been THERE? Didn't think so. Or how about Dan Perrin's Cross-Ram Dual 4-barrell Chambered exhaust 68 Z/28 that he turned into an 'f' gas 287 cid 13,000 rpm 10.2 1/4 cart in 1974?
Do you think he used components that were designed to operate at wildly different rpm?
God, please deliver me from the fools who konw more than people who have actually DONE something.
Better go back to math class JR. You'd need a 4.25" bore with a 2.5 stroke to get a 287. That wasn't happenin in the late 60's in a small block Chevy.Glidden was running a 358 cid Cleveland motor with a 3.5" crank and Dan was running a 287 cid with about a 2.5" crank...you DO see the difference...don't you.
Turbo 305? I don't think so. It wasn't a Cheby motor in there but a turd Poncho 301. My wife had one. And it WAS a turd.I'd match a 289's torque against a 301's anytime. 8500? don't NEED to go there. And finally 13K engine's ? Who you trying to ****? Had to roll the pants legs up when I read that. The Indy DOHC's didn't quite go there.
You needn't pray to the Almighty for salvation, just get up from the computer.God, please deliver me from the fools who konw more than people who have actually DONE something.
Man, with all your knowledge you must have a lot of car and bike magazines...You're right, it was a 301...I know that is a huge difference to a 305....but I digress and the 13k..you just don't know Dan. Try this...how tight did Ronnie Sox twist a 409 Chevy in 1962? Before you jump, I grew up in Burlington, NC during that time and stood behind Mr. 409 #1 and saw the tach at launch. It was 8500 rpm. and the guy who said a sbc couldn't have a 4.25 bore in the 1970's....tell me what block Dan was running....it started out as a 2 bolt passenger car unit...NOT a 302 or 350 4 bolt.Ever hear of boring the cylinder all the way out and sleeving the motor? Street 250 LM Ferrarris were turning 8500 in 1960. Honda motorcycles saw 18,500 in 1968....Randy's 494 cid BB Chevy turned 8200 in 1970.
Pete Hill(you do know who Pete is, don't you...NHRA Top Fuel bike 4 years running) built a 150 cid Harley clone motor that turn 8500 and it's stroke is something like 4.5".
Get a clue guys, drag motors were always ahead of roundy pounders back then when it came to rpm. Even the Cosworth DFV (you DO know what DFV stands for, right) engine at Indy.
wow this thread changed a bit but even though I think carbs suck on that combo an autolite 4100 on a performer would run great almost as good as TBI, BTW I just bought a friend a summit racing chinese rpm knockoff for 118.00 and the quality was very nice, they just raised the price in a week to 129.00.....
You needn't pray to the Almighty for salvation, just get up from the computer.
Glidden was running a 358 cid Cleveland motor with a 3.5" crank and Dan was running a 287 cid with about a 2.5" crank...you DO see the difference...don't you.
You didn't read my 1st post....did you.
Here are the facts:
1. You need 145 cfm per 100 hp
a. This means you need at least 450 for 300hp and more for more.
2. Most carbs flow only 85% of their rated flow.
a. This means a 650 will flow about 555 in real life.
b. This means a 650 will allow you to build about 365 hp (real world numbers)
3. To size a carb for a hipo application double your cid and add 50
4. This means 650 cfm @ whatever the vacum number Holley uses
5. Get the double pumper. It already has a 6.5 power valve
6. Also get a very good electric fuel pump soley for the elimination of vapor lock.
Don't listen to people who tell you to run a smaller carb. I've run the 650 dp on 289's for 37 years with killer results. Throttle responce from idle to max put some fi cars to shame.
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