650 holley carb or stick with what i got?
10-09-03, 01:22 PM
#1
Rotartist
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650 holley carb or stick with what i got?
I have the 465cfm Holley but have the oppertunity to go with a 650cfm for pretty cheap. should i switch or stay where i am? what are the differences? the 650 has mechanical secondaries where the 465 has vacume...lemme know.
thanks
trevor
"Beer, now there's a temporary solution"
thanks
trevor
"Beer, now there's a temporary solution"
10-09-03, 02:15 PM
#2
if you know somebody who can tune the 650 in for you, go for it. i just took my 650 off. was told the 600 single was a better carb and will do better times than the 650 double. this guy is awsome and i trust him. i wanted the 650 cause it has more power! yet if the 600 is set up right it has more power. kinda weird i thought. well, i'll see. good luck with your decision.
10-09-03, 02:38 PM
#3
Nikki-Modder Rex-Rodder
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Location: Trying to convince some clown not to put a Holley 600 on his 12a.
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Do the math, folks!
A 70 cid rotary (12a) eats up 340 cubic feet of air @ a suggested highest RPM of 8,400.
This is in a perfect world where everything is 100% efficient, including the intake volume of the engine.
Paul Yaw brags a VE of 88% on his dyno sheet that he uses to sell his modded Nikkis. It's a realistic VE.
Multiply that into the equasion, and you'll see the maximum intake go down to 299 CFM @ 8.4 K RPM.
I've said it many times before- A 650 is just too damn big to do you any good.
Pick a carburetor that has about half agin the maximum flow "rating" that you need. Once dialed in, it will blow away anything bigger. It all has to do with velocity, not volume. The engine's displacement and characteristics determine what it will ingest. The carburetor can't force more volume into the engine.
-If anything, because a smaller carb will have more velocity, it will help your engine to be more volumetrically efficient. (It'll eat a tiny bit more.)
High velocity will have much more vacuum signal to the main jets, and you'll be able to curtail the incoming fuel to what you need.
If the carb is too big, you won't have enough vacuum to richen the mixture enough at the low end, and you'll have crap for power in the low to mid range.
Yeah-yeah, "Rotaries don't make any power down low anyway, so what's the difference?"...Sure-if you need to justify that gargantuan thing you just bought.
But fact of the matter is, obviously the engine is putting something out at low RPMs, and I'd rather be going as fast as I can when the RPMs finally do hit that "sweet zone" than have to dawg it waiting.
My modded carb flows 429 CFM as of yet. I'm hoping for just a touch more. But on a STOCKPORT 12a, I'll stack one that I've tuned up against any Holley 650 or 600!
Unfortunately, I don't have a dyno sheet to show all you "Yeah, right!"ers.
Soon.
A 70 cid rotary (12a) eats up 340 cubic feet of air @ a suggested highest RPM of 8,400.
This is in a perfect world where everything is 100% efficient, including the intake volume of the engine.
Paul Yaw brags a VE of 88% on his dyno sheet that he uses to sell his modded Nikkis. It's a realistic VE.
Multiply that into the equasion, and you'll see the maximum intake go down to 299 CFM @ 8.4 K RPM.
I've said it many times before- A 650 is just too damn big to do you any good.
Pick a carburetor that has about half agin the maximum flow "rating" that you need. Once dialed in, it will blow away anything bigger. It all has to do with velocity, not volume. The engine's displacement and characteristics determine what it will ingest. The carburetor can't force more volume into the engine.
-If anything, because a smaller carb will have more velocity, it will help your engine to be more volumetrically efficient. (It'll eat a tiny bit more.)
High velocity will have much more vacuum signal to the main jets, and you'll be able to curtail the incoming fuel to what you need.
If the carb is too big, you won't have enough vacuum to richen the mixture enough at the low end, and you'll have crap for power in the low to mid range.
Yeah-yeah, "Rotaries don't make any power down low anyway, so what's the difference?"...Sure-if you need to justify that gargantuan thing you just bought.
But fact of the matter is, obviously the engine is putting something out at low RPMs, and I'd rather be going as fast as I can when the RPMs finally do hit that "sweet zone" than have to dawg it waiting.
My modded carb flows 429 CFM as of yet. I'm hoping for just a touch more. But on a STOCKPORT 12a, I'll stack one that I've tuned up against any Holley 650 or 600!
Unfortunately, I don't have a dyno sheet to show all you "Yeah, right!"ers.
Soon.
10-09-03, 06:08 PM
#4
Airflow is my life
Why do you think RB sizes the holleys the way they do? 465 for stockport, 600 for SP. The 600 is overkill for a stockport. And a 650 (I have to assume 4150 or 3310) Dual line double pumper mech secondaries? Youll kill all your intake velocity. A 600 with vacuum secs would be better, at least then you can limit the opening of the secs with a heavier spring. But the 465 is the "right" Holley for you IMHO.
on a stockport 13B for autox racing. LOL, it was a dog. 
12-03-03, 12:57 PM
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TEAM MAZDA
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"My modded carb flows 429 CFM as of yet. I'm hoping for just a touch more. But on a STOCKPORT 12a, I'll stack one that I've tuned up against any Holley 650 or 600!
Unfortunately, I don't have a dyno sheet to show all you "Yeah, right!"ers.
Soon."
This sounds like a challenge to me? I am currently running a non-rotary 600, which Iam unpleased with. Compared to my old street port 13b with stock carb.
With a stock port engine the 600 ran a 10.6 - 10.8, on my street port 12a it runs 9.5, this is obviously in the 1/8th mile. The Challenge I present to Sterling/Carl is if I purchase one of your carbs will you gaurantee it will run better than my 600? Meaning after I run it for a while, if it doesnt run faster you will refund my money with the return of the carb in the same condition you sent it to me? Iam thinking about saving for the RB Holley, but if your carb runs better? If you 2 are interested I would need to find an Holley Nikki adapter? Know where to find one? Iam not trying to bust any ***** around here just trying to find a cheap high performance carb. Cant afford Webbers or FI!
Unfortunately, I don't have a dyno sheet to show all you "Yeah, right!"ers.
Soon."
This sounds like a challenge to me? I am currently running a non-rotary 600, which Iam unpleased with. Compared to my old street port 13b with stock carb.
With a stock port engine the 600 ran a 10.6 - 10.8, on my street port 12a it runs 9.5, this is obviously in the 1/8th mile. The Challenge I present to Sterling/Carl is if I purchase one of your carbs will you gaurantee it will run better than my 600? Meaning after I run it for a while, if it doesnt run faster you will refund my money with the return of the carb in the same condition you sent it to me? Iam thinking about saving for the RB Holley, but if your carb runs better? If you 2 are interested I would need to find an Holley Nikki adapter? Know where to find one? Iam not trying to bust any ***** around here just trying to find a cheap high performance carb. Cant afford Webbers or FI!
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12-03-03, 01:52 PM
#8
Nikki-Modder Rex-Rodder
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813KR$-
Yeah- I make that challenge. What are you gonna do, ask for your money back? lol I already guarantee your satisfaction. You have one month to decide if it sucks and send it back for a FULL refund.
Who loses? Me, that's who. It's my reputation associated with a carb that has my name on it.
(This is a money back warrantee specific only to the "Sterling Carb".)
Email me for details.
Yeah- I make that challenge. What are you gonna do, ask for your money back? lol I already guarantee your satisfaction. You have one month to decide if it sucks and send it back for a FULL refund.
Who loses? Me, that's who. It's my reputation associated with a carb that has my name on it.
(This is a money back warrantee specific only to the "Sterling Carb".)
Email me for details.
12-04-03, 08:20 AM
#9
TEAM MAZDA
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Sounds like a plan! What do you need, my old carb and $300? Do you know where I can get a holley to nikki adapter? I have a RB intake. Also where are you located at, I see rx7carl is in Orlando, but you seem to be in your bedroom with a wife I dont have? j/k If you are also in Orlando I can drop my old carb off to you, Iam in Tampa.
12-04-03, 08:42 AM
#10
Airflow is my life
Sounds kool to me too. An adapter would have to be fabricated. Not a big deal. He's in NY. I can fab the adapter as I have a RB intake to work off of. You guys work out the details of the rest. 
12-04-03, 08:55 AM
#11
Nikki-Modder Rex-Rodder
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It'll cost you the carb, $300, plus $20 for S&H.
I'm a bit swamped with work at the moment, so Email me for schedule details.
Also, packing the carb well is HUGELY important!
...just click a link...
I'm a bit swamped with work at the moment, so Email me for schedule details.
Also, packing the carb well is HUGELY important!
...just click a link...
12-04-03, 11:04 AM
#12
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Rx7Carl: How much would you charge for the adapter? and what would you make it from? I have seen a post, where someone made an adapter for the stock manifold to a Carter carb, which is supposed to be the same pattern as a Holley. It should work, if the adapter was flipped and used the other way around. Not sure if he is selling them or not?
Sterling: The wait is not a problem, I am not made of cash, I will need to start saving.
Sterling: The wait is not a problem, I am not made of cash, I will need to start saving.
12-15-03, 12:23 PM
#14
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Brandt:
Iam talking about using my RB intake and a modified Stock carb from sterling. I will need an adapter to go from the Holley pattern on the RB intake to the stock carb pattern to make the stock carb fit on my RB intake.
Iam talking about using my RB intake and a modified Stock carb from sterling. I will need an adapter to go from the Holley pattern on the RB intake to the stock carb pattern to make the stock carb fit on my RB intake.
