Carburtor CFM?

[Craig -1965]

Question for the Corvette guy's that know the actual specifications? I have a 327/350 and would like to know the cfm of the original holley (model# 4150) carburtor.

Mine currently has a 600 but hopeing the original was more..... Or maybe to hell with the original and make room for a 700/750 double pumper...

 

[paul67]

I believe it was 585 or 600.

I have one in the basement.

 

[BarryK]

Craig

if i'm not mistaken, your '65 L79 used the same Holley 2818-1 carb (#4150) as the L76 motor and it's a 600cfm according to my holley chart.

 

[Craig -1965]

Carburetor CFM

Thanks for the info. Now I have a desision to make...... 600 in the box of a new 700 double pumper. Ain't life grand.

 

[cfalson]

Original OEM PN was 585 CFM, Holley replacement which is still sold today is 600 CFM.
Charlief
66 Coupe

 

[BarryK]

Original OEM PN was 585 CFM, Holley replacement which is still sold today is 600 CFM.
Charlief
66 Coupe

ahhhh, thanks for the correction Charlie. I didn't know the service replacement 2818-1's were a different cfm than the original 2818-1's.

I wonder when they made the change so I can look at the date code on mine and determine which mine is, a 585 or a 600

 

[JohnZ]

Makes no difference; 585/600CFM is more than adequate for the air demands of any 327; putting more carb on it won't make any more power - it will just degrade the low-to-mid-range metering signal. Over-carbing is right up there with over-camming as the most common mistake made with street engines.

 

[gmjunkie]

Makes no difference; 585/600CFM is more than adequate for the air demands of any 327; putting more carb on it won't make any more power - it will just degrade the low-to-mid-range metering signal. Over-carbing is right up there with over-camming as the most common mistake made with street engines.

I 2nd That!! And 3rd if need be!! junk!!

 

[Ken Anderson]

Makes no difference; 585/600CFM is more than adequate for the air demands of any 327; putting more carb on it won't make any more power - it will just degrade the low-to-mid-range metering signal. Over-carbing is right up there with over-camming as the most common mistake made with street engines.

Do you remember the 302 w/ 850 from factory? How about the 2x4 version?
I think the answer is: it depends on the use and engine cofiguration.

 

[gmjunkie]

Do you remember the 302 w/ 850 from factory? How about the 2x4 version?
I think the answer is: it depends on the use and engine cofiguration.

Yeah, I remember Most of them were Scattered by 30,000 mi.'s!! I had 2 buddy's in high School that had 69 302 Z Camaro's Both Yellow 1 Cp. 1 Vert Both 4sp. they both had engine's in less than 30,000 mi. 1 with less than 15'000 They'd Run Though!!! junk!!

 

[JohnZ]

Do you remember the 302 w/ 850 from factory? How about the 2x4 version?
I think the answer is: it depends on the use and engine cofiguration.

Ken, yup - I remember them well, and still have one (all-original unrestored/unmolested '69 Z/28). The only reason the production Z/28 had the big 780/800 #4053 on it was to be SCCA-legal for Trans-Am racing, where it spent its whole life at WOT between 4500-8500 rpm. Even the over-the-counter-only cross-ram setup was released for the same reason, and had two 390's on it. Both setups suck on the street; between the torqueless "30-30" and large venturis (and huge common plenum on the cross-ram), they need a LOT of rear gear to keep them spooled-up. When I was having my #4053 restored, I ran a 600 Holley #0-80145 on it, and it was a LOT more pleasant car to drive, with much sharper throttle response, and still ran like gangbusters.

 

[Tom Bryant]

They (302/Z28) sure do like wide open throttle and open headers too. I have a friend over by Auburn that traded in his '66 triple black L79 Chevy II SS for a new '68 bright blue Z28. He ordered it with basically no options other than the Z28 package and an AM radio. He put headers on it and drove it that summer some. In 1970 he got interested in Buick Grand Sports and the Z28 was left to gather dust. I rode in it with the headers open in 1971 and it ran like a bear at WOT. It had about 2300 miles on it at that time and I don't think it has seen the sun more than a couple times since. The calipers started leaking shortly after that so he stopped even buying plates for it and wisely didn't do any more open header tune up runs after that. I don't think he has fixed it yet.

In fact I think of all his cars the only one he keeps up for occasional driving is his Auburn.

 

[Craig -1965]

JohnZ,
The believe the old Z28's had a cam with .5+ lift for intake which can handle a rather large carb..... 850cfm. Ah the good old days..........

My 65 327/350 has a mild (don't know the specifications) since it was there prior to my purchase. The current carb seems to be a little on the small side. So I applied the 3 day rule..... Which is if I see something I have to have for the vet I wait 3 days and see just how much I can't live with out it. So My current plan is a 650 doubel pumper mech secondaries, the current carb is a 600 cmf with a vaccum secondaries. This thread has some good information thanks guys.