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Andy302
20-06-05, 05:50 PM
For a Ford 302 with full rpm kit, 4.030 pistons.

I had thought about a 600 cfm Edelbrock but I notice Repower put the 750cfm Edelbrock with their rpm based engine. Is the 750 a tad overkill?:confused:

Id like to make my mind up as Ive got my eye on a carb on e-bay and in the club classifieds!! Ones 600 and the others 750.:thumb:

Cheers

dingocooke
20-06-05, 06:02 PM
Hi Andy,

I've got 302 with same kit and a 600 cfm Holley, Holley part number 1850 (I was surprised just how many 600 cfm Holley models there are!)
I'd say it was Ok for general street use; still tractable, with plenty of mid range torque, and good top end, and it builds revs very quickly; there is no way i'd go 750 cfm on my combination, butthats only my opinion!

Steve

wilf
20-06-05, 07:37 PM
600 cfm plenty for a 302 IMHO.

JamesP
20-06-05, 08:03 PM
Go for the 600, a 750 will kill any off idle response on a 302 as the vacumn signal to the carb will be significantly lower, hence poor fuel atomisation and delivery at low revs.

A 650 will still be more than sufficient to handle your upper RPM limits as well.

James

Andy302
20-06-05, 08:05 PM
Had to admit I was plumming for the 600 so Ill stick that way. Now lets see how cheap I can get one for!!


Thanks Guys. :thumb: :thumb:

craigh
20-06-05, 08:08 PM
i was also advised to go no bigger than a 600 on my engine

Clarkson
20-06-05, 08:12 PM
Anyway the 750cfm is sold:D :thumb:

craigh
20-06-05, 08:37 PM
cheap as chips from summit 235 dollars

tarmacscratcher
20-06-05, 08:45 PM
650 barry Grant Speed Demon is the way to go....good bit of kit....far better than Holley or Edelbrock

gareth08
20-06-05, 08:58 PM
Had a 750 cfm on my 347 Ford and changed back to a 600cfm.
The 750 just did not work properly and ran to rich.
600 cfm is much better
Gareth

Clarkson
20-06-05, 08:58 PM
Yes I agree, I have now got the 750 mighty demon, nice carb.:thumb:

queeniee
20-06-05, 09:15 PM
According to Holley, the carburetor size could be decided according to the formula:
Engine size (CID) X maximum RPM/3456 = CFM @100% VE
Note that most street engines have a 90% volumetric efficiency while a fully racing prepared engine has 100%.
On my 482 cu.in; FE, I have two Holley 450cfm each. I set my maximum rpm at 6500 which gives 906 cfm assuming a 100% efficiency (roughly 2X450=900) and still in the correct range for an efficiency of 95% which seems realistic.

MetaJacko
21-06-05, 09:04 AM
According to Holley, the carburetor size could be decided according to the formula:
Engine size (CID) X maximum RPM/3456 = CFM @100% VE
Note that most street engines have a 90% volumetric efficiency while a fully racing prepared engine has 100%.
On my 482 cu.in; FE, I have two Holley 450cfm each. I set my maximum rpm at 6500 which gives 906 cfm assuming a 100% efficiency (roughly 2X450=900) and still in the correct range for an efficiency of 95% which seems realistic.

On that calc, 700cfm should be fine for my engine (402ci) It came with a 3310 750cfm though
so I'll stick with that for the mo.

What is your FE :confused: Its a stroked something I would guess, is it a new ali block?

Paul

FatBoy
21-06-05, 11:00 AM
I ran a 780 on a 427 S/O, which is about right based on Queeniee's calculations.
On a similar vein, what carb. setup are you all using ? i.e. double-pumper, sequential throttle valves etc.
I used a 780 with sequential throttle valves i.e. a pair of smaller primarys followed by a pair of dustbins. This worked really well on the 427 and made it really nice and tractable at the bottom end.

Paul

queeniee
21-06-05, 08:54 PM
Yes, the new Shelby alu block prepared by Keith Craft
On that calc, 700cfm should be fine for my engine (402ci) It came with a 3310 750cfm though
so I'll stick with that for the mo.

What is your FE :confused: Its a stroked something I would guess, is it a new ali block?

Paul

MetaJacko
22-06-05, 08:43 AM
Yes, the new Shelby alu block prepared by Keith Craft

How do you get round emitions rules with that since I would have thought it would be classed as a new engine and therefore need to fit into tight CO2 emitions but I cant see an FE managing that :confused:

Must be fun to drive though :D

Paul

MetaJacko
22-06-05, 08:44 AM
Just noticed your in Paris.

I would have thought French emitions rules must be similar though?

Paul

FatBoy
22-06-05, 08:45 AM
Most if not all the alloy blocks have original '60's casting numbers on them. So you should be able to get away with it being and "old" engine.

Paul

MetaJacko
22-06-05, 08:53 AM
Most if not all the alloy blocks have original '60's casting numbers on them. So you should be able to get away with it being and "old" engine.

Paul

Hmm,

Seems to be streaching the point a bit to claim that. I guess the idea being that its an old FE casting mold but they are using alu instead of iron :confused:

It would be nice to hear from anyone in UK with an alu FE block or even a new iron genesis block I guess, to find out how they got round it.
I'm assuming yours is a genuine 60s FE?
Getting an Alu FE is something I may do next (If and/or when I can get the cash for it :D)

Paul

FatBoy
22-06-05, 10:24 AM
I "had" a 1967 427 S/O block, but I've just sold it because I've been offered an alloy 427 complete at a price that I can't refuse.

Paul

MetaJacko
22-06-05, 11:31 AM
Sounds good :D

But are you changing Toploader to a David Kee alu one as well :p

How will that affect requirements for CO2 emmition testing though? Unless you
are going to claim its still a 60s block and therefore exempt?

Paul

queeniee
23-06-05, 10:34 AM
You are right: the engine has same external dimensions as my previous 390FE; metal has changed!!! The engine is 4.25 bored and 4.25 stroked. The oiling is the same type as the ford racing blocks in Nascar. All previous accessories were fitted providing minor modifications. It is coupled to a D.Kee aluminium Toploader (short ratio).
Hmm,

Seems to be streaching the point a bit to claim that. I guess the idea being that its an old FE casting mold but they are using alu instead of iron :confused:

It would be nice to hear from anyone in UK with an alu FE block or even a new iron genesis block I guess, to find out how they got round it.
I'm assuming yours is a genuine 60s FE?
Getting an Alu FE is something I may do next (If and/or when I can get the cash for it :D)

Paul

queeniee
23-06-05, 10:38 AM
6 CO2 + 6 H2O = C6H12O6 + 6 O2

More CO2 means more O2 produced by green plants via chlorophyll and light :angel:
How do you get round emitions rules with that since I would have thought it would be classed as a new engine and therefore need to fit into tight CO2 emitions but I cant see an FE managing that :confused:


Must be fun to drive though :D

Paul

MetaJacko
23-06-05, 11:52 AM
6 CO2 + 6 H2O = C6H12O6 + 6 O2

More CO2 means more O2 produced by green plants via chlorophyll and light :angel:

:confused: :eek:

I don't think they will accept that for an MOT test as a reason why the CO2 emmitions are not low enough :D

Paul

FatBoy
23-06-05, 11:52 AM
Sounds good :D

But are you changing Toploader to a David Kee alu one as well :p

How will that affect requirements for CO2 emmition testing though? Unless you
are going to claim its still a 60s block and therefore exempt?

Paul

My budget is dissappearing fast, so I'm sticking with a large dia. output shaft iron toploader. It may well be from DK though as it's coming direct from Kirkham and I know they deal with DK.

"Of course it's an original '60's block Mr. Vehicle Inspector, see, it's even got the original casting number on it. :thumb: "

Paul

MetaJacko
23-06-05, 12:17 PM
Just don't try a magnet on it :D

FatBoy
23-06-05, 01:02 PM
I'll make sure it's been running for some time before any inspection, that way it'll be far too hot to check :D