Keith Craft stage II Head Flow Data
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Keith Craft stage II Head Flow Data
I just got this information for Keith Craft stage II heads. Numbers will vary from machine to machine on any given day. .650 lift is what we will be using on our build.
Stage II Edelbrock RPM heads, 2.19 intake and 1.75 exhaust valves:
Intake @ .650 lift is 330cfm
Exhaust 247cfm
Stock Edelbrock RPM heads:
Intake @ .650 lift is 252 cfm
Exhaust 205 cfm
Stock 428cj/scj heads:
Intake @ .650 lift is 242 cfm
Exhaust 181 cfm
Stage II Edelbrock RPM heads, 2.19 intake and 1.75 exhaust valves:
Intake @ .650 lift is 330cfm
Exhaust 247cfm
Stock Edelbrock RPM heads:
Intake @ .650 lift is 252 cfm
Exhaust 205 cfm
Stock 428cj/scj heads:
Intake @ .650 lift is 242 cfm
Exhaust 181 cfm
FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
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From: Smith Mountain Lake, VA
Lloyd are you sure those #s arent KC Stage III numbers @ .700" to .800" lift?? because Brian has KC's CNCed Max effort Edelbrock 427 heads and there 370cfm on the intake at .800" lift if I'am not mistaken...
I'am pretty sure with KC the max on the Edelbrock heads 390/428 heads are 330 cfm... As I recall.....and that was @.800" lift.... "I" think....hell its been so long!!
Well good luck with the build!!
I'am pretty sure with KC the max on the Edelbrock heads 390/428 heads are 330 cfm... As I recall.....and that was @.800" lift.... "I" think....hell its been so long!!
Well good luck with the build!!
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Lloyd are you sure those #s arent KC Stage III numbers @ .700" to .800" lift?? because Brian has KC's CNCed Max effort Edelbrock 427 heads and there 370cfm on the intake at .800" lift if I'am not mistaken...
I'am pretty sure with KC the max on the Edelbrock heads 390/428 heads are 330 cfm... As I recall.....and that was @.800" lift.... "I" think....hell its been so long!!
Well good luck with the build!!
I'am pretty sure with KC the max on the Edelbrock heads 390/428 heads are 330 cfm... As I recall.....and that was @.800" lift.... "I" think....hell its been so long!!
Well good luck with the build!!
No these were the figures given to me for my heads, stage II by a tech at KC. The 390/428 heads are from the factory 72cc. Depending on what stage you want, Keith opens up the chambers up to 76cc. Ours actually measured 77cc do to the tulip valves. The cores of the 427 head and the 428 head are basically the same, before Edelbrock cuts them for the different chamber and valve sizes(and exhaust bolt patterns). This is what the Edelbrock Tech told me before I purchased the heads, because I was concerned that I would not be able to put the larger valves in the (72cc) 390/428 head. The KC person did give me .700 lift flow numbers, but I did not keep them because I was only concerned with what they flowed at the lift I will be using. He did not say nor did I ask about .800 lift.
My chambers are now the same size as the 427 head size after KC ported them.
BTW:
If you have a 4.13 bore 428, the 1.75 exhaust valves will not clear the cylinder wall using the Edlebrock heads. Our bore is 4.17 so the 1.75 exhaust valves clear.
I found the .700 flow numbers... Intake 335 cfm and exhaust 253. Not much more than the .650 lift.
I think Brian had larger valves... Like 2.25 intakes and I can't remember what his exhausts were.
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From: Evanston, WY
I know I like to compare my stuff with other stuff, so I have a general idea where I fit in. Just in case you are the same way, here are the flow numbers from my Tunnelports and my KCIIIs in your lift range.
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
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FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
Likes: 4
From: Smith Mountain Lake, VA
Ok Lloyd...I know that edelbrock advertise's the 390/428 heads as being a 72cc Chamber ..But I have never ran across any that were...they usually average about 74 to 75cc's... If your running a 1.750" ex valve in those what are you using for an Intake valve?
I did notice one of your posts where you said the valve spring pressure on the nose was 325#s if I recall.... And that doesnt seem right to get a valve float at as you posted 7800rpm's?? Hell the roller cam I just sold Wes was a Mid .600" grind..and I think that was like 500 something on the nose and almost 300 on the seat best I remember...?
Maybe it me just getting to damn many builds stuck in my head...between the 5.0 I was building for a local rod shop..and the Fe's..and Now the Mountain motors..Its a damn wonder I can remember my own name!! LOL...
Ask Glenn !! He'll tell yeah I'am about brain dead with Numbers these days!! LOL
I did notice one of your posts where you said the valve spring pressure on the nose was 325#s if I recall.... And that doesnt seem right to get a valve float at as you posted 7800rpm's?? Hell the roller cam I just sold Wes was a Mid .600" grind..and I think that was like 500 something on the nose and almost 300 on the seat best I remember...?
Maybe it me just getting to damn many builds stuck in my head...between the 5.0 I was building for a local rod shop..and the Fe's..and Now the Mountain motors..Its a damn wonder I can remember my own name!! LOL...
Ask Glenn !! He'll tell yeah I'am about brain dead with Numbers these days!! LOL
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FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
Likes: 4
From: Smith Mountain Lake, VA
I know I like to compare my stuff with other stuff, so I have a general idea where I fit in. Just in case you are the same way, here are the flow numbers from my Tunnelports and my KCIIIs in your lift range.
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
Well a blast from the past !! I thought I was close!! LOL... Brian hows the new project coming!! Any updates you care to share with the class ??
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Ok Lloyd...I know that edelbrock advertise's the 390/428 heads as being a 72cc Chamber ..But I have never ran across any that were...they usually average about 74 to 75cc's... If your running a 1.750" ex valve in those what are you using for an Intake valve?
I did notice one of your posts where you said the valve spring pressure on the nose was 325#s if I recall.... And that doesnt seem right to get a valve float at as you posted 7800rpm's?? Hell the roller cam I just sold Wes was a Mid .600" grind..and I think that was like 500 something on the nose and almost 300 on the seat best I remember...?
Maybe it me just getting to damn many builds stuck in my head...between the 5.0 I was building for a local rod shop..and the Fe's..and Now the Mountain motors..Its a damn wonder I can remember my own name!! LOL...
Ask Glenn !! He'll tell yeah I'am about brain dead with Numbers these days!! LOL
I did notice one of your posts where you said the valve spring pressure on the nose was 325#s if I recall.... And that doesnt seem right to get a valve float at as you posted 7800rpm's?? Hell the roller cam I just sold Wes was a Mid .600" grind..and I think that was like 500 something on the nose and almost 300 on the seat best I remember...?
Maybe it me just getting to damn many builds stuck in my head...between the 5.0 I was building for a local rod shop..and the Fe's..and Now the Mountain motors..Its a damn wonder I can remember my own name!! LOL...
Ask Glenn !! He'll tell yeah I'am about brain dead with Numbers these days!! LOL
The Edelbrock rpm heads are new and have never been on an engine. They are still in the box fresh from KC. They will go on the 428cj engine that I am building this winter. The 428cj engine will get a roller cam, so as of yet, I have not purchased the roller cam, springs, lifters, or rocker arms.
Intake valves are 2.19
FE "Freakin Expensive"
Joined: Dec 2003
Posts: 6,461
Likes: 4
From: Smith Mountain Lake, VA
No Lloyd I was talking about your 428 your building...and at a .650" lift with only 300lbs on the nose and a valve float of 7800rpm..just doesnt seem right..when I have used lesser cam "Max" valve float with that much on the seat is all?? I dont think I have your motors crossed ? But maybe I do??
Thread Starter
|
Posting Guru
Joined: Jul 2003
Posts: 1,287
Likes: 3
I know I like to compare my stuff with other stuff, so I have a general idea where I fit in. Just in case you are the same way, here are the flow numbers from my Tunnelports and my KCIIIs in your lift range.
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
Needsmorecoffee.
Joined: Oct 2004
Posts: 3,624
Likes: 2
From: CT
I know I like to compare my stuff with other stuff, so I have a general idea where I fit in. Just in case you are the same way, here are the flow numbers from my Tunnelports and my KCIIIs in your lift range.
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
TP
.600 294 182
.700 306 182
KCIII
.600 351 236
.700 375 246
-Scouder
Brian were those tunnelports ported with those numbers? Mine are bone stock and thought they were in the 280 range @ .600.
Thanks!
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Posting Guru
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No Lloyd I was talking about your 428 your building...and at a .650" lift with only 300lbs on the nose and a valve float of 7800rpm..just doesnt seem right..when I have used lesser cam "Max" valve float with that much on the seat is all?? I dont think I have your motors crossed ? But maybe I do??
fwiw,,, the spring pressure is listed on the cam card as 325 lbs. open.
Posting Guru
Joined: Aug 2001
Posts: 2,117
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From: Evanston, WY
-Scouder