Which head for a stout 427 SBC ???
Thread Starter
Racer
Joined: Mar 2006
Posts: 276
Likes: 1
From: Pistoia PT (ITALY)
Which head for a stout 427 SBC ???
Ok guys..... I need your advise! 
I'm going to change heads and camshaft on my 427 small-block, and I can't take a decision between:
Dart PRO 1 227cc CNC
AFR Eliminator 227cc CNC
Brodix Track 1 227cc CNC
I have only one thing clear on me..... Dart heads have a stounning efficience on the exhoust (80% of intake
) so I will need a single pattern camshaft.
Anyway the cam selection will be in the 250-255 range @0.050" .... roller hydraulic.
Opinions?
...thanks guys!
I'm going to change heads and camshaft on my 427 small-block, and I can't take a decision between:
Dart PRO 1 227cc CNC
AFR Eliminator 227cc CNC
Brodix Track 1 227cc CNC
I have only one thing clear on me..... Dart heads have a stounning efficience on the exhoust (80% of intake
) so I will need a single pattern camshaft.Anyway the cam selection will be in the 250-255 range @0.050" .... roller hydraulic.
Opinions?
...thanks guys!
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
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From: South of giving a damn
St. Jude Donor '11, '17
IMO you are going with too much head, unless you're building a true race car. Those heads don't turn on until about 4000 and then work great up to 7000+. You've stated that hydraulic rollers will be used, so you'll never see the top end of the heads. I think that something in the 210 - 215 range would be a lot better, maybe even a tad smaller. You'll need the higher intake speed of the smaller heads on the street.
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I ran a 421 SB with AFR 227 heads but the cam was a 260 @ .050 with .660 lift solid roller. Made right at 600HP and ran to 7K= rpm. Unreal power. Hyd roller you will never use the 227 heads to full potential.
Team Owner
Joined: Apr 2002
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From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
If we assume that a 227cc head is right for a screaming 427, a 383 will like in and around 205cc head and a 350 will like around 186. Kind of neat, as this actually follows High Performance motors kind of closely. At least I find it neat. 350s with AFR 180s arent hurting any.
If we assume good mild 350s like the 167cc heads(Dart S/R, World S/R, Pro topline torkers, Edelbrock everything, etc). A mild 427 would like a 204cc head, and a 383 would like a 182cc head. Which also follows real world results.
Just my thoughts.
Some race rite AFR 210s maybe?
If we assume good mild 350s like the 167cc heads(Dart S/R, World S/R, Pro topline torkers, Edelbrock everything, etc). A mild 427 would like a 204cc head, and a 383 would like a 182cc head. Which also follows real world results.
Just my thoughts.
Some race rite AFR 210s maybe?
Last edited by Guru_4_hire; Dec 3, 2007 at 02:37 PM.
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
I think that you guys are forgetting that a 427 ci places a high demand on airflow, so bigger flowing heads are in order to make it work. It will not suffer from low intake charge speeds as does a smaller engine.
However with that airflow, i would also use mech. roller cam to be able to use them to their full potential.
However with that airflow, i would also use mech. roller cam to be able to use them to their full potential.
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Thread Starter
Racer
Joined: Mar 2006
Posts: 276
Likes: 1
From: Pistoia PT (ITALY)
Actually I have Trick Flow heads.... 195cc fully hand ported!
The feeling is that the engine is under-headed..... at 6000 rpm !
The cam is 234° - 242° @ 0.050" 112 LSA
In the quarter mile I'm allready 0.4 sec faster than Viper SRT10..... which was my faster competitor (between Viper GTS, C6 Corvette, C6 Z06...... and many other muscle cars)
This if my engine during my last "check-control" !!!
..... I'm very proud of my beauty!
The feeling is that the engine is under-headed..... at 6000 rpm !
The cam is 234° - 242° @ 0.050" 112 LSA
In the quarter mile I'm allready 0.4 sec faster than Viper SRT10..... which was my faster competitor (between Viper GTS, C6 Corvette, C6 Z06...... and many other muscle cars)
This if my engine during my last "check-control" !!!
..... I'm very proud of my beauty!
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
This was a custom roller that was ground for the motor. It was a little while ago and I don't have the exact specs on it anymore.
Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
I would have to agree with bigger heads than smaller for that size engine. doesnt the ls7 have a 240 or bigger runner volume? I must ask if you have thought about getting a used 15/18 degree setup if you are willing to go solid roller. not that much more money in the grand sceem of heads. Sorry for that, ,i forgot it would require a piston change.
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Step up to a solid roller and use whichever head flows the best. I am looking a 227 AFR heads for my small block 427ci but I want guaranteed flow numbers from AFR not magazine numbers. If no guarantee I am looking a Dart 18 degree, go big or go home
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
the Brodix 18X would be good, you can use your rocker arms with it
with just a change in stud girdle. a new stud girdle is way cheaper then
a shaft system, would still get the job done.
Go raised runner, longer valves, deeper pockets, straiter runners, problem is the manifold height, better like a raised hood.
Last edited by Little Mouse; Dec 3, 2007 at 09:00 PM.
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I agree about the manifold height, I am looking into that and whether one can be milled down a bit where the carb bolts on.
The reason for the Dart's is a friend has a set in his shop that someone bailed on. They are unfinished but they did port one intake and exhaust and he told me it broke all their records for 18 deg small block heads. They have been in business for over 25 years and while I didn't get the flow numbers I would imagine they are way up there
The reason for the Dart's is a friend has a set in his shop that someone bailed on. They are unfinished but they did port one intake and exhaust and he told me it broke all their records for 18 deg small block heads. They have been in business for over 25 years and while I didn't get the flow numbers I would imagine they are way up there
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
I agree about the manifold height, I am looking into that and whether one can be milled down a bit where the carb bolts on.
The reason for the Dart's is a friend has a set in his shop that someone bailed on. They are unfinished but they did port one intake and exhaust and he told me it broke all their records for 18 deg small block heads. They have been in business for over 25 years and while I didn't get the flow numbers I would imagine they are way up there
The reason for the Dart's is a friend has a set in his shop that someone bailed on. They are unfinished but they did port one intake and exhaust and he told me it broke all their records for 18 deg small block heads. They have been in business for over 25 years and while I didn't get the flow numbers I would imagine they are way up there
they are both high quality. a 23 degree runner head I don't care what
BS they put out for flow numbers is not going to touch a raised runner
they have all the advantages not to mention better valve angle.
Dart makes a raised runner from 235 on up, unless they are really huge
runners jump on them, just my opinion but I would not back up from a
250 to 270 runner on a 434 with a solid cam.
All the raised runner manifolds I have been able to look at are very
tall, doubt very much your low profile hood can work.
Last edited by Little Mouse; Dec 3, 2007 at 10:52 PM.
Thread Starter
Racer
Joined: Mar 2006
Posts: 276
Likes: 1
From: Pistoia PT (ITALY)
I would like to stay with 23° heads..... because of hood clearance, Headers, Intake andmany oter things that I have to use.
AFR need offset rockers or shaft mounted rockers.... this is a minus for me.....
Dart look very impressive about flow numbers ( more than 300 CFM @ 0.700" of lift and a very good flow @ 0.200").... and can accept standard valvetrain
Brodix.... very close to Dart.
Of course I will follow your suggestions, buying a solid roller cam in the range of 255-260° @ 0.050" ..... but with not so tight LSA in order to have some vacuum at idle.
Some feedback from guys with similar combos should be very appreciated!
..... I'm talking about lots of money (at least for me....) so I would like to do it one time only!
AFR need offset rockers or shaft mounted rockers.... this is a minus for me.....
Dart look very impressive about flow numbers ( more than 300 CFM @ 0.700" of lift and a very good flow @ 0.200").... and can accept standard valvetrain
Brodix.... very close to Dart.
Of course I will follow your suggestions, buying a solid roller cam in the range of 255-260° @ 0.050" ..... but with not so tight LSA in order to have some vacuum at idle.
Some feedback from guys with similar combos should be very appreciated!
..... I'm talking about lots of money (at least for me....) so I would like to do it one time only!
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95