AFR Head choice for small block
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
AFR Head choice for small block
I have been offered a good deal on built up AFR Eliminator Racing Cylinder Heads in 245, 235, or even Competition ported 227 cc.
All of them with T&D 1.7 shaft rockers, upgraded springs, titanium retainers. I was told that the 245's were worth 25 extra HP from 4500 - 7500.
The problem I have is I don't want to drop crompression. So the 245 & 235 would require angle milling to go from 70cc to about 62cc. By the time that it is all done angle milling and figuring out intake milling...... It is another $600 bill or so.
Is any body out there happy with comp ported 227cc?
When you look at the head flow charts. Look at the .700 lift numbers because that it where the valves will be lifted to
http://www.airflowresearch.com/index.php?cPath=24
All of them with T&D 1.7 shaft rockers, upgraded springs, titanium retainers. I was told that the 245's were worth 25 extra HP from 4500 - 7500.
The problem I have is I don't want to drop crompression. So the 245 & 235 would require angle milling to go from 70cc to about 62cc. By the time that it is all done angle milling and figuring out intake milling...... It is another $600 bill or so.
Is any body out there happy with comp ported 227cc?
When you look at the head flow charts. Look at the .700 lift numbers because that it where the valves will be lifted to
http://www.airflowresearch.com/index.php?cPath=24
Last edited by gkull; Jan 25, 2012 at 06:18 AM.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
I would go with the 227 competition ported. Milling the bigger heads will reduce the flow numbers. How much I don't know but with the extra work and $$$ it takes to get them right for your application quite possibility they won't do much better than the 227's by the time they are milled. They were designed to flow with big chambers. Might want to look at your existing intake. Will the existing port sizes work with the 227's? If not add intake porting to the bill.
Last edited by 63mako; Jan 25, 2012 at 12:07 PM.
Safety Car
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From: anchorage ak
I personaly havnt went any bigger than 195's. But with displace ment your running, it might be best to change the pistons to achieve the desired compression ratio so that you can run the 245's. Just my .02$
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I'm refreshing my 434. The problem is the pistons are 15 - 16 cc dished. They are more like for a blower motor using 75 cc heads. I have been using 60 cc to keep compression up.
I'm kind of screwed either way because pistons are $900
The good deal on the optioned heads is like $3500 for the 227cc and $4100 for the 235/245
Regular price is like $2029 for 227 heads $1170 shaft rockers $680 springs $185 titanium retainers What ever the sales tax would be. all ready to install delivered to my door
Safety Car
Joined: Jan 2009
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From: anchorage ak
I would still vote pistons. Angle milling heads becomes a game of fitment, not saying it can't be done, but can be a pain in the ***, I'm not aware of angle milling damping flow.600 is cheaper than 900.
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Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
AFR suggested the angle milling because you take less metal off the head to make less chamber cc. You mill and then rebore the head bolt holes. You fit and then machine the intake manifold and often use bigger thicker intake gaskets
Steve, Dart heads that only flow 306 CFM. So the jump to 320 cfm with afr 227 comp ported might make the motor run. I need shaft rockers anyway. My rocker arms are at an angle now and head guides go bad in just a couple of years with my high lift
No I'm using a Cometic MLS heads gasket of .030 and a .005 deck height to get a .035 quench. I just ran a online compression calc program and my C/R is @ 11.42. for some reason I was thinking that I had 11.7.
My roller cam is so big that I can drive around with super unleaded. The DCR was not all that high for a performance motor.
4.155 bore 4.00 stroke -15 pistons 62 cc heads .030 gasket .005 deck
No I'm using a Cometic MLS heads gasket of .030 and a .005 deck height to get a .035 quench. I just ran a online compression calc program and my C/R is @ 11.42. for some reason I was thinking that I had 11.7.
My roller cam is so big that I can drive around with super unleaded. The DCR was not all that high for a performance motor.
4.155 bore 4.00 stroke -15 pistons 62 cc heads .030 gasket .005 deck
Last edited by gkull; Jan 27, 2012 at 08:14 AM.
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I wouldn't mill anything and I would get AFR to port match the intake, what's the use in paying for 320cfm heads and the intake isn't perfectly matched to the head. I had my 227's flowed with and without the Vic Jr intake that was port matched at AFR and there was a 3% different with the intake bolted on. You could get 10-15% or more loss if it is not perfect and there goes $600 down the drain.
Once you get the shaft rockers you will never go back to anything else the stability of the shaft rockers is incredible.
Once you get the shaft rockers you will never go back to anything else the stability of the shaft rockers is incredible.
Burning Brakes
Joined: May 2009
Posts: 1,232
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From: Tucson AZ
St. Jude Donor '12
I'm refreshing my 434. The problem is the pistons are 15 - 16 cc dished. They are more like for a blower motor using 75 cc heads. I have been using 60 cc to keep compression up.
I'm kind of screwed either way because pistons are $900
The good deal on the optioned heads is like $3500 for the 227cc and $4100 for the 235/245
Regular price is like $2029 for 227 heads $1170 shaft rockers $680 springs $185 titanium retainers What ever the sales tax would be. all ready to install delivered to my door
I'm kind of screwed either way because pistons are $900
The good deal on the optioned heads is like $3500 for the 227cc and $4100 for the 235/245
Regular price is like $2029 for 227 heads $1170 shaft rockers $680 springs $185 titanium retainers What ever the sales tax would be. all ready to install delivered to my door
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
AFR talked me into 245 cc or a minimum of the 235 cc heads angle milled and the intake side cut for standard big single plane. I'm just waiting for the quote.
Robb, I know for $4000 I could do a supercharger. Every time I hit the go pedal I wonder if I'm going to hear bad noises from the tranny back
Shark Racer, port matching on a quality intake is only a couple of hours labor
Burning Brakes
Joined: May 2009
Posts: 1,232
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From: Tucson AZ
St. Jude Donor '12
Remember, you can easily make those noises go away by turing up the radio...
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
FR suggested the angle milling because you take less metal off the head to make less chamber cc. You mill and then rebore the head bolt holes. You fit and then machine the intake manifold and often use bigger thicker intake gaskets
Same boat as you, 230cc Dart heads at 300ish on a good day...love to have a slightly smaller but better flowing head.
Youll love shaft rockers they are the cats azz. NO movement
Race Director
Joined: Apr 2000
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
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From: Fremont CA
We angle milled my AFR's from 72cc to 64cc chambers. Angle milling and intake face correction ran around $240 for the pair at the Machine shop I used. Flow numbers didn't decline in my testing. As far as I can remember, it was an 0.080" cut on the major side to get the reduction.
Thread Starter
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
We angle milled my AFR's from 72cc to 64cc chambers. Angle milling and intake face correction ran around $240 for the pair at the Machine shop I used. Flow numbers didn't decline in my testing. As far as I can remember, it was an 0.080" cut on the major side to get the reduction.
Always big problems when building a motor
Race Director
Joined: Jan 2000
Posts: 12,399
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From: San Jose CA
My AFR race ready 210's were flat milled to 64cc They were nice heads for a 383. I do have this question if the 245 cc really are to big if I was just doing 3000 rpm driving down the street or should I say highway in OD. Because AFR said they were for racing big SBC between 4500 and .............. rpm
Always big problems when building a motor
Always big problems when building a motor
LS7 heads have less flow @ low lift (<0.5) and are bigger (265cc), and I have no complaints. I'm sure your cam will be the deciding factor for low end torque. You're running a little over 427ci right?
