AFR head ????
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
AFR head ???? Need to know if there is a benefit to this model
I have the opportunity to purchase competion package AFR 227cc spread port (exhaust) heads plus some other parts to build a blown or turbocharged 434 small block.
Cola 4.00" stroker crankshaft
·Eagle 5.850" connecting rods with ARP 2000 rod bolts
·Probe custom blower pistons with tapered wrist pins and LOKO skirt coating (about 8.5:1)
·Erson custom blower camshaft .645 lift, 268I/276E duration at .050"
·Probe roller rocker arms 1.6I, 1.5E
·Double roller timing chain set
·**Everything Brand New In boxes. all for $3000.
Lemons has said that they can make headers to fit the exhausts spread bore.
My question is: What is, if any, the benefit of using the spread bore head versus the standard one?
Thanx
[Modified by BlackKnight, 9:28 PM 7/18/2002]
Cola 4.00" stroker crankshaft
·Eagle 5.850" connecting rods with ARP 2000 rod bolts
·Probe custom blower pistons with tapered wrist pins and LOKO skirt coating (about 8.5:1)
·Erson custom blower camshaft .645 lift, 268I/276E duration at .050"
·Probe roller rocker arms 1.6I, 1.5E
·Double roller timing chain set
·**Everything Brand New In boxes. all for $3000.
Lemons has said that they can make headers to fit the exhausts spread bore.
My question is: What is, if any, the benefit of using the spread bore head versus the standard one?
Thanx
[Modified by BlackKnight, 9:28 PM 7/18/2002]
Melting Slicks
Joined: Jul 2000
Posts: 2,112
Likes: 2
From: Peoria IL
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
The only reason I can think of that they would do that was if increased the flow. Gkull I think recently stated that the engine simulation programs really reward split duration cams, that is cams with longer duration and higher lift on the exhaust side. I imagine if the spreadports offer a decent gain a cam without split duration would be optimal. I'm not sure how exhaust flow is related to blown applications but that may be another reason as it seems the person had a fairly extreme setup in mind. The blower you should use for that motor would be labeled a race piece by its manufacturer, but don't pay attention to that. That motor with optimal compression and no blower would easily make 600+hp. I'd like to build a motor with those parts only naturally aspirated, so obviously not using those pistons. Good luck! :)
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
Re: AFR head ???? Need to know if there is a benefit to this model (korvetkeith)
:)
Thanx for the input korvetkeith, it makes sense that they might be used to increase flow, but I do not know, that's why I asked the question.
Thanx for the input korvetkeith, it makes sense that they might be used to increase flow, but I do not know, that's why I asked the question.
Racer
Joined: Jun 2000
Posts: 294
Likes: 0
From: WA
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
The spread exhaust port allows better cooling jackets between the two ports. Another modification sometimes used is to plumb an external coolant supply line from the water pump directly to the head between the two exhaust ports - this gets cooler water directly to the hottest portion of the head. Theoretically this will reduce the chance of detonation.
Instructor
Joined: Mar 2002
Posts: 239
Likes: 0
From: Fredericksburg VA
Re: AFR head ???? Need to know if there is a benefit to this model (torquejunky)
Most cams are split duration. For heads with a 0.75E:1.00I flow bais, the duration for I and E tends to be fairly equal in a medium-performance naturally-aspirated engine. All this goes out the window when you supercharge it. The 0.75E:1.00I ratio isn't correct any longer. You need more exhaust. For restrictor-plate and restricted carburetion race engines, the opposite is true. You need more intake. The cam should reflect this.
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
Re: AFR head ???? Need to know if there is a benefit to this model (HeaderDesign.com)
HeaderDesign.
Thanx for the reply. I am a bit confused. :confused:
Are you saying this is a good combo as long as I supercharge it or should I try and use the combo, but with regular heads and supercharge it?
Thanx for the reply. I am a bit confused. :confused:
Are you saying this is a good combo as long as I supercharge it or should I try and use the combo, but with regular heads and supercharge it?
Instructor
Joined: Mar 2002
Posts: 239
Likes: 0
From: Fredericksburg VA
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
I think the heads are probably designed for naturally aspirated conditions. If you supercharge it, you just need to make sure you know the head flows, the boost, and cam it right. It can be done very successfully, just don't open the intake valve too early.
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Melting Slicks
Joined: Jul 2000
Posts: 2,112
Likes: 2
From: Peoria IL
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
It seems like the cam that came would all those parts is a blower grind due to its larger exhaust lift and duration. Those heads flow in excess of 300cfm, airflowresearch.com has all info on the heads. It seems this guy had a very extreme buildup in mind easiy 1000hp. 900hp shouldn't be hard on pump gas as long as you have a large enough blower. Vortech and ATI have all the specs and recomendations for their various on their respective websites. Expect atleast another $3000 for the aftermarket fuel injection setup that you'd need to run. Possibly custome tubing for supercharger and intercooler (if you choose one), the whole supercharger setup will run you anywhere from 3000 to 6000. Once you consider all of the other money that you'll need to spend it may not seem like such a good deal. :)
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
Re: AFR head ???? Need to know if there is a benefit to this model (korvetkeith)
korvetkeith.
I already have a superram and as you said vortech and ATI make kits that come will all the appropriate brackets and accessories to fit my GTA.
I already have a superram and as you said vortech and ATI make kits that come will all the appropriate brackets and accessories to fit my GTA.
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
Okay I spoke with AFR today and they setup with those heads would make a great combo. They recommended using 1 7/8' headers inot 2' primaries with 3.5 in collectors. They also recommended I use a tunnel ram setup for the fuel injection, such as a sheetmetal setup like hogan makes. They also said that a t-trim vortech would be good if I upped the boost by using a gog drive pulley. They also recommended intercooling the blower. I know vortech does not make a intercooled setup for 3rd gens', but I think ATI does. It looks like this project might be a go, even though I would have prefered a twin turbo setup.
What do you think?
What do you think?
Melting Slicks
Joined: Jul 2000
Posts: 2,112
Likes: 2
From: Peoria IL
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
The superram can't take much boost and it would be a restriction anyway. A custom intake would be opimal but extremel expensive. A single plane 4bbl intake converted to injection would be cheaper and make just as much power, it may require a cowl hood however. The T-trim will be holding you back BIG TIME on that setup, its max efficient power is 825hp. The engine could make 600+hp w/o a blower. They may have told you that just because that was the kit that they had. Your best option for an off the shelf kit would be an ATI kit with a D1 and intercooler, the D1 can support 925hp efficiently. I think with a custom intercooled setup on a large blower you could make 1000+hp on pump gas. If you wanted to go a little less expensive you could skip the intercooler, as 8.5 to 1 is very low, and run a kit made for a carb motor but run it to an injected carb intake. Use a large blower for about 15psi on pump gas, you could probably make 700+ rwhp on that setup.
Thread Starter
Instructor
Joined: Jan 2001
Posts: 190
Likes: 1
From: Verona, NJ
Re: AFR head ???? Need to know if there is a benefit to this model (korvetkeith)
korvetkeith
I appreciate the suggestion to go with the ATI, it seems there has always beena big debate on which one gives you the best bang for the buck. Someone one the thirdgen.org board is actually working on a twin intercooler for the ATI to fit, once it gets done, ATI will offer it a an option. What do you think about using the holley stealth ram. Do you think it could handle the boost? Isn't Monty's Hogan setup a similar manifold for his 1200hp twin turbo? I know the Hogan setup is a nice peice but you are right it is expensive. The holley seems to be a shortned tunnel ram and looks similar to the Hogan, but then again I am not too familar with the Hogan stuff.
[Modified by BlackKnight, 8:42 AM 7/20/2002]
I appreciate the suggestion to go with the ATI, it seems there has always beena big debate on which one gives you the best bang for the buck. Someone one the thirdgen.org board is actually working on a twin intercooler for the ATI to fit, once it gets done, ATI will offer it a an option. What do you think about using the holley stealth ram. Do you think it could handle the boost? Isn't Monty's Hogan setup a similar manifold for his 1200hp twin turbo? I know the Hogan setup is a nice peice but you are right it is expensive. The holley seems to be a shortned tunnel ram and looks similar to the Hogan, but then again I am not too familar with the Hogan stuff.
[Modified by BlackKnight, 8:42 AM 7/20/2002]
Melting Slicks
Joined: Jul 2000
Posts: 2,112
Likes: 2
From: Peoria IL
Re: AFR head ???? Need to know if there is a benefit to this model (BlackKnight)
The new stealth ram looks great, but its just that, new. I haven't seen or read about anyone running one yet. The Miniram is an option too, but I think some people complained of air distribution problems in blown applications. You should confirm all of this though before you take it to heart.
