Post by DJ20 on Mar 31, 2005 9:53:13 GMT -5
I'm looking for the right head for my current engine build. The bore is 4.185" and the stroke is 3.050" for 335ci. The compression is 11:1 with 475 gram 6" billet rods and 44lb. Cola billet crank and feather weight JE pistons. Current heads are 180cc Pro Toplines with titanium DelWest 2.02 1.6 valves and titanium retainers. The mechanical roller cam I was advised to stongly consider is the Comp Cams XR286R. I was told this cam closely matches my head, compression and cubic inch combo. And it will make max power at 6,800 to 7,000 rpm.
The requirement for the project is 500 honest horsepower on pump gas. The other requirement was that it make max power at at least 7,500 rpm. I was told that because the cross sectional area of my heads being only 1.9 would not allow my heads to build power past 7,025 RPM. That is not to say that these heads with this combination won't supply me with the horsepower goal I'm looking for. It's just not at the RPM I'm looking for.
For those wondering, the reason that I need to make good power at 8 grand is because the goal for the vehicle is 200mph. To achieve that, according to my gear chart, I need to still be making around 500 horses at 7,800 RPM.
Question: Can these topline 180cc's be made to breathe deeply enough to make usable power at the 8,000 rpm mark? And if not, then what head do I need to look at to allow this while keeping port velocity high enough to not completely kill the bottom end? Is this an AFR 195 competition series, or Pro Topline 200cc with after purchase port work? Or is this a game of compromise and therefore I can't have it all?
The requirement for the project is 500 honest horsepower on pump gas. The other requirement was that it make max power at at least 7,500 rpm. I was told that because the cross sectional area of my heads being only 1.9 would not allow my heads to build power past 7,025 RPM. That is not to say that these heads with this combination won't supply me with the horsepower goal I'm looking for. It's just not at the RPM I'm looking for.
For those wondering, the reason that I need to make good power at 8 grand is because the goal for the vehicle is 200mph. To achieve that, according to my gear chart, I need to still be making around 500 horses at 7,800 RPM.
Question: Can these topline 180cc's be made to breathe deeply enough to make usable power at the 8,000 rpm mark? And if not, then what head do I need to look at to allow this while keeping port velocity high enough to not completely kill the bottom end? Is this an AFR 195 competition series, or Pro Topline 200cc with after purchase port work? Or is this a game of compromise and therefore I can't have it all?
