Needing advise on a 598ci street friendly drag radial Foxbody on pump gas

c.evans wrote:

Copperhead wrote:

supervel45 wrote:I would also send the heads to Charlie and have them max ported and flowed, since it is such a large engine, and you want 900 plus HP, before I picked a cam, but thats just me.

 
Head Porting is not necessary to acheive the desired results.
 
EX:
My previous combo (originally a Seth Hembree 557 w/ A-460 heads w/ 2.30 valves[stock castings], 10.8:1 compression) w/ a small cam, made 850hp
 
My new 598 engine w/ unported A-460 heads [2.35 valve] made just under 1000 (995.1 @6500 to be exact).  BUT,......it does have a lot more compression and cam.

 
 
Since my name was mentioned by supervel45, I'd like to say this.
 
1. I agree that head porting the new style TFS A-460 heads is not necessary to acheive the desired results. Those particular heads are very nice out of the box, however with other brands of heads it might be much more necessary to port and flow test the heads.
 
2. However, there are no downsides to proper head porting and flow testing.
 
3. The more "mechanically correct" we can make the intake runner, the intake port, and the exhaust port, in terms of flow,,, then the less camshaft and compression you have to run in order to achieve the same desired results.
 
4. In other words, with a mechanically better flowing head, you don't have to "crutch" the airflow as much with increased duration and lift from your cam, and the milder camshaft you can run.
 
Hope this helps,
Charlie Evans

Mr. Evans.... Will it be worth having the heads ported for my build and will it be cost effective by having the heads ported what are my gains vs cost. My headers are 2 1/8 x 4

Years and years ago, I asked that same question to myself. So I built a 462 CID Buick Stage 1 engine with a hydraulic cam. A Quadra-Jet four barrel, dual plane manifold, street strip engine. I prepped two identical sets of Stage 1 heads, identical casting numbers, big valves, valve springs and everything. I cc'ed the chambers so that both sets of heads had the exact same compression ratio. We dynoed this engine with the unported Stg 1 heads and made 452 Hp. Then leaving the engine on the dyno, we swapped heads to the ported Stg 1 set. With all other factors being identical, the engine made 504 HP. That was + 52 Hp on a 462 CID street-strip engine.

Doing a little math to obtain HP gain/CID, that would give you 65-70 Hp on a big Ford with a hydraulic street/strip cam. Since you are building a max effort street/strip engine, I would expect even a little more, such as + 75 Hp. The cost would be in the neighborhood of $1100, more or less depending on whether or not you are redoing the valve job. Only you can decide whether or not it is worth it to you. IMO it is.

Charlie Evans

c.evans wrote:Years and years ago, I asked that same question to myself.  So I built a 462 CID Buick Stage 1 engine with a hydraulic cam.  A Quadra-Jet four barrel, dual plane manifold, street strip engine.  I prepped two identical sets of Stage 1 heads, identical casting numbers, big valves, valve springs and everything.  I cc'ed the chambers so that both sets of heads had the exact same compression ratio.  We dynoed this engine with the unported Stg 1 heads and made 452 Hp.  Then leaving the engine on the dyno, we swapped heads to the ported Stg 1 set.  With all other factors being identical, the engine made 504 HP.  That was + 52 Hp on a 462 CID street-strip engine.

Doing a little math to obtain HP gain/CID, that would give you 65-70 Hp on a big Ford with a hydraulic street/strip cam.  Since you are building a max effort street/strip engine, I would expect even a little more, such as + 75 Hp.  The cost would be in the neighborhood of $1100, more or less depending on whether or not you are redoing the valve job.  Only you can decide whether or not it is worth it to you. IMO it is.

Charlie Evans

Wow that is a great gain in porting the heads. I think that is something to think about real soon. Would the intake need to be port match as well?