Horse Power VS Hood clearance
- Thread starter AZ Steve
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I would consult a pro head porter, regarding your raised port theory. (Maybe Dwayne Porter, PRH here). The best exhaust port in the world wont make a bit of power without sufficient intake flow. I dont necessarily believe computer simulations.
Some porters do 90% of their work on the intake ports.
Some porters do 90% of their work on the intake ports.
AZ Steve
Well-Known Member
I have never seen one. Thanks, Ill have to do some research.
Somewhere you have to make a tradeoff. You have to use something that fits, that's why with my 68 GTX
I went with the Indy Dual Plane and ported my 906's out. I'd like more power, but I want to drive it and
enjoy it before I DIE!
I went with the Indy Dual Plane and ported my 906's out. I'd like more power, but I want to drive it and
enjoy it before I DIE!
AZ Steve
Well-Known Member
You are correct. the Head porters I have spoken with say they don't see any thing wrong with it given the exhaust port was so poor to start with. The head intake flows very close to 305 CFM, ported it flows 355. both intake flows are adequate for most mid range power motors. however the exhaust flows are poor. Mopar had exhaust flow issues. port raising was to help stop the flow wall. So raising the port and CNCing provided huge power gains.
AZ Steve
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yep, me to, there is one other thing cost, I've ported a cast head or two. I really don't want to look like, smell and taste it for the next few days.
Yeah, I know all of that's not fun but hey, it's mine! I put on my little respirator on, Crank up
the compressor, put on some tunes, and before you know it you're done. I don't do this for
other people. Too labor intensive. Good luck with whatever you choose and be sure to show
us the pic's!
the compressor, put on some tunes, and before you know it you're done. I don't do this for
other people. Too labor intensive. Good luck with whatever you choose and be sure to show
us the pic's!
Lefty71
Well-Known Member
I have the dual plane version.... ill look for the number and see if i can find some pix..... It was available over the counter at Chrysler dealers only way, way back in the day.
AZ Steve
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Thanks
BSB67
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I've lost track. What heads are you refering too? Certainly not factory heads
AZ Steve
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Ive look at two, the indy sez and the indy SR the basic SR head is the one I'm exploring for the work.
Ironbuilt
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Stock look is overrated!!
Street trim I don't see raised ports helping 80hp (if your talking on a car with mufflers). We do a lot of port work and mopar oems heads "Ported" are respectable and are not lacking. What we see the most on a flow bench is Larger exhaust valves really wake them up. Yes there is a bunch more potential with raised ports heads if you want a 700+hp engine, but the raised ports are really not needed with a 515 hp engine. A head like the edelbrock or stealth should work.
We fit a rb m1 single plane that sat on top of intake spacers with raised port stage VI heads ...stock hood no scoop in our 69 charger. We had a 3" dropped air cleaner on a 850 holley. It basically touched the hood. You can make up a lot w the right air cleaner with a stepped base.
We fit a rb m1 single plane that sat on top of intake spacers with raised port stage VI heads ...stock hood no scoop in our 69 charger. We had a 3" dropped air cleaner on a 850 holley. It basically touched the hood. You can make up a lot w the right air cleaner with a stepped base.
AZ Steve
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Thanks for the reply the numbers and work are based on a set of IDNY SR heads.
Dan64
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For what it's worth to deal with the low hood problem i went with ( 493) Trick Flow 270's and a Deep port matched Indy dual plane by Hughes, 850 Holley. Dyno numbers were 652 tq at 4300/ 629 hp at 5600. Motor has 9.9 compression with a 252/258 hyd. roller.
PRHeads
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Imo, you don’t need..... or want...... MW sized intake ports for a stock stroke 440 in the 525hp range.
With a build like that, the raised exhaust port will be worth almost nothing.
That basic build has been done countless times in the last 40-50 years.
No latest/greatest parts needed.
Not that I advocate using OE heads for this type of build, but they would be perfectly suitable for the desired power levels.
10:1-ish 440 with 915/906/346/902/452 heads with 2.14/1.81 valves, mildly ported to flow in the 260 range, decent SFT cam, SD, 750+ carb, 1-7/8” or 2” headers, done.
“Prepped” aftermarket heads would add about 25hp(assuming the stock heads were done “right”........ which is often not the case).
With a build like that, the raised exhaust port will be worth almost nothing.
That basic build has been done countless times in the last 40-50 years.
No latest/greatest parts needed.
Not that I advocate using OE heads for this type of build, but they would be perfectly suitable for the desired power levels.
10:1-ish 440 with 915/906/346/902/452 heads with 2.14/1.81 valves, mildly ported to flow in the 260 range, decent SFT cam, SD, 750+ carb, 1-7/8” or 2” headers, done.
“Prepped” aftermarket heads would add about 25hp(assuming the stock heads were done “right”........ which is often not the case).
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Lefty71
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This sounds awesome.....like you turned your attention from hood clearance to traction very quickly lol.
66Satellite47
Well-Known Member
My Satellite came with a 500" EDE RPM head motor, Torker(I think second gen, but not a TorkerII) & 850 DP, K&N air filter. Fit fine under the stock hood. IMHO the EDE RPM head is a real good stock replacement head.
But you can make the 906 or 915's as good with very little die grinder effort.
I enlarged my exhaust ports to about 1.30 tall x 1.80 wide. That was the size of my Hooker 2" adjustable race headers. I raised the exhaust opening and the width at the flange, removed the ridge in the bowl & remove the guide boss some. IMHO the exhaust was very straight forward.
The intake was the most time consuming.
But you can make the 906 or 915's as good with very little die grinder effort.
I enlarged my exhaust ports to about 1.30 tall x 1.80 wide. That was the size of my Hooker 2" adjustable race headers. I raised the exhaust opening and the width at the flange, removed the ridge in the bowl & remove the guide boss some. IMHO the exhaust was very straight forward.
The intake was the most time consuming.
BSB67
Well-Known Member
AZ Steve
Well-Known Member
Thanks for the info, the base motor .030 over 440, 10.5 comp. roller cam (head choice will determine lift and duration) I will run an after market head, to reduce weight and detonation, I don't want to mess with my stock 915 heads. The fuel will be supplied by a stealth EFI. the real issue is hood clearance VS horsepower.
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