mikesduster
Well-Known Member
Im just wondering what kind of flow numbers you guys are getting out of a X,J,O type head after porting???
Iron heads; casting # 4448308
Combustion Chamber Volume: 65cc; 2.02" Intake; 1.60" Exhaust
Flow Numbers
Intake Exhaust
0.100 Lift 64 50
0.200 Lift 132 98
0.300 Lift 184 136
0.400 Lift 226 175
0.500 Lift 254 189
0.600 Lift 247 196
I'm running these on my 408 with an LD-340 intake and Holley 950.
Dyno results:
443 HP @ 5800 rpm
460 Ft lbs Torq @ 4100 rpm
Is this the result of a full porting/polishing? Or cleaning up the bowls and adding 2.02 valves?
Iron heads; casting # 4448308
Combustion Chamber Volume: 65cc; 2.02" Intake; 1.60" Exhaust
Flow Numbers
Intake Exhaust
0.100 Lift 64 50
0.200 Lift 132 98
0.300 Lift 184 136
0.400 Lift 226 175
0.500 Lift 254 189
0.600 Lift 247 196
I'm running these on my 408 with an LD-340 intake and Holley 950.
Dyno results:
443 HP @ 5800 rpm
460 Ft lbs Torq @ 4100 rpm
what cam might you be running?
I'm running the same intake, smaller carb [for now], I wanna get a 950 or 1050 annular with a victor single plain.
Did you use a mill to shorten down the long guide? did you completely remove the long guide tail that curves on the top of the roof ? i'm going to start on a set of J's for my 427" but will use 2.05 Ferras.270's-280's int 180's-190's exh
Here are mine [j's] that I'm running on a 410 right now.
2.02-1.60 11/32 undercut at the stem and back cut, exhaust valve are ferrea.
.100 75 52
.200 142 101
.300 200 141
.400 249 169
.500 278 180
.530 281 184
.600 248 187
I used a harbor freight grinder w/ 3 different shaped '3 1/4'' long shank' carbide bits, and rolls to do a lil polishing.
I stopped porting at 267 in my first intake port.
Starting on my 2nt intake port with some new idea.
Cutting in the 2.02 w/nail head valve, netted me 21 cfm at .500" after i put a nice 3 angle cut to the seat it brought my .100" cfm up from 57 to 77 cfm.:cheers:
So there's a lot to be gained just by cutting in a 2.02" and having a 3 angle valve job done to it, while i'ts at the machine shop getting rebuilt.
then if you want more,.... smooth and round every thing in the port.................From there you real need a flow bench to know what works and what should have!..... but killed the flow.:angry7:
Just my 2Cents :-D
Did you use a mill to shorten down the long guide? did you completely remove the long guide tail that curves on the top of the roof ? i'm going to start on a set of J's for my 427" but will use 2.05 Ferras.
And the one pic of the J and magnum head is to show why magnums can't do these numbers & are meant for 318's. ha ha
hay 1wild&crazyguy are those the chevy 100 long valv. your useing?????