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Hi Gang. Would anyone know the flow rate of 1977 stock cast iron open chamber 2V 400 heads. Even a site that I could go to and run it down. Need to know for a computer Horsepower/torque estimate.
I just got some information on my heads - D5AE for my 78 Bronco.
I would say they have a "moderate" home porting job, Ferrea 2.070" intake and 1.650" exhaust valves. The heads got a 3 angle valve job but because of narrow margins on the valves they didn't want to do a 3 angle on the valves. I will do a little more clean-up, but here is a base for a "moderate" home ported head...
I might as well say I'm surprised at the exhaust flow. While I did spend quite a bit of time on the exhaust, I never really thought they would flow all that well.
. Were these '78 heads? What kind of constriction did you run into in the intake ports? Especially in the bowl area? Are there air reactor bosses in the exhaust ports like the ones blocking up 351W heads?
Thanks SDDL-UP. I spent a LOT of time on the exhaust ports to. Removing the "smog bumps" and gasket matching the port its self. I gasket matched the intake a little but pretty much left it alone. The cam I am using is a Comp roller grind with a .513/.513 lift @ .050, 224/230 duration and a 110 LSA and Crane GOLD roller rockers with a 1:73 ratio. I am hoping to get this put in by the fall. I still have to do the tranny AND the rear gears (3:70). If my Dad was still alive I KNOW he would be shaking his head and asking WTF are you doing????. lol I am 64 This September. What are your plans for your engine?
Try looking up Bubba's M Block page. Its an old website buy very interesting and he has tech info also. I'm working at getting a set of cleveland heads and putting them on my 400.
BuzzLOL - yes, these are the factory 1978 cylinder head. I removed the themactor bumps and did some trimming of the huge plateau around the exhaust valve that contains the water jacket on later model heads. The intakes are pretty good, but I did a bowl blend, tapered the valve guides a bit, rounded in front and tapered like a football in back, then opened up the intake side to very near gasket dimensions.
POPAJON - my plans for this engine are to put back in the original vehicle, a 1978 Bronco. My camshaft is a Howard's roller - 217/225 @ .050" lift and .571/.577 lift - grind no. 233215-10. I should be solidly in the 375 to 400 HP range which is why I will be driving the Bronco and not my 15 year old son, at least not yet!
Had some 4v heads worked bowl work and smoothed.520 lift was flowing 280 cfm@28" through worked air gap intake. Made sure all flow numbers checked through intake manifold. Air gap intake needed lots of work to get flowing evenly at all ports. Did fill the lower part of port to fix the dead spot on btm of port. My roller cam is.520 lift 4wd perf towing application. Have a good day.
Curious on intake? Did you flow head only? I lost up to 20 cfm at different ports when flowed thee intake. I wanted even flow to prevent a lean condition at a cylinder. Detonation prevention 101! Have a good day.
4wd application, read up on annular booster carbs! I like my quickfuel carbs!!!! They work! Good tech page on different booster designs for different application.
Yes the head only was flowed. I actually didn't even request it, but the guy that did the valve job does lots of head work and must have been curious. I will have them flowed at another shop right before engine assembly. There is still a little work to do and I should probably try working the intake short side turn, I haven't touched that.
Intake will be an Edelbrock Performer 400 I picked up used for cheap! I'll do a little work there just to make sure ports are lined up after I can bolt everything together.
I know there is quite a bit of room to improve the intake side, if I could gain another 20CFM or so I'd be thrilled.
Thanks for the tip on the annular discharge carbs.
There's certainly more performance in the "boat anchor" head than head than people would think!