Thread: Choose A Cam By Head Flow Rates.

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Pat, with your experience you have a feel for the way to improve flow while I would have to go back to the good articles SBC linked to except that I know you really can't solve problems in fluid dynamics without a computer, although charts help. Since I am going to use the lowly 882 heads at first on my SBC350 for economy and low rpm torque, maybe you or someone else can explain to me how the 882 heads flow as well as they do with the smallest runner volume in the list? Maybe that is a case where the smaller runners help velocity which helps flow up to some limiting rpm. Clearly the 882 heads are limited for high rpm but maybe the GM engineers did a good job designing these heads as a way to detune the earlier heads and still get good low rpm torque back in the day of the '70s gas crunch. So far all I have had done is to have the exhaust ports smoothed and shaved the heads down to a 73 cc volume.

Don Shillady
Retired SCientist/teen rodder

Don, I have an idea your motor is gonna be a little sweetheart and that you'll be very happy with it.

i have been lucky?? i have looked at heads that my friend made and he spent good money to get it flow good numbers. i have had a good look at a lot of ports and have talk to one of the best porters and read some about flow. and i talk about this with all my engine builder friends all the time and get down to small port hi speed = velocity i can not talk about you head. but for what you do with it will work i do not have a flo bench so if you are looking for number i can not help but i can tell you flo bench is a tool it will not help with what is really go on inside your engine .the exhaust is so very important header tub size leigh of primary. your carb cfm and intake and cam all this has to work to gether the port that i think about is the exhaust. when the exhaust leaves the the head that is not it. better this works the better the heads works .on your head i would back cut the ex valves up to the 45 and work in the bowl the valve angles 30 45 60 70 hand blend the blowl to 75 and to 60 tring to make a radii and make the valve hit the 45 at the upper part of the 45 on the ex valve if not work on the seat till you get it rigth and i do not like wide seats on the ex 0.60 and clean the floor of the chamber so the vavles works good at low lift

that why i did not say cut the head out the short side radii as were it at

that ok i am a little up tight work on a set dart heads all day setting them up for 800 lift roller cam

Pat, Tech1 and DennyW, thanks for the comments. I am getting impatient to get the engine running but I still have several details to finish on the chassis first. I forgot to mention that I had the valves on the 882 ground at 30/45/60 so I guess I have a pretty good "poor man's" econo-head.

Don Shillady
Retired Scientist/teen rodder