1wild&crazyguy
Banned
So Ive playing around with a slant head that I have, a couple actually...I have a stock valved '67 cast head that Have done bowl work to and another that has big valves 1.70 1.44 that I have worked pretty good..
Initially when I flowed the big valve head 'as is' with nothing more than its machine shop seat blend from the larger seat being cut, they flowed no more than 166cfm....keep in mind stock is 160'ish on the intake....
Next I flowed the stock valve head that I had done a conservative bowl blend to about 9 yrs ago..lol...'I never got to finishing that head', but none the less...it flowed 170cfm... just shows the importance of follow though..as in, if you are going to go with larger valves....you MUST blend them in right. If the machine shop had done no smoothing at all...I bet the big valve head would have flowed LESS than stock.lol
Now onto the big valve head for now...
In typical fashoin 'after a good amount of bowl work and guide shortening'.. I started playing with the roof, streamlining the guide and trying to equalize the roofs height on each side of the guide, 1st mistake...the lower side of the guide is not cast very thick so u cannot raise the low side of the roof/guide as much as the other, even as cast...or you will go into water...so that lesson learned and epoxy applied...ha ha I then flowed the that port with the work done to that point and saw 175cfm At that point I moved to the line of sight approach to the valve and realized the floor and walls were all that was left...so I worked the walls straighter to the bowl and removed .040-.050 off of the floor and lengthened the floors flattish entrance and then worked it down toward the valve, stopping about an 1 1/4 away to give this exaggeration of a nice ramp/ssr 'rough total removed from the floor between ssr & entrance was about .080'....I then blended the 3 sections and then flow tested again= 185cfm
The flow could go up a bit with a back cut and real performance vj, the vj on these is something u see on a tractor...lol...but none the less an idea of what u can do..
btw Keith black was quoted as saying the slant 6 intake ports were some of the best as cast flowing inline 6 heads he'd ever seen.....I wonder if the ''as cast'' mention was a disclaimer.lol
I will get pics up soon
Initially when I flowed the big valve head 'as is' with nothing more than its machine shop seat blend from the larger seat being cut, they flowed no more than 166cfm....keep in mind stock is 160'ish on the intake....
Next I flowed the stock valve head that I had done a conservative bowl blend to about 9 yrs ago..lol...'I never got to finishing that head', but none the less...it flowed 170cfm... just shows the importance of follow though..as in, if you are going to go with larger valves....you MUST blend them in right. If the machine shop had done no smoothing at all...I bet the big valve head would have flowed LESS than stock.lol
Now onto the big valve head for now...
In typical fashoin 'after a good amount of bowl work and guide shortening'.. I started playing with the roof, streamlining the guide and trying to equalize the roofs height on each side of the guide, 1st mistake...the lower side of the guide is not cast very thick so u cannot raise the low side of the roof/guide as much as the other, even as cast...or you will go into water...so that lesson learned and epoxy applied...ha ha I then flowed the that port with the work done to that point and saw 175cfm At that point I moved to the line of sight approach to the valve and realized the floor and walls were all that was left...so I worked the walls straighter to the bowl and removed .040-.050 off of the floor and lengthened the floors flattish entrance and then worked it down toward the valve, stopping about an 1 1/4 away to give this exaggeration of a nice ramp/ssr 'rough total removed from the floor between ssr & entrance was about .080'....I then blended the 3 sections and then flow tested again= 185cfm
The flow could go up a bit with a back cut and real performance vj, the vj on these is something u see on a tractor...lol...but none the less an idea of what u can do..
btw Keith black was quoted as saying the slant 6 intake ports were some of the best as cast flowing inline 6 heads he'd ever seen.....I wonder if the ''as cast'' mention was a disclaimer.lol
I will get pics up soon
