I even wonder if the vertical wall is good. In the 'what makes sense to me' category, I see a vertical wall better for low lift flow because of less shrouding. The inside radius and tapered chamber wall should help high lift flow. But the bench has a way of changing 'what makes sense to me'.
I bought Drill Hog brand drill bits to drill the holes for the 9/16 and 17/32 brass tubing that you recommended in your old thread. One of the two sizes was difficult to get in the hole and I would be concerned about scraping all the epoxy out of the joint when inserting the tube. Is there a way to peen or solder the ends to make sure they cannot come out. In the case of the oiling head bolt tube - if the brass even rotated in the bore it would be disaster. Or does drilling for the oil hole automatically create enough damage to the brass to lock it in place?
I don't do anything with the 38 top cut...just leave it 38 and hand shape the chamber wall...I only concave the area nearest the valve OD...then I taper the concave shape both towards the plug side and the opposite side more angled and less concave. The quench side needs attention more than anything. I don't lose any flow up top with this valve job/chamber shape.
Thanks Brian. I think I understand the approach. I was probably extending the concave cut too far and creating as many problems as were solved.
Look at post #1 of this thread. It shows the 5 (initial) steps that are being taken to try to unlock 15 cfm or more. Beside those five steps are a list of the tools needed to achieve that step. Only step 1 requires specialty tools and that is clearly stated. We are still following that original plan. The flow bench is used to verify the progress.
Budget can mean many things, these heads will probably be for 475 ish hp engine so budget in those terms.
I am. That part of post #1 is a little misleading. I posted it that way because most people do not have a seat and guide machine and will need to hire it out. Sorry for the confusion.
That's okay. I do appreciate that you are sharing this information with everyone. I'd like to ask you a question, for the street, is a 3 or 5 angle valve job better? I heard about a machine shop that doesn't do 3 angle valve jobs on daily driver as it doesn't matter as the rpm's are not over 5500 rpm's he claims
I can tell you that on the flow bench 3 angles is not enough. The proper valve job will boost flow throughout the flow range. I'll let the guys that run the engines on the dyno and down the track give a better answer.
Good stuff. Thanks for the tips. Was Wal-Mart out of stock?
