SM Head Modifications on a budget
Here are the steps that I am considering, in no particular order. Please feel free to suggest additions.
*Valve job for 2.055 intake valve (must be done by a machine shop)
*Back cut angles on 2.055 intake valve (drill press and die grinder)
*Enlarge PRP width (die grinder and cartridge rolls)
*Bowl blend (die grinder and cartridge rolls)
*Head bolt bulge reduction (die grinder and cartridge rolls)
I intend to flow test between each modification to show the changes along the way.
Going back to look at the original objectives of this post, we have completed 4 of the 5 initial goals. PBR was hoping to unlock 15 cfm with some very simple modifications. We are quite close to that initial goal and we have not yet touched the head bolt bulge.
There have been several excellent posts and ideas shared about unlocking the true potential of this head. I am so excited to get the input and wisdom that many of you can share. PBR always stresses the importance of area over the short turn. PRH has emphasized the importance of getting the short turn right early in the process. Brian has given some insight into unlocking the potential of the chamber. I think we have just made the case for steps 6, 7 and 8, in no particular order. Before we get there, I think it's important to do a good job with steps 1-5.
As a reminder to everyone, the initial plan for the valve job and chamber work were limited to what a machine shop could do on the seat and guide machine. No hand blending by Joe. With that said, I do not think we have optimized the valve job. I'm going to continue playing with some things (mostly with clay) to try to come up with a better shape. The objective is still the same - come up with a valve job combination that does not include hand work or sinking the valves (which would alter valvetrain geometry).
When we feel like we have taken steps 1-5 as far as possible, I want to try one final bowl blending to remove a couple of ridges that remain between the 70 degree cut and the bowl. It will enlarge the throat a little more, but I believe the shape will be better. I'll wait on that one.
Now, unless PBR has another idea, on to the head bolt bulge. I'm going to try to get some sonic readings and measurements in the bulge area for initial data. All the pushrod holes and two head bolt holes in this head are already tubed, so I'm not too concerned about creating a hole at the head bolt. The tubing process is quite easy. I followed one of PBR's old posts for the supplies and process needed. I have had no problems with keeping the tubes in place on the flow bench. Maybe PBR will talk about how to keep the tubes in place in a running engine.