OST-058: "Q"

[oldeskewltoy]

more to come......

[oldeskewltoy]

Not a whole lot going through my mind....... but of course 4AG head porting


Recently I've acquired 5 20V 4AG heads. Two Silvertop, and three Blacktop




One of the Blacktop heads went to a client in Indiana, this head is #2 from that lot.... and it is available....


disassembled, ready to get cleaned





more to come....

[oldeskewltoy]

the head came back pretty clean...


This was the first 20V head I spent any time on deburring the casting flash



Most of the casting flash was around the spark plug tube supports, and in the end areas. Some of the area are purposefully cast with a ledge, those areas stand out around the exhaust side bucket cylinders



More to come......

[oldeskewltoy]

and so it begins.... biggest thing on a Blacktop head is core shift... you can kind of see it in top photo's short radius as it isn't centered





Chamber #2 on top, chamber #1 on the bottom....


You can also see where I've done blending around the valve seats



more to come......

[oldeskewltoy]

working the bowls to correct the core shift, and to create "gentle" short radii.....




more to come......

[oldeskewltoy]

2 down... 2 to go....




more to come....

[oldeskewltoy]

with the port work finished, its off to the machine shop to get its valve job, and re-surfacing




more to come.....

[oldeskewltoy]

back from its valve job(ain't those back cuts purdy..... ), and re-surface... ready for re-assembly.




more to come....


PS... this head still needs a new owner.......

[Davegt27]

Do ever get feed back on how much HP a head produced?

[oldeskewltoy]

Do ever get feed back on how much HP a head produced?

a few.... but I wished more. Some are still waiting final assembly