New XB Heads

[aswracing]

Originally Posted by saatananteri

How much/what would one gain if newer style XB-heads were properly ported, keeping standard valves? Valve seat bases had noticable step in ports from factory, that was solved easily (did not touch valve/seat contact-area + valves were seated properly). I suppose some would rise floor a bit on (at least on newer) XB-heads? If ports were CNC:d, both heads would be identical > working as efficiently?

I have newer XB heads, regular valves, valve seats smoothed, 10,5:1 Hammer Pistons, 536 cams, HSR42, 2-2 XR Trapp.

An IMPACT porting job adds about 20cfm of peak intake flow and translates into roughly 7-8% more power capability, assuming proper cam timing.

That mismatch you were seeing on the valve seats is common on XB & late model XL1200 heads and believe it or not it doesn't hurt anything. If you notice, the mismatch was all in the opposite direction of what we used to see on pre-rubbermount heads (and still see in 883 heads for that matter), in other words the intake seat i.d. on these late 1200 heads is almost always larger than the aluminum right above it, and the exhaust seat i.d. is smaller than the aluminum right above it. This actually gives both a little bit of anti-reversion.

CNC porting does get the two heads very close to the same, and the porting programs are identical, just mirrored images of each other. But the ports don't come out identical, simply because these things are castings, and every casting is a little different. There's some places we don't touch by CNC because they don't have enough material there to begin with, and they vary in those areas from head to head. In those areas HAMMER Dan hand blends the cut and non-cut areas after the CNC process. It's more work but it beats the hell out of CNC'ing every port too big just so you machine it all.

[rocketmangb]

So I guess my Factory 06 Rubbermount Heads are worth about a grand now to the right buyer ?

And my Sledge Heads that are somewhere in Idaho (Sandpoint) right now must be pretty good stuff in that they are 09-10 castings with the Carb Intake flange mounting ?

[aswracing]

Well, they sell new for $958 bare, so used, I dunno, whatever the market will pay I guess.

[rocketmangb]

Guess that makes them worth about a grand complete.

To a willing buyer !

[madnss]

Originally Posted by rocketmangb

Guess that makes them worth about a grand complete.

To a willing buyer !

What are you smoking?

[rocketmangb]

Nothing Ryan
They wont be for sale anyway
Im just saying
I'll just save em for the day I kin do an 88-90 Incher.