78 SC Intake Ports: Normal?

[MotoSook]

I stripped my motor down today and saw this. Do these look stock? Or did someone attack the ports with a grinder?

It is tough to tell in these pictures, but they don't look factory. I can see the grind marks. I can imagine that someone did that to open up the port, but didn't do a very nice job. Regardless, the motor seems pretty strong, so although not nice and smooth, it is effective...

..so I'm I imagining it or did some take some metal off those ports?





Thanks,

[jluetjen]

The picture look fairly normal to me. I've often seen some grinding marks around the seats.

Usually if someone does a bad porting job, the first thing that they do is take off is the valve guide boss, which is still there in your pictures.

[MotoSook]

John,

The area just before the valve does not look like the original casting surface. I'm not concerned, just trying to learn something about my motor.

Thanks,

[jluetjen]

I've never seen the assembly process for heads but whenever I've seen aluminum heads with valve seat inserts, I've seen what looks like some sort of quick clean-up to remove any edge between the seat and the port wall.