Stealth Head Port Work

[Garys1969RR]

Does it help low lift flow to remove the ridge from the valve seat insert, where it meets the aluminum casting? There is a small ridge there, looks like it would disrupt airflow. 440 heads.

 

[Challenger340]

Never hurts to blend the seat ridge into the port wall, but that said....
far better Seat Angle preps should be applied to the Stealth's FIRST, then making that blend job easier.... and providing substantially more Flow/worth the effort.

 

[wagonman]

One issue my head guy pointed out was where the exhaust seat overlaps to the intake seat. He said it should be the other way. The Source heads leaked around the seats, like a chunk of material got caught under when pressing the seat in. Decided not to invest any more $$$ in them and went with some Trick flows. Pay your $ and take your chances. My ridge was way worse than your pic.

 

[Garys1969RR]

Yea I noticed the overlap. Looks like a cut was made before they put in the second seat. That removed a curved part on the edge of the insert. These heads do need a little work, for sure. Shining a light on the chamber side, I can see light coming past 1 ex valve. Not good.

 

[cryplydog]

Yes. Do you have a good head/porting book? I have 2 David Visard head and porting books and a couple old no name books but and you can of good with the right equipment and info.

 

[Garys1969RR]

Yes. Do you have a good head/porting book? I have 2 David Visard head and porting books and a couple old no name books but and you can of good with the right equipment and info.

I've ported some 906, and 915 heads. Have read some of the Visard info. I got a detailed step by step article from a hot Rod Magazine, showing how to do the 915 heads. Came out pretty darn good, the 451 I put them on ran great! Not planning on doing any extensive work on these stealth heads, just a valve job and some blending.

 

[Garys1969RR]

Never hurts to blend the seat ridge into the port wall, but that said....
far better Seat Angle preps should be applied to the Stealth's FIRST, then making that blend job easier.... and providing substantially more Flow/worth the effort.

Are we talking like a 5 angle valve job here? Then blend the bottom cut into the alum casting? What about the pushrod pinch area? Does it help much to widen that area of the port? We need a thread showing how to improve the flow on these heads. There are alot of them out there.

 

[wagonman]

Hopefully you guy can pull a vaccum on the port after the valve job. The shop I use has a new Rottler dedicated head machine. That is how he found the leaking seats. I had him go over the T Flows and he said the guides and valve job were A ok. I have never had a set of aluminum heads before and the difference between the 2 are like nite and day.