906 Porting Tips

[dragondan64]

IMO you should have them flowed first to keep a record of what you got. Then you need to have cam specs so you can have them ported to flow with your cam or you can hurt performance and its easy to take material out but you cant put it back! Depending on what exactly you will use the engine for will help you make the right choice. Good luck!

 

[RustyRatRod]

I didn't think core shift was a big problem in heads. Since they are not very deep, I wouldn't think they would shift much. Do dat bees wrong?

 

[fratzog lover]

Just wondered what some of the builders thought. 906's are on the 383 I just grabbed. I have seen some heads being cleaned up on you tube today(slow day) and some of the casting defects and rough areas were pretty bad.

https://www.youtube.com/watch?v=bnJOtTj1f5A"

 

[IQ52]

Some 906 castings can be real bad. I've seen the seams inside the water jackets mis-aligned as much as .060". Just looking at the differences between the bowls and where the guide hole is centered in the intake bosses can give you the willies. You gotta be smarter than the cylinder heads you are working on.

 

[fratzog lover]

A lot of cleanup for a resto. Stealth or edelbrock would be s much easier... builders didnt have it this easy in the 70's.

 

[roccodart440]

Have you used these porting templates or know anyone who has used them? Anybody have any feedback on how easy they are to use?

I had a machinist use these on my heads. After using them the heads leaked in 5/8 cylinders. Had to be fixed with epoxy.

 

[fratzog lover]

I had a machinist use these on my heads. After using them the heads leaked in 5/8 cylinders. Had to be fixed with epoxy

I guess everything in moderation! Sorry to hear about that.

 

[MRL Performance]

Some 906 castings can be real bad. I've seen the seams inside the water jackets mis-aligned as much as .060". Just looking at the differences between the bowls and where the guide hole is centered in the intake bosses can give you the willies. You gotta be smarter than the cylinder heads you are working on.

LOL I just went thru this on a set of 906's. Misaligned seam was WAY off. plus it had casting flash between the guide boss and the wall on 6 of the 8 ports, blocking any air flow, total Mopar! And people wonder why Bobs 440 ran so much better than Toms 440 of the same year. Way to many loose tolerances back in the day.

And talking about the guide hole being aligned in the bowl, the RHS were real bad about this. Took many hours of grinding to get them right. I don't miss them at all!

 

[RustyRatRod]

Learn sumffin new everyday. Thanks yall. I just assumed that since the heads were short in height, there wasn't much room for core shift. You know what they say about assuming. lol

 

[mguner]

Some of the images here are good...

http://www.hotrod.com/how-to/engine/mopp-0906-mopar-906-cylinder-heads/