Hey Ford Folks,

I'm putting a 75' 460 in my 78' f-250 4x4. I'm curious about how to grind the smog bump out of the exhaust ports. If anybody could give me directions and some advice about exactly how much stock to take out of the exhaust ports i would appreciate it. Pictures of before and after would greatly help also as I am not sure exactly what all to grind out. By the way, these heads are D3VE-A2A's, I'm putting +0.030 flat top +6 c.c. hypertec pistons in the motor and I'm curious if anyone knows the c/r.

Thanks.

 

I have the same heads on my 460 for now....... D0VE-C in the the works. Here is the way the D3VE-A2A's turned out. The pics don't show great detail but here they are anyway.

http://www.ats-inc.net/Stuff/engn7.jpg
And another view
http://www.ats-inc.net/Stuff/engn8.jpg

Good luck
Craig

 

Have a look at this site.
It's pretty interesting.

http://www.sa-motorsports.com/diyport.htm




Dennis



It's Almost Time Everyone.
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78 F-150 429CJ C6 ,Silver w/Explorer Pkge
641/2 Mustang,Pre-World's Fair Car #8092
64 Fairlane S/C waiting for a 390-4spd.
68-Mustang.Sunlit Gold 80,000 miles

 

First of all there is ALOT of material that can be taken out of the exhaust port. Don't take too much off the bottom of the port near the valve seat because there's a water jacket there (just smooth off the rough edge below the valve seat). Don't take off any in the bottom of the port, itself. The smog hump can be completely ground flush. The two humps on the valve guide can be ground down. Make the guide boss look like a cone that blend in with the valve stem. The long hump that is parallel to the head bolt can be ground smooth and there is nothing between the head bolt and the port to hit so the sides of the ports can be opened up considerably. The top of the exhaust port is narrower than the bottom so you want to open the top to where it is atleast as wide as the bottom, not just near the flange but most of the way into the port. The whole process will take time but it will be worth it if you have the time. I hope you didn't gat a valve job yet, it's pretty common to bump one of the seats. Put masking tape on any surfaces you don't want to damgage by accidently hitting them. There's also work to do in the combustion chamber if you're interested. Good luck

 

Thanks for the information bigsnag,

I am also interested in the advice you can offer for the combustion chamber. This forum is very helpful in helping me decide exactly what I want to do to make my ford run its best. Thanks for all the advice.

Chad

 

I'm doing the same thing to the same series heads... I questioned Kevin Kemmer and we swapped pictures back and forth so he could try to educate me... here's some pics of what I've done so far... I've really only roughed them in... the finish work is still to be done.. hope this shows what you want to know.. I'd also welcome any pointers from the experts...

john


before....http://www.clubfte.com/users/jniolon/19a1.jpg
after.....http://www.clubfte.com/users/jniolon/1.jpg
more after http://www.clubfte.com/users/jniolon/1a.jpg

 

When removing smog bumps and other head material, I normally use my die grinder with carbide rotary burrs for the big pieces and then go to the Dremel with a stone to clean everything up. Takes a little longer, but I have far better control with the Dremel.

I stongly suggest that you get a junk head to use for some test grinds, as a full-sized die grinder at 20-30,000 rpm can remove more material than you can believe in the blink of an eye. Even though recommended speeds are 15-20,000 rpm, it takes a pro who does heads for a living to keep the speed down on a consistant basis. Ask me how I know.

Anything you do to the intake ports and combustion chambers of your heads can be wasted motion unless you match the ports to your intake manifold. I've seen aftermarket aluminum intake manifolds with runners 1/2" smaller than stock head intake ports.

This site covers all the basics of porting and manifold matching:

http://www.sa-motorsports.com/diyport.htm

Good luck! You're improving the most inefficient component of the 385 series engine (especially the smog bump) and the results are well worth the effort.

 

Ford Guys,

I'm just about done with my heads. I'm pretty satisfied with how it's going. If any one could help me with the compression ratio now, i would be very thankful. Like I said before, it is a 75' 460, so it has the taller deck height, .030 +6c.c. hypertec pistons with two valve reliefs, standard felpro head gaskets, and D3VE-A2A heads. Any help would be appreciated.

Thanks,
Chad

 

We'll need a little more info, like a part number on the pistons or a compression height perhaps, also how much are the heads/block going to be milled, have you had your chambers cc'd? The chambers can vary depending on how many valve jobs have been done, whether you have new seats, if you did any work on the chanbers while doing your porting, etc. etc. Later.

 

The heads didn't need milled, they were straight as was the block. I used felpro head gaskets with .040 squish. The pistons are +6 c.c. .030 hypertec. It is a 460 bored .030 over with d3ve-a2a heads that have 91 c.c. chambers I believe.

Thanks,
Chad