The above info is correct. The exhaust ports cast into the 385 series heads, whether they be C9VE's, D0VE's, PI heads, D3VE's, etc, all have poor flow characteristics. This does not mean you can't make a lot of power with stock heads, it is simply a place to easily gain some cheap power. You can do the porting work yourself and reincarnation auto has some great info on how to do it and what not to do. You can also send the heads to someone to have them worked over. A lot of local shops do port work, Scott at Reincarnation does it, Scott at MPG heads does CNC machining on cast iron Ford heads (he's the only guy in the country that I know of that does this). As was mentioned for most engines, you want to be a minimalist. Less is more. You might want to work on smoothing the bowls and the shortside radius and a little bit elsewhere. Simply going bigger can actually hurt flow. By improving flow you should definitely improve power and may help mileage (it shouldn't hurt). Oh almost forgot, Scott at MPG heads has some port plates for the exhaust on D0VE's and D3VE's. These are supposed to give about 25 hp on a set of mildly ported heads. The main problem with the exhaust port was the sharp turn on the short side and the low floor. His port plates correct the low floor problem.

JJ

 

Thank you...bigsnag..."smoothing the bowls and the shortside radius and little bit elsewhere..." Uhh, could you expand or define what that means...you lost me there...thank you. EagleWalk By the way, I appreciate the less is more approach...it's a matter of me identifying which less is better than which more...or something like that....

 

Well, http://www.reincarnation-automotive.com/index_2.html has all the info you need. Unfortunately, they had to start charging for this info. The bowl is the area just past where the valve seats. If you are looking at the port from where the valve goes, the area of the port readily visible is the bowl. The short side radius is the area of the port floor just beyond the bowl. If you are looking at the exhaust port as it comes out of the head, it would be the bottom part as it makes the turn toward the valve. Those areas are the most critical and really the least work to clean up. It doesn't take more than a cleanup really. Here is a quote from something I found a while back. "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."

JJ

 

JJ...thank you...your answer is above and beyond and I appreciate you taking the time...EagleWalk