Anyone have any experience with these? I am not a fan of the long tube headers (at least the ones in my price range), so I am looking for anything that can help the flow of my exhaust manifolds. Does this design make sense or this a snake oil type of thing? The following is the excerpt from the dick miller racing website:

http://www.dickmillerracing.com/Engine_page.htm

Exhaust flow plates. These plates will increase the flow on your cast iron production heads by up to 15 CFM by flattening out the floor from the short side radius to the exhaust. The plate bolts between the head and exhaust requiring two exhaust gaskets on each head. Final fitting into the runners will need to be done with hand tools to allow for the closest fit possible in the head being used.


d1

 

If you're not using headers I believe they'd be a waste of money. Scavenging or lack thereof is a big part of the issue, not just flow.

 

Agree with the above - you'd probably get more of an increase with an 'X' pipe on dual exhaust!
Possibly for less money, too.

 

Probably right. I had never heard of them used before, so I figured I'd pose the question.

d1

 

The plates are intended to be a simple way to raise the floor of the Olds exhaust ports to improve flow. Unfortunately, they are a poor compromise at best. They require careful fitting to each port and still are far from perfect. I don't know of any actual flow tests on these plates.

 

I have a set which coincidentally arrived yesterday from the States. I am to using these plates solely because I am worried,if I alternatively weld the floor (to raise it), I may crack the heads.Sure the consensus is that the plates are a poor alternative but hopefully ,if carefully fitted, I will gain a little improvement. Hard facts? I have none.
I am using headers .

mike

 

Fwiw --see pic--about a 0.5 in raise from existing ex port base using the ex plates(this could be altered easily if one so wished

And FYI the plates are very close to 0.045" thick

mike