Milzy 3500 Stage 2 Flowsheets and Pics

[SappySE107]

MMS cnc ported stage 2 heads, with flowsheets and port volume measurements. Should be good for some conversation before we do the dyno comparison.

[dbral]

STAGE 2: - Full port and polish, port-matching the intake runners, D-shaping/re-angling of exhaust ports, significant bowl work, correcting the short side radius, polished cc-matched combustion chambers

Race Valve Job (9-angle Intake, radiused Exhaust)
CC-matched combustion chambers
stainless steel swirl-polished under-cut valves in OEM diameter
Comp Cams valve springs (128lbs at install height), Comp Cams retainers, and Comp Cams keepers
bronze valve guide liners
new Viton valve seals
assembled and toleranced
clearanced for safe lifts up to .560"
milling up to .020 free of charge

​From a customer standpoint, we would be curious to know if all of the above was performed as stated by MMS on the heads in your possession.

I'm currently running a set of MMS stage 2 heads on one of my vehicles. Should I be concerned that a portion of each valve guide was machined away? Have you ever tried that before? What is the advantage? In the very last picture from the list above it looks like the guide may have slightly shifted in its bore at some point after being machined? Could this procedure cause durability issues?

Thanks for posting the data and pictures!

[SappySE107]

I don't know what he was advertising them as when you got them, so I can't say for sure that you did or didn't get what you paid for. There aren't 9 angles on this intake valve and the valve itself wasn't even back cut. Undercut would be the stem, and thats a non issue since they are machined valves, not stock replacement versions that still have casting on the back side. CC matched chambers, probably. They are CNC done and touch most of the chamber. Its manley retainers, stock keepers as far as I can tell. That or Comp changed to the manley design. Comp doesn't used machined locks that I can remember so telling the difference between stock and comp locks would be difficult. Bronze liners? since when. These aren't, thats for sure and I don't recall them ever being listed as such. New viton seals, which are all you can really get these days. They are Felpro/stock style seat/seals.

Oh I skipped the top. Full port, no. Polished, no. Port matching intake runners, yes, its bigger than the intake gasket by a little bit but it doesn't hurt flow. D shaping? It was a D already. Re angled I guess....its totally hogged out. 20cc or something like that on the exhaust. Correcting the short side radius, he does change the short side radius. Is that corrected? Not a polished combustion chamber.

So that is comparing the description now to 2019 work. If your car has older MMS work, then its probably different heads. They were hand ported by high school kids in 2008. The set of heads and manifolds I had back then didn't look anything like what these cnc heads are.

Cutting the guides out of the ports like these aren't may or may not cause the guides to wear faster, but it 100% didn't help flow.