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Grooved Heads For Clean Burn..?


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I knew a well respected engine builder once who said the technology was "snake oil". He showed me an MM head that had alot of carbon buildup in the grooves. I too would be curious to here real experiences.

75 2002 polaris 2365430

88 325ix zinnoberrot

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MM still does that, I believe. I guess the grooves replaced the golf ball dimples they used to machine in their heads.

Budweiser...It's not just for breakfast anymore.

Avatar photo courtesy K. Kreeger, my2002tii.com ©

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I knew a well respected engine builder once who said the technology was "snake oil". He showed me an MM head that had alot of carbon buildup in the grooves. I too would be curious to here real experiences.

+1 on snake oil.  Once the grooves or whatever get fouled, what good are they besides adding stress risers in the surface, a place for a nice crack to develop.

A radiator shop is a good place to take a leak.

 

I have no idea what I'm doing but I know I'm really good at it.

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Not to mention hot spots.

 

Beyond back cutting valves and getting rid of any casting ridges in the combustion chamber, there really isn't much you can do to a combustion chamber. I much prefer having a mirror finish on mine (after volume matching, of course) to keep carbon buildup to a minimum. 

1974 Grey European Market BMW 2002 

1976 Yellow BMW 2002 "GOLDENROD" SOLD

1972 Yellow Austin Mini 1000

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Complete bunk,

 

First:Multipoint ignition from some cuts in the combustion chamber? Nonsense. The flame grows from the spark plug. J-gap spark plugs create a single flame kernel. A multi-torch (snowmobile style) spark plug develops multiple flame fronts (until they form one large front late in the burn) due to jets of flame exiting the spark chamber. The only way to create multiple ignition sources with shapes in the combustion chamber is if you create hot spots that cause runaway pre-ignition.

 

Second: There are several ways of changing in-cylinder charge motion (turbulent kinetic energy): 1. By shaping the flow pre-intake valve (turbulent vanes, curves to create a spin etc). 2. By shaping the head right by the intake valve (masking, scallops). 3. By shaping piston crown geometry. That's it. Shapes near the spark plug will have negligible or localized effect around the spark plug and will not impact bulk charge motion.

 

Third: Increase in laminar flame speed will often increase knocking tendencies, requiring spark timing to be reduced to keep the engine out of knock. This often mitigates the benefits of the faster burn. The paper does not even mention this and how it was overcome. You can get a phd on this sub-point so I'll stop here.

 

I don't want to call BS on MM but I would not spend my money on the technology without a lot more convincing.

Edited by Pamola

76 '02 owned 20 years.....project for the last 13. I should probably be faster than the rust I'm chasing.

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Great input gents. I stumbled onto that guy's name when googling "surface turbulence", after seeing the MM blog post about it. (Did I mention MM. Wait, yeah. Ok)

I was actually researching proper m10 fly wheel lightening. Need more pics and data here.

2002 newbie, and dead serious about it.
(O=o00o=O)
Smart Audio Products for your 2002

 

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