Piston Tops- ColorationI

BritishTurbo · Post by **BritishTurbo** » Sun Dec 11, 2005 10:38 am

With my turbo setup I get a nice even discoloration ont he piston tops, but the combustion chambers are pretty clean normally I think...

Only time I had a clean piston top was when I blew a head gasket... so on a turbo app, when you should be running richer than N/A, I think you should always have a discoloration of the pistons... if it's clean, your either lean, or have a blown head gasket/water injection...

ChrisU · Post by **ChrisU** » Sun Dec 11, 2005 7:24 pm

If you examine the plug position of the Kasse head compared to the topline head that'll give a pretty good indication of the issue.

automotive breath · Post by **automotive breath** » Sun Dec 11, 2005 9:34 pm

ChrisU wrote:If you examine the plug position of the Kasse head compared to the topline head that'll give a pretty good indication of the issue.

Assuming you are referring to the fact that the Kasse head has the plug located on the side of the combustion chamber with the larger squish pad.

I would say that plug location is superior but I don't see it as "the issue".

The reduced valve angle, the piston top design, the high state of tune, the duel squish pads and the high squish to bore ratio of the Kasse engine are also key reasons for the near complete burn.

mike fabish · Post by **mike fabish** » Mon Dec 12, 2005 9:12 am

Good Morning Guys, I was out of town over the weekend and was unable to view the feedback untill this morning, Thanks for responding. I'll try to post some pictures of both piston tops and the corresponding chamber. I'll also check out Darrin's comments. I never saw those types of "Grooves" in the combustion chamber before. How are they supposed to help? Mike Fabish

ChrisU · Post by **ChrisU** » Mon Dec 12, 2005 10:01 am

automotive breath wrote:
ChrisU wrote:If you examine the plug position of the Kasse head compared to the topline head that'll give a pretty good indication of the issue.
Assuming you are referring to the fact that the Kasse head has the plug located on the side of the combustion chamber with the larger squish pad.

I would say that plug location is superior but I don't see it as "the issue".

The reduced valve angle, the piston top design, the high state of tune, the duel squish pads and the high squish to bore ratio of the Kasse engine are also key reasons for the near complete burn.

Agreed... I should have typed 'a issue'...

automotive breath · Post by **automotive breath** » Mon Dec 12, 2005 10:11 pm

mike fabish wrote:...I'll try to post some pictures of both piston tops and the corresponding chamber.... Mike Fabish

Mike, we also need the squish clearance measured at engine assembly and the type of connecting rods (steel/aluminum)

automotive breath · Post by **automotive breath** » Mon Dec 12, 2005 10:32 pm

T RICK wrote:... I understood this to be normal in a wedge engine with a domed piston. The flame front pushes from the spark plug against the dome. By the time the the flame front gets over the dome the piston is already traveled down to the point that the fuel doesn't burn on the back side and will acctuely wash the piston.... Rick

Rick,
I too believe a large dome piston can cause poor flame travel. To my surprise I'm seeing very similar burn patterns when comparing 23 degree SBC dome piston engines to flat tops engines. This leads me to believe the burn pattern found is related to the valve layout and combustion chamber design rather than the piston design. Anybody have insight on this?

These heads came off of a flat top 355, it appears to have been running a good state of tune.

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