I'm prepping my #1 225 for my upcoming '80 Volare,this is a BH 225 block
.030 over with cast pistons and rods out of a 80K mile B'cuda getting a 360.
The head is on the bare block to check for bore overhang.Now here's my
"bright" idea. After shaving the edges of the chamber back to the cyl walls,
I'm going to mock up some "quench pads" to be fastened to the open portion of the chamber opposite of the spark plug.These will be about the size of a small thumb, made of ductile grey iron, and will be thick enough to leave .030 thickness from the pistontop.These will be held by 2 stainless studs set into the head with nuts countersunk into the pads and spotwelded fast.
The C.R. should only increase from 8.5 to 9.0 and the added swirl and quench,though not ideally located,should add noticible performance, a few more m.p.g. & maybe less tendancy to 'ping'. This is a crutch to make do until the 'long-rod'225 gets built.

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"Faith in Science"

Please see this thread.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Went back & re-read the thread, old thread it is,wondering if Josh ever finished up & ran the head.If so, what was the result,performance-wise?
As I admitted in my opening post this a stop-gap endeavor 'till I can build the long-rod 225($$$$$!!) & in the meantime I have most of what is needed to put together a slightly warmer than stock 225 (cheaply)that should pass DEQ smog test.One benefit of this way of adding quench to a SL6 head is no warping from heavy welding, and also the pistontop should stay cool and clean from the 'squished' mixture flowing across.

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"Faith in Science"

I would be concerned about heat transfer from anything bolted into the chamber.

I have never brought this up for automotive heads, because I don't think it is that feasible. But it did work great on two strokes where the rules did not allow any decking to the cylinder but did allow any kind of machining to the stock head.

What was done was called a "drop Squish". The head was set on up on a Bridgeport with a rotary table. They were centered on one chamber at a time (there are only two) and a clean cut was made around the chamber where the fire ring would sit. It was cut so the protruding section was a few thousanths less in diameter than the block bore. Then the other chamber was done, and then the rest of the surface was cut to match, being careful to stay out of the first two cuts.

The chambers would then end up "dropped" into the cylinder and we could get the squish as tight as we wanted, without touching the block. compression was adjusted by machining the center sections of the chambers if it was too high.

It had to be carefully indexed, and with a short two cylinder aluminum head was not hard to make it work. The only real area of concern for sealing was around the fire ring, and with the first clean cuts was just fine.

It could not be done with the same process on a car head, but maybe someone using modern computer operated milling equipment could do something like this. The hard part would be matching it to the block. Maybe it would have to start with some accurate block machining? Or a template taken off the block and digitized?

It seems like more work than is reasonable, but maybe someone might have the equipment to make this work. It would be really nice to have this part of a slant work right, myself I have pretty much given up on the idea of having a functioning squish or quench.

No, I never ran the welded head. I sold it.

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Joshua

No cnc milling, just careful measuring & test-fitting. I'm also somewhat concerned about heat transfer. If detonation and/or pinging is actually made worse it's just a matter of pulling the head & removing the quench inserts.Perhaps a heat-blocking coating on all sides of inserts except for area contacting the combustion chamber surface will keep heat & pinging
out.

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"Faith in Science"