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  1. #1
    PolarisNut's Avatar
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    What 1200 heads are these?

    I've got two sets of 1200 heads here. One set says 10.75 on them. I belive they are Polaris "limited" domes, that require 100+ octane. I also have some that I believe to be Hot Seat. They said "27" on them, but that was ground off and they now say "32". They appear to have had the squish band recut, and have low volume bowls. Anybody run the 100 octane heads and compare to the 92? I'm guessing a bit more down low, but little to nothing up top?


  2. #2
    Connecticut CrazyA's Avatar
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    The ones that say 10.75 are indeed the Polaris limited domes. The HotSeat ones have been altered it sounds, probably should CC them to be sure about what they are. Here are the limited Polaris domes...
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  3. #3
    PolarisNut's Avatar
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    Yeah, I'm going to cc them...I suppose they could be just about anything.

  4. #4
    Watcon's Avatar
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    Domes

    The others are most likely R&D domes... Be careful using them on a runabout with pump gas... CC them first..

  5. #5

    CRAZY

    ARTIE ART, i'm back brother allllllllllllllllllllllllllllllllllllllll done cleaning snow off everything for about 6hrs. a day ready to get back on track with the 1450. i just got AL's 1200 cyl.s waiting for the crank case we are pretty excited about the new venture with polaris on the hydroplane boat. JOE came down thurs. got some 1200 crankcases with msx motor mounts and some virage tx mounts. one of his boats is at polaris when you enter the front door. he's looking to run around 118 mph to be competetive. the motor he is running now is a 860 at 96 mph. we are building him an 1165. thats the limit for cc's in this class (prob. could sneek a 1450 in ) HA! HA! i'll give ya a call later .

  6. #6
    PolarisNut's Avatar
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    OK, so I cc'd the heads. Got ~40cc for the Polaris Limited domes and ~35cc for the unknown heads. Using a -10cc installed volume, I came up with 14:1 and 16.5:1 respectively. Does anybody know what the volume for the sleeper heads is?

  7. #7
    Connecticut CrazyA's Avatar
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    I don't know the volume, but MOST 92 octane domes are 12:1 ish, give or take. Randy from WatCon would know for sure.

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