 Domed exhaust valve face, vs flat |
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| dfelz |
 Dec 4 2020, 06:49 PM
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beach bum  Group: Members Posts: 419 Joined: 7-June 12 From: San Diego Member No.: 14,538 Region Association: Southern California 
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Just got the exhaust valves in I ordered from aircooled.net, that are supposed to be for my year 914 1700. They have a dome in the face, which my stock ones do not. Just curious if anyone has experience using these on the T4? Anything I should be aware of, any change in performance or setup or tuning when rebuilding the engine/head with these?? Thanks,
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| 914werke |
Dec 4 2020, 06:51 PM
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"I got blisters on me fingers" Group: Members Posts: 11,231 Joined: 22-March 03 From: USofA Member No.: 453 Region Association: Pacific Northwest
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OE Sodium filled
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| barefoot |
Dec 5 2020, 07:40 AM
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Senior Member Group: Members Posts: 1,369 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States
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QUOTE(914werke @ Dec 4 2020, 07:51 PM)  OE Sodium filled Did all displacements use sodium filled exhaust valves, or just the 2L ? Never re-use 50 yr old sodium filled valves !  |
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| bdstone914 |
Dec 5 2020, 09:58 AM
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bdstone914 Group: Members Posts: 4,888 Joined: 8-November 03 From: Riverside CA Member No.: 1,319 |
@dfelz
The disc will have a small affect on the chamber volume. Measure the volume of the disc with a medicine syringe and add thstvto the CR calculation.What did you compute as the compression ratio? |
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| dfelz |
Dec 5 2020, 11:26 AM
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#5
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beach bum Group: Members Posts: 419 Joined: 7-June 12 From: San Diego Member No.: 14,538 Region Association: Southern California
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QUOTE(bdstone914 @ Dec 5 2020, 07:58 AM) @dfelz The disc will have a small affect on the chamber volume. Measure the volume of the disc with a medicine syringe and add thstvto the CR calculation.What did you compute as the compression ratio? Thanks Bruce! I have not calculated CR yet, but will take the volume measurement of these valves before I install them. I’m still in the engine tear down and parts acquisition stage of the engine rebuild, and I don’t recall what we calculated the CR to be from the last rebuild (7 years ago now). |
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