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Semi-Peripheral Port Compression?

Old 05-06-19, 06:28 PM
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Semi-Peripheral Port Compression?

Here’s some info about the setup:

13b REW, Semi peripheral port, RA super seals, slightly larger intake port, and about 3k miles on build. Housings were in great condition and all the plates were all surface grinded to the same spec.

Car turns on hot perfectly every time (even after major highway pulls) but I decided to check compression with a RCT.

~70psi across the board. That sound pretty normal for this setup? Thanks!
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Old 05-06-19, 11:36 PM
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with only 3k miles on a rebuild, i would think compression should be higher than that.
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Old 05-07-19, 09:39 AM
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with those seals you should test it cold and test it hot.

go with Mazda's specs for the difference between chambers, and rotors.

max, 20psi between chambers, and 20psi between rotors. you also have to remember Mazda's 7.0 spec is the minimum
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Old 05-07-19, 10:40 AM
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not sure what normal compression is for Semi PP but man that looks like an awesome setup.

Will PM you for more info.
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Old 05-10-19, 08:24 PM
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Enough boost will make up for the low compression
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Old 05-11-19, 01:37 PM
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Compression changes are somewhat negligible in reference to port configuration unless you're duration is whack, seal and sealing surface is where you'll see variances.

Last edited by dguy; 05-11-19 at 01:40 PM.
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