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Compression results

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Old 08-06-2022, 05:22 PM
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How are my compression results?

I did my a compression test today on my 105k miles RX8, Here are the results.

All readings normalized at sea lvl and 250rpm With the engine warm. Readings are PSI

Rear rotor:

test 1- 89.90 / 90.84 / 91.79

test 2- 92.44 / 91.48 / 89.56

test 3- 92.44 / 90.52/ 93.41

FRONT Rotor:

Test 1- 88.79 / 89.75 / 92.65

Test 2- 87.82 / 88.79 / 92.65

Test 3- 88.79 / 91.68 / 88.79

Its just about time for the rebuild. Gonna get as much out of this motor as i can.

Last edited by Tanner; 08-06-2022 at 05:46 PM.
Old 08-06-2022, 06:02 PM
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how did you check it (the process/conditions)?
Old 08-06-2022, 06:16 PM
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Originally Posted by TeamRX8
how did you check it (the process/conditions)?
I used a ebay rotary compression tester. https://www.ebay.com/itm/323517659813

Warm engine and used trailing plug holes
Old 08-08-2022, 12:37 PM
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the results are not really that bad for the mileage
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Old 08-08-2022, 04:08 PM
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Once you start dipping down past the 75-70psi range you will likely fall down the hot start rabbit hole. There's like 100 threads of various troubleshooting, just know that'll be the first sign of the engine being done. At this point your rotors are probably toast. Upgrading components like battery, starter, coils, plugs will only prolong a few hundred more miles till compression degrades to the point where the engine will stall at idle.

Considering you are running the engine into the ground are you already planning to get a reman engine? (My suggestion instead of rebuilding with bad components at that mileage....like I did)
Old 08-08-2022, 06:53 PM
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Originally Posted by MincVinyl
Once you start dipping down past the 75-70psi range you will likely fall down the hot start rabbit hole. There's like 100 threads of various troubleshooting, just know that'll be the first sign of the engine being done. At this point your rotors are probably toast. Upgrading components like battery, starter, coils, plugs will only prolong a few hundred more miles till compression degrades to the point where the engine will stall at idle.

Considering you are running the engine into the ground are you already planning to get a reman engine? (My suggestion instead of rebuilding with bad components at that mileage....like I did)
I have OEM coils plugs and wires and i change them every 25k. The plan is to run this motor until i cant keep it running, then pull it and use as much of the insides as i can. Want to have something in it while im saving for the REW swap
Old 08-08-2022, 06:54 PM
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Originally Posted by TeamRX8
the results are not really that bad for the mileage
.
Yeah thats what i was thinking after looking through other peoples results with this mileage.
Gonna pull it soon and use what i can from it to rebuild.
Old 08-09-2022, 07:02 PM
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well you might want to research that out a bit too or else it may not end up much better with less mileage.
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