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-   -   Leak down tested motor. Results query. (https://www.miataturbo.net/diy-turbo-discussion-14/leak-down-tested-motor-results-query-93681/)

adryargument 06-21-2017 04:06 AM

Leak down tested motor. Results query.
 
So I have boosted. My shitty junkyard motor for 17k km.
Its now running like shit and feeling rubbish. Vibrations. The lot.

So, leak tested :

1: 20-25%
2 35-40%
3 20-25%
4 20-25%

Now how much leakage is shit on these motors? Is this enough to give no power past 80km/h? -> 11.8psi on TD04
Or can i expect more than just ring damage?

No blue smoke, just blowby 11/10

Reason for the leak down test was I used to reach 123km/h on my favourite Hill... I struggled to hit 85. Just no power.

Note that the junkyard motor came with lovely compression figures of 155-178. They lied and said it was 198. From a fucking porsche wrecker.
Cheers

psyber_0ptix 06-21-2017 07:44 AM

Maybe buy another motor, tear down, hone, rering, and try again?

alsmedic 06-21-2017 03:15 PM

Rather than just go by leakdown numbers, when you do a leak down test listen for where the air escapes to. You can use a length of hose - one end in your ear, the other to probe. Listen in the throttle body for bad intake valve seal, the exhaust for bad exhaust valve seal, and in the valve cover for bad ring seal. You can do this for each cylinder, and decide if any one are "too bad" for your liking

adryargument 06-21-2017 08:30 PM

Yeah rings are gone.
Hopefully no other damage. I'll find out this weekend.
Going to lap the valves and check clearances. I have another head so I'm sure I can build one decent one out of both.


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