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-   -   Losing Compression On Dyno, Any Ideas? (https://www.nopistons.com/single-turbo-discussion-13/losing-compression-dyno-any-ideas-36359/)

j9fd3s 03-28-2004 03:21 PM

could maybe be something wired like a bent e shaft?

93FDGT3540 03-28-2004 03:38 PM


Originally Posted by j9fd3s' date='Mar 28 2004, 01:21 PM
could maybe be something wired like a bent e shaft?

what would the side effects of that cause? I am looking into any and all possibilities. I have replaced most items that could cause such a failure that i know of. I will ask the engine builder what else to look for but i wanted to get some opinions from here to start me off.

1Revvin7 03-28-2004 03:59 PM


Originally Posted by pluto' date='Mar 28 2004, 01:29 PM
The only thing I could really think off is the exhaust port or the shape of the port causing it to run higher EGT than normal.

Sounds like a good suspect

jspecracer7 03-28-2004 04:15 PM


Originally Posted by j9fd3s' date='Mar 29 2004, 06:21 AM
could maybe be something wired like a bent e shaft?

If his e-shaft was bent, he wouldn't get past 500 miles. You'd know if your motor was blown due to a bent e-shaft. It would sound like a diesel(clunk, ka-clunk, ka-clunk, ka-clunk) and as soon as took the oil pan off...bronze fairy dust everywhere. https://www.nopistons.com/forums/pub...IR#>/blink.png

FikseRxSeven 03-28-2004 04:18 PM

im not a rotary engine builder or expert... but for the edge to be sharp as described... something must have been eating it.... so most likely the exhaust port like i stated before https://www.nopistons.com/forums/pub...IR#>/smile.png

93FDGT3540 03-28-2004 07:12 PM


Originally Posted by FikseRxSeven' date='Mar 28 2004, 02:18 PM
im not a rotary engine builder or expert... but for the edge to be sharp as described... something must have been eating it.... so most likely the exhaust port like i stated before https://www.nopistons.com/forums/pub...IR#>/smile.png

I am no expert either. this motor has been taken apart 3 times and has been inspected for damage, all parts. The engine builder took a real good look this last time and didn't notice any damage. Checked all parts, inspected closely and reassembled with new seals. The car was pulling good vaccum -14 inches as we strapped it too the rollers. I had almost 1k miles on it of very careful driving, no high rpms, no or very little boost. Idled perfectly. Even after closely scutinizing the air/fuels and the timing, fuel pressure and boost levels. the motor slowly started to lose vaccum. we were goin so slow it took us 3 hours on the dyno just to get it up to 13+ psi. There wasn't anything we could see to show why we were losing vaccum at idle. Because this has happened 3x before I knew the signs, I heard the car start to sound like a chopper and the vaccum drop to -10 inches. We stopped there so it would still start and drive until it got sorted out. I had apex seals with me from the previous motors and these are what you see here. I have more pics i took, I hope they show more detail. I have confidence in my engine builder that he will eventually work this out. Sometimes its a slow process. Has anyone ever heard of this happening before?

ccarlisi 03-28-2004 07:40 PM

1 Attachment(s)
Another front rotor seal.

ccarlisi 03-28-2004 07:42 PM

1 Attachment(s)
seal # 2, 3

ccarlisi 03-28-2004 07:46 PM

1 Attachment(s)
A good shot of the 'ridge.'

93FDGT3540 03-28-2004 07:51 PM

thanks for shaving the pics to fit chris


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