Bent apex seal springs and corner seal springs
 

Hey guys well since I put my turbo I've been noticing my idle quality has been getting worse and worse. I put about 15k miles on this engine NA and about 5k with turbo. Then one day driving up a hill on the freeway going about 80mph the car starts jerking a bit. I start thinkings its my spark plugs that got fouled again, because I just installed wolf3d and its not tuned. Turns out spark plugs didnt fix the problem so I do a compression test. 60-60-60 in the front rotor and like in the 40s for the rear rotor.

Next thing I do is I took the engine apart and find out the engine isnt blown. First thing I notice is one of the apex seal spring is almost flat. The rest are just kind of weak. About 5 of the corner springs went totally flat. These are FD corner springs I used. Then one corner seal is cracked but was still in place.

The seals and springs used in this motor were rotary aviation and I have detenated this motor before while in boost.

Now my question, is this detnation the only reason for these problems or something else caused them also?

some of the rotary aviation seals have a defect with the way they were cut.. that may be your problem.

flattened apex seal springs indicates over revving

um, I would say one thing to consider is the side seal -> corner seal clearance, was there enough clearance for the seals to move freely when hot? The cracked corner seal combined with flattened corner seal springs makes me think they were getting stuck in the compressed position.

I would also guess they experienced some serious heat, enough to make them lose their spring and flatten out. Do you have an egt gauge on the car?

Nope, i know I leaned out boosting though. Need to get the car tuned. Anways I just ordered new parts so engine should be back up soon. I didnt over revv but I did lean out cuz my LM1 said so.

Flatteded apex seal springs is signs of overly high EGT's.
This can either mean overly lean conditions or detonation.
The RA apex seal springs have been getting a bad rap recently - see threads on this for more info.


-Ted

I've seen flattened corner springs on engines with improper spacers installed (too much end-play)

Not all of them were flat, just random ones. The end play was towards the lower limit when I put the engine together.