jetblast

all right then, did anyone ever see or heard of an engine pass the compression test with really good results, have a steady 15hg vacuum signal, fail the leak down ck but, with even results accross the board? no oil consumption problems, just the average catch can build-up.
engine builders use a blow-by meter. what kind of reading is it and what's the worse reading anyone has ever heard on a relatively smooth strong running motor, like mentioned above?.
can the pvc be disabled and cappped at idle to ck. for blow-by, how much should be present?. i know, a lot of ?'s for all the engine heads.
thanks a milion for all the replies guys.

jetblast

just did the leakdown ck. yesterday. it took about an hour. the engine was cold, it sat overnight. the 4gal. sears compressor was enough for the job. i did make a gauge and shut off valve to have right by the engine and used the compressors reg. and set it to 100psi.
all the cylinders came in at 90% to 92%. so aside from dismantling the engine, is there anything else i could do to ck the health of the engine?

for those that don't know i also passed the compression ck. #6,8 came in at 195psi, the rest were 200psi. the ck. was done hot.

Robin L

I am with Erik on this. With the nitrous your probably rattling the rings just a bit. Keep taking timing out to see if it improves.

Also remember that these engines come from the factory with very tight ring end gaps. You could be putting enough heat to the rings to have the end gaps close up.

Unless you build a nitrous specific engine it may be something that will always be there.

Good luck!


Robin

jetblast

thanks for the reply. how would rattling the rings show up on the walls? perhaps it's a common problem inherent with the stock n/a motors that see boost and nitrous.

jetblast

one other thing i thought of doing is to replace the dipstick with an adjustable low press. {2psi} one way check valve and a hose to see how much blowby press. i'm actually building up.