Jazsun

I removed all rockers, and hookedup an air compressor to piston #1 and it filles up w/ air, but I can hear a hissing noise. Its hard to hear where it is coming from, as it can be heard equally on both sides of the block. (piston ring, leak echoing inside? But if it was a piston ring I think I would be burning a **** load of oil. I turned the PSI down to like 20 psi and I could still hear the hiss and when I put it up to 150 psi I can still hear the hiss. I then took an hooked up the compressor to the cylinder next to #1 and it did the same thing. Any ideas on what is causing this hiss? It causes the air compressor to have to turn out every once in a while to regain pressure. Would old valve seals make a hiss/leak if they are warn/old? Bent valve, bad rings? I did a compresson test like a week ago and all cylinders came up good, the only cylinders in which plugs would foul were the ones on the passengers side, the plugs on the drivers side were always perfect/no oil residue. Any ideas? This scares the crap out of me, and I almost dont wana put my comp cams on.

HardcoreRM125

If you checked out OK on the compression test last week, chill out the bottem end is 99% perfectly fine. Maybe one of the new valve seals is bad? but the most likely thing is that your not on TDC for the Cylender your on and so the compressed air is leaking past one of the valves which would be just barely opened. Your motor is probably fine

Lonnie Pavtis

It is normal to hear a hissing sound from the cylinders. You will likely hear this from the valve cover area.

If it is coming out of the exhaust or the throttle dody you have a burnt/bent valve or broken spring.

shoebox

The hissing is normal. The air is passing by the rings.

MachinistOne

You guys didnt read his post..."REMOVED ROCKERS" TDC does not matter in this case, you cant change seals and springs with the valve partway open, so his problem is not that the valves are at partial lift....

But yes, the hissing will still be there...how much depends on the ring seal and ring end-gap. Give a couple raps on each valve with a mallet to seat them, when the valve is slowly backed off full lift as in removing a rocker, it sometimes doesnt seal well. You refered to a compression test, was is a leakdown test or just a compression test?

Jazsun

feew, I feel much better now. So its normal to have some air leak past the rings, ok.

It was just a compression test, I know leakdown is better but its just too much work and I already had a compression tester. I have a small like 2 gallon air compressor so the thing rungs like continously while I work on my valvesprings/seals..really annoying. Its hard to tell where the hiss is coming from, you can hear it all over the engine, its not a ton of air leaking just a continus small leak which causes my small air compressor to kick on every 5 minutes to maintane pressure..Sounds like its leaking past the rings and echoing throughout the block, thus is why I can hear it all over. I got some questions tho, as this is my first time w/ valve seals.

Questions 1:

I only installed one today (after taking all rockers off etc...god damn its hot out outside) using this crap compressor tool provided by autzone as a loaner. The new seals I got which are from felpro seems to be a hair longer then the stock one which I removed, ok?. I couldnt see how far the stock one went on, cuz it kinda came off w/ my spring somehow. So when installing the new one I pushed it down pretty hard ( I was friggen scared as hell cuz I didnt want to drop a valve ) Its down pretty hard I belive and there is like a 1/2 cm gap still left from where the end of the valve seal meets the larger metal part lip which is the next lower tear. Is it suppose to be snug against it?

Questions 2:

I can regulate the PSI coming from my air compressor, right now I have it at like 80 psi, is that good enough to keep the valves closed good? Could I go lower or should I go higher? I am utilizing both methods, I set the crankshaft so that two of the pistons are at TDC and work on those while apply air as well, just cuz im scared.

Questions 3: Is the valve just one straight metal cylinder (after the flap inside the head)? Or does it have a hump on it when it appears on the other side of the head by the rockers?( prolly a dumb dumb question)


Any tips on how to remove/install them fasteR?

shoebox

If you just put the cylinder you are working on at TDC, the valves won't go far and you won't have to use the air. That would speed things up.

Jazsun

Ya but I am not the sole owner of the car so I dont know if the flywheel pulley has ever been removed and thus the arrow would be off which would indicate TDC, correct?

Kreinmc

I find that the fastest way to doing springs is to have a helper spin the crank after you have a spring compressed(do not remove locks or spring) and the valve as low as it will go. When the valve pops up you know that the piston is up and you can now remove both springs from that cylinder.

Transamdriver

Take out the spark plug and insert a long piece of a coat hanger into the hole. Then turn the crank and feel when the piston is at the top.

Jazsun

My new valve seals (felpro) are a tad bit differnt design and dont quite seem to go down as far as the stock ones did over the little tear. How hard should I push them down? I pushed them down pretty hard and they just seem to stop. Are they suppose to completely cover the lip which surrounds the valve stem? I hope I did these right, so far I got 10 of the 16 done. I would stick them down and try and wiggle them down as far as I could and pushed on them while holding onto the top of hte valve but they dont seem to go all the way down. Do the seals ride on the stem while the engine is in motion or do they stick to the lip and let the stemd ride up and down through it?

**** ***, I looked at this picture http://shbox.com/ci/ci175.jpg, seems that the seal is down pretty far, mine is not down that far, it has like a 1/4 cm gap. Am I suppose to hit them down using a ratchet/ hammer? Is that much force really needed? I would push them down as hard an I could by hand, but I was kinda scared cuz I didnt want to pushthe valve in.