Hi guys,
today i fired up the spare engine. Makes a strange sound like tac tac tac.
Anybody knows what it could be? Think it comes from the right head. Valves are fresh adjusted.
http://www.michael-kost.de/forumbilder/film_0001.wmv
Too much lash. Should be a nice little tickle, tickle, tickle sound, not a tac, tac, tac. Check those adjustments again. I would say they are too big and need to be snugged up just a tad.
Hi Dan,
are you sure it´s the valve clearance? I measured the clearance twice. 0,15 mm cold. A friend suggested a broken piston ring? I have no experience about that sound. Is this possible?
here is a link for an 6 minute video warming up the engine and idling.
It is approximately 8 mb!!
http://www.michael-kost.de/forumbilder/film_0003.wmv
...Hang on.... downloading now.....
I dunno man, it sure sounds like valve lash to me. It gets quieter as the engine warms up. Plus, when you give it a little throttle, I don't hear anything. So I don't think you have a bad wrist pin or rod knock etc. Those stick out like a soar thumb when you bump the throttle.
.015, dang, I am at work right now and can't remember the conversion. Is that .006"? Most people I know do .006 across the board, but if you live in a cooler climate, I would go .004 intake and .006 exhaust. Pop off a valve cover and check the #1 again. Maybe it is the rockers? It is valve train noise for sure though. I have heard that a bazilion times. Other than that, motor sounds great!
Mild hijack (please forgive).
Is it true that over time as the valves get "out of adjustment" that they actually get tighter? not looser?
I adjusted my valves two weeks ago and they were all sitting at .003-.004.
thanks
oh, cool test setup on the engine.
yes 0,006 is 0,15 (inch vs. mm)
thanks for advice, i will check that stupid valves again
QUOTE (michelko @ Jan 8 2005, 09:21 AM) |
i will check that stupid valves again |
QUOTE (jr91472 @ Jan 8 2005, 09:09 AM) |
Is it true that over time as the valves get "out of adjustment" that they actually get tighter? not looser? |
QUOTE (SirAndy @ Jan 8 2005, 11:09 AM) | ||
that doesn't sound good ... rod-knock? i had an engine that sounded similar after it lost a rod-bearing ... Andy |
Sounds like valves and a rod.
Check the compression/leakdown test
this will help you diagnose the issue.
I would adjust the valves again making sure you are TDC when you do each one.
Rich
QUOTE (Root_Werks @ Jan 8 2005, 09:03 AM) |
I dunno man, it sure sounds like valve lash to me. It gets quieter as the engine warms up. Plus, when you give it a little throttle, I don't hear anything. So I don't think you have a bad wrist pin or rod knock etc. Those stick out like a soar thumb when you bump the throttle. .015, dang, I am at work right now and can't remember the conversion. Is that .006"? Most people I know do .006 across the board, but if you live in a cooler climate, I would go .004 intake and .006 exhaust. Pop off a valve cover and check the #1 again. Maybe it is the rockers? It is valve train noise for sure though. I have heard that a bazilion times. Other than that, motor sounds great! |
QUOTE (newdeal2 @ Jan 9 2005, 11:38 AM) | ||
Sounds a little like my engine as it's warming up. I recently adjusted my exhaust valves to .008 and that's what they sound like. It does quite down quite a bit when warm/accelerating. I assume this is a fresh rebuild? |
Noises can be difficult to pin down. You need to determine whether they're at crank speed or cam speed. In this recording it certainly sounds like valve noise, but the possibility of a piston being upside down is also there. Without knowing the RPM and the location of the mic, it's difficult to tell one sound from another. I know the rods aren't directional, but I'm pretty sure the pistons are, and they'll make a noise like this at piston speed. This clatter, however, sounds more like cam (or valve) speed. One way to locate a lower engine noise is to run it at a steady speed where the noise is obvious, and remove the plug wires one at a time. A rod or piston noise will lessen or disappear as that cylinder goes dead. A big-end rod noise will also be stronger when you snap the throttle open. Another common cause of noises such as this one is a worn or improperly sized wristpin bushing. Many people fail to have the rods reconditioned when they replace the pistons. While the big ends of T4 rods rarely need resizing (unlike 356/912 motors), the little ends are usually out of tolerance, and wrist pins are notoriously variable in diameter from set to set. The Cap'n
Powered by Invision Power Board (http://www.invisionboard.com)
© Invision Power Services (http://www.invisionpower.com)