Valve adjustment questions
#16
#20
Makmov and everyone else, Thank you for taking the time to explain the procedure to me. I think I have the feel for it now with all your input. I am just going to take my time and run through them a couple more times.
#21
I use the dial indicator method as I could never quite get it right with the feeler gauge. Also, as the elephant foot rotates you will get different readings. go around at least twice. good luck.
#22
I don't know if it's still available, but the VAS(valve adjusting screwdriver)helped me last time I did an adjustment. It gets you very close to the correct clearance, and you can use it to hold the correct clearance, while you tighten the nut. Course, you still need to check with a feeler guage.
http://forums.rennlist.com/rennforum...9M+screwdriver
http://tomnjudy.com/strategist/valve...g-screwdriver/
http://forums.rennlist.com/rennforum...9M+screwdriver
http://tomnjudy.com/strategist/valve...g-screwdriver/
#24
#25
I don't have to adjust the valves on my 993, but I do on my daily driver and BMW motorcycles.
Every time I do a valve check, I take note of all the clearances and log them in an Excel spread sheet. That has two purposes: 1) it tells you if something is heading in the wrong direction (like a tight valve at every valve check over time) and 2) if you can extend your valve check intervals. That can be done if you have a history built up.
It is important to insert and maintain the gauge parallel to the gap and not skewed at any angle. Put a bend in the feeler gauge if you have to.
If my Intake is 0.004" and Exhaust is 0.008", I always use a 0.005" and 0.009" gauge as a no-go gauge...you can get them in, but they are very tight.
Using my thumb, I always apply pressure to the opposite side of the rocker when taking and adjusting my valve clearance measurements. Slight drag is what you are looking for.
Never turn the crankshaft "back" if you overshot your timing mark. Go around (almost) twice if you have to, or leave it till you get there after doing the other valves.
And in the end, your valves are better off slightly loose than slightly tight. Clappy valves are happy valves.
#26
Sorry guys, I have moved the screwdriver links to the OBD1 site...
I have about 8 more then they're gone.
http://obd1interface.com/valve-adjusting-screwdriver/
My bad for not providing redirects...
I have about 8 more then they're gone.
http://obd1interface.com/valve-adjusting-screwdriver/
My bad for not providing redirects...
#27
Alex, I did write down the existing condition of each valve. Tight/loose/good. Your right I think it is good information long term.
Now that you mention it I did over shoot #1 valve on my second round slightly and then went CCW back to TDC. This might explain why my valves both intake and exhaust were tight on the second go around. I know you shouldn’t turn the crank CCW but it was just a few mm. Since my last post I have gone through them twice more and I think they are dead on.
Now that you mention it I did over shoot #1 valve on my second round slightly and then went CCW back to TDC. This might explain why my valves both intake and exhaust were tight on the second go around. I know you shouldn’t turn the crank CCW but it was just a few mm. Since my last post I have gone through them twice more and I think they are dead on.
#28
Alex, I did write down the existing condition of each valve. Tight/loose/good. Your right I think it is good information long term.
Now that you mention it I did over shoot #1 valve on my second round slightly and then went CCW back to TDC. This might explain why my valves both intake and exhaust were tight on the second go around. I know you shouldn’t turn the crank CCW but it was just a few mm. Since my last post I have gone through them twice more and I think they are dead on.
Now that you mention it I did over shoot #1 valve on my second round slightly and then went CCW back to TDC. This might explain why my valves both intake and exhaust were tight on the second go around. I know you shouldn’t turn the crank CCW but it was just a few mm. Since my last post I have gone through them twice more and I think they are dead on.
That is good to hear, you will know when you drive it. It will purr like a kitten, run great, and get better mileage.
#29
That amount isn't the end of the world. When you get right down to it, it is 2 turns of the crank to one turn of the cam, so that cam could not have been off my any amount to be of concern.
Another trick to determine if TDC is accurately marked on a pulley, isn't to dial it in at TDC. It is best to dial in 0.200 BTDC, mark the pulley, then dial in 0.200 ATDC, mark the pulley. TDC is exactly between those two marks.
Another trick to determine if TDC is accurately marked on a pulley, isn't to dial it in at TDC. It is best to dial in 0.200 BTDC, mark the pulley, then dial in 0.200 ATDC, mark the pulley. TDC is exactly between those two marks.