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Opel Rallier since 1977
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Wow, now that is really great information for a first time valve adjuster like myself and makes a lot of sense and better than that makes me feel more confident knowing I won't fry the engine. :) Between you and Manta Rallier I will soon be an expert. Thanks, Carl
So Carl, just use the numbers that you have been given by Gil; I would expect him to know the right lash settings. Don't let me confuse the situation!

And as far as lash variation between adjustments, that is not unusual. The rockers seem to take slightly different 'sets' on the rockers pivots and valve tips when you rotate the engine slowly by hand, and that causes the variations. But small variations like .001" or .002" are not important, IMHO.

A 'hot and running' lash procedure will get all around that, but these Opel engines tend to fling oil all over the place when idling with the valve cover off! (Ask me how I know ... ooops... 'clean-up on aisle 9' LOL.) It is not a problem on something like a Mopar 225 slant 6 engine, where the oil supply up on top just dribbles at idle.
 

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1970 Opel Gt - Purchased July 1972 - Chartreuse - restored - 3000 miles as of 02-16, 2021 -
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867 Posts
Discussion Starter · #22 ·
So Carl, just use the numbers that you have been given by Gil; I would expect him to know the right lash settings. Don't let me confuse the situation!

And as far as lash variation between adjustments, that is not unusual. The rockers seem to take slightly different 'sets' on the rockers pivots and valve tips when you rotate the engine slowly by hand, and that causes the variations. But small variations like .001" or .002" are not important, IMHO.

A 'hot and running' lash procedure will get all around that, but these Opel engines tend to fling oil all over the place when idling with the valve cover off! (Ask me how I know ... ooops... 'clean-up on aisle 9' LOL.) It is not a problem on something like a Mopar 225 slant 6 engine, where the oil supply up on top just dribbles at idle.
OK, So today, I got around to adjusting the valve, again. I did it twice so feel pretty comfortable that it is consistent with each valve. Last time I set them at 15 so since I did it cold that should = 13 hot or there abouts right. So going lower just did not seem to make sense and since I tried 18 cold which should = 16 hot and that did not work so only one direction to go and that was back up the scale. I set the lash at 20 cold, again thinking that would about equal 18 hot and it is purring like a kitten. Since that increased my idle to around 14, I was able to turn the main idle mixture screw about 3/4 turns in which that puts me at around 1 and 3/4 turns out and I then lowered the idle to 8 using the idle screw. The car sounds really good at idle and up to about 3000 rpm's. There was also a click that has all but vanished that is coming from the middle of the valve cover, bought a stethoscope, best 9 dollars I ever spent. Kind of cool to listen to how the sound changes as you move the probe around.
I don't think it is related but perhaps someone reading this can help me figure it out. The over all sound coming from under the hood is very good up to around 3000 RPM's at that point is when a howling roar begins and increases as the rpms increase. This is something I do not recall hearing in the past - was wondering if it could be the difference between a 5 and a 7 blade fan as I have recently replaced both the water pump and the five blade with a 7 blade fan and also the aluminum radiator. The noise is quite loud. Perhaps a video would help. Thanks all....Best. Carl
 

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1970 Opel Gt - Purchased July 1972 - Chartreuse - restored - 3000 miles as of 02-16, 2021 -
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867 Posts
Discussion Starter · #23 ·
OK, So today, I got around to adjusting the valve, again. I did it twice so feel pretty comfortable that it is consistent with each valve. Last time I set them at 15 so since I did it cold that should = 13 hot or there abouts right. So going lower just did not seem to make sense and since I tried 18 cold which should = 16 hot and that did not work so only one direction to go and that was back up the scale. I set the lash at 20 cold, again thinking that would about equal 18 hot and it is purring like a kitten. Since that increased my idle to around 14, I was able to turn the main idle mixture screw about 3/4 turns in which that puts me at around 1 and 3/4 turns out and I then lowered the idle to 8 using the idle screw. The car sounds really good at idle and up to about 3000 rpm's. There was also a click that has all but vanished that is coming from the middle of the valve cover, bought a stethoscope, best 9 dollars I ever spent. Kind of cool to listen to how the sound changes as you move the probe around.
I don't think it is related but perhaps someone reading this can help me figure it out. The over all sound coming from under the hood is very good up to around 3000 RPM's at that point is when a howling roar begins and increases as the rpms increase. This is something I do not recall hearing in the past - was wondering if it could be the difference between a 5 and a 7 blade fan as I have recently replaced both the water pump and the five blade with a 7 blade fan and also the aluminum radiator. The noise is quite loud. Perhaps a video would help. Thanks all....Best. Carl
So after a test drive today, up to operating temperature, and listening to that whirring sound some more I put the stethoscope on the alternator and guess what not only did I hear that whirring noise but at higher RPM's a screeching noise came into play, that was hard to listen to with a stethoscope. Anyway, I have a replacement coming for the rebuilt alternator that I just installed a couple months ago along with some of the Christmas specials listed on OGTS. More projects for Jan. and Feb.
 
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