Lan-Engine M30B30 tuning thread, steps, values, specs, and so on

deQuincey

deQuincey

Quousque tandem...?
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Planing to do this complete process. please help and feel free to contribute

it will involve:

1- VALVE CLEARANCE ADJUSTMENT
2- IGNITION
3- CARBURETOR TUNING AND SYNCHRONIZATION













1st- VALVE CLEARANCE ADJUSTMENT


10 N.m is the torque that should be applied to the securing nut


1601736356554.png



some details to address this,








please read carefully, ON NO ACCOUNT CHECK CLEARANCES BETWEEN ROCKER ARM SLIDE PADS AND THE LOBES OF THE CAMSHAFT





 
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deQuincey said:
question: how much torque should be applied to the securing nut (1) see picture, found nothing in the books ?????


View attachment 103266
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I normally am not too fastiduous about the precise torque values on non-rotating parts, but for these, I too would like an answer to this. If not done properly, oil can seep out and into the plug wells.
 
This is a timely post.

ON NO ACCOUNT CHECK CLEARANCES BETWEEN ROCKER ARM SLIDE PADS AND THE LOBES OF THE CAMSHAFT

I've been schooled to adjust M30 valve clearances (E28 vintage) at the cam to account for rocker wear. The Mye28 forum suggests this method also. In fact, I just adjusted mine using the go/no go method at .007" and .009" clearances even though a marque expert recommended .006" and .008". I decided not to go that skinny.

Not challenging, but wondering what others do.
 
Ohmess said:
I normally am not too fastiduous about the precise torque values on non-rotating parts, but for these, I too would like an answer to this. If not done properly, oil can seep out and into the plug wells.
Click to expand...


a couple of comments, first i did answer my own question in the first post, so this was solved, it is 10 N.m
second, as per your answer i wonder if we are talking about the same nut, in the mentioned first post there is a photo to identify it, i hardly can imagine it as to “if not done properly, oil can seep out and into the plug wells.”
 
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Great thread!! I'm in the middle of an enginge cylinderhead replacement. Old head removed and replacement head cleaning/checking/reworking. So within a couple of weeks I can use these notes to adjust all the components.
 
I'd second TodB regarding on the cam adjustment. With my 100,000 mile E28, until I set the gap on the cam it was always noisy. Used the same safer gap as TodB. The large contact area between the lobe and the pad lets you be more confident about the go/no go accuracy.
 
oldcoupe said:
I'd second TodB regarding on the cam adjustment. With my 100,000 mile E28, until I set the gap on the cam it was always noisy. Used the same safer gap as TodB. The large contact area between the lobe and the pad lets you be more confident about the go/no go accuracy.
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i try to keep apples with apples, and lemons with lemons,
the warning was found in a book for m30 engines, and i transcribe as it was written
i always set the gap in the eccentric/valve top side with excellent results
larger contact area makes no good, like a four legged chair, three points define a plane, the fourth one is always wrong
the larger the area, the worst the missalignments
i conceal that maybe is easier to avoid making pressure on the spring
but, hey it is your cat, so well done :)
 
so more carbs today,

as rechecking all the settings i found that some values had changed, so i set them to their specified values

3mm for the choke butterfly
0,7mm for the fast iddle screw
and no pressure in the lower second butterfly















@dj_efk maybe missing some of this in your zeniths ?
 
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i use two markers,

first check, if ok red mark, if not i fix it and paint red mark



once done, i make a complete turn to recheck

if ok i paint a blue mark, if not, fix once more, a new recheck turn and if ok a blue mark

but in the first turn, the exhaust valve of the second cyl gave a wrong check, so i had to fix, and the nut was too big for the wrench, WTH ?
 
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