350:sen venttiilien säätö?

Kuinka tehdä moinen "toimenpide"?

 

Pikkulohkoseevussa menee näin:
Käännä kone ykkössylinterin puristustahdin yläkuolokohtaan. Tällöin on dampperin ajoitusmerkki nollakohdassa ja ykkösylinterin molemmat venttiilit ovat kiinni.

Nyt voit säätää ykkössylinterin venttiilit. Löysää keinuvivun mutteri ja kiristä sitä pikkuhiljaa samalla kun toisella kädellä pyörittelet työntötankoa. Kun vastusta alkaa tuntua, on kaikki välys pois. Tästä kiristät keinuvivun mutteria vielä puoli kierrosta.

Käännä kampiakselin päästä moottoria 90 astetta ja säädä sylinteri 8
Käännä 90 ja säädä 4
Käännä 90 ja säädä 3
Käännä 90 ja säädä 6
Käännä 90 ja säädä 5
Käännä 90 ja säädä 7
Käännä 90 ja säädä 2

Helppoa ja hauskaa!

Ja sylinterien numerointihan menee niin, että kuskin paikalta katsottuna vasemmalla edestä päin lukien järjestyksessä ovat 1-3-5-7 ja vastaavasti oikealla puolella 2-4-6-8.

 

Jos oikein laiskottaa niin niin säädä näin.
1 ykk ja säädettävissä:säädä imu 1-2-5-7
pako 1-3-4-8

6 ykk ja säädettävissä:säädä imu 3-4-6-8
pako 2-5-6-7

 

Ohessa vielä ohje mekaanisten nostajien säätöön. Tällä ohjeella voi venttilit säätää kone kylmänä ja sammuksissa vs. perinteinen tapa kone kuumana ja käynnissä.

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"30-30" AND OTHER OEM SB SOLID LIFTER CAM VALVE ADJUSTMENT

By John Hinckley and Duke Williams


The traditional method of adjusting valves one or more cylinders at a time with each cylinder at TDC is fine for hydraulics and for most solid-lifter cams, but NOT for the factory "30-30" solid-lifter cam used in '64-'65 L-76 365 HP and L-84 375 HP (FI) Corvette engines (and in '67-'69 Camaro 302/290 Z/28 engines); this cam has VERY long clearance ramps that are .020" high, and at TDC for any cylinder, both the intake and exhaust valve for that cylinder are still on their ramps, NOT on the cam's base circle, which is why the Service Manual for all cars so equipped says specifically to set them "hot and running".

There is, however, a better way to adjust the valves with a "30-30" - you can set them "cold and not running" by setting the intakes at 90 degrees ATDC and the exhausts at 90 degrees BTDC - so the lifters are on the base circle, not on the ramps. This has been confirmed with cam lift/crank-angle diagrams, and I've done mine this way - results in a nice mechanical "singing" sound, no "clacking", it runs better, sounds better, idle is more stable, and throttle response is improved. Several other Z/28 owners have followed this procedure as well since we developed it, and all of them have seen the same positive results.

Set them cold at .026"/.026". The actual measured (stamped rocker arm) ratio at the lash points is actually about 1.37:1 (not the design 1.5:1, which is a max lift measurement), so the clearance ramp, which is exactly .020" high on the lobe, is all taken up at .0274" clearance; .030" clearance with the valve closed is too loose - the ramp ends/begins before the .030" clearance is taken up, resulting in the valve being lifted off and returned to the seat at greater than ramp velocity. This will contribute to valve seat recession, and can cause valve bounce at the seats at high revs - it will also be noisy.

You can adjust two valves at each 90-degree rotation point, starting at #1 TDC, turning the crank 90 degrees at a time seven times (measure and mark your balancer first at 90-degree intervals from TDC). Removing the plugs simplifies rotating the crank, but you were going to change them anyway, right? Proceed as follows:

TDC #1 - 8E, 2I
90 deg. - 4E, 1I
180 deg. - 3E, 8I
270 deg. - 6E, 4I
0 - 5E, 3I
90 deg. - 7E, 6I
180 deg. - 2E, 5I
270 deg. - 1E, 7I

Start at TDC #1, then rotate 90 degrees at a time, setting at .026" cold. If you like, you can then go back after you're done to each cylinder's TDC position and check clearance on that cylinder's two valves, and you'll find that they've closed up to .024", indicating that both valves are still on the ramps at TDC, as I pointed out in the beginning.

Trivia - the point of max inlet lift on the "30-30" cam is at 112 degrees, with a lobe separation angle of 114 degrees (angle between points of max lift, not the geometric center of the lobe - the lobes on the "30-30" cam are asymmetrical).


Addendum (May 19, 2003)

This procedure should also be used for the LT-1 cam. The exhaust is “on the ramp” at TDC. The inlet is not, but just barely. With the Duntov cam this indexing procedure may be used, or both valves may be set with the cylinder at TDC of the compression stroke, or all 16 valves may be adjusted at TDC #1 and TDC #6 as outlined in the 1963 Corvette Shop Manual. The Duntov cam has shorter ramps than the 30-30 or LT-1 cam.

This indexing procedure may be used with ANY cam to assure that the lobe is on the base circle, and MUST be used for cams with very long ramps.

The following inlet/exhaust valve clearances are recommended with the engine cold and not running. The difference between “hot” (engine idle speed) and cold clearance on a cast iron pushrod engine is negligible, so clearances can be set cold, which is more convenient. These clearances are computed by “factoring” the OEM recommended clearances by the ratio 1.37/1.5 to compensate for the actual rocker ratio of 1.37 at the lash point. The computed number is then rounded down. The factory clearances are derived from multiplying the maximum height of the ramp above the base circle by 1.5. When running hard, such as sustained WOT, the exhaust valve head will heat up considerably. About 80 percent of exhaust valve cooling is through the seat, but the stem temperature will increase, which will cause the stem to grow and decrease running clearance. This is why exhaust ramps are typically higher than inlet ramps – to allow for more stem growth and maintain some running clearance to ensure the valves fully seat. Since the inlet valve is cooled with every fresh intake charge, it’s temperature and clearance will remain more consistent over the entire engine operating spectrum.

The rocker arm nut should be tightened until a light drag is felt on the feeler of the same thickness as the recommended clearance. Then the clearance may be verified by inserting a .001” larger gage, and if it does not go the clearance is between the two gages, which is just right. Note that the inlet clearance specification for the 1963 Corvette was tightened to .008” to give a bit more effective duration. This does not need to be “factored” anymore. We recommend this tighter clearance for all 327s, and it is optional for 283s for a little more top end power though the effect may not be noticeable. Normal engine service will usually result in slight loosening of the clearance, and Chevrolet service recommendations from the sixties recommend a lash check every 12,000 miles as part of a normal tuneup.

Duntov cam (283) .010”/.015”
Duntov cam (327) .008”/.015”
30-30 cam .026”/.026”
LT-1 cam .021/.026”

Note: Clearances are listed inlet/exhaust.

 

Kuten edellä ja jos tarkoitit välyksien säätöä hydraulinokan kanssa niin venttiilin ollessa kiinni pyöritä työntötankoa sormilla ja kiristä hiljaa säätömutterista kunnes tanko lakkaa pyörimästä öljyisin sormin ja kierrä säätömutteria sitten puoli tai 3/4 kierrosta kiinni ja se on siinä.
Huomioitavaa on että nostimien on syytä olla mahdollisimman täynnä öljyä tätä tehtäessä.